An Active Matrix Flat Panel Dosimeter (AMFPD) for inâ phantom dosimetric measurements

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135086/1/mp5012.pd

Differences in the Acute Toxic Effects of Breast Radiotherapy by Fractionation Schedule: Comparative Analysis of Physician-Assessed and Patient-Reported Outcomes in a Large Multicenter Cohort

IMPORTANCE: Randomized trials have established the long-term safety and efficacy of hypofractionated whole-breast radiotherapy, but little is known about the acute toxic effects experienced by patients treated with hypofractionation as compared with conventional fractionation, particularly in real-world settings and from the patient\u27s own perspective. OBJECTIVE: To evaluate prospectively collected data on acute toxic effects and patient-reported outcomes in a cohort treated with varying radiation fractionation schemes in practices collaborating in the Michigan Radiation Oncology Quality Consortium (MROQC). DESIGN, SETTING, AND PARTICIPANTS: We compared toxic effects in patients receiving hypofractionation (HF) vs conventional fractionation (CF) during treatment (through 7 days after treatment) and in follow-up (posttreatment days 8-210), after adjustment for sociodemographic, clinical, and treatment characteristics. The MROQC includes academic and community radiation oncology practices across Michigan. All 2604 patients who received adjuvant whole-breast radiotherapy after lumpectomy for unilateral breast cancer at MROQC participating sites from October 2011 through June 2014 were registered; we analyzed 2309 for whom there was a comprehensive physician toxicity evaluation within 1 week of completion of radiotherapy and at least 1 weekly toxicity evaluation during treatment. EXPOSURES: Hypofractionation vs CF. MAIN OUTCOMES AND MEASURES: Physicians reported dermatitis, pain, fatigue, and other common toxic effects associated with breast radiotherapy at baseline, weekly during radiotherapy, and in follow-up. Patients who consented also rated their own experiences, including breast pain, fatigue, and being bothered by symptoms. RESULTS: Of the 2309 evaluable patients, 578 received HF. During treatment, after adjustment for sociodemographic, clinical, and treatment factors, patients receiving CF had significantly higher maximum physician-assessed skin reaction (moist desquamation, 28.5% vs 6.6%, P \u3c .001; grade ≥2 dermatitis, 62.6% vs 27.4%, P \u3c .001), self-reported pain (moderate/severe pain, 41.1% vs 24.2%, P = .003), burning/stinging bother (often/always, 38.7% vs 15.7%, P = .002), hurting bother (33.5% vs 16.0%, P = .001), swelling bother (29.6% vs 15.7%, P = .03), and fatigue (29.7% vs 18.9%, P = .02) but slightly greater absence of skin induration in follow-up (84.5% vs 81.2%, P = .02). No significant differences were observed in any other measured outcomes during follow-up extending through 6 months. CONCLUSIONS AND RELEVANCE: Hypofractionation not only improves convenience but also may reduce acute pain, fatigue, and the extent to which patients are bothered by dermatitis in patients with breast cancer undergoing whole-breast radiotherapy

Evaluating organ delineation, dose calculation and daily localization in an open-MRI simulation workflow for prostate cancer patients

BACKGROUND: This study describes initial testing and evaluation of a vertical-field open Magnetic Resonance Imaging (MRI) scanner for the purpose of simulation in radiation therapy for prostate cancer. We have evaluated the clinical workflow of using open MRI as a sole modality for simulation and planning. Relevant results related to MRI alignment (vs. CT) reference dataset with Cone-Beam CT (CBCT) for daily localization are presented. METHODS: Ten patients participated in an IRB approved study utilizing MRI along with CT simulation with the intent of evaluating the MRI-simulation process. Differences in prostate gland volume, seminal vesicles, and penile bulb were assessed with MRI and compared to CT. To evaluate dose calculation accuracy, bulk-density-assignments were mapped onto respective MRI datasets and treated IMRT plans were re-calculated. For image localization purposes, 400 CBCTs were re-evaluated with MRI as the reference dataset and daily shifts compared against CBCT-to-CT registration. Planning margins based on MRI/CBCT shifts were computed using the van Herk formalism. RESULTS: Significant organ contour differences were noted between MRI and CT. Prostate volumes were on average 39.7% (p = 0.002) larger on CT than MRI. No significant difference was found in seminal vesicle volumes (p = 0.454). Penile bulb volumes were 61.1% higher on CT, without statistical significance (p = 0.074). MRI-based dose calculations with assigned bulk densities produced agreement within 1% with heterogeneity corrected CT calculations. The differences in shift positions for the cohort between CBCT-to-CT registration and CBCT-to-MRI registration are -0.15 ± 0.25 cm (anterior-posterior), 0.05 ± 0.19 cm (superior-inferior), and -0.01 ± 0.14 cm (left-right). CONCLUSIONS: This study confirms the potential of using an open-field MRI scanner as primary imaging modality for prostate cancer treatment planning simulation, dose calculations and daily image localization

Recent Time Trends and Predictors of Heart Dose From Breast Radiation Therapy in a Large Quality Consortium of Radiation Oncology Practices

PURPOSE: Limited data exist regarding the range of heart doses received in routine practice with radiation therapy (RT) for breast cancer in the United States today and the potential effect of the continual assessment of the cardiac dose on practice patterns. METHODS AND MATERIALS: From 2012 to 2015, 4688 patients with breast cancer treated with whole breast RT at 20 sites participating in a state-wide consortium were enrolled into a registry. The importance of limiting the cardiac dose has been emphasized in the consortium since 2012, and the mean heart dose (MHD) has been reported by each institution since 2014. The effects on the MHD were estimated for both conventional and accelerated fractionation using regression models, with technique (intensity modulated RT [IMRT] vs 3-dimensional conformal RT), deep inspiration breath hold use, patient position (supine vs prone), nodal RT (if delivered), and boost (yes vs no) as covariates. RESULTS: For left-sided breast cancer treated with conventional fractionation, the median MHD in 2012 was 2.19 Gy versus 1.65 Gy in 2015 (P CONCLUSIONS: The MHD for left-sided breast cancer decreased during a recent 4-year period, coincident with an increased focus on cardiac sparing in the radiation oncology community in general and a state-wide consortium specifically. These data suggest a positive effect of systematically monitoring the heart dose delivered