Clinical survey for registering treatment decision criteria in advanced non-small-cell lung cancer radiotherapy and determination of the dose–response relationship for 1-year survival

Purpose: Recent studies have suggested significant variations in radiotherapy schedules used to treat advanced non-small-cell lung cancer (NSCLC), both between different centers in one country as well as between countries. In this study, different treatment methodologies have been explored using management plans proposed by radiation oncologists regarding general questions and theoretical case histories for patients with advanced NSCLC. Materials and methods: The survey was conducted by sending a questionnaire to 24 radiotherapy centers in Europe. The questionnaire was composed of two sections. The first section concerned reasons for giving radiotherapy, parameters that influence the choice of total dose and fractionation for radiotherapy and kind of equipment used. The second section concerned the management of five theoretical patients (A–E) regarding the selection of the radiotherapy technique and the aim of treatment (radical or palliative). Furthermore, 19 trials comparing different regimens of palliative radiotherapy in patients with NSCLC were reviewed. There were marked differences in the doses of the investigated radiotherapy schemes, the patient characteristics and the assessed outcome measures. Results: 70% of the responders answered that the most important factors for deciding what dose and fractionation scheme to use were: metastases, performance status (PS) of the patient, lung function and size of the primary tumour. The most common reasons for giving the treatment were symptom relief, prolongation of life and, in some cases, possibly cure. More than 95% of the responders stated that they would give radiotherapy in each of these cases. The total doses proposed where 20 Gy in five fractions or 30 Gy in ten fractions in 2 weeks for the cases A and D. If the previous two schemes were converted to a fractionation scheme delivering 2 Gy per fraction, the equivalent doses would be 23 and 33 Gy, respectively. For the cases B, C and E, the proposed fractionation schemes were 2 Gy daily to 60–68 Gy in Correspondence to: Panayiotis Mavroidis, Division of Medical Physics, Department of Radiation Oncology, University of Texas Health Sciences Center at San Antonio, 7979 Wurzbach Rd, MC 7889, San Antonio TX 78229-4427, USA. Tel: 11 210-450-1027. Fax: 11 210-450-1076. E-mail: mavroidis@uthscsa.edu