Intensity Modulated Radiotherapy

Semi-automated segmentation using deformable registration of selected atlas cases consisting of expert segmented patient images has been proposed to facilitate the delineation of lymph node regions for three-dimensional conformal and intensity-modulated radiotherapy planning of head and neck and prostate tumours. Our aim is to investigate if fusion of multiple atlases will lead to clinical workload reductions and more accurate segmentation proposals compared to the use of a single atlas segmentation, due to a more complete representation of the anatomical variations. Atlases for lymph node regions were constructed using 11 head and neck patients and 15 prostate patients based on published recommendations for segmentations. A commercial registration software (Velocity AI) was used to create individual segmentations through deformable registration. Ten head and neck patients, and ten prostate patients, all different from the atlas patients, were randomly chosen for the study from retr...

PURPOSE-To estimate the rate of disease control after conformal radiation therapy using reduced clinical target volume (CTV) margins and determine factors that predict for tumor progression. METHODS AND MATERIALS-Eighty-eight children (median age 8.5 years, range 3.2-17.6 years) received conformal or intensity-modulated radiation therapy between 1998 and 2009. This included those prospectively treated from 1998 to 2003 using a 10 mm CTV, defined as the margin surrounding the solid and cystic tumor targeted to receive the prescription dose of 54 Gy. The CTV margin was subsequently reduced after 2003 yielding two groups of patients: those treated with a CTV margin greater than 5 mm (n=26) and those treated with a CTV margin less than or equal to 5 mm (n=62). Disease progression was estimated on the basis of additional variables including sex, race, extent of resection, tumor interventions, target volume margins, and the frequency of weekly surveillance MR imaging during radiation therapy. The median follow-up was 5 years. RESULTS-There was no difference comparing progression-free survival based on CTV margin (>5mm vs. ≤ 5mm) at 5 years, 88.1 + 6.3% vs. 96.2 + 4.4% (P=0.6386). There was no difference based on the planning target volume (PTV) margin (or combined CTV+PTV). The PTV was systematically reduced from 5 to 3mm during the time period of the study. Factors predictive of superior progression-free survival included Caucasian race (P=0.0175), absent CSF shunting requirement (P=0.0066), and the number of surveillance imaging studies during treatment

PURPOSE-To estimate the rate of disease control after conformal radiation therapy using reduced clinical target volume (CTV) margins and determine factors that predict for tumor progression. METHODS AND MATERIALS-Eighty-eight children (median age 8.5 years, range 3.2-17.6 years) received conformal or intensity-modulated radiation therapy between 1998 and 2009. This included those prospectively treated from 1998 to 2003 using a 10 mm CTV, defined as the margin surrounding the solid and cystic tumor targeted to receive the prescription dose of 54 Gy. The CTV margin was subsequently reduced after 2003 yielding two groups of patients: those treated with a CTV margin greater than 5 mm (n=26) and those treated with a CTV margin less than or equal to 5 mm (n=62). Disease progression was estimated on the basis of additional variables including sex, race, extent of resection, tumor interventions, target volume margins, and the frequency of weekly surveillance MR imaging during radiation therapy. The median follow-up was 5 years. RESULTS-There was no difference comparing progression-free survival based on CTV margin (>5mm vs. ≤ 5mm) at 5 years, 88.1 + 6.3% vs. 96.2 + 4.4% (P=0.6386). There was no difference based on the planning target volume (PTV) margin (or combined CTV+PTV). The PTV was systematically reduced from 5 to 3mm during the time period of the study. Factors predictive of superior progression-free survival included Caucasian race (P=0.0175), absent CSF shunting requirement (P=0.0066), and the number of surveillance imaging studies during treatment

Breast cancer (BC) is a highly prevalent and significant health concern influencing women worldwide. This is crucial for understanding the impact of breast cancer and developing targeted prevention and treatment strategies. The research aims to investigate the performance of the 3DCRT model by comparing BCS and MRM plans in terms of mean lung dose. Purpose: A comparative analysis of MRM and BCS treatment plans was conducted to determine the most appropriate strategy for breast cancer, with an emphasis on minimizing radiation dose to the lungs. Methods and materials: Breast cancer (BC) RT was performed for 174 patients' treatment planning. The treatment plans for BCS are compared to the MRM plans based on mean dose lung and target coverage. To create a 3DCRT plan for Breast cancer, applying 3DCRT in Monaco and evaluating an outcome of Breast cancer irradiation procedure, analyse the main dosimetric parameters of the planned treatment plans for BCS and MRM plans. This study divided the patients into two groups according to the type of surgery breast-conserving surgery (BCS) and modified radical mastectomy (MRM) groups. Each group is also divided into different subgroups according to the dose of radiotherapy given (4050, 4256, and 5000 cGy) and whether the lymph nodes in the axillae and the supraclavicular regions are irradiated or not have been taken into account. Different strategy plans were performed to get the best result according to the size of the PTV. The dose Prescribed for MRM was 4050 cGy, 270 cGy per fraction (270 cGy/Fx), 4256/16 fraction while BCS was 5000 cGy, 200 cGy per fraction (200 cGy/Fx), 4050/15 fraction 270 cGy per fraction (270 cGy/Fx). Results: The total number of patients in this study was 174 breast cancer patients with ages ranging from 18 to 77 years with a mean age ± SD (49.2 ± 11.5) years, and the results showed the highest incidence of breast cancer among patients in 6th (50-59 years) and they are (29.3 %) and the 5th and 7th decades of life and (23.5 %) each, while the lowest incidence of breast cancer among patients in 3rd decade of life (below 1 %).

In IMRT for prostate cancer, MU verification is performed by the actual measurement. We have experienced a remarkable improvement in results, once succeeding in finding out the more suitable and optimal evaluation dose point in some cases even though the deviation between a designed MU score and our actual record gained at the iso-center was more than 3％. In this study, we tried to demonstrate how much influence would be given to the point dose verification by the 3D arrangement between an ion chamber and tips of the MLC. The five cases in which the bias between each actual datum and planed MU score showed that about 3％ were picked up and through these MLC configurations, 8 leaf-ends around the chamber were highlighted as the influential ones. After each distance from 4 pairs, a total of 8 leaves to the axis (the mid-line) of our ion chamber were mapped. The indexes (PlanLeafScores) were computed through these distances and segmental MU scores. The ratio of these scores and results obtained at the 12 sites within 1 cm from the iso-center were carried out by single regression analysis. In all cases the ratios of planed MU values to the actual ones tended to go down in inverse proportion to the increase in PlanLeafScores (r<-0.77, p<0.002) . As the dimensional arrangement between the ion chamber and the edges of the MLC were thought to determine the result of the verification. PlanLeafScores will enable us to determine the optimal evaluation of the dose point.

Background: Breast cancer sensitivity to large fraction size may be enhanced using hypofractionated concomitant boost radiotherapy (CBRT), thereby shortening overall treatment time. This ethics approved, prospective single cohort feasibility study was designed to evaluate the dosimetry and toxicity of CBRT using an intensity-modulated radiotherapy (IMRT) technique, compared with a standard sequential boost technique (SBT). Methods: Fifteen women (11 right-sided; 4 left-sided) received 42.4 Gy to the whole breast and an additional 10.08 Gy to the tumor bed in 16 daily fractions, using IMRT and standard dose constraints. Each patient was replanned with the SBT, using mixed photon-electrons. Clinical target volume (CTV), dose evaluation volume (DEV), and organs at risk (OAR) dose distributions were compared with the SBT. Toxicity and treatment times were prospectively recorded. Results: All 15 CBRT plans achieved the desired CTV (V 49.9Gy P 99%) and DEV (V 49.9Gy P 95%), coverage of the boost, compared with only 10 (66.7%, p = 0.03), and 12 (80%, p = 0.125) SBT plans, respectively. Ipsilateral lung (p < 0.0001), and heart (right-sided, p = 0.001; left-sided, p = 0.13) doses were lower. Grade 3 acute toxicity occurred in 1 (6.7%) patient. At 1 year, two (13.3%) additional patients had overall grade 2 late toxicity, compared with baseline. No grade 3-4 late toxicity was observed. Conclusions: CBRT using IMRT improved boost coverage and lowered OAR doses, compared with SBT. Toxicities were acceptable using a daily boost of 3.28 Gy. While resource utilization was greater, overall treatment time was reduced.

To determine the overall burden of disease vis-a-vis head and neck cancers in Thailand, as indicated by visits to healthcare units, admissions for treatment and expenditures at all levels of the healthcare delivery system. A descriptive study was conducted by retrieving and analysing data for the fiscal year 2010 from the National Health Security Office (NHSO) and the Social Security Office, Thailand and from in-patient data of the Civil Servants Benefit System from the Comptroller General&#39;s Department. In 2010, there were 167,199 visits to outpatient departments (OPDs) and 26,012 admissions to hospital (IPD) for diagnosis and treatment of head and neck cancers. The most common diagnosis for visits to OPD and admission to IPD was oral cancer (28.2% and 25%, respectively). The mean length of hospital stay was 9 days. About half of admissions took place in the central region. The hospital charges totalled 691 million Baht (US$ 21.8 million), or an average of 26,556 Baht (USS 838) ...

A protocol is presented for the calculation of monitor units (MU) for photon and electron beams, delivered with and without beam modifiers, for constant source‐surface distance (SSD) and source‐axis distance (SAD) setups. This protocol was written by Task Group 71 of the Therapy Physics Committee of the American Association of Physicists in Medicine (AAPM) and has been formally approved by the AAPM for clinical use. The protocol defines the nomenclature for the dosimetric quantities used in these calculations, along with instructions for their determination and measurement. Calculations are made using the dose per MU under normalization conditions, , that is determined for each userˈs photon and electron beams. For electron beams, the depth of normalization is taken to be the depth of maximum dose along the central axis for the same field incident on a water phantom at the same SSD, where = 1 cGy/MU. For photon beams, this task group recommends that a normalization depth of 10 cm be...

To investigate the outcomes of the selective neoadjuvant concurrent chemoradiotherapy (CCRT) in lower 3rd rectal cancer patients in different groups (with or without neoadjuvant CCRT), especially in survival rate, local recurrence rate, and sphincter preservation rate.From January 1999 to December 2012, 69 consecutive patients who had histologically proven adenocarcinoma of lower 3rd rectum, defined preoperatively as lower tumor margin within 7 cm from the anal verge as measured by rigid sigmoidoscopy, received total mesorectum excision (TME). Our inclusion criteria of neoadjuvant CCRT are lower 3rd rectal cancer, stage II/III, and large (diameter &gt;5 cm or &gt;1/2 of circumference). Neoadjuvant concurrent CCRT had begun to apply lower 3rd rectal cancer patients or not. The radiation techniques of neoadjuvant CCRT for lower 3rd rectal cancer patients were all conventional fraction intensity modulated radiotherapy (IMRT) and concurrent fluoropyrimidine chemotherapy.Five-year overal...

To quantify the variability between radiation oncologists (ROs) when outlining axillary nodes in breast cancer. For each participating center, three ROs with different levels of expertise, i.e., junior (J), senior (S) and expert (E), contoured axillary nodal levels (L1, L2, L3 and L4) on the CT images of three different patients (P) of an increasing degree of anatomical complexity (from P1 to P2 to P3), according to contouring guidelines. Consensus contours were generated using the simultaneous truth and performance level estimation (STAPLE) method. Fifteen centers and 42 ROs participated. Overall, the median Dice similarity coefficient was 0.66. Statistically significant differences were observed according to the level of expertise (better agreement for J and E, worse for S); the axillary level (better agreement for L1 and L4, worse for L3); the patient (better agreement for P1, worse for P3). Statistically significant differences in contouring were found in 18% of the inter-center...

Results of stereotactic radiotherapy (SRT) for spinal intradural metastases developing inside or adjacent to the previous external-beam radiation therapy (EBRT) field are shown in 3 cases. One case of spinal intramedullary metastasis and two cases of intradural extramedullary metastases were treated using a Novalis shaped-beam SRT.  Case 1 developed an intramedullary metastatic tumor in the C1 spinal medulla inside the previous whole brain EBRT field and another lesion adjacent to the field in the C2 spinal medulla. Case 2 developed intradural extramedullary metastasis around C6-8 inside the previous EBRT field for the primary lung adenocarcinoma. Case 3 developed multiple spinal intradural extramedullary metastatic deposits after surgical resection and following whole brain EBRT for brain metastasis. We delivered 24 to 36 Gy in 5 to 12 fractions. The treated tumors were stable or decreased in size until the patients’ death from the primary cancer (10, 22, and 5 months). Neurologica...

Purpose To analyze the outcome and dose distribution of intensity-modulated radiation therapy (IMRT) by helical tomotherapy in women treated for large supradiaphragmatic Hodgkin’s disease. Material and methods A total of 13 patients received adjuvant radiation at a dose of 30 Gy to the initially involved sites with a boost of 6 Gy to those areas suspected of harboring residual disease on the simulation CT scan. Results With a median follow-up of 23 months, the two-year progression-free survival was 91.6%, and the 2- and 3-year overall survivals were 100%. We did not report any heart or lung acute side effects. The conformity index of PTV (Planning Target Volume) was better for IMRT than for 3D-CRT (p=0.001). For the breasts, lungs, heart, thyroid and esophagus, the volume distributions favored the IMRT plans. For the breasts, the V20Gy, V25Gy and V30Gy were 1.5, 2.5 and 3.5 times lower, respectively, for IMRT than for 3D-CRT. For the lung tissues, the V20Gy and V30Gy were 2 times an...

But RCTs have often exposed the weaknesses of other trial designs. One example is the case of autologous bone marrow transplantation (BMT) for metastatic breast cancer. In the mid-1980s, BMT gained many proponents who reasoned that if higher chemotherapy doses could be given to patients getting BMT, cancer cells would be killed more effectively and that would translate into a survival benefi t. The fi rst study on efficacy, a phase II uncontrolled trial, appeared in 1988 and showed a 58% response rate, noted Gilbert Welch, M.D., professor of medicine at Dartmouth College in Hanover, N.H. A few months later a similar study with an 80% response rate was published. At the time, study authors were cautious about these data, noting that controlled studies were needed and that improved response rates were not yet associated with better survival. But press reports were encouraging, and by 1990, because patients sought insurance coverage for the procedure, the National Cancer Institute fi nally began an RCT. On that basis, one insurer moved to cover the costs of the trial. But by the mid-1990s, results from RCTs were in: Four of fi ve trials did not support the use of BMT and high-dose chemotherapy for treating metastatic breast cancer, and so insurance coverage was revoked.

Background and purpose-A tumor subvolume-based, risk-adaptive optimization strategy is presented. Methods and materials-Risk-adaptive optimization employs a biological objective function instead of an objective function based on physical dose constraints. Using this biological objective function, TCP is maximized for different tumor risk regions while at the same time minimizing NTCP for organs at risk (OAR). The feasibility of risk-adaptive optimization was investigated for a variety of tumor subvolume geometries, risk-levels, and slopes of the TCP curve. Furthermore, the impact of a correlation parameter, δ, between TCP and NTCP on risk-adaptive optimization was investigated. Results-Employing risk-adaptive optimization, it is possible in a prostate cancer model to increase EUD by up to 35.4 Gy in tumor subvolumes having the highest risk classification without increasing predicted normal tissue complications in organs at risk. For all tumor subvolume geometries investigated, we found that the EUD to high-risk tumor subvolumes could be increased significantly without increasing normal tissue complications above those expected from a treatment plan aiming for uniform dose coverage of the PTV. We furthermore found that the tumor subvolume with the highest risk classification had the largest influence on the design of the risk-adaptive dose distribution. The parameter δ had little effect on risk-adaptive optimization. However, the clinical parameters D 50 and γ 50 that represent the risk classification of subtumor volumes had the largest impact on risk-adaptive optimization. Conclusions-On the whole, risk-adaptive optimization yields heterogeneous dose distributions that match the risk level distribution of different subvolumes within the tumor volume.

Background/Aim: We experienced an unexpected high incidence of gastrointestinal (GI) toxicity in patients undergoing image-guided intensity-modulated radiotherapy (IG-IMRT) using helical tomotherapy in our initial 2.2 Gy/fraction schedule for prostate cancer; hence, a dosereduction trial from 2.2 Gy to 2 Gy/fraction was conducted using modified planning target volume (PTV) contouring. Patients and Methods: We compared 130 patients treated using 2.2 Gy/fraction (Group A) and 144 treated using the 2 Gy/fraction (Group B) with modified PTV (excluding rectal volume) with a median follow-up period of 62 months. Prescribed dose was 72.6-74.8 Gy in 33-34 fractions (Group A) and 72-74 Gy in 36-37 fractions (Group B). Results: Patients in Group B had a reduced rectal and bladder V10-V70 and were irradiated at the maximal dose. Their cumulative incidence of grade ≤2 GI toxicity at 5 years improved from 10.1% [95% confidence interval (CI), 4.9-15.3%] to 1.4% (0-3.3%). Grade 2≤ urinary toxicity also decreased from 5.5% (1.5-9.4%) in Group A to 1.4% (0-3.3%, p=0.0167) in Group B. The biochemical failure-free 5-year survival rate was 89.1% (95%CI=83.6-95.4%) and 87. 5% (82.0-92.9%, p=0.75) in groups A and B, respectively. Conclusion: The reduced dose fraction schedule decreased the incidence of late GI toxicity without compromising prostate-specific antigen control. Careful target volume definition and fraction size are important even for IG-IMRT.

Introduction: Radiotherapy is a standard treatment for prostate cancer, and image-guided radiotherapy is increasingly being used to aid precision of dose delivery to targeted tissues. However, precision during radiotherapy cannot be maintained when unexpected intrafraction organ motion occurs. Case presentation: We report our experience of internal organ motion caused by persistent gas production in a patient taking an alpha-glucosidase inhibitor. A 68-year-old Japanese man with prostate cancer visited our institution for treatment with helical tomotherapy. He suffered from diabetes mellitus and took an alpha-glucosidase inhibitor. Routine treatment planning computed tomography showed a large volume of rectal gas; an enema was given to void the rectum. Subsequent treatment planning computed tomography again showed a large volume of gas. After exercise (walking) to remove the intestinal gas, a third scan was performed as a test scan without tight fixation, which showed a sufficiently empty rectum for planning. However, after only a few minutes, treatment planning computed tomography again showed extreme accumulation of gas. Therefore, we postponed treatment planning computed tomography and consulted his doctor to suspend the alpha-glucosidase inhibitor, which was the expected cause of his persistent gas. Four days after the alpha-glucosidase inhibitor regimen was suspended, we took a fourth treatment planning computed tomography and made a treatment plan without gas accumulation. Thereafter, the absence of rectal gas accumulation was confirmed using daily megavolt computed tomography before treatment, and the patient received 37 fractions of intensity-modified radiotherapy at 74Gy without rectal gas complications. In this case study, the alpha-glucosidase inhibitor induced the accumulation of intestinal gas, which may have caused unexpected organ motion, untoward reactions, and insufficient doses to clinical targets. Conclusions: We suggest that patients who are taking an alpha-glucosidase inhibitor for diabetes should discontinue use of that particular medicine prior to beginning radiotherapy.

Radiochromic film has become an important tool to verify dose distributions for intensity‐modulated radiotherapy (IMRT) and quality assurance (QA) procedures. A new radiochromic film model, EBT3, has recently become available, whose composition and thickness of the sensitive layer are the same as those of previous EBT2 films. However, a matte polyester layer was added to EBT3 to prevent the formation of Newton&#39;s rings. Furthermore, the symmetrical design of EBT3 allows the user to eliminate side‐orientation dependence. This film and the flatbed scanner, Epson Perfection V750, form a dosimetry system whose intrinsic characteristics were studied in this work. In addition, uncertainties associated with these intrinsic characteristics and the total uncertainty of the dosimetry system were determined. The analysis of the response of the radiochromic film (net optical density) and the fitting of the experimental data to a potential function yielded an uncertainty of 2.6%, 4.3%, and 4....

Stereotactic radiosurgery (SRS) is the accurate, conformal delivery of high-dose radiation to well-defined targets while minimizing normal structure doses via steep dose gradients. While inverse treatment planning (ITP) with computerized optimization algorithms are routine, many aspects of the planning process remain user-dependent. We performed an international, multi-institutional benchmark trial to study planning variability and to analyze preferable ITP practice for spinal robotic radiosurgery. 10 SRS treatment plans were generated for a complex-shaped spinal metastasis with 21 Gy in 3 fractions and tight constraints for spinal cord (V14Gy&lt;2 cc, V18Gy&lt;0.1 cc) and target (coverage &gt;95%). The resulting plans were rated on a scale from 1 to 4 (excellent-poor) in five categories (constraint compliance, optimization goals, low-dose regions, ITP complexity, and clinical acceptability) by a blinded review panel. Additionally, the plans were mathematically rated based on plan i...

The term &quot;computed tomography&quot; (CT) is often used to refer to X-ray CT, because it is the most commonly known form. But, many other types of CT exist, such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT). This study was carried out in the north central part of Nigeria which includes Abuja and Keffi (Nasarawa State). This study has established local diagnostic reference levels (LDRLs). Dose report and scan parameters for chest was assessed during the period (January – July, 2016) of seven months at the three study centres (A, B and C in which two are located in Abuja and the other one (C) located in Keffi. Data on CT Dose index (CTDIw) and dose length product (DLP) available and achieved on CT scanner control console was recorded for a minimum of 10 average sized patients for each facility to established a local Diagnostic reference level (LDRLs) and radiation dose optimization Data was collected using a purposive sampling techni...

Background and purpose: The study aimed to examine specific avoidance of functional lung (FL) defined by a single photon emission computerized tomography (SPECT) lung perfusion scan, using intensity modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3-DCRT) in patients with non-small cell lung cancer (NSCLC). Materials and methods: Patients with NSCLC underwent planning computerized tomography (CT) and lung perfusion SPECT scan in the treatment position using fiducial markers to allow co-registration in the treatment planning system. Radiotherapy (RT) volumes were delineated on the CT scan. FL was defined using co-registered SPECT images. Two inverse coplanar RT plans were generated for each patient: 4-field 3-DCRT and 5-field step-and-shoot IMRT. 3-DCRT plans were created using automated AutoPlan optimisation software, and IMRT plans were generated employing Pinnacle 3 treatment planning system (Philips Radiation Oncology Systems). All plans were prescribed to 64 Gy in 32 fractions using data for the 6 MV beam from an Elekta linear accelerator. The objectives for both plans were to minimize the volume of FL irradiated to 20 Gy (fV 20 ) and dose variation within the planning target volume (PTV). A spinal cord dose was constrained to 46 Gy. Volume of PTV receiving 90% of the prescribed dose (PTV 90 ), fV 20 , and functional mean lung dose (fMLD) were recorded. The PTV 90 /fV 20 ratio was used to account for variations in both measures, where a higher value represented a better plan. Results: Thirty-four RT plans of 17 patients with stage I-IIIB NSCLC suitable for radical RT were analysed. In 6 patients with stage I-II disease there was no improvement in PTV 90 , fV 20 , PTV/fV 20 ratio and fMLD using IMRT compared to 3-DCRT. In 11 patients with stage IIIA-B disease, the PTV was equally well covered with IMRT and 3-DCRT plans, with IMRT producing better PTV 90 /fV 20 ratio (mean ratio -7.2 vs. 5.3, respectively, p = 0.001) and reduced fMLD figures compared to 3-DCRT (mean value -11.5 vs. 14.3 Gy, p = 0.001). This was due to reduction in fV 20 while maintaining PTV coverage. The use of IMRT compared to 3-DCRT improves the avoidance of FL defined by perfusion SPECT scan in selected patients with locally advanced NSCLC. If the dose to FL is shown to be the primary determinant of lung toxicity, IMRT would allow for effective dose escalation by specific avoidance of FL.

Purpose/Objective(s): We have started the clinical trials with amplitude-based gating for carbon ion scanning beam and evaluated the positional accuracy including the gating accuracy and the treatment workflow. Materials/Methods: A total of 10 patients with tumors of the lung and liver participated. Four-dimensional computed tomography (4DCT) was performed for the planning CT under free-breathing conditions. The gaiting window (GW) was defined by evaluating 4D treatment planning. The GW region was calculated by a 2-mm or 3-mm setup margin added outside of the encompassing clinical target volumes within the GW. Treatment beam was on when tumor position moved within the GW region. The tumor position was detected in real time by a marker-less tumor tracking system using a paired x-ray fluoroscopic imaging system in our treatment room. Fluoroscopy imaging conditions were a tube voltage of 100 kV, tube current of 20e80 mA, exposure time of 4 ms per frame, at 15 fps. Our markerless tumor tracking uses multitemplate matching and machine-learning algorithms; template images and a machine-learning dictionary file were generated. We evaluated setup accuracy, gating positional accuracy, radiation dose, and treatment workflow retrospectively. Patient setup accuracy was calculated between the final setup FPD images and the reference DRR images by 2D-3D image registration. We measured the treatment room occupancy time, which consists of the following steps: entry into the room, patient setup, preparation for internal gating, irradiation, and exit from the room. Results: Patient setup error (mean AE SD) was 1.1AE1.2 mm/0.6AE0.4 . Internal gating accuracy was 0.5 mm (95% confidence interval [CI]) (<2.2 mm among all patients) throughout the treatment course. If external gating was applied to this treatment, the gating accuracy could be decreased to 4.1 mm (95% CI) (<11.2 mm among all patients). Fluoroscopic radiation doses were 23.7AE21.8 mGy per beam and 131.5 mGy throughout the treatment course. Setup, preparation, and irradiation times were 8.9AE8.2 min, 9.5AE4.6 min, and 4.0AE2.4 min, respectively. Treatment room occupant time was 36.7AE67.5 min. Conclusion: Gating positional error was less than 2.2 mm at a 95% CI. Our approach to a moving target (amplitude-based gating, markerless tumor tracking, and adequate phase-controlled rescanning) has been successfully integrated into clinical applications.

Background: This monocentric study evaluates the activity and tolerability of docetaxel (Taxotere), cisplatin and 5fluorouracil (5-FU) (TPF) induction chemotherapy followed by intensity-modulated radiotherapy (IMRT) concurrent with high-dose cisplatin in Epstein-Barr virus -related locally advanced undifferentiated nasopharyngeal cancer. Patients and methods: We retrospectively reviewed the records of patients who received induction docetaxel 75 mg/m 2 and cisplatin 75 mg/m 2 on day 1, and 5-FU 750 mg/m 2 /day (96-h continuous infusion). Following induction, patients received full doses of IMRT concurrently with cisplatin 100 mg/m 2 every 21 days for three cycles. Results: Thirty patients received three TPF cycles (median). Induction was well tolerated; the main toxicity was neutropenia (33%, grade 3-4). During chemoradiotherapy, neutropenia (40%) and mucositis (43%) were the most frequent grade 3-4 adverse events. Mean dose of IMRT was 68.8 Gy. Worst late toxicity was xerostomia. Complete response rate was 93%. At 35 months, two patients had locoregional recurrence, three had distant metastases, and one had both. Three-year progression-free survival and overall survival were 79% [95% confidence interval (CI) 64% to 94%] and 87% (95% CI 74%-to 100%), respectively. Conclusions: In this high-stage nonendemic cancer population, TPF followed by high-dose cisplatin IMRT was promising; this treatment approach deserves evaluation in randomized trials.

Background-The purpose of this study was to quantify the effect of treatment duration on locoregional progression after definitive concurrent chemoradiation (CCRT) for squamous cell carcinoma of the head and neck (SCCHN). Methods-We conducted a retrospective chart review of patients treated between 2004 and 2010. After a prior analysis, measures were taken to limit therapy beyond 7 weeks. Comparison of outcomes were made between cohorts 1 (2004-2007, n = 78) and 2 (2007-2010, n = 62). Results-Median therapy duration was statistically significantly different between cohorts as follows: 51 days, cohort 1 and 46 days, cohort 2 (p < .01). Locoregional progression in cohorts 1

Purpose:Electronic portal imagers (EPIDs) with high detective quantum efficiencies (DQEs) are sought to facilitate the use of the megavoltage (MV) radiotherapy treatment beam for image guidance. Potential advantages include high quality (treatment) beam&#39;s eye view imaging, and improved cone‐beam computed tomography (CBCT) generating images with more accurate electron density maps with immunity to metal artifacts. One approach to increasing detector sensitivity is to couple a thick pixelated scintillator array to an active matrix flat panel imager (AMFPI) incorporating amorphous silicon thin film electronics. Cadmium tungstate (CWO) has many desirable scintillation properties including good light output, a high index of refraction, high optical transparency, and reasonable cost. However, due to the cleave plane inherent in its crystalline structure, the difficulty of cutting and polishing CWO has, in part, limited its study relative to other scintillators such as cesium iodide an...

An independent in vivo dose verification procedure for IMRT treatments of head and neck cancers was developed. Results of 177 intracavitary TLD measurements from 10 patients are presented. The study includes data from 10 patients with cancer of the rhinopharynx or the thyroid treated with dynamic IMRT. Dose verification was performed by insertion of a flexible naso-oesophageal tube containing TLD rods and markers for EPID and simulator image detection. Part of the study focussed on investigating the accuracy of the TPS calculations in the presence of inhomogeneities. Phantom measurements and Monte Carlo simulations were performed for a number of geometries involving lateral electronic disequilibrium and steep density shifts. The in vivo TLD measurements correlated well with the predictions of the treatment planning system with a measured/calculated dose ratio of 1.0029/0.051 (1 SD, N0/177). The measurements were easily performed and well tolerated by the patients. We conclude that in vivo intracavitary dosimetry with TLD is suitable and accurate for dose determination in intensity-modulated beams.

Background: Stereotactic Radiosurgery (SRS) is a common tool used to treat Arteriovenous Malformations (AVMs) in anatomical locations associated with a risk of surgical complications. Despite high rates of clinical effectiveness, SRS carries a risk of toxicity as a result of radiation injury to brain tissue. The use of intensity-modulated radiotherapy (IMRT) has increased because it may lead to improved PTV conformity and better Normal Tissue (NT) sparing compared to 3D Conformal Radiotherapy (3DCRT). The aim of this study was twofold: 1) to develop simple patient stratification rules for the recommendation of IMRT planning strategies over 3DCRT in the treatment of AVMs with SRS; and 2) to estimate the impact of IMRT in terms of toxicity reduction using retrospectively reported data for symptomatic radiation injury following SRS. Methods: Thirty-one AVM patients previously treated with 3DCRT were replanned in a commercial treatment planning system using 3DCRT and static gantry IMRT with identical beam arrangements. The radiotherapy planning metrics analyzed included AVM volume, diameter, and volume to surface area ratio. The dosimetric endpoints analyzed included conformity index improvements and NT sparing measured by the maximum NT dose, and the volume of surrounding tissue that received 7Gy and 12Gy. Results: Our analysis revealed stratified subsets of patients for IMRT that were associated with improved conformity, and those that were associated with decreased doses to normal tissue. The stratified patients experienced an improvement in conformity index by -6-68%, a reduction in the maximum NT dose by -0.5-12.3%, a reduction in the volume of NT receiving 7Gy by 1-8 cc, and a reduction in the volume of NT receiving 12Gy by 0-3.7 cc. The reduction in NT receiving 12Gy translated to a theoretical decrease in the probability of symptomatic injury by 0-9.3%. Conclusions: This work indicates the potential for significant patient improvements when treating AVMs and provides rules to predict which patients are likely to benefit from IMRT.

Purpose: Acute vulvitis, acute urethritis, and permanent sexual dysfunction are common among patients treated with chemoradiation for squamous cell carcinoma of the anal canal. Avoidance of the genitalia may reduce sexual dysfunction. A vaginal dilator may help delineate and displace the vulva and lower vagina away from the primary tumor. The goal of this study was to evaluate the positional reproducibility and vaginal sparing with the use of a vaginal dilator. Materials and methods: Ten female patients treated with IMRT for anal cancer were included in this study. A silicone vaginal dilator measuring 29 mm in diameter and 114 mm in length was inserted into the vagina before simulation and each treatment. The reproducibility of dilator placement was investigated with antero-posterior and lateral images acquired daily. Weekly cone beam CT (CBCT) imaging was used to confirm coverage of the GTV, which was typically posterior and inferior to the dilator apex. Finally, a planning study was performed to compare the vaginal doses for these 10 patients to a comparable group of 10 female patients who were treated for anal cancer with IMRT without vaginal dilators. The absolute values of the location of the dilator apex were 7.0 ± 7.8 mm in the supero-inferior direction, 7.5 ± 5.5 mm in the antero-posterior, and 3.8 ± 3.1 mm in the lateral direction. Coverage of the GTV and CTV was confirmed from CBCT images. The mean dose to the vagina was lower by 5.5 Gy, on average, for the vaginal dilator patients, compared to patients treated without vaginal dilators. The vaginal dilator tended to be inserted more inferiorly during treatment than during simulation. For these ten patients, this did not compromise tumor coverage. Combined with IMRT treatment planning, use of a vaginal dilator could allow for maximum sparing of female genitalia for patients undergoing radiation therapy for anal cancer.

The 3D-CRT plan could be further improved if a better choice of beam angles was made. The 3D-CRT plans were able to meet the RTOG criteria, which suggests the added time and expense of IMRT planning was not justified for these cases. However, it is true that allowing the TPS to work toward the RTOG criteria achieved a more homogeneous dose inside the target volume. To rationalize the use of IMRT treatment when a 3D conformal plan would suffice, the FCCC criteria could be used to fully exploit the benefits IMRT offers.

The aim of this paper is to evaluate sensitivity and specificity of two commercial EPID-based software solutions for in vivo dosimetry of VMAT treatments to identify dosimetric and geometric errors and anatomical variations. Materials and methods: Measurements were performed by using TrueBeam STx accelerator equipped with EPID aSi1000 (Varian, Palo Alto, CA), Portal Dosimetry (PD) (Varian, Palo Alto, CA) and PerFraction (PF) software (Sun Nuclear Corporation, Melbourne, FL). Both PD and PF are commercial EPIDbased dosimetry software, which allows performing transit dosimetry to provide an independent daily verification of the treatment. Their performances on anthropomorphic phantom were studied, simulating 21 perturbations of the reference VMAT plan. Systematic variations in dose values and dose-rate (1%-5% output variation, 100-600 MU/min), shifts (2.5-11 mm in anterior direction), anatomical variations (adding bolus over phantom), and MLC positioning were applied. The difference in local and global gamma pass rate (%GP) between the no-error and error-simulated measurements with 1%/1 mm, 2%/2 mm and 3%/3 mm tolerances was calculated. The clinical impact of these errors was also analyzed through the calculation of the difference between reference DVH and perturbed DVH (%DE). A %GP value of 95% and a %DE equal to 3% were used to calculate sensitivity (SE) and specificity (SP) of PD and PF, and compared them. Results: Repeatability and reproducibility of no-error measurements were excellent with %GP = 100% for all gamma methods and for both PD and PF. SE of PF is slightly higher than SE of PD, reaching a maximum of 1 with 1%/1 mm and local normalization criteria. SP is comparable for the two software. Conclusions: PD and PF can be confidently used in the clinic to detect dosimetric, geometrical and anatomical discrepancies and they could have a very positive impact on improving daily patient QA.

graduation rates (OR 0.92, p<0.001) were also less likely to die within 30 days of their diagnosis. Conclusion: Approximately 7% of newly diagnosed NSCLC patients have died within 30 days of their diagnosis over the past decade. The majority of these individuals (65%) present with stage IV disease. Increasing awareness about lung cancer screening programs, improvements in access to care, and better medical optimization especially for elderly patients with multiple comorbidities may help further reduce the rates of early mortality in NSCLC.

Radiation therapy is an effective cancer treatment that is constantly being transformed by technological innovation. Dedicated devices for fraction-by-fraction imaging and guidance within the treatment room have enabled image guided radiation therapy (IGRT) allowing clinicians to pursue highly conformal dose distributions, higher dose prescriptions, and shorter fractionation schedules. Capitalizing on IGRT-enabled accuracy and precision requires a strong link between IGRT practices and planning target volume (PTV) design. This is clearly central to high quality, safe radiation therapy. Failure to properly apply IGRT methods or to coordinate their use with an appropriate PTV margin can result in a treatment that is 'precisely wrong'. The white paper summarized in this executive summary recommends foundational elements and specific activities to maximize the safety and effectiveness of IGRT.

Aim: The objective was to quantify dose calculation accuracy of TiGRT TPS for head and neck region in radiotherapy. Background: In radiotherapy of head and neck cancers, treatment planning is difficult, due to the complex shape of target volumes and also to spare critical and normal structures. These organs are often very near to the target volumes and have low tolerance to radiation. In this regard, dose calculation accuracy of treatment planning system (TPS) must be high enough. Materials and methods: Thermoluminescent dosimeter-100 (TLD-100) chips were used within RANDO phantom for dose measurement. TiGRT TPS was also applied for dose calculation. Finally, difference between measured doses (D meas ) and calculated doses (D calc ) was obtained to quantify the dose calculation accuracy of the TPS at head and neck region. Results: For in-field regions, in some points, the TiGRT TPS overestimated the dose compared to the measurements and for other points underestimated the dose. For outside field regions, the TiGRT TPS underestimated the dose compared to the measurements. For most points, the difference values between D calc and D meas for the in-field and outside field regions were less than 5% and 40%, respectively. Conclusions: Due to the sensitive structures to radiation in the head and neck region, the dose calculation accuracy of TPSs should be sufficient. According to the results of this study, it is concluded that the accuracy of dose calculation of TiGRT TPS is enough for in-field and out of field regions.

Introduction Radiotherapy is regarded as the first treatment of choice for nasopharyngeal carcinoma. Despite the advantages of radiotherapy, patients may suffer from a wide range of side-effects due to the presence of many sensitive normal tissues in these regions. If the absorbed dose exceeds the tolerance level in parotid glands and the spinal cord, myelopathy, Lhermitte&#39;s sign and xerostomia cannot be avoided. Materials and Methods The head and neck of a RANDO phantom (reference man), which was regarded as a hypothetical patient with nasopharyngeal carcinoma was evaluated. The full course of treatment consisted of three phases. At the beginning of each phase, an oncologist marked conventional fields on the RANDO phantom using a simulator. For measuring the absorbed dose, Thermoluminescent Dosimeters(TLD) chips (TLD-100) were utilized.The absorbed dose by TLDs was read by Harshaw 3500 TLD reader. Results The total absorbed dose was calculated by measuring the absorbed dose in ...

Dynamic conformal radiotherapy with helical TomoTherapy(®) (HT) offers a more quantitative paradigm for total body irradiation. Treatment planning, delivery, dose verification of the first French experiences of total body irradiation using helical TomoTherapy(®) are presented. Patients planned for total body irradiation at our institution from February 2012 to May 2013 were reported. Total body irradiation consisted in a single fraction of 2Gy. Planning target volume was divided in two due to the limited translation length of the table. Delivery quality assurance was performed with cylindrical phantom, ionization chamber and films. Thermoluminescent dosimeters and radiochromic films were used for in vivo dosimetry and junction region heterogeneity assessment. Six patients were included. One finally did not receive the treatment but dosimetric data were analyzed. Planned V95% was covered by D95% and V2% did not exceed D107% for five of the six patients. The mean relative difference b...

Background: Health-related quality of life (HRQOL) assessment is a key component of clinical oncology trials. However, few breast cancer trials comparing adjuvant conventional radiotherapy (CR) and hypofractionated tomotherapy (TT) have investigated HRQOL. We compared HRQOL in stage I-II breast cancer patients who were randomized to receive either CR or TT. Tomotherapy uses an integrated computed tomography scanner to improve treatment accuracy, aiming to reduce the adverse effects of radiotherapy. Methods: A total of 121 stage I-II breast cancer patients who had undergone breast conserving surgery (BCS) or mastectomy (MA) were randomly assigned to receive either CR or TT. CR patients received 25 × 2 Gy over 5 weeks, and BCS patients also received a sequential boost of 8 × 2 Gy over 2 weeks. TT patients received 15 × 2.8 Gy over 3 weeks, and BCS patients also received a simultaneous integrated boost of 15 × 0.6 Gy over 3 weeks. Patients completed the EORTC QLQ-C30 and BR23 questionnaires. The mean score (± standard error) was calculated at baseline, the end of radiotherapy, and at 3 months and 1, 2, and 3 years post-radiotherapy. Data were analyzed by the 'intention-to-treat' principle. Results: On the last day of radiotherapy, patients in both treatment arms had decreased global health status and functioning scores; increased fatigue (clinically meaningful in both treatment arms), nausea and vomiting, and constipation; decreased arm symptoms; clinically meaningful increased breast symptoms in CR patients and systemic side effects in TT patients; and slightly decreased body image and future perspective. At 3 months post-radiotherapy, TT patients had a clinically significant increase in role-and social-functioning scores and a clinically significant decrease in fatigue. The post-radiotherapy physical-, cognitive-and emotional-functioning scores improved faster in TT patients than CR patients. TT patients also had a better long-term recovery from fatigue than CR patients. ANOVA with the Bonferroni correction did not show any significant differences between groups in HRQOL scores. Conclusions: TT patients had a better improvement in global health status and role-and cognitive-functioning, and a faster recovery from fatigue, than CR patients. These results suggest that a shorter fractionation schedule may reduce the adverse effects of treatment.

The purpose of the study was to investigate the potential of direct machine parameter optimization (DMPO) to achieve parotid sparing without compromising target coverage in IMRT of oropharyngeal cancer as compared to fluence modulation with subsequent leaf sequencing (IM) and forward planned two-step arc therapy (IMAT). IMRT plans were generated for 10 oropharyngeal cancer patients using DMPO and IM. The resulting dose volume histograms (DVH) were evaluated with regard to compliance with the dose volume objectives (DVO) and plan quality. DMPO met the DVO for the targets better than IM, but violated the DVO to the parotids in some cases. DMPO provided better target coverage and dose homogeneity than IM and was comparable to IMAT. Dose to the parotids (23Gy) was significantly lower than for IMAT (48Gy), but somewhat higher than for IM (20Gy). Parotid sparing with IM was, however, only achieved at the cost of target coverage and homogeneity. DMPO allows achieving parotid sparing in the treatment of oropharyngeal cancer without compromising target coverage and dose homogeneity in the target as compared to two-step IMAT. Better overall plan quality can be delivered with less monitor units than with IM.

This study evaluated the secondary cancer risk after 3D-conformal radiotherapy (3DCRT), intensity modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) for spine. Computed tomography image set of a RPC spine anthropomorphic phantom was exported to the Pinnacle 3 treatment planning system. Radiation treatment plans for spine were created using the four-field 3DCRT, seven-field IMRT and dual-arc VMAT techniques. The mean and maximum doses, dose-volume histograms and volumes receiving more than 2 Gy and 4 Gy of organs-at-risk (OARs) were calculated and compared. The lifetime risk for secondary cancers was estimated according to NCRP Report 116. Quality Assurances of IMRT and VMAT were performed using the ArcCHECK method with gamma index criteria set to 3%/3mm. For our dosimetric comparisons, planning target volume coverages were found to be 90.5 %, 91.4 % and 95.9 %, for 3DCRT, IMRT and VMAT, respectively. VMAT was found to deliver the lowest maximum dose to esophagus (3.22 Gy), bone (6.48 Gy), heart (1.69 Gy), spinal cord (5.15 Gy) and the whole lung (4.52 Gy). Volumes of esophagus receiving more than 4 Gy were 0% for VMAT, 37.56% for IMRT and up to 43.76% for 3DCRT. The estimated risk for secondary cancer in the respective OAR is considerably lower in VMAT compared to other techniques. Results of maximum doses and volumes of OARs suggest that the risk of secondary cancer induction for spine in VMAT is lower than IMRT and 3DCRT, whereas VMAT has the best target coverage.

This study investigated the dose-volume dependences of planning target volume (PTV) and organs-at-risk (OARs) on prostate volumetric modulated arc therapy (VMAT), when the collimator angle is varied. Single-arc VMAT plans at different collimator angles (0 o , 15 o , 30 o , 45 o , 60 o , 75 o and 90 o ) were created systematically based on a Harold pelvis phantom and the 6 MV photon beams. The conformity index (CI), homogeneity index (HI), gradient index (GI), machine monitor units (MUs), dose-volume histogram and mean and maximum dose of the PTV were calculated and analyzed (Table ). The dose-volume histogram and mean and maximum doses of OARs such as bladder, rectum and femoral heads for different collimator angles were determined from the plans (Table ). From our dosimetric results, there was no significant difference, according to the planned dose-volume evaluation criteria, found in the VMAT optimizations for all studied collimator angles. However, a higher CI (0.53) and lower HI (0.064) resulted from the 45 o collimator angle. The 15 o collimator angle provided a lower value of HI similar to the 45 o angle while collimator angles of 75 o and 90 o were found to be good for rectum sparing. In addition, collimator angles of 75 o and 30 o worked well for sparing the right and left femur. The PTV dose coverage for each plan was comparatively independent of the collimator angle. The dosimetric results in this study provide support and guidance in the collimator angle selection for prostate VMAT to improve the PTV coverage and OARs sparing.

The use of intensity modulated radiation therapy (IMRT) has been rapidly growing in the United States. This technology is now being used in a multitude of academic and community centers throughout the country and is being incorporated into the treatment of cancers in almost every anatomical site, most commonly head and neck cancer, central nervous system tumors, and prostate cancer. In addition, current protocols are investigating the use of IMRT for the treatment of breast cancer, lung cancer, abdominal/retroperitoneal malignancies, and gynecological diseases. This article presents a brief technical review of IMRT and addresses specific clinical concerns and caveats that radiation oncologists should be aware of when utilizing this technology.

In this study, we investigated the potential of radiomic models to discriminate nasopharyngeal carcinoma from benign hyperplasia on MRI, which is important to enable screening programs to detect cancer early. We found that whereas radiomics showed promising performance, instability was presented by the feature selection step in the radiomics pipeline, which could undermine its reliability. Therefore, we built a radiomics model using 17 features selected from a pool of 422 features by a proposed ensemble technique that improved the feature selection stability using a combination of bagging and boosting. This radiomic model achieved an area under the curve of 0.85 and 0.80 for discriminating the two abnormalities on the training and testing data, respectively. In addition, the proposed feature selection technique significantly improved stability when compared to well-established techniques.

To analyze quality of life (QoL) and functional state (FS) by patient-reported outcome (PRO) questionnaires (FACT-G, FACT-NP, PSS-HN, XeQOLS, and EQ-5D-3L) in long-term survivors nasopharyngeal carcinoma (NPC) treated with conventional radiotherapy (RT) and intensity modulated radiotherapy (IMRT). 25 patients answered to five questionnaires about QoL and FS. All patients were assessed also for late toxicity. Functional Assessment of Cancer Therapy-General (FACT-G) and Performance Status Scale Head and Neck (PSS-HN) scores were significantly elevated (better QoL) in age &lt;50 years (p = 0.03). PSS-HN score was higher in IMRT group. The observed xerostomia was lower in the IMRT group and in patients who received conventional RT had worse QoL according to XeQOLS (University of Michigan Xerostomia-Related Quality of Life Scale) score questionnaire. Lower PSS-HN score and higher XeQOLS score were significantly related with the late xerostomia (p = 0.009 and 0.002, respectively). Our pre...

Background Vulvar carcinoma is a rather uncommon gynecological malignancy affecting elderly women and the treatment of loco-regional advanced carcinoma of the vulva (LAVC) is a challenge for both gynecologic and radiation oncologists. Definitive chemoradiation (CRT) is the treatment of choice, but with disappointing results. In this multicenter study (OLDLADY-1.1), several institutions have combined their retrospective data on LAVC patients to produce a real-world dataset aimed at collecting data on efficacy and safety of CRT. Methods The primary study end-point was 2-year-local control (LC), secondary end-points were 2-year-metastasis free-survival (MFS), 2-year-overall survival (OS) and the rate and severity of acute and late toxicities. Participating centers were required to fill data sets including age, stage, histology, grading as well as technical/dosimetric details of CRT. Data about response, local and regional recurrence, acute and late toxicities, follow-up and outcome mea...

Background Recent studies have reported improvement of outcomes (progression-free survival, overall survival, and prolongation of androgen deprivation treatment-free survival) with stereotactic body radiotherapy (SBRT) in non-small cell lung cancer and prostate cancer. The aim of this retrospective, multicenter study (MITO RT-01) was to define activity and safety of SBRT in a very large, real-world data set of patients with metastatic, persistent, and recurrent ovarian cancer (MPR-OC). Materials and Methods The endpoints of the study were the rate of complete response (CR) to SBRT and the 24-month actuarial local control (LC) rate on “per-lesion” basis. The secondary endpoints were acute and late toxicities and the 24-month actuarial late toxicity-free survival. Objective response rate (ORR) included CR and partial response (PR). Clinical benefit (CB) included ORR and stable disease (SD). Toxicity was evaluated by the Radiation Therapy Oncology Group (RTOG) and the European Organiza...

Adjuvant RT after quadrantectomy or lumpectomy plays an essential role in breast conserving therapy for early stage carcinoma and 60 Gy delivered in 30 fractions in 6 weeks is generally considered the standard dose. The present study aims to evaluate acute, sub-acute and short term late side effects in patients with early stage breast cancer treated with adjuvant radiotherapy (RT) using concomitant boost. Materials and Methods: Between June 2010 and October 2013, 586 patients (median age 60 years, range 27-96 years) with early-stage breast cancer were treated with a hypofractionated schedule of external beam RT after conserving surgery; 143 patients underwent post-operative chemotherapy before starting RT. RT was delivered as follow: 45 Gy in 20 fractions (225 cGy/fr) in 4 weeks to the whole breast and a daily concomitant boost dose (5Gy) to the lumpectomy cavity (25 cGy/fr). The cumulative nominal dose was 50 Gy. The technique used was 3D-conformational RT with 2 tangential fields for the whole breast and 2 oblique fields for the boost. The surgical bed was primarily defined with clips. Toxicity was scored according to LENT-SOMA scale. Results: Twenty-five patients experienced grade 3 skin toxicity within one week from the end of the RT course (eight after adjuvant chemotherapy administered before breast RT). After 19-month median follow-up (range 12-52 months), no grade 4 toxicity were detected; only 5 patients experienced grade 3 skin toxicity and thirty-nine patients reported grade 2 breast pain. Concerning cosmetic results, one patients developed scar retraction; the others 585 patients showed excellent or good cosmetic results. Disease recurrences were recorded in 4 patients: one of them with local relapse, the others three with systemic spread. Conclusions: The explored regimen seems to be feasible providing consistent clinical results with excellent toxicity profile.

Purpose-We previously found that up to 75% of treatment failures after chemoradiation for unresectable esophageal cancer appear within the gross tumor volume (GTV) and that intensitymodulated [photon] radiation therapy (IMRT) may allow dose escalation to the tumor without increasing normal-tissue toxicity. Proton therapy may allow further dose escalation with even lower normal-tissue toxicity. Here we compared dosimetric parameters for photon IMRT with intensity-modulated proton therapy (IMPT) for unresectable, locally advanced distal esophageal cancer. Methods and Materials-Four plans were created for each of 10 patients: IMPT delivered via anteroposterior/posteroanterior (AP/PA) beams, left posterior oblique/right posterior oblique (LPO/RPO) beams, or AP/LPO/RPO beams; and IMRT delivered with a concomitant boost to the GTV. Doses were 65.8 Gy to the GTV and 50.4 Gy to the planning target volume (PTV) in 28 fractions.

Extensive work has been done on the characteristics, dosimetry, and efficacy of flattening filter free (FFF) beams in radiosurgery. However, no study has addressed the dosimetric impact of FFF beam energy selection on treatment plan quality. This study aims to present a systematic dosimetric comparison of plan quality between 10 FFF vs 6 FFF beams in intracranial stereotactic radiosurgery (SRS) treatments using volumetric modulated arc therapy (VMAT). The dosimetric evaluation is based on radiation therapy oncology group (RTOG) dose conformity (CI RTOG ) and gradient (GI RTOG ) indices, and irradiated normal brain tissue volume. Thirty-five VMAT-based intracranial SRS treatments to multiple brain metastases using a 2.5 mm multileaf collimator (MLC) and 10 MV FFF beam were replanned with a 6 MV FFF and same MLC. The replans incorporated the same arc arrangement, planning target volume (PTV) and organs at risk structures, PTV coverage and prescription isodose normalization. The 6 MV FFF had a sharper dose fall-off compared to the 10 MV FFF (GI RTOG-10 FFF = 4.70, GI RTOG-6 FFF = 4.56; p < 0.05) and comparable conformity index (CI RTOG-10 FFF = 1.11, CI RTOG-6 FFF = 1.10; p = 0.9). On average, the irradiated normal brain tissue volume was 11% lower with 6 MV FFF compared to 10 MV FFF ( p < 0.05). However, this difference was diminished for large target volumes and increased number of targets treated. The main dosimetric improvement of a 6 MV FFF over a 10 MV FFF beam is the sharper dose fall-off which directly correlates with less normal brain tissue volume irradiation.