Computed tomography (CT) scan evaluation of late toxicity following hypofractionated/accelerated radiotherapy with cytoprotection (HypoARC) in breast cancer patients treated with conservative surgery.

Background: In the present study we evaluated the long-term radiation toxicity of an hypofractionated accelerated radiotherapy scheme supported with amifostine cytoprotection (hypoARC).

Patients And Methods: A cohort of 32 breast cancer patients, pretreated with conservative surgery and adjuvant doxorubicin or taxane based chemotherapy, were treated with hypoARC. In contrast to the 45 days required for the delivery of standard breast (+/-supraclavicular) radiotherapy, the proposed scheme delivers the whole radiation dose in 16 days (10 fractions of 3.5Gy plus 2 additional 4Gy fractions to the tumor bed), which is convenient for elderly patients or patients residing away from radiotherapy departments.

Results: After a minimum follow up of 24 months (range, 24-36), none of the patients showed any clinical signs of lung or arm toxicity. Increased palpable breast density was evident 16 out of 32 cases. Computed tomography (CT) scan evaluation of the lung and breast densities (calculated in Haunsfield units) showed no signs of lung fibrosis, while increased density of the irradiated breast (1.1-1.3-fold) was confirmed in 8 out of 17 patients examined. None of the patients has relapsed locally.

Conclusions: Although longer follow-up is required to confirm safety of the described radiotherapy regimen, these data are encouraging as the toxicity reported within 2 to 3 years of follow-up is even lower than the one expected from standard radiotherapy.