Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Radiation Oncology cung cấp cho các bạn kiến thức về ngành y đề tài: Sparing the contralateral submandibular gland without compromising PTV coverage by using volumetric modulated arc therapy. | Doornaert et al. Radiation Oncology 2011 6 74 http content 6 1 74 RADIATION ONCOLOGY RESEARCH Open Access Sparing the contralateral submandibular gland without compromising PTV coverage by using volumetric modulated arc therapy Patricia Doornaert Wilko FAR Verbakel Derek HF Rietveld Ben J Slotman and Suresh Senan Abstract Background Salivary gland function decreases after radiation doses of 39 Gy or higher. Currently submandibular glands are not routinely spared. We implemented a technique for sparing contralateral submandibular glands CLSM during contralateral elective neck irradiation without compromising PTV coverage. Methods Volumetric modulated arc therapy RapidArc plans were applied in 31 patients with stage II-IV HNC without contralateral neck metastases all of whom received elective treatment to contralateral nodal levels II-IV. Group 1 consisted of 21 patients undergoing concurrent chemo-radiotherapy with elective nodal doses of Gy PTVelect and 70 Gy to tumor and pathological nodes PTVboost in 7 weeks. Group 2 consisted of 10 patients treated with radiotherapy to Gy to PTVelect and 70 Gy to PTVboost in 6 weeks. All clinical plans spared the CLSM using individually adapted constraints. For each patient a second plan was retrospectively generated without CLSM constraints non-sparing plan . Results PTV coverage was similar for both plans with of PTVelect and of PTVboost receiving 95 of the prescription dose. The mean CLSM dose in group 1 was Gy for clinical plans versus Gy in nonsparing plans p . In group 2 mean CLSM dose was Gy for clinical plans and Gy for non-sparing plans p . Conclusions Elective radiotherapy to contralateral nodal levels II-IV using RapidArc consistently limited CLSM doses well below 39 Gy without compromising PTV-coverage. Future studies will reveal if this extent of dose reduction can reduce patient symptoms. Keywords submandibular gland sparing volumetric .
