Abstract Book

S255

ESTRO 37

Material and Methods Clinical data of 106 patients (pts) from 5 Institutions treated with RT concomitant to TKI (including 30 days before and after TKI) were revised. Overall survival (OS) and toxicities were analysed as endpoint of the study. Kaplan-Meyer curve and log-rank test were elaborated for analysis of survival, while Chi-square and Anova test were calculated to compare different variables Results

Baseline clinical and demographic characteristics were comparable between the two groups. At twelve months, LC was 100% for patients receiving concurrent IT and 52% in the adjuvant IT group (p=0.02). Similarly, DBC was 70% and 28%, respectively ( p=0.01). OS was not significantly different between the two groups (p = 0.15). On multivariate analysis, concurrent IT was predictive of both improved LC (HR = 0.12, p = 0.03) and improved DBC (HR = 0.41, p = 0.03). Figure 1 (A)Kaplan-Meier curve for Local Control stratified by timing of IT with number at risk table, p=0.02 by log-rank test

Median age of pts was 65 years. TKI for EGFR-mutant and ALK positive metastatic NSCLC was used in 81% and 19% of cases, respectively. Four pts (4%) received 2 TKI. RT was performed within 30 days before TKI, concomitant to TKI and within 30 days after TKI in 25%, 58% and 17%. Median duration of TKI administration in the whole series was 14 (1.7-68.4) months, while was of 11 (2.5-49.8), 15.8 (1.7-68.4) and 12.8 (2.8-32.8) months for pts treated with RT before, concomitant and after TKI, respectively. The aim of RT was ablative (stereotactic RT) for 49 pts (46%) and palliative for 57 pts (54%). Site of RT was brain, bone, lung or others in 46%, 27%, 14% and 13%, respectively. Stereotactic RT was performed more frequently for pts with ECOG PS 0-1 (p < 0.00), oligometastatic/oligoprogressive disease (p < 0.00), lung sites (p < 0.00) and before or concomitant to TKI (p = 0.03). Moreover, stereotactic RT was significantly related to longer duration of TKI than palliative RT (19 vs 11 months, p = 0.001). Median OS was 23 months and 1,2 and 3 yrs OS was 76.3% and 48.6% and 29.5%, respectively. Stereotactic RT, ECOG PS 0-1, oligometastatic/oligoprogressive disease, lung sites and a TKI duration higher than median favourably affected OS (all p < 0.00). Multivariate analysis including significative factors at univariate analysis, confirmed Stereotactic RT (HR 2.8, CI 95% 1.68-4.71; p < 0.00) and median duration of TKI > 14 months (HR 0.17, 95% CI 0.10-0.30 ; p < 0.00) as independent factors related to better OS. Toxicities were low and very rarely of grade 3 (CTCAE v.4.0). Data of toxicities are reported in table 1. Neurological symptoms in brain RT were more common in palliative group (p = 0.035)

(B) Kaplan-Meier curve for Distant Brain Control by timing of IT with number at risk table, p=0.01 by log-rank test

Conclusion In this heavily pre-treated cohort undergoing radiosurgery for NSCLC brain metastases, concurrent administration of PD-1 IT appears to improve LC and DBC when compared to adjuvant PD-1 blockade. OC-0496 Concomitant radiotherapy and TKI in EGFR or ALK positive stage IV NSCLC: a multicentric analisys P. Borghetti 1 , A. Bruni 2 , M. Bonù 3 , N. Giaj Levra 4 , M. Perna 5 , M. Taraborelli 6 , R. Giubbolini 2 , L. Triggiani 3 , D. Franceschini 7 , C. Greco 8 , V. Scotti 5 1 ASST - Spedali Civili, Radiation Oncology, Brescia, Italy 2 University Hospital, Radiation Oncology, Modena, Italy 3 University of Study, Radiation Oncology, Brescia, Italy 4 Sacro Cuore Don Calabria Hospital, Radiation Oncology, Negra VR, Italy 5 AOU Careggi, Radiation Oncology, Firenze, Italy 6 SS. Annunziata, Radiation Oncology, Chieti, Italy 7 Humanitas, Radiation Oncology, Rozzano MI, Italy 8 Policlinico Campus Biomedico, Radiation Oncology, Roma, Italy Purpose or Objective To investigate the role of radiotherapy (RT) in the management of EGFR-mutant or ALK positive metastatic non-small cell lung cancer (NSCLC) treated with TKI

Palliative RT n (%) p

Toxicity

Grade Stereotactic RT n (%)

Neurological symptoms

0

20 (83)

13 (52)

0,035

49 Brain RT 1

0 (0)

5 (20) 5 (20)

2

4 (17)

≥ 3

0 (0)

2 (8)

0

Pain

3 (100)

7 (28)

ns