Radiaton pneumonitis with the combination of irinotecan and carboplatin concomitantly with radiation for stage III non-small cell lung cancer

Abstract

7582 Background: We evaluated the efficacy and safety of carboplatin (C) and irinotecan (I) concomitantly with radiation therapy followed by docetaxel (D) in patients (pts) with stages IIIA/B NSCLC. Methods: We enrolled 32 pts. The daily dose of radiation was 1.8 Gy, 5 days a week for 5 weeks, 25 fractions, (45 Gy) to the primary tumor and mediastinum (primary planning target volume: PPTV. After 45 Gy, the primary tumor and involved nodal metastasis (secondary planning target volume: SPTV) was boosted at 2 Gy per day to 18 Gy in 9 fractions. The total dose given was 63 Gy in 35 fractions over 7 weeks. C was given with an AUC=2 and I was given at 30mg/m2 both of them weekly for 7 weeks. D was given at 75mg/m2 as consolidation chemotherapy for 3 cycles. Results: Median age was 55 years (range: 42–78), most pts were females (74%), 57% were Caucasian and 57% were Hispanic. The most common histologies were poorly differentiated and squamous cell carcinomas. Half of the pts were stage IIIB. The overall response rate (ORR) was 63% (95%CI: 43.7 to 78.9%). Three pts achieved complete response (CR) and 17 pts partial response (PR). Also, 5 pts (16%) achieved stable disease (SD) for a disease control rate of 79% (63%+16%). Overall survival at 1 and 3 years were 55% (95% CI, 35% to 71%), and 34% (95% CI, 12% to 57%), respectively. Median survival was 16.6 months. Thirteen of 31 patients treated (41%) developed clinical radiation pneumonitis (RP). Clinical RP is expected in about 5–35% of pts treated with thoracic irradiation, and asymptomatic radiological findings might be found in as many as 50% of pts. The risk of RP depends on the dose and volume of lung exposed. Different literature data reported a correlation between the occurrence of RP of grade 2 or higher and dose-volumetric parameters (V20). If the V20 of pts treated is <31% then less than 10% of the pts will develop RP, however if the V20 >32% then 13–36% of the pts will develop RP. In our study the V20 was approximately 30%, for that reason we believe that the increase in the incidence of RP in our study is most probably due to this chemotherapy combination with radiation. Conclusions: The CI combination with radiation therapy is effective for the treatment of stage III NSCLC however the rate of RP might be too high for the expected toxicity. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration sanofi-aventis Pfizer, sanofi-aventis Pfizer, sanofi-aventis