螺旋光子刀對不同體重之肺癌患者的散射劑量及危險度評估

To Evaluate Scattered Dose and Risk for Male Patients of Different Weights with Lung Cancer Undergoing Tomotherapy

葉俞伶(Yu-Ling Ye) ； 朱欣怡(Hsin-Yi Chu) ； 蔡筱涵(Hsiao-Han Tsai) ； 陳健懿(Chien-Yi Chen) ； 劉文山(Wen-Shan Liu)

《中華放射線技術學雜誌》 35卷2期 (2011/06) Pp. 104-110

https://doi.org/10.30045/CJRT.201106.0006

摘要

利用熱發光劑量計(Thermoluminescent dosimetry, TLD)來量測肺癌患者進行螺旋光子刀(Tomotherapy)治療時的散射光子劑量，並評估各器官及組織的危險度(risk)。以侖道擬人假體(Rando phantom)及由10公斤至90公斤不同體重數的自行研發假體(Self-developed mathematic phantom, SDMP)，來取代肺癌患者進行治療，且參考ICRP 60號報告所提出的重要組織器官以及Kawaura等人的佈點方式來佈植TLD，由TLD評估假體除了照野範圍外，各部位所受的散射劑量，且藉由ICRP 60的有效劑量(effective dose)及危險度定義來評估假體所受的有效劑量及危險度，以及各個不同體重假體與劑量之間的關係，隨著體重的增加，所受的有效劑量有減少的趨勢，危險度由2.18%至3.63%。螺旋光子刀具有高監控單位(Monitor Units, MU)的劑量輸出，在動態多葉式準直儀(Dynamic Multi-Leaf Collimator, DMLC)下光子洩漏及散射問題實在不容忽視，可能造成病患額外的劑量增加，所以希望藉此研究可提供醫師、放射師更多的參考，亦希望在治療時可將病患的後遺症發生率降至最低。

關鍵字

肺癌 ； 螺旋光子刀 ； 熱發光劑量計 ； 假體

並列摘要

Thermoluminescent dosimetry (TLD) is applied to evaluate the scattered photon dose as well as the risks of organ and tissue of lung cancer patients undergoing Tomotherapy. Rando phantom and self-developed mathematic phantom (SDMP) ranging from 10 to 90 kg were used to simulate lung cancer patient. Following ICRP 60 and Kawaura et al. insert TLDs into the phantoms and the scattered dose of each organ or tissue of these phantoms was evaluated by TLDs. ICRP 60 was applied to evaluate effective dose and risk in relation to different weights ad phantoms. Meanwhile, as Tomotherpy can deliver high dose of monitor units (MU), photon leakage and scattered dose coming from dynamic multi-leaf collimator (DMLC) may increase unwanted dose to patients. Effect doses decreased with increasing with body-weight. Risk ranged from 2.18% to 3.63%. The findings of this study will be crucial knowledge to physicians and radiologists which will contribute to minimizing the risks of lung cancer during treatment.

並列關鍵字

Lung dose ； Tomotherapy ； TLD ； Phantom