[Very accelerated partial breast irradiation (VAPBI) with high-dose-rate interstitial brachytherapy following breast- conserving surgery of low-risk breast cancer patients].

AIM: To evaluate the efficacy and safety of high-dose-rate interstitial VAPBI in women undergoing conservative surgery for low-risk, early invasive breast cancer.

METHODS

Between December 2018 and December 2024, 28 patients were enrolled in this prospective, non-randomized trial. Targeted radiotherapy of the tumor bed was delivered using thin plastic catheters placed at the surgical site, through which a high-dose-rate Ir-192 source was administered. Prescribed doses were 4×6.25 Gy (25 Gy total) or 3×7.45 Gy (22.35 Gy total), delivered over two consecutive working days.

RESULTS

With a median follow-up of 60 months (range: 9-84), local recurrence was observed in 2 patients (7.1%). One patient (3.6%) died of liver metastases, and another (3.6%) from a second primary tumor. The 5-year local control rate was 93.7% (95% CI: 88.1-99.4). Late toxicity was limited to grade 1 fibrosis in 6 patients (21.4%) and grade 1 pain in 2 patients (7.1%); no grade ≥2 toxicities occurred. Cosmetic results were excellent or good in all cases.

CONCLUSIONS

Reducing interstitial treatment duration from 5 to 2 days appears safe and more convenient for patients.