目的：回溯性報告本院在強度調控放射治療（IMRT）時代，使用主程（definitive）根除性放射治療，在攝護腺腺癌的初步療效及治療毒性結果，並分析可能的影響因子。
材料與方法：在 2003-2010 年間，連續 564 位無遠端轉移的攝護腺腺癌病人，在本院完成主 程根除性放射治療。回溯分析追蹤中位數為 63 個月。在 CT 或 MRI 上，沒有局部淋巴轉移 （N0）的 542 人中，依美國國家綜合癌症網絡（National Cancer Comprehensive Network, NCCN） 風險群組為低、中、高、和非常高風險組的病人，分別有 97（17.2%）、181（32.1%）、214 （37.9%）、和 50（8.9%）人。另外有 22（3.9%）人，在 CT 或 MRI 上，判斷有局部的淋巴轉 移（N1）。處方劑量的中位數為 78 Gy。在本院接受過雄性素抑制療法（Androgren Deprivation Therapy, ADT）有 453 人（80.3%），其中 62 人（11%）接受超過兩年的輔助性 ADT。
結果：五年整體存活率（OS）為 90.3%，五年疾病特定存活率（DSS）為 97.9%，五年無遠 端轉移存活率（DMFS）為 94.1%。五年無生化失敗存活率（Biochemical Failure Free Survival, BFFS）為 87.1%，在 NCCN 低、中、高、和非常高風險群組的病人，分別為 98.2%, 94.6%, 81.2%和 75.7%，在 N1 組則為 49.9%。高和非常高風險組的 BFFS 預後，需要 MRI 才能顯著區 分。多變數 Cox 迴歸分析發現，較高的腫瘤局部侵犯風險分組（risk group）、Gleason 分數風險 分組、初始 PSA 值風險分組、和年齡 80 歲以上，為顯著的 BFFS 風險因子。骨盆淋巴照射會增 加急性腸胃道（GI）毒性，比值比為 1.486（95%信賴區間：1.059-2.086）。在三級以上的延遲 毒性方面，泌尿道（GU）有 23 位（4.1%），GI 有 33 位（5.9%）病人。在最後一次訪查仍有三 級以上延遲毒性者，GU 有 4 位（0.7%），GI 有 1 位（0.2%）。多變數分析發現，直腸劑量> 48 Gy 是影響出血唯一顯著的因子。
結論：初步判斷本院療效，與文獻中使用 IMRT 的結果相當。較高風險分組的腫瘤局部侵犯、 Gleason 分數、和初始 PSA 值、以及年齡 80 歲以上，為顯著的 BFFS 風險因子。骨盆淋巴照射 略為增加急性 GI 毒性。在預後判斷上，MRI 較 CT 正確。直腸出血與高劑量有關。

Purpose : We here report the preliminary treatment and toxicity outcome of definitive radical radiotherapy for patients with adenocarcinoma of prostate in an era of intensity modulated radiotherapy (IMRT) in our institution and analyze the possible prognostic factors.
Materials and Methods : During 2003 and 2010, 564 consecutive patients with adenocarcinoma of prostate receiving radical definitive radiotherapy in our institution were retrospectively reviewed with a median follow-up of 63 months. Among the 542 patients without evident lymphadenopathy (N0) on CT or MRI, there were 97 (17.2%), 181 (32.1%), 214 (37.9%), and 50 (8.9%) in low, intermediate, high, and very high risk groups respectively, based on the National Comprehensive Cancer Network (NCCN) risk classification criteria. Another 22 (3.9%) patients showed regional lymphadenopathy (N1). Median prescription dose was 78 Gy. There were 453 (80.3%) patients receiving androgen deprivation therapy (ADT). Among them, 62 (11.1%) received adjuvant ADT for more than 2 years.
Results : The 5-year overall survival (OS), disease specific survival (DSS), distant metastasis free survival (DMFS) and biochemical failure free survival (BFFS) of all patients were 90.3%, 97.9%, 94%, and 87.1% respectively. The 5-year BFFS were 98.2%, 94.6%, 81.2%, and 75.7% for patients of low, intermediate, high, and very high risk groups, respectively. For patients with N1 disease, the 5-year BFFS was down to 49.9%. The difference of BFFS between patients of high and very high risk groups was significant only in those who had MRI for staging. Multivariate Cox regression analysis showed that T-stage, Gleason score, and initial PSA risk groups, and age of 80 or older were significant risk factors of BFFS. Pelvic irradiation significantly increased acute GI toxicity with odds ratio of 1.486 (95% confidence interval 1.059 – 2.086). Grade 3 or more late toxicity was noted in 23 patients (4.1%) in GU system and 33 patients (5.9%) in GI system. Only 4 (0.7%) patients had persistent GU toxicity and 1 (0.2%) had persistent GI toxicity at the last follow-up date. Multivariate Cox regression showed the mean dose to rectum above 48 Gy to be the only significant factor for late GI bleeding.
Conclusions : The treatment outcome of our institution was comparable to published results of IMRT. The higher risk groups of T stage, Gleason score, initial PSA, and age of 80 or older, were significant risk factors for BFFS. Pelvic irradiation modestly increased acute GI toxicity. MRI was more accurate for BFFS prognosis. Late GI bleeding was associated with a mean dose above 48 Gy to the rectum.