Clinical outcome of whole‐body gamma‐knife combined with pemetrexed concurrent chemoradiotherapy in elderly patients with locally advanced lung adenocarcinoma

Abstract

AbstractObjectiveCurrently, concurrent chemoradiotherapy has become the standard treatment for locally advanced non‐small cell lung cancer, but it is often difficult for elderly patients to tolerate. In this study, we evaluated the curative effect, acute radiation reaction, and clinical application of stereotactic radiotherapy with whole‐body gamma‐knife combined with pemetrexed treatment in elderly patients with locally advanced lung adenocarcinoma.MethodsA total of 37 elderly patients with lung adenocarcinoma from Hubei Provincial Armed Police Corps Hospital from 2 January 2013 to 30 December 2015, who were treated with stereotactic radiotherapy with super‐gamma‐knife, were included in the study. The radiotherapy plan was made according to the patient's physical condition, tumor location and size, and therapeutic purpose. A dose of 3.5–5 Gy was administered by 50–70% isodose curve, with a total dose range of peripheral irradiation 35–45 Gy. In the same period, pemetrexed was administered at 500 mg/m2, the first day of chemotherapy (d1), intravenous drip, with 21 days as one cycle, and the number of cycles was more than two.ResultsThe median follow‐up duration was 18 months, and the 1‐, 2‐, and 3‐year follow‐up rates were 86.49% (32/37), 59.46% (33/37), and 21.62% (8/37), respectively. There were no missing cases. After 2–3 months of treatment, computed tomography showed that 13 patients (35.14%) had complete remission, 22 patients (59.46%) had partial remission, one patient (2.70%) achieved a stable status, and one patient (2.70%) still had progression, and the total response rate was 94.59%. The 1‐year local control rate was 67.57%. The 1‐, 2‐, and 3‐year overall survival rates were 86.49%, 45.45%, and 25.00%, respectively. The median overall survival time was 17.0 months (95% CI 14.5–21.3 months); the progression‐free survival time was 12.0 months (95% CI 11.6–12.8 months). Multivariate analysis showed that lymph node stage N ≥2 and radiotherapy biological effective dose <60 Gy were the adverse prognostic indicators of overall survival (P = 0.016 and P = 0.032, respectively). The 1‐year local control rate and median survival time were 62.50% and 71.43%, and 19 and 17 months in the gross tumor volume ≥120 cm3 subgroup and gross tumor volume <120 cm3 subgroup, respectively. There was no significant statistical difference (P = 0.061 and P = 0.400, respectively). The incidence rates of grade 3–4 neutropenia and thrombocytopenia were 10.81% (4/37) and 5.41% (2/37), respectively, during the period of concurrent chemoradiotherapy. The incidence of grade 2 radiation‐induced pneumonitis and esophagitis was 13.51% and 16.22%, respectively. No grade >2 acute or late lung and esophagus toxicity was observed.ConclusionsIn elderly patients with lung adenocarcinoma, stereotactic body radiotherapy with super‐gamma‐knife combined with pemetrexed treatment is safe and definitive, with mild adverse effects.