Purpose: At our center, approximately 30% of radical radiotherapy (RRT) candidates become ineligible for RRT for non-small-cell lung cancer (NSCLC) after positron emission tomography (PET). We hypothesized that early cancer death rates would be lower in patients receiving RRT after PET staging compared with conventionally staged patients.
Methods and materials: Two prospective cohorts were compared. Cohort 1 consisted of all participants in an Australian randomized trial from our center given 60 Gy conventionally fractionated RRT with or without concurrent carboplatin from 1989 to 1995. Eligible patients had Stage I--III, Eastern Cooperative Oncology Group status 0 or 1, <10% weight loss, and had not undergone PET. Cohort 2 included all RRT candidates between November 1996 and April 1999 who received RRT after PET staging and fulfilled the above criteria for stage, Eastern Cooperative Oncology Group status, and weight loss.
Results: Eighty and 77 eligible patients comprised the PET and non-PET groups, respectively. The PET-selected patients had significantly less weight loss; 73% and 49% of the PET and non-PET patients, respectively, received chemotherapy. The median survival was 31 months for PET patients and 16 months for non-PET patients. Mortality from NSCLC and other causes in the first year was 17% and 8% for PET patients and 32% and 4% for non-PET patients, respectively. The hazard ratio for NSCLC mortality for PET vs. non-PET patients was 0.49 (p = 0.0016) on unifactorial analysis and was 0.55 (p = 0.0075) after adjusting for chemotherapy, which significantly improved survival.
Conclusion: Patients selected for RRT after PET have lower early cancer mortality than those selected using conventional imaging.