ESTRO 2024 - Abstract Book

S1641

Clinical - Lung

ESTRO 2024

Only three of the patients who underwent PCI or TRT experienced G2 toxicities and no patients had G3 toxicity.

In both the group who received PCI and the group who did not, 2 patients progressed in the brain. Patients who received TRT were less likely to progress within the thorax compared to patients who did not receive TRT (6/27 (22.2%) vs 23/42 (54.8%), p=0.0154). Of the 6 patients in the TRT group who progressed in the thorax, only 3 recurrences were within the radiation field.

There was a trend to improved PFS (6.5 v 6 months) and OS (22 v 20 months) in the groups that received both PCI and TRT, but neither reached statistical significance.

Conclusion:

This real-world study shows that ES-SCLC patients eligible for TRT and PCI according to international guidelines are not always referred after completion of chemoimmunotherapy. PCI and TRT were well tolerated with no G3 toxicity seen. Patients were less likely to progress in the thorax if they had received radiotherapy to that site. Our data suggests that there remains a role for PCI and TRT for ES-SCLC in the era of chemoimmunotherapy. However, we acknowledge the small number of patients, and it is anticipated that ongoing prospective studies such as RAPTOR and PRIMALung will further help clarify our practice.

Keywords: Small cell lung cancer, PCI, thoracic radiotherapy

References:

1. Horn L, Mansfield AS, Szczęsna A, Havel L, Krzakowski M, Hochmair MJ, Huemer F, Losonczy G, Johnson ML, Nishio M, Reck M. First-line atezolizumab plus chemotherapy in extensive-stage small-cell lung cancer. New England Journal of Medicine. 2018 Dec 6;379(23):2220-9.

1059

Digital Poster

Predictive value of tumor volume change during chemoradiotherapy in non-small cell lung cancer

Hye In Lee, Eun Kyung Choi, Su Ssan Kim, Young Seob Shin, Si Yeol Song

Asan Medical Center, Department of Radiation Oncology, Seoul, Korea, Republic of

Purpose/Objective:

There are no established biomarkers to predict early response during concurrent chemoradiotherapy (CCRT) in patients with unresectable stage III non-small cell lung cancer (NSCLC). This study investigated the potential of gross tumor volume (GTV) and its changes during CCRT as a reliable predictor of treatment outcomes.