NEW YORK (Reuters Health) – Stereotactic body radiation therapy (SBRT) for early-stage non-small-cell lung cancer (NSCLC) results in “excellent 3-year local control and survival rates,” researchers report based on 4-year results of a prospective phase II study.

In an online report by the International Journal of Radiation Oncology, Biology and Physics, Dr. Achilles J. Fakiris from Indiana University School of Medicine, Indianapolis, and colleagues describe 70 patients with inoperable stage T1 (34 patients) or T2 (36 patients) NSCLC, measuring 7 centimeters or less, who were treated with a high potency SBRT regimen consisting of 60 to 66 Gy total radiation dose in three fractions.

“With median follow-up of 50.2 months, only 5.7% of patients experienced local recurrence,” the study team reports, “for a Kaplan-Meier 3-year local control rate of 88.1%, which rivals the control rates reported after lobectomy.” Rates of regional and distant recurrence were 8.6% and 12.9%, respectively.

Median survival was 32.4 months and the 3-year overall survival was 42.7%. Cancer-specific survival at 3 years was 81.7%.

For patients with T1 tumors, median survival was 38.7 months and for T2 tumors it was 24.5 months. Median survival did not differ significantly in patients with peripheral versus central tumors (33.2 vs 24.4 months; p = 0.697).

According to the investigators, grade 3 to 5 toxicity was seen in 5 of 48 patients with peripheral lung tumors (10.4%) and in 6 of 22 with central lung tumors (27.3%). “The safety of this regimen,” they note, “was also demonstrated in a separate analysis of our serial pulmonary function test data.”

In a prepared statement, study investigator Dr. Ronald C. McGarry of University of Kentucky College of Medicine, Lexington, said: “I think of this as ‘lung-sparing’ treatment, in which many patients with early-stage lung cancer can have effective treatment in as few as three treatment sessions with a low risk of side effects. The data we are reporting now show that long-term control of these localized cancers is possible.”

Reference:
Int J Radiation Oncology Biol Phys 2009.