應用強度調控多葉式準直儀放射治療技術在全身光子照射治療

Intensity Modulated Radiotherapy in Total Body Irradiation

范璽(Fan-xi Fan)

指導教授 ： 趙　敏

中臺科技大學/健康科學院/放射科學研究所/碩士(2010年)

摘要

全身光子放射治療（TBI）是作為骨髓移植治療惡性血液腫瘤疾病的
預照之前置作業。由於在TBI 的照射期間會有大量的正常組織會曝照到；正常組織所受到的暴露，是有可能造成風險的，尤其最重要的是肺部組織的風險劑量。透過強度調控放射治療（IMRT）是有可能能夠降低這些風險的並透過直接針對骨髓的照射，同時盡量減少對正常組織的照射。本研究是運用日蝕治療計劃軟體（Eclipse）設計IMRT 的治療計畫，並運用藍道假體（Randophantom）來進行劑量之量測。本研究使用熱方光劑量計(TLD)與EBT2 底片驗證本次研究之劑量。使用三中心點的照野技術方法進行強度調控全身光子照射治療（IMTBI）。IMTBI 使用藍道假體並與其治療技化之劑量驗證比較。劑量測量是利用TLD 與EBT2 進行，並比較計劃之劑量。本研究使用IMTBI 之成果也比與傳統計劃做簡易之比較。本研究之IMTBI
治療計畫證明，可以達到 95％的體積包覆著 95％的劑量。最後，從本研究結果是可以證明利用三中心點之IMTBI 技術是可應用於治療TBI 的。

關鍵字

最佳化 ； 照野重疊區 ； 田口方法 ； EBT2 底片 ； 全身光子放射治療 ； 強度調控放射治療

並列摘要

Total body irradiation (TBI) is used as a preconditioning regimen prior to bone marrow transplant for treatment of hematologic malignancies. Large volumes of normal tissue are irradiated in the TBI process. The irradiated normal tissue might have the risk of radiation damage, and the most concerned normal tissues at risk are lungs. Intensity Modulated Radiation Therapy (IMRT) may be able to reduce these risks by directly targeting the bone marrow while minimizing the dose to critical structures. The feasibility study was initiated to apply the Eclipse treatment planning system of IMRT for TBI procedure on
Rando phantom. The dosimetry was verified with TLD dosimeter and EBT2 film in this study. A three-isocenter technique was used to conduct an Intensity modulated total body irradiation (IMTBI) procedure on a linear accelerator.
Individual IMRT plan for IMTBI was delivered to a Rando phantom for dosimetry comparison. Dose measurements with ion chamber, EBT2 film and TLD dosimeter were performed and compared to the planned dose. The IMTBI planning results for target coverage doses are also compared with that from the conventional planning for TBI. The IMTBI treatment plan comparison indicated that target coverage was achieved with IMTBI technique as conventional TBI techniques do. Can reach 95% of the volume containing cover
95% of the dose in this experiment. Results from this study conclude that the three-isocenter IMTBI technique can be applied to TBI treatment with acceptable target coverage.

並列關鍵字

Optimization ； Intensity Modulated Radiation Therapy ； Field Junction ； Taguchi methodology ； EBT2 film ； Total body irradiation

參考文獻

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