• The Journal of Korean Society for Radiation Therapy
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• v.29 no.1
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• pp.85-92
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• 2017

purpose: Image Guide System offers therapy precise, especially Intensity Modulated Radiation Therapy. However, organs at pelvis have variation and uncertainties each therapy. it brings IG system for verifying patient's position. In this study, analysis the variation at pelvis during rectal cancer radiation therapy. Moreover design the patient re-setup technique and apply to patients. Material and Method: 40 rectal cancer patient who have radiation therapy. The 530 image which acquired from IG system are analyzed. The bone structure, bladder, gas in the rectum, small bowel, soft tissue, weigh loss are evaluated by the criterion. The criterion are classified by best, good, bad and figure out the ratio with count. The re-setup proceed in case of one or over the two get the bad criterion and figure out the ratio of re-setup results: The ideal of therapy ratio is 19.2 % each criterion. And the good for therapy ratio is 54.9 %, the cases of bad for therapy is 25.8 %. The bad cases are have therapy after re-setup with post process. conclusion: Each pre-treatment image that acquired IG system has different results despite of same patients. The 25.8 % need to re-setup in order to unsuitable therapy. It is implies that the IG system is necessary establishing precise treatment plan like IMRT especially rectal cancer.

• Radiation Oncology Journal
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• v.31 no.4
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• pp.206-215
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• 2013

Purpose: Re-irradiation (re-RT) is considered a treatment option for inoperable locoregionally recurrent head and neck cancer (HNC) after prior radiotherapy. We evaluated the efficacy and safety of re-RT using Helical Tomotherapy as image-guided intensity-modulated radiotherapy in recurrent HNC. Materials and Methods: Patients diagnosed with recurrent HNC and received re-RT were retrospectively reviewed. Primary endpoint was overall survival (OS) and secondary endpoints were locoregional control and toxicities. Results: The median follow-up period of total 9 patients was 18.7 months (range, 4.1 to 76 months) and that of 3 alive patients was 49 months (range, 47 to 76 months). Median dose of first radiotherapy and re-RT was 64.8 and 47.5 $Gy_{10}$. Median cumulative dose of the two courses of radiotherapy was 116.3 $Gy_{10}$ (range, 91.8 to 128.9 $Gy_{10}$) while the median interval between the two courses of radiation was 25 months (range, 4 to 137 months). The response rate after re-RT of the evaluated 8 patients was 75% (complete response, 4; partial response, 2). Median locoregional relapse-free survival after re-RT was 11.9 months (range, 3.4 to 75.1 months) and 5 patients eventually presented with treatment failure (in-field failure, 2; in- and out-field failure, 2; out-field failure, 1). Median OS of the 8 patients was 20.3 months (range, 4.1 to 75.1 months). One- and two-year OS rates were 62.5% and 50%, respectively. Grade 3 leucopenia developed in one patient as acute toxicity, and grade 2 osteonecrosis and trismus as chronic toxicity in another patient. Conclusion: Re-RT using Helical Tomotherapy for previously irradiated patients with unresectable locoregionally recurrent HNC may be a feasible treatment option with long-term survival and acceptable toxicities.