Introduction: A survey regarding radiobiological questions in the treatment of lung cancer (LC) was done to study the clinical aspects of radiotherapy in Spain, in order to standardise treatment decisions.
Methods and materials: From November 2007 to March 2008, a survey was performed among radiation oncologists in Spain specialising in LC treatment via e-mail, which included questions regarding different radiobiological aspects of radiotherapy LC treatment. The extent of the resulting material made it necessary to divide it into two parts; the first is presented in this article. The second, which includes items about alpha/beta-NTCP/TCP values and reirradiation criteria, will be reported elsewhere.
Results: Thirty-one radiation therapists from 29 radiation oncology departments answered the survey. 77.4-93.5% of responders used the basic formula from the linear-quadratic model and/or computer software for radiobiological calculations; 100% used lung (mostly V20, median <30%) and spinal cord constraints (mostly a median of physical maximum dose <45.5 Gy); and 90.3% used heart and oesophagus constraints (very heterogeneous parameters in both organs).
Conclusions: Radiobiological considerations are clearly present in the planning process of radiotherapy of LC in Spain, with a high coincidence with the literature regarding lung and spinal cord constraints. The heterogeneity shown for oesophagus and heart results demonstrates the need for continuing investigation into the standardisation of clinical, dosimetric and radiobiologic aspects of the treatment of this cancer.