Hypo-fractionated stereotactic radiation therapy for lung malignancies by means of helical tomotherapy: report of feasibility by a single-center experience.

BACKGROUND: Several experiences in the literature report SBRT as an effective treatment option for medically inoperable early stage non-small cell lung cancer (NSCLC) and oligometastatic disease. The optimal fractionation schedules and total dose remain controversial. In this study, we evaluated the safety in terms of toxicity and efficacy of using of 8-10 fractions schedules with Helical Tomotherapy (HT) for primary and metastatic lung lesions. METHODS: Between March 2014 and May 2016, a total of 39 patients (median age 72 years, range 26-91) were treated with HT-SBRT for malignant lung lesions: 22 patients with early stage NSCLC, 17 with oligometastases. Patients received 8-10 fractions with lower daily dose for central and ultracentral lesions. Treatment-related toxicity was evaluated using CTCAE v 4.0 scale. Local control (LC), overall survival (OS) and toxicity rates were prospectively collected. RESULTS: Median duration of RT was 15 days (range 10-26 days) and no interruption occurred. With a median follow-up of 13 months (range 3-29), we reported one G2 pneumonitis (2.6%) and one G2 chest pain (2.6%); no ≥ G2 esophagitis was registered. Actuarial local control rate was 95.5% both at 12 and 24 months for early stage NSCLC and 92.9% both at 12 and 24 months for metastatic patients. OS rate was 94.4 and 92.3% at 1 year, and 94.4 and 83.9% at 2 years in primary and metastatic group, respectively. CONCLUSIONS: The use of 8-10 fractions schedule HT-SBRT for lung malignancies results in high LC and OS rates with minimal toxicities reported.