灰色系統理論(Gray System Theory)於1982年由中國學者鄧聚龍教授發表至今已然20餘年，而臺灣在資訊、電機、土木、機械、水利、建築、企業管理等方面皆有相關的研究報告成果，且在國內迅速的發展當中。本文目的在於針對直腸癌手術前的傅統放射治療和順形放射治療方式使用灰色系統理論之灰關聯分析做不同之分析比較。主要針對37位直腸癌術前放射治療之患者，接受傅統放射治療(conventional radiotherapy)以及順形放射治療(three-dimensional conformal radiotherapy)，分析兩種治療技衡的劑量分怖狀況，且探討其中25位病人的均質性指標(homogeneity index)、順形指標(conformal index)及50%之腫瘤和膀胱所接受到的劑量。用來評估治療時的腫瘤給予劑量以及對正常組織的影響。研究結果顯示，利用灰色關聯分析直腸癌術前的傅統放射治療和順形放射治療之治療方式，其順形放射治療的各項均值指標較傅統放射治療為佳；而95%等劑量曲線時順形指標亦以順形放射治療結果較好；另外膀胱所接受的劑量在順形放射治療明顯比傅統放射治療來低了40.557cGy，這正好輿使用灰色關聯分析之結果相符合。利用此案例分析結果，致式灰色系統理論轉放射醫學及輻射理論之相關領域範圍上，提供新的可行性。

Developed by Deng (1982), the Grey System Theory is highly promising for use in Taiwanese industry, especially information technology, electrical machinery, construction and building activities, water conservation, architecture. This study analyzes patients diagnosed with carcinoma who underwent rectum preoperative conventional radiotherapy and conformal radiotherapy by adopting grey relational analysis of the grey system. Thirty seven patients diagnosed with carcinoma of the rectum underwent conventional radiotherapy and conformal radiotherapy, with those results analyzed according to the various dose distributions during treatment, homogeneity index, conformal index, with a 50% dosage for the tumor and bladder. Those results were used to assess tumor dosage and the effect of treatment on normal tissues. Analysis results indicate that each homogeneity index of conformal radiotherapy performs better than conventional radiotherapy ones by using grey relational analysis. Additionally, the conformal index of 95% isodose curve for conformal radiotherapy is better than that for conventional radiotherapy. Moreover, the accepted dose of bladder of conformal radiotherapy was lower than 40.557cGy in conventional radiotherapy. This is only related to the grey relational analysis results. Based on these analysis results, the grey system theory is highly promising for use in medical radiology and radiation theory. Furthermore, the grey systematic theory is also applicable to radiating the relevant domain ranges of medical science and radiation.