The standard partial breast postoperative treatment for early breast carcinomas with
multi-catheter interstitial brachytherapy (MIBT) requires 7-8 fractions in 4-5 days
as used in the APBI GEC-ESTRO phase III trial. In 2017 the GEC-ESTRO Breast Cancer
Working Group started a Phase I-II trial to study if very accelerated partial breast
irradiation (VAPBI) using 3-4 fractions could be equivalent.81 patients with low-risk
invasive carcinomas underwent high dose rate MIBT. Mean age was 68 (51-90); 33 women
received 4 fractions of 6.25 Gy in 2-3 days, and 48 subsequent patients 3 fractions
of 7.45 Gy in 2 days, 36 perioperatively and 45 postoperatively.Median follow-up was
62 months, with 5-year actuarial breast recurrence of 3.4 % (two cases). One patient
died due to metastasis. Pigmentation changes in the entrance of tubes remained visible
only in 12.3 % in long term (skin G1 toxicity). Fibrosis or slight induration (G1)
in 22.2 % and G2 in 9.9 %. No case of telangiectasia has been described. Cosmetic
outcome is good or excellent in 95 % and fair in 5 %. Four tumors located in the retroareolar
area showed nipple retraction.VAPBI with MIBT using four fractions of 6.25 Gy or three
fractions of 7.45 Gy in two or three days offers good local control, with a 5-year
rate of fibrosis G2 similar to the GEC ESTRO phase III trial. VAPBI in two days is
a good choice to decrease the total time of treatment, which is beneficial for the
patient and reduces the workload.
