Stereotactic hypofractionated high‐dose irradiation for stage I nonsmall cell lung carcinoma

TLDR

Stereotactic irradiation is used in Japan to improve local control of stage I non‑small cell lung carcinoma. The study retrospectively evaluated 245 stage I NSCLC patients across 13 Japanese institutions who received hypofractionated high‑dose stereotactic irradiation delivered with noncoplanar dynamic arcs or static ports, with total doses ranging from 18 to 75 Gy in 1–22 fractions. With a median biologic effective dose of 108 Gy and median follow‑up of 24 months, hypofractionated high‑dose STI achieved low grade > 2 pulmonary toxicity (2.4 %) and improved local control and 3‑year overall survival—8.1 % recurrence versus 26.4 % and 88.4 % versus 69.4 % OS—for BED ≥ 100 Gy compared with < 100 Gy, indicating that BED ≥ 100 Gy yields outcomes comparable to surgery.

Abstract

Stereotactic irradiation (STI) has been actively performed using various methods to achieve better local control of Stage I nonsmall cell lung carcinoma (NSCLC) in Japan. The authors retrospectively evaluated results from a Japanese multiinstitutional study.Patients with Stage I NSCLC (n = 245; median age, 76 years; T1N0M0, n = 155; T2N0M0, n = 90) were treated with hypofractionated high-dose STI in 13 institutions. Stereotactic three-dimensional treatment was performed using noncoplanar dynamic arcs or multiple static ports. A total dose of 18-75 gray (Gy) at the isocenter was administered in 1-22 fractions. The median calculated biologic effective dose (BED) was 108 Gy (range, 57-180 Gy).During follow-up (median, 24 months; range, 7-78 months), pulmonary complications of National Cancer Institute-Common Toxicity Criteria Grade > 2 were observed in only 6 patients (2.4%). Local progression occurred in 33 patients (14.5%), and the local recurrence rate was 8.1% for BED > or = 100 Gy compared with 26.4% for < 100 Gy (P < 0.05). The 3-year overall survival rate of medically operable patients was 88.4% for BED > or = 100 Gy compared with 69.4% for < 100 Gy (P < 0.05).Hypofractionated high-dose STI with BED < 150 Gy was feasible and beneficial for curative treatment of patients with Stage I NSCLC. For all treatment methods and schedules, local control and survival rates were better with BED > or = 100 Gy compared with < 100 Gy. Survival rates in selected patients (medically operable, BED > or = 100 Gy) were excellent, and were potentially comparable to those of surgery.