Accelerated hypofractionated breast radiotherapy with simultaneous integrated boost: a feasibility study

Abstract

Purpose: To assess the feasibility of accelerated hypofractionated radiotherapy with simultaneous integrated boost (SIB) in patients with breast cancer.Materials and Methods: A total of 27 patients after breast-conserving surgery were included in this study. Patients were planned on a four-dimensional computerized tomogram, and contouring was done using RTOG guidelines. The dose was 34 Gy/10#/2 week to the breast and 40 Gy/10#/2 week to the tumor bed as SIB with volumetric modulated arc technique. The primary endpoint was grade 2 acute skin toxicity. Doses to the organs-at-risk were calculated. Toxicities and cosmesis were assessed using RTOG/LENT/SOMA and HARVARD/NSABP/RTOG grading scales, respectively. Disease-free survival (DFS) and overall survival (OS) were calculated with Kaplan-Meier curves.Results: The mean age of the patients was 42 years. Left and right breast cancers were seen in 17 (63%) and 10 (37%) patients, respectively. The mean values of ipsilateral lung V16 and contralateral lung V5 were 16.01% and 3.74%, respectively. The mean heart doses from the left and right breast were 7.25 Gy and 4.37 Gy, respectively. The mean doses to the contralateral breast, oesophagus, and Dmax to brachial plexus were 2.64 Gy, 3.69 Gy, and 26.95 Gy, respectively. The mean value of thyroid V25 was 19.69%. Grade 1 and 2 acute skin toxicities were observed in 9 (33%) and 5 (18.5%) patients, respectively. Grade 2 hyperpigmentation, edema, and induration were observed in 1 (3.7%), 2 (7.4%), and 4 (14.8%) patients, respectively. Mild breast pain and arm/shoulder discomfort were reported by 1 (3.4%) patient. The median follow-up was 51 months (range, 12 to 61 months). At four years, breast induration, edema, and fibrosis were observed in 1 (3.7%) patient. Cosmesis was excellent and good in 21 (78%) and 6 (22%) patients, respectively. Local recurrence and distant metastases occurred in 1 (3.7%) and 2 (7.4%) patients, respectively. DFS and OS at four years were 88% and 92%, respectively.Conclusion: With this radiotherapy schedule, acute and late toxicity rates were acceptable with no adverse cosmesis. Local control, DFS, and OS were good.

Preliminary results of hypofractionated radiotherapy in breast cancer in Chandigarh, India: single-centre, non-inferiority, open-label, randomised, phase 3 trial

“…Acute grade 2 skin toxicity rates of 15–17% are also comparable to our simultaneous integrated boost study of 18.5%. 11 Boost was delivered in 17% of patients in the present study. Boost dose is also known to increase acute skin toxicity rate.…”

HYPofractionated Adjuvant RadioTherapy in 1 versus 2 weeks in high-risk patients with breast cancer (HYPART): a non-inferiority, open-label, phase III randomised trial

“…With α/β of 3.5 for the breast, it behaves like a late responding tissue, which means high dose per fraction (hypofraction) is more suitable to treat breast cancer. So, accelerated hypofractionation (34 Gy delivered in 10 fractions over 2 weeks) is also a possibility in breast cancer [ 10 – 13 ]. With this background, we think that it is possible to reduce this treatment duration further.…”

HYPofractionated Adjuvant RadioTherapy in 1 versus 2 weeks in high-risk patients with breast cancer (HYPART):A non-inferiority, open-label, phase III randomized trial.

“…7 So accelerated hypofractionation is also a possibility in breast cancer. [9][10][11][12] In this study we want to test a 1-week schedule of hypofractionated adjuvant whole breast/chest wall and/or regional nodal radiotherapy against 2 weeks for loco-regional control, acute and late toxicities, quality of life (QoL), survival and second cancers after primary surgery in patients with breast cancer.…”