Stereotactic radiotherapy of primary lung cancer and other targets: Results of consultant meeting of the international atomic energy agency (Int J Radiat Oncol Biol Phys 2011;79:660-669)

摘要

To the Editor: We read with great interest the article by Nagata et al. (1) in which they nicely evaluated the current status of stereotactic body radiotherapy (SBRT) in developing countries and recommendations following the meeting of consultants of the International Atomic Energy Agency (IAEA). We very much appreciate their contribution, as their findings and experiences will have major implications for our clinical daily practice of SBRT treatment and planning in the developing world.In their report, Nagata et al. advised using the minimum methodology, technology, and quality assurance requirements for SBRT in treating primary lung tumors and other body tumors. Patients who are candidates for SBRT for lung tumors are generally those whose cases are medically inoperable and have poor performance status, with cardiac or other comorbid-ities, and a significant number of those patients may present with implanted cardiac pacemakers (ICP). Such a report should also have discussed this potential problem. We would like to share our experience with and opinion regarding image-guided SBRT for early-stage lung cancer patients with ICP, in that respect.Among our 25 SBRT lung patients treated since 2008, we treated a 76-year-old medically inoperable patient who was diagnosed with early-stage lung cancer, who had received an ICP in 2006. Total dose of 5,500 cGy was given in 5 fractions with our Trilogy linear accelerator-based system, with daily pre- and posttreatment kV-kV imaging and cone beam computerized tomography (CBCT) for image guidance. We reported this case, in which we followed the recommendations of the American Association of Physicists in Medicine Task Group report for treating this patient, which was published in 1994 (2). We limited the total dose to the ICP to less than 5 Gy and refrained from using direct beams through the ICP device. During treatment, an erratic pacing happened due to the transient interference, and this was retrospectively recorded by the ICP device memory analysis. No immediate severe side effect happened during SBRT. The patient had cardiac problems and expired 1 month after treatment. However, these cardiac problems were not found to be related to pacemaker malfunction.