The use of postoperative radiation therapy after breast-conserving surgery was longstanding standard practice. The treatment protocol used a standard fractionation of 50 Gy in 25 fractions plus a boost. Recently, the hypofractionation approach has gained support based on Canadian and English studies that claimed equal tumor control and similar toxicity to the standard protocol.We conducted a review of the literature of hypofractionation studies and compared the reported toxicity with the general literature. We placed special emphasis on breast fibrosis after hypofractionation versus standard fractionation. We found a striking difference in the breast toxicity reported by the hypofractionation literature regarding breast fibrosis as compared to standard fractionation. Breast fibrosis should be explored further via additional studies and discussed with potential breast-conserving surgery patients.

No abstract

ObjectiveTo determine the long-term normal tissue complication probability with stereotactic body radiation therapy (SBRT) treatments for targets that move with respiration and its relation with the type of respiratory motion management (tracking vs. compression or gating).MethodsA PubMed search was performed for identifying literature regarding dose, volume, fractionation, and toxicity (grade 3 or higher) for SBRT treatments for tumors which move with respiration. From the identified papers logistic or probit dose-response models were fitted to the data using the maximum-likelihood technique and confidence intervals were based on the profile-likelihood method in the dose-volume histogram (DVH) Evaluator.ResultsPooled logistic and probit models for grade 3 or higher toxicity for aorta, chest wall, duodenum, and small bowel suggest a significant difference when live motion tracking was used for targeting tumors with move with respiration which was on the average 10 times lower, in the high dose range.ConclusionLive respiratory motion management appears to have a better toxicity outcome when treating targets which move with respiration with very steep peripheral dose gradients. This analysis is however limited by sparsity of rigorous data due to poor reporting in the literature.

Purpose/Objective(s): Stereotactic body radiation therapy (SBRT) is an effective treatment for patients with early-stage non-small cell lung cancer (NSCLC) who are not surgical candidates or who refuse surgical management. In this study, we report on our clinical outcomes and toxicity in the treatment of early-stage NSCLC with SBRT. Methods and Materials: Fifty-five patients with 59 T1-2N0M0 NSCLC lesions were treated at our institution between December 2009 and August 2014. The majority of the patients [38 (69%)] were treated with 50 Gy in 5 fractions, 7 patients (13%) with 48 Gy in 4 fractions, 8 patients (14%) with 60 Gy in 3 fractions, 1 patient (2%) with 62.5 Gy in 10 fractions, and 1 patient (2%) with 54 Gy in 3 fractions. Tumor response was evaluated using RECIST 1.1, and toxicity was graded using the CTCAE (Common Terminology Criteria for Adverse Events) version 3.0. The primary endpoints of this retrospective review included rates of overall survival, disease-free and progression-free survival, local failure, regional failure, and distant failure. A secondary endpoint included radiation-related toxicities. Results: The median follow-up was 23.8 months (range 1.1-57.6). The 3-year local control, progression-free survival, and overall survival rates were 91, 55, and 71%, respectively. The median age at diagnosis was 67.9 years (range 51.4-87.1). There were a total of 54 T1N0 tumors (92%) and 5 T2N0 lesions (8%). Adenocarcinoma was the most common pathology, comprising 54% of the lesions. A total of 16 of the patients (29%) failed. Among these, 5 local (9%), 14 regional (25%), and 4 distant failures (7%) were observed. On follow-up, one patient had grade 2 and another had grade 5 pneumonitis. Three patients experienced grade 2 chest wall tenderness. Two patients had grade 1 rib fractures, one of which could not be discerned from radiation-induced toxicity versus a traumatic fall. Conclusion: The University of Mississippi Medical Center SBRT experience has shown that SBRT provides satisfactory local control and overall survival rates with minimal toxicity in early-stage NSCLC patients.

Purpose: IGRT imaging procedures have emerged as a common method of patient position verification in radiotherapy, though imaging dose is generally neglected in the treatment plan. Consequently, evaluating and optimizing the dose from these procedures is worthwhile. This process is especially important for children, who are more radiosensitive than adults. The aim of this work was to gain some understanding of the relative doses involved with various XVI‐preset parameters for an “adult” and “child” phantom set, with the hopes that imaging dose for a child can be reduced. Methods: 32 and 16cm CTDI‐phantoms were used as surrogates for adult and child torsos, respectively. Dose was measured in the central and peripheral chamber positions of the phantoms. CBCT scans were made for both phantoms using Elekta's Chest‐preset to establish a dose baseline. The child‐phantom was then scanned using the Elekta Head and Neck (HN) preset. A modified HN‐preset (named Peds Abd‐pelvis) was also created with a doubled mAs to maintain a reduction in dose to the child‐phantom (relative to the baseline), while providing clinically‐usable image quality. Results: The baseline dose to the child‐phantom from the Chest‐preset was 310% that of the adult‐phantom for the center chamber position and 150% at the periphery. An average dose reduction of 97% was obtained in the childphantom by switching from the Chest‐preset to the HN‐preset, while the Peds Abd‐pelvis‐preset similarly reduced the dose by an average of 92%. Conclusion: XVI‐preset parameters significantly affect dose, and should be optimized to reduce dose, while ensuring clinically‐usable image quality. Using a modified imaging preset (Peds Abd‐pelvis‐preset) greatly reduced the dose to the child‐phantom compared to the dose for the Chest‐preset for both the child and adult‐phantoms. This outcome provides support for the development of child‐specific protocols for IGRT imaging in pediatric patients.