Purpose: Lung cancer remains one of the tumour diagnoses with high lethality, although innovative treatment approaches have yielded improvements in local control and survival rates. There is still no consensus on how to treat local relapse in patients after first-line treatments. Radiotherapy may be considered in this situation; however, data supporting its effectiveness are rare. The purpose of this retrospective analysis was to evaluate outcomes of patients re-irradiated for thoracic tumours in terms of overall survival (OS), local progression-free survival (LPFS), toxicity and dose-volume parameters.
Patients and methods: Sixty-two patients with locally recurrent previously irradiated lung cancer were analysed retrospectively (NSCLC n = 52, SCLC n = 10). Target volumes both in lung and mediastinum were re-irradiated with conventional three-dimensional or intensity-modulated radiotherapy techniques. Median overall dose of re-irradiation was 38.5 Gy (range 20-60 Gy) with a median single dose per fraction of 2 Gy (1.8-3.0 Gy). Clinical documents and treatment plans were evaluated.
Results: Median follow-up was 8.2 months (range 0-27 months). OS following re-irradiation was 9.3 months (range: 0-27 months) and LPFS was 6.5 months (range: 0-24 months). OS and LPFS were not affected by histology, total dose or patient age and gender. OS was improved in patients whose re-irradiation volumes included less than two mediastinal lymph node stations (p = 0.016). Twelve patients suffered from pneumonitis ≥grade II (19%) and two from pneumonitis grade III. One patient presumably died from pneumonitis grade V. A slight decline in forced expiratory volume (FEV1) was detected in post-re-irradiation lung function testing.
Conclusions: Re-irradiation is an option for patients with tumour recurrence to control local progression and lower the symptom burden. Oncological outcome appears to be affected by size, location of mediastinal target volumes and lung function. Prospective clinical trials are warranted to substantiate the role of re-irradiation in recurrent lung cancer.
Keywords: Lung cancer; Pneumonitis; Radiotherapy; Toxicity; Tumour relapse.