ESTRO 2024 - Abstract Book

S597

Clinical - Breast

ESTRO 2024

the Radiation Oncology service at the Hospital Clinic. Acute and chronic toxicities were registered using the Common Terminology Criteria for Adverse Events (CTCAE) v5.0. The statistical analysis was carried out through the IBM SPSS version 25.0.

Results:

98 patients were recruited with a median age of 45 years (range 27-76), and a median follow-up of 50 months (range 9-112). The most frequent histology was infiltrating ductal carcinoma in 79.6% (78 patients), stage IIB in 34.7% (34 patients) and luminal B prognostic subtype in 49% of cases. Regarding surgical treatment, total mastectomy was performed in 96.9% of cases and lymphadenectomy in 78.6%. Reconstruction was performed in 61 cases (62.2%) with a tissue expander, 23 (23.5%) with silicone prosthesis and 14 (14.3%) with autologous tissue (Table 1). Complications after surgery included pain (29.6%), seroma (20.4%), skin necrosis (13.3%), haematoma (12.2%), suture dehiscence (9.2%) and infection (5.1%). Fourteen (14.3%) patients requiring a reintervention due to post-surgical complications. All patients underwent PMRT, with total dose of 50Gy in 97.9% (96 patients) but only 3 patients had a boost on tumour bed. Acute toxicities found secondary to PMRT were grade 1 epithelitis in 72.4% (71) patients, grade 2 in 24.5% (24) patients and grade 3 in only 1 patient (1%), which required discontinuation of treatment. Sixty-one patients (62.2%) presented asthenia. Regarding chronic toxicities, 26.5% (26) of patients presented mild hyperpigmentation, 12.2% (12) of patients had lymphedema, 29.6% (29) presented chronic pain in the irradiated region, patients with implants (expansor or silicone) presented contracture in 16/61 patients with expander and in 11/23 patients with silicone, no significant differences were evident between both groups in relation to implant type (p: 0.059) (Table 2).

Local control rate was 100%, regional control rate was 99%, 1 patient had recurrence at supraclavicular level. Ten patients (10.2%) had distant recurrence (bone, liver or lung progression).