ESTRO 2024 - Abstract Book

S1659

Clinical - Lung

ESTRO 2024

regional failure-free (RF), 2-year distant free-failure (DF) and 2- year grade ≥2 toxicity rates were analyzed following the CTCAE v5.0 scale.

Results:

A total number of 64 patients with a median age of 71 were included in this study. 42 patients with central tumors (65,6%) versus 22 patients with ultracentral lesions (34,4%). Thirty-seven patients had primary lung tumors (57,8%) and 27 patients lung metastatic tumors (42,2%). The most frequent pathological anatomy was adenocarcinoma lung (35,9%), followed by squamous carcinoma lung (20,3%). The most frequent metastatic origin were other tumors lung (51,8%), followed by metastasis from colorectal cancer (10%).

Focusing on the RT treatment, 43 patients received SBRT (8 x 7.5 Gy) (67,2%) and 21 patients were treated with hypofractionated RT (15 x 4 Gy) (32,8%).

With a median follow-up of 20 months (2-92 range) 1 and 2-year OS were 86,9% and 70%, respectively. 2- year LF was 96%, 2-year RF was 84,8% and 2-year DF was 90,1%.

Stratifying into central and ultracentral tumors, we obtained 2-year OS 64.8% and 2-year LF 92.2% for central tumors and 2-year OS 83.4% and 2-year LF 87,9% for ultracentral tumors. Comparing the 2-year OS of both schemes we observe 2-year OS 86.1% in the hypofractionation RT scheme and 2-year OS 92.6% in the SBRT group, without statistically significant differences (p= 0.28). Focusing on toxicity, there were found grade G≥2 toxicity in 3.1% of the patients (2/64), being 4,5% in the ultracentral subgroup and 2,4% in the central subgroup. This difference did not reach statistical significance (p=0.35).

Conclusion:

Both SBRT for central tumors and the hypofractionated regimen for ultracentral tumors had high rates of local control and were well tolerated being good treatment options for these populations. We have not found statistically significant differences in terms of local control, overall survival or toxicity between the two schemes used. Regional and distant failure are more frequent than local failure in our population.

Keywords: Lung, SBRT, survival

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