Is tumour volume a predictive factor for survival in patients after accelerated radiotherapy (CHART) or chemoradiotherapy for Non-Small-Cell Lung Cancer (NSCLC)?


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Waheeda Owadally1, Emma Gray1, Peter Jenkins1
1Gloucestershire Oncology Centre, Cheltenham General Hospital, Cheltenham, Gloucestershire, UK

Background

Previous studies have suggested that the gross tumour volume (GTV) is a predictive factor for survival in patients receiving conventionally fractionated radiotherapy for NSCLC. We investigated whether GTV was similarly predictive of survival in patients treated with either accelerated radiotherapy (CHART) or chemoradiotherapy.

Method

We reviewed the cases of 144 patients treated with CHART for medically or surgically inoperable NSCLC between 2001 and 2009.

Results

Mean and median pre-treatment GTV were 146cm3 and 109cm3 (range 3-679cm3). The median overall survival for all patients was 16.0 months (CI 13.0-19.0). We defined two groups based on the median value of the GTV. The overall survival of patients with a GTV < 109cm3 was 24.0 months (CI 15.5-32.5) compared to 11.0 months (CI 9.7-12.3) for those with GTV > 109cm3 (log-rank p=0.002). A simple Cox regression model was constructed entering age, gender, stage, histology, chemotherapy and GTV as covariates. Pre-treatment GTV (p=0.004) and the use of chemotherapy (p=0.03) were significant variables predictive of survival. 53 patients received induction chemotherapy. In 45 patients with retrievable data, mean GTV pre chemotherapy and post chemotherapy were 177 cm3 and 99 cm3 retrospectively with mean shrinkage of 44%.

Conclusion

Tumour volume is an important predictor of survival in lung cancer patients treated with CHART or with combined modality chemoradiotherapy.