METHODS AND MATERIALS: The bladder dose-surface maps of 754 participants from the TROG 03.04-RADAR trial were generated from the volumetric data by virtually cutting the bladder at the sagittal slice, intersecting the bladder center-of-mass through to the bladder posterior and projecting the dose information on a 2-dimensional plane. Pixelwise dose comparisons were performed between patients with and without symptoms (dysuria, hematuria, incontinence, and an International Prostate Symptom Score increase of ≥10 [ΔIPSS10]). The results with and without permutation-based multiple-comparison adjustments are reported. The pixelwise multivariate analysis findings (peak-event model for dysuria, hematuria, and ΔIPSS10; event-count model for incontinence), with adjustments for clinical factors, are also reported.
RESULTS: The associations of the spatially specific dose measures to urinary dysfunction were dependent on the presence of specific symptoms. The doses received by the anteroinferior and, to lesser extent, posterosuperior surface of the bladder had the strongest relationship with the incidence of dysuria, hematuria, and ΔIPSS10, both with and without adjustment for clinical factors. For the doses to the posteroinferior region corresponding to the area of the trigone, the only symptom with significance was incontinence.
CONCLUSIONS: A spatially variable response of the bladder surface to the dose was found for symptoms of urinary dysfunction. Limiting the dose extending anteriorly might help reduce the risk of urinary dysfunction.
METHODS AND MATERIALS: Between October 2007 and May 2016, 106 patients with untreated squamous cell carcinoma of the cervix were enrolled in the present study. Radiation therapy consisted of pelvic irradiation (total dose, 50 Gy in 25 fractions including central shielding), prophylactic paraortic regional irradiation (36-40 Gy in 20 fractions), and either high- or low-dose-rate intracavitary brachytherapy (ICBT) according to institutional practice. The planned point A dose was 21 to 28 Gy in 3 to 4 fractions for high-dose-rate ICBT and 40 to 41 Gy in 1 to 2 fractions for low-dose-rate ICBT. Five cycles of weekly cisplatin (40 mg/m2) were administered during the radiation therapy course.
RESULTS: A total of 106 patients were enrolled. Of these, 9 had major protocol violations and 2 did not receive treatment because of worsened general condition. Thus, 95 patients were evaluable. The median follow-up was 56 months. Of the 95 patients, 76 (80%) received 4 or 5 cycles of chemotherapy. Acute grade 3 leukopenia was observed in 20 of the patients (21%), and late grade 3 gastrointestinal toxicity was observed in 3%. The 2-year local control, progression-free survival, and overall survival rate for all patients were 96%, 78%, and 90%, respectively.
CONCLUSIONS: The results indicated that prophylactic extended-field concurrent chemoradiation therapy using weekly cisplatin is feasible and effective for patients with locally advanced cervical cancer in East and Southeast Asia.
MATERIALS/METHODS: Participants interested in a 12-week virtual training program completed a needs assessment survey via a data collection web application. The survey included demographics, practice characteristics, and interests in contouring and plan evaluation education and training. Herein we provide descriptive statistics of the reports from participant surveys.
RESULTS: Across Thailand, Myanmar, Malaysia, Indonesia, and Nepal, 116 participants (82 attendings, 33 residents, 1 other) responded from 23 participating medical institutions (20 public, 3 private). The average number of radiation oncologists per medical institution was 6.81 (range 1-30) and radiation oncology residents was 17.50 (range 2-56). In the 7 centers with residency programs, 0 (0%) indicated that residents were solely involved in contouring, 5 (71.4%) that residents were jointly involved in contouring with attendings, and 2 (28.6%) that attendings contour without residents. Commonly cited obstacles to providing radiotherapy included: patient financial barriers (61.4%), inadequate training (51.8%), too many patients (48.2%), lack of modern equipment (40.4%), shortage of staff (39.5%), and malfunctioning equipment (36.8%). The most common, top-rated obstacle was inadequate training (24.8%). The most seen disease sites were head and neck (38.2%) and breast (30.3%). Respondent time spent contouring the target was greatest for head and neck, pediatric, and lymphoma disease sites with 66 (56.9%), 59 (50.8%), and 46 (29.3%) indicating more than 1 hour, respectively. Respondent time spent contouring the normal tissues was greatest for head and neck, pediatric, and CNS disease sites with 51 (44%), 46 (39.7%), and 30 (26.1%) indicating more than 1 hour. For head and neck cases, 34 (29.3%) respondents typically contour 6-10 Organs at Risk (OARs), 47 (40.5%) contour 11-15 OARs, 18 (15.5%) contour 16-20 OARs, and 15 (12.9%) contour > 20 OARs. 85 (76.3%) respondents believe their practice would most benefit from head and neck contouring education, while 114 (98.3%) were interested in receiving contouring and plan evaluation training.
CONCLUSION: The biggest physician-reported obstacle to providing radiotherapy in Southeast Asian practices is inadequate training. There is both high need and interest for well-developed virtual training, particularly in head and neck contouring, which currently appears time-intensive and heterogeneous among practices.
METHODS AND MATERIALS: This retrospective cohort study identified all phase three RCTs evaluating anticancer therapies published from 2014 to 2017. RCTs were classified according to anticancer modality and country of origin. Descriptive statistics were used to compare key characteristics of radiotherapy RCT studies according to study design characteristics, tumor types evaluated, types of intervention appraised, treatment intent and main funding sources.
RESULTS: The study cohort included 694 RCTs of which 64 were radiotherapy RCTs (9%) compared to 601 (87%) systemic therapy RCTs. 47% of all radiotherapy RCTs focused on two areas of evaluation; combining radiotherapy with systemic agents (25%) and changes in dose fractionation (22%). The most common cancers studied were head and neck (22%), lung (22%) and breast (14%) with cervical cancer trials only representing 3% of the cohort. 33% of radiotherapy RCTs met their primary end point. 62% of radiotherapy RCTs assessed interventions in the curative setting compared to 31% in systemic therapy RCTs. 77% of the radiotherapy RCTs were performed in high-income countries (HIC), 13% in low-and-middle-income countries (LMIC) and 11% in both HIC and LMICs. 17% of radiotherapy RCTs received funding from industry compared to 79% of systemic therapy RCTs.
CONCLUSION: This study has highlighted the need for greater investment in radiotherapy RCTs and the disparities in conduct of RCTs globally. The study emphases the urgent need for more capacity building for cancer clinical trials in LMICs and more sustainable funding sources.
MATERIALS/METHODS: A total of 10 patients with synchronous bilateral breast cancer who were treated with VMAT at our institution were retrospectively analyzed. Clinical target volume (CTV) included chest wall and regional nodes (supraclavicular fossa and internal mammary chain) and prescription dose was 40.05 Gy in 15 daily fractions. HT and IMPT plans were generated for each patient. Dose-volume statistics, including planning target volume (PTV) coverage and dose to OAR: lungs, heart, thyroid, spinal cord, brachial plexus and esophagus, were compared between modalities using a paired T-test.
RESULTS: Mean age of patients was 61 years (43-84). Majority of the patients (80%) were ER+ PR+ and HER2-. 40% of patients underwent breast reconstruction following surgery. All 3 techniques provided adequate target volume distribution and OAR sparing. Compared to VMAT and HT plans, IMPT had better heart and lung sparing effects, resulting in lower mean and V25 Gy heart dose; mean, V20 Gy and V5 Gy lung dose (p<0.0001). There was no significant difference in VMAT and HT plans for mean heart and lung dose. VMAT plans showed significantly lower V25 Gy heart dose on average (p = 0.04). V5 Gy lung dose was slightly lower in HT compared to VMAT plans, approaching statistical significance (p = 0.08). PTV coverage was adequate for all 3 techniques. All techniques fulfilled cord, esophagus, thyroid and brachial plexus constraints.
CONCLUSION: IMPT plans showed significantly better OAR sparing compared to photon techniques. All 3 techniques met OAR constraints, and resulted in adequate target volume coverage. As IMPT is significantly more costly than VMAT or HT techniques, appropriate patient selection is important to deliver treatment in the most resource-effective manner for patients who would derive the most benefit, for example those with young age or existing heart or lung comorbidities.