CONVERT: An international randomised trial of concurrent chemo-radiotherapy comparing twice-daily and once-daily radiotherapy schedules in patients with limited stage small cell lung cancer
Session type: Oral
Theme: Diagnosis and therapy
Concurrent chemo-radiotherapy (cCTRT) is the standard of care for good PS LS-SCLC but there is no international consensus on a standard regimen. Our aim was to compare overall survival and toxicity of twice-daily (BD) with once-daily (OD) RT using modern conformal RT techniques given concurrently with chemotherapy.
Patients were randomised 1:1 to receive 45Gy in 30 BD fractions over 3 weeks or 66Gy in 33 OD fractions over 6.5 weeks starting on day 22 of cycle 1 chemotherapy (4 to 6 cycles of Cisplatin 25mg/m2 days 1-3 or 75mg/m2 day 1 with Etoposide 100mg/m2 days 1-3), followed by PCI if indicated. RT was planned using 3D conformal or IMRT. Patients were stratified by centre, 4/6 cycles CT and PS 0,1/2. The primary endpoint was 2-year survival and all analyses were by intention to treat.
547 patients were recruited between 2008-2013 from 88 centres. Patients’ characteristics were well balanced in both arms. At a median follow up of 45 months for those alive; two-year survival was 56% (95% CI 50-61) vs 51% (95% CI 45-57) and median overall survival was 30 months (95% CI 24-34) versus 25 months (95% CI 21-31) (HR 1.17, 95% CI 0.95-1.45; p=0.15) for BD and OD treatment, respectively. Toxicities were comparable except for significantly more grade 3/4 neutropenia (74% BD vs 65% OD, p=0.03). There was no statistical difference, between BD and OD respectively, in rates of grade 3/4 oesophagitis (19%, 19%), and grade 3/4 radiation pneumonitis was rare (2.5%, 2.2%).
OD RT did not result in a superior survival or worse toxicity than BD RT, supporting the use of either regimen for standard of care treatment of LS-SCLC with good PS. The survival for both regimens was higher than previously reported and using modern RT techniques radiation toxicities were lower than expected.