ESTRO 2024 - Abstract Book

S1612

Clinical - Lung

ESTRO 2024

Keywords: NSCLC, Immunotherapy, Stage III

500

Digital Poster

HYPOFRACTIONATED RADIOTHERAPY IN LUNG CANCER: A SINGLE CENTER EXPERIENCE

Pedro Ferreira, Nelson Ferreira, Miriam Abdulrehman, Filomena Santos

Portuguese Institute of Oncology of Lisbon, Radiation Oncology, Lisbon, Portugal

Purpose/Objective:

Hypofractionated Radiotherapy (HypoRT) is an alternative to surgery, Stereotatic Body Radiotherapy (SBRT) or chemoradiotherapy-based treatments if patient and tumor factors preclude the ability to deliver these treatments. It may also be an option sequentially after systemic therapy. This study aims to demonstrate the experience of our center in lung cancer treatment HypoRT.

Material/Methods:

We conducted a retrospective study of patients diagnosed with primary lung cancer treated with HypoRT schemes between January 2017 and October 2022. Local control (LC) and overall survival (OS) were calculated from the start of treatment until the date of last imaging or the date of death/last follow-up. LC and OS were calculated in R using Kaplan-Meier curves. Acute toxicities were classified according to CTCAE v5.0.

Results:

A total of 33 patients were included. Median follow-up was 17 months (range 1-72). Most patients were male (72.7%, n=24). Median age was 77 years (range 48-89) and more than two-thirds of patients were over 70-years-old (69.7%, n=23). ECOG performance status was 0 or 1 in 21 patients (63.3%). The majority of patients had localized disease (stage I: 9 (27.3%), stage II: 13 (39.4%)), with fewer patients having locally advanced (stage III: 8 (24.2%)) or metastatic disease (stage IV: 3 (9.1%)). Nodal involvement was present in 10 patients (30.3%) - N1 disease in 8 patients (24.2%), N2 disease in 1 patient (3.0%) and N3 disease in 1 patient (3.0%). Most lesions were central (93.9%, n=31). In 11 (33.3%) cases, patients had previously been treated for their lung cancer. The median tumor size was 35mm (range 11-80mm) and the median size of PTV was 119.3cm3 (range 11.8-544). The most prevalent fractionation schemes were 60Gy in 15 fractions (57.6%, n=19) and 48Gy in 12 fractions (21.2%, n=7).