Treating Limited-stage Small-cell Lung Cancer With Proton-beam Tx
Radiotherapy is critical for effective lung cancer treatment, though when used with chemotherapy serious adverse events can occur.
With concurrent chemotherapy, proton-beam therapy is safe and may be effective for patients with limited-stage small-cell lung cancer (SCLC), according to a study published in Cancer.1
Radiotherapy is critical for effective lung cancer treatment, though when used with chemotherapy serious adverse events can occur. While some data show that proton-beam therapy reduces toxicity for patients with non–small cell lung cancer, there are limited data for patients with SCLC.
For this prospective study, researchers enrolled 30 patients with limited-stage SCLC to receive proton-beam therapy with concurrent cisplatin plus etoposide or carboplatin plus etoposide.
The median dose of 63.9 cobalt gray equivalents were delivered once daily to 18 patients and twice daily to 12 patients; the total number of fractions ranged from 33 to 37.
The dosimetry of proton-beam therapy regimens was compared with that of generated intensity-modulated radiotherapy (IMRT) clinical backup plans.
Median follow-up was 14 months. The 1- and 2-year local control rates with proton-beam therapy were 85% and 69%, respectively. Median overall survival was 28.2 months; the 1- and 2-year overall survival rates were 72% and 58%, respectively.
Proton-beam therapy significantly improved dosimetry over IMRT of at least 5 Gy for the heart and spinal cord, “but not in the esophagus mean dose or the lung volume receiving at least 20 Gy.”
One patient who received proton-beam in twice daily–fractions had grade 4 esophagitis. There were 3 other cases of grade 3 adverse events among all patients receiving proton therapy.
The authors concluded that “[proton-beam therapy] as part of a combined modality therapy for [limited stage]-SCLC is feasible and safe, with preliminary evidence showing encouraging efficacy in comparison with photon radiation.”
Rwigema JC, Verma V, Lin L, et al. Prospective study of proton-beam radiation therapy for limited-stage small cell lung cancer [published online July 5, 2017]. Cancer. doi:10.1002/cncr.30870