We report on a comparative dosimetrical study between deep inspiration breath hold (DIBH) and shallow breathing (SB) in prone crawl position for photon and proton radiotherapy of whole breast (WB) and locoregional lymph node regions, including the internal mammary chain (LN_MI). We investigate the dosimetrical effects of DIBH in prone crawl position on organs-at-risk for both photon and proton plans. For each modality, we further estimate the effects of lung and heart doses on the mortality risks of different risk profiles of patients. Thirty-one patients with invasive carcinoma of the left breast and pathologically confirmed positive lymph node status were included in this study. DIBH significantly decreased dose to heart for photon and proton radiotherapy. DIBH also decreased lung doses for photons, while increased lung doses were observed using protons because the retracting heart is displaced by low-density lung tissue. For other organs-at-risk, DIBH resulted in significant dose reductions using photons while minor differences in dose deposition between DIBH and SB were observed using protons. In patients with high risks for cardiac and lung cancer mortality, average thirty-year mortality rates from radiotherapy-related cardiac injury and lung cancer were estimated at 3.12% (photon DIBH), 4.03% (photon SB), 1.80% (proton DIBH) and 1.66% (proton SB). The radiation-related mortality risk could not outweigh the ~ 8% disease-specific survival benefit of WB + LN_MI radiotherapy in any of the assessed treatments.

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Introduction: Acceleration of radiotherapy in 5 fractions for breast cancer can reduce the burden of treatment. We report on acute toxicity after whole-breast irradiation with a simultaneous integrated boost in 5 fractions over 10e12 days. Material and methods: Acute toxicity and health-related quality of life (HRQoL) of 200 patients, randomized between a 15-or 5-fractions schedule, were collected, using the CTCAE toxicity scoring system, the Multidimensional Fatigue Inventory, EORTC QLQ-C30 and BR23 and the BREAST-Q questionnaire. The prescribed dose to the breast was either 15*2.67 Gy (40.05 Gy) or 5*5.7 Gy (28.5 Gy). 90% of patients received a SIB to a cumulative dose of 46.8 Gy (15*3.12 Gy) or 31 Gy (5*6.2 Gy). Results: Physician-assessed toxicity was lower for the 5-fractions group. A significant difference was observed for breast pain (p ¼ 0.002), fatigue (p < 0.0001), breast edema (p ¼ 0.001) and dermatitis (p ¼ 0.003). Patients treated in 5 fractions reported better mean HRQoL scores for breast symptoms (p ¼ 0.001) and physical well-being (p ¼ 0.001). A clinically important deterioration in HRQoL of 10 points or more was also less frequently observed in the latter group for physical functioning (p ¼ 0.0005), social functioning (p ¼ 0.0007), fatigue (p ¼ 0.003), breast symptoms (p ¼ 0.0002) and physical wellbeing (p ¼ 0.002). Conclusion:In this single institute study, acute toxicity of accelerated breast radiotherapy in 5 fractions over 10e12 days seems to compare favourably to hypofractionated breast radiotherapy in 15 fractions. Less breast edema, dermatitis, desquamation, breast pain and fatigue are seen. Social and physical functioning are also less disturbed and patients have a better future perspective.

Prone positioning for whole-breast irradiation (WBI) reduces dose to organs at risk, but reduces set-up speed, precision, and comfort. We aimed to improve these problems by placing patients in prone crawl position on a newly developed crawl couch (CrC). A group of 10 right-sided breast cancer patients requiring WBI were randomized in this cross-over trial, comparing the CrC to a standard prone breastboard (BB). Laterolateral (LL), craniocaudal (CC) and anterioposterior (AP) set-up errors were evaluated with cone beam CT. Comfort, preference and set-up time (SUT) were assessed. Forty left and right-sided breast cancer patients served as a validation group. For BB versus CrC, AP, LL and CC mean patient shifts were − 0.8 ± 2.8, 0.2 ± 11.7 and − 0.6 ± 4.4 versus − 0.2 ± 3.3, − 0.8 ± 2.5 and − 1.9 ± 5.7 mm. LL shift spread was reduced significantly. Nine out of 10 patients preferred the CrC. SUT did not differ significantly. The validation group had mean patient shifts of 1.7 ± 2.9 (AP), 0.2 ± 3.6 (LL) and − 0.2 ± 3.3 (CC) mm. Mean SUT in the validation group was 1 min longer (P < 0.05) than the comparative group. Median SUT was 3 min in all groups. The CrC improved precision and comfort compared to BB. Set-up errors compare favourably to other prone-WBI trials and rival supine positioning.