ESTRO 2024 - Abstract Book

S510

Clinical - Breast

ESTRO 2024

[3] Chatterjee S, Chakraborty S, Moses A, Nallathambi C, Mahata A, Mandal S, et al. Resource requirements and reduction in cardiac mortality from deep inspiration breath hold (DIBH) radiation therapy for left sided breast cancer patients: A prospective service development analysis. Pract Radiat Oncol 2018;8:382 – 7.

[4] Kiran G, Mohan I, Kaur M, Ahuja S, Gupta S, Gupta R. Escalating ischemic heart disease burden among women in India: Insights from GBD, NCDRisC and NFHS reports. Am J Prev Cardiol 2020;2:100035.

[5] Darby SC, Ewertz M, McGale P, Bennet AM, Blom-Goldman U, Brønnum D, et al. Risk of ischemic heart disease in women after radiotherapy for breast cancer. N Engl J Med 2013;368:987 – 98.

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Digital Poster

Stereotactic Partial Breast Irradiation: 4-year Clinical Results and Cosmetic Outcomes

Norbert Meszaros 1,2 , Levente Janvary 1 , Viktor Smanyko 1 , Tibor Major 1,2 , Gabor Stelczer 1 , Zoltan Nagy Takacsi 1,2 , Csaba Polgar 1,2 1 National Institute of Oncology, Center of Radiotherapy, Budapest, Hungary. 2 Semmelweis University, Faculty of Medicine, Department of Oncology, Budapest, Hungary

Purpose/Objective:

The aim of this study was to evaluate the clinical results and cosmetic outcomes of 4-fraction stereotactic accelerated partial breast irradiation (SAPBI).

Material/Methods:

Between November 2018 and November 2022, 71 patients with low risk early invasive (St I-II) breast cancer underwent BCS were enrolled in our phase II prospective study. SAPBI was performed with Cyber-Knife (CK) M6 machine, to a total dose of 25 Gy (4 x 6.25 Gy, delivered daily). Respiratory movements were followed with implanted gold markers and optical markers using Synchrony system. Corrections for patient displacement and respiratory movement during treatment were performed with the robotic arm. Clinical results, side effects, and cosmetic results were assessed.

Results:

In all patients, the treatments were successfully completed, and the dose prescriptions and dose limits were observed. Median follow-up time was 48 months (range:11-60 months). During the follow-up, we did not detect any local or regional recurrence or distant metastases. Acute side effects included Grade 1 (G1) erythema, which occurred in 8 (11.2%) patients, while G1 oedema was observed in 7 (9.8%) cases. G1 pain was reported by 1 (1.4 %) patient. Late side effects included G1 fibrosis in 11 (15.5%), G1 pain in 4 (5.6%) patients respectively. Asymptomatic