Timmerman RD, et al. - Researchers assessed if delivering noninvasive stereotactic body radiation therapy (SBRT) on an outpatient basis could safely eliminate lung cancer and cure selected patients with operable lung cancer, removing the need for surgical resection. A probable association of SBRT with a high rate of primary tumor control, low treatment-related morbidity, and infrequent need for surgical salvage in patients with operable early-stage lung cancer was seen.

Methods

• Experts enrolled patients from December 2007 to May 2010 with median follow-up of 48.1 months in this single-arm phase 2 NRG Oncology Radiation Therapy Oncology Group 0618 study (range, 15.4-73.7 months), set in a multicenter North American academic and community practice cancer center consortium.
• Operable biopsy-proven peripheral T1 to T2, N0, M0 non–small cell tumors no more than 5 cm in diameter, forced expiratory volume in 1 second (FEV1) and diffusing capacity greater than 35% predicted, arterial oxygen tension greater than 60 mm Hg, arterial carbon dioxide tension less than 50 mm Hg, and no severe medical problems were seen in the patients.
• They performed the data analysis in October 2014.
• In 3 18-Gy fractions over 1.5 to 2.0 weeks, the SBRT prescription dose was 54 Gy.
• Primary tumor control was the primary end point; survival, adverse events, and the incidence and outcome of surgical salvage were secondary end points.

Results

• As per data, out of 33 patients, 26 were evaluable (23 T1 and 3 T2 tumors; 15 [58%] male; median age, 72.5 [range, 54-88] years).
• Findings suggested that median FEV1 and diffusing capacity of the lung for carbon monoxide at enrollment were 72.5% (range, 38%-136%) and 68% (range, 22%-96%) of predicted, respectively.
• Primary tumor recurrence was seen in only 1 patient, and involved lobe failure, the other component defining local failure, was not seen in any patients, so the estimated 4-year primary tumor control and local control rate were both 96% (95% CI, 83%-100%).
• The single patient with local recurrence underwent salvage lobectomy 1.2 years after SBRT, complicated by a grade 4 cardiac arrhythmia.
• Researchers noted the 4-year estimate of disease-free survival was 57% (95% CI, 36%-74%) and overall survival was 56% (95% CI, 35%-73%).
• They found 55.2 months to be the median overall survival (95% CI, 37.7 months to not reached).
• Two (8%; 95% CI, 0.1%-25%) patients, reported protocol-specified treatment-related grade 3 adverse events, while zero patients reported grade 4 or 5 adverse events.