Study of the Decrease of Length of Stereotactic Body Radiation Therapy in Lung Cancer

Purpose : Non small cell lung cancer (NSCLC) is among the most common cancers in the werstern world. Patients with stage I have the most satisfactory outcomes. The gold standard for treatment is still surgery, but this approach has recently been challenged by hypofractionnated stereotactic body radiation therapy (SBRT). Therefore, for patients who are not eligible for surgery due to their significant co-morbidity, or for those who refuse surgical resection, stereotactic radiotherapy is an efficient practical alternative. SBRT is well tolerated and efficient, in fact local control rate at 3 years reaches more than 90%. Most of guidelines recommand a dose between 48 and 60 Gy delivered in 3 at 8 fractions and 3 weeks. Biological effect depends on the dose distribution in time and decreases when the number of fractions or length of radiation treatment increase. Decreasing the length of treatment and the interval between fractions may improve efficiency of treatment and local control rate. Moreover, it may improve quality of life of patients. Nevertheless, an evaluation of safety of such shorter treatment course, with a phase I-II clinical study is needed.