ESTRO 2023 - Abstract Book

S1298

Digital Posters

ESTRO 2023

approach was used to monitor patients during fraction. The first patient was discharged from the hospital 1 week after STAR, while the second patient after 3 weeks. No acute or late toxicities related to STAR were reported. At 8 months and 4 months follow up for the first and second patients, respectively, no rVT were recorded during in hospital clinical evaluation and home monitoring ICD interrogation.

Conclusion The present report confirms the efficacy and safety of STAR as a reasonable treatment option for patients with rVT not suitable for CA. Further investigations and longer follow up are needed to draw definitive conclusions.

PO-1598 SBRT with CDK4/6 inhibitors for oligorecurrent/oligoprogressive breast cancer patients

E. Ippolito 1 , E. Onorati 2 , C. Greco 1 , M. Fiore 1 , S. Silipigni 2 , P. Matteucci 2 , L. Cerasani 2 , S. Carrafiello 2 , V. Palumbo 2 , S. Ramella 1 1 Università Campus Biomedico, Fondazione Policlinico Campus Biomedico, Radiation Oncology, Rome, Italy; 2 Fondazione Policlinico Campus Biomedico, Radiation Oncology, Rome, Italy Purpose or Objective Stereotactic body radiotherapy (SBRT) for oligoprogressive/oligorecurrent metastases can delay next line systemic therapy. We evaluated safety and efficacy of concurrent SBRT with CDK4/6 inhibitors in stage IV breast cancer patients. Materials and Methods The clinical records of metastatic breast cancer patients treated with SBRT to oligoprogressive/oligorecurrent lesions concurrently with anti-CDK4/6 inhibitors were reviewed. Toxicities were measured according to CTCAE 4.0. Response was evaluated according to RECIST/PERCIST criteria. PFS was evaluated from SBRT to local/systemic failure. Results Twenty-three patients treated to a total of 50 lesions were included in the analysis. Median age was 62 years (range 38 86 years). Mean Biological Effective Dose (BED) delivered (alpha/beta=4 Gy) was 89.3 (SD = 45). SBRT was delivered to bone metastases (58%), brain metastases (16%) and visceral metastases (26%). 10 patients were treated with concurrent Palbociclib (43.5%), 9 with concurrent Ribociclib (39.1%) and 4 with concurrent Abemaciclib (17.4%). Median FUP was 15 months (range 2-65 months). All lesions were evaluable for response: no patients experienced local failure on sites treated with SBRT. Response was evaluated on a per lesion basis. Complete response was achieved in 19 sites (38%), partial response in 17 sites (34%). After SBRT, 1-year and 3-year PFS were 16.8% and 30.5 % respectively. Mean duration of anti-CDK4/6 therapy after SBRT was 17.6 13.9 months. Only two toxicities were observed: a G1 dysphagia developed in a patient treated to a cervical spine lesion and a G3 neutropenia developed in a patient treated to a central lung lesion in 8 fractions. Conclusion SBRT for oligoprogressive/oligorecurrent breast cancer metastases delivered concurrently with CDK4/6 inhibitors seems safe and effective and should be tested in prospective studies.

PO-1599 Chemotherapy-Induced Alopecia: A Ray of Hope about Hair Regrowth?

A. Jribi 1 , S. Mhamdi 2 , A. Hmad 2 , W. Khechine 2 , A. Daldoul 3 , S. Zaied 2

1 CHU Fattouma Bourguiba , Medical Oncology Department, Sfax, Tunisia; 2 CHU Fattouma Bourguiba, Medical Oncology Department, Monastir, Tunisia; 3 CHU Fattouma Bourguiba, Medical Oncology Dapartment, Monastir, Tunisia