[Outcome after PET-CT based radiotherapy for non-small cell lung cancer]

The value of PET-CT in radiotherapy for non-small cell lung cancer (NSCLC) with regard to determination of target volumes is established. It is less clear whether its use can improve clinical outcomes of irradiated NSCLC patients compared to conventional staging. The outcome of NSCLC patients included in a previously published prospective study of the value of PET-CT in curative radiotherapy candidates was assessed.

Patients were treated according to the PET-CT findings. The survival data were compared between 67 patients treated curatively and 22 patients with palliative treatment given after upstaging based on the PET-CT findings. Survival of curatively treated stage III patients was compared with a previously published outcome of 173 stage III patients treated in the same institution with the same radiation schedule but without PET-CT.

The 3-year overall survival was 42% and 0% (median: 21 months and 7 months), for curatively and palliatively managed patients, respectively (p 〈 0.0001). However, the median overall survival of 17 months for 50 stage III patients was the same as that in a previously published series of stage III patients treated with the same radiation schedule but without PET-CT. Three-year overall survival rates were 33% for the PET-CT group and 19% for historical group, p = 0.1. Twenty-one local recurrences and 21 distant metastases were reported. Three of 50 patients (6%) treated without elective nodal irradiation developed isolated nodal failure (without local recurrence).

The high early mortality rate in the patients disqualified from curative radiotherapy after PET-CT suggests the potential value of PET-CT for improving the radiotherapy outcome. However, this benefit seems to be limited in stage III patients.