Clinical practice and workflow of radiation therapy for lung tumors at the University of Tokyo Hospital

At the University of Tokyo Hospital, we mainly explained how to obtain images of computed tomography (CT) for treatment planning in stereotactic body radiation therapy (SBRT) and multi-segment irradiation, treatment planning, and precautions during irradiation. For multi-segment irradiation, we described a case of stage III non-small cell lung cancer who underwent intensity modulated radiation therapy (IMRT). In SBRT, it is necessary to reduce the margin given to gross tumor volume (GTV), and especially in lung cancer, measures against respiratory movement are indispensable. Stage III non-small cell lung cancer is treated with a 60 Gy / 30 Fr PTV D 50% prescription. The dose constraints are shown in the table. An example of dose distribution in stage III non-small cell lung cancer is illustrated. It is recommended that dose verification be performed in advance for treatment plans using IMRT. Beam matching is performed with two linac devices, and even if one device fails, the other device can be used for treatment. (S.S.)