Yonemoto L T, Slater J D, Rossi C J, Antoine J E, Loredo L, Archambeau J O, Schulte R W, Miller D W, Teichman S L, Slater J M
Department of Radiation Medicine, Loma Linda University Medical Center, CA 92354, USA.
Int J Radiat Oncol Biol Phys. 1997 Jan 1;37(1):21-9. doi: 10.1016/s0360-3016(96)00311-2.
A study was developed to evaluate the use of combined photons and protons for the treatment of locally advanced carcinoma of the prostate. This report is a preliminary assessment of treatment-related morbidity and tumor response.
One hundred and six patients in stages T2b (B2), T2c (B2), and T3 (C) were treated with 45 Gy photon-beam irradiation to the pelvis and an additional 30 Cobalt Gray Equivalent (CGE) to the prostate with 250-MeV protons, yielding a total prostate dose of 75 CGE in 40 fractions. Median follow-up time was 20.2 months (range: 10-30 months). Toxicity was scored according to the Radiation Therapy Oncology Group (RTOG) grading system; local control was evaluated by serial digital rectal examination (DRE) and prostate specific antigen (PSA) measurements.
Morbidity evaluation was available on 104 patients. The actuarial 2-year rate of Grade 1 or 2 late morbidity was 12% (8% rectal, 4% urinary). No patients demonstrated Grade 3 or 4 late morbidity. Treatment response was evaluated on 100 patients with elevated pretreatment serum PSA levels. The actuarial 2-year rate of PSA normalization was 96%, 97%, and 63% for pretreatment PSAs of > 4-10, > 10-20, and > 20, respectively. The 13 patients with rising PSA demonstrated local recurrence (3 patients), distant metastasis (8 patients), or no evidence of disease except increasing PSA (2 patients).
The low incidence of side effects, despite the tumor dose of 75 CGE, demonstrates that conformal protons can deliver higher doses of radiation to target tissues without increasing complications to surrounding normal tissues. The initial tumor response, as assessed by the high actuarial rate of normalization with pretreatment PSA < or = 20, and the low rate of recurrences within the treatment field (2.8%), are encouraging.
开展一项研究以评估联合使用光子和质子治疗局部晚期前列腺癌的效果。本报告是对治疗相关发病率和肿瘤反应的初步评估。
106例T2b（B2）、T2c（B2）和T3（C）期患者接受了盆腔45 Gy光子束照射，并用250 MeV质子对前列腺追加30钴灰当量（CGE）照射，前列腺总剂量为75 CGE，分40次给予。中位随访时间为20.2个月（范围：10 - 30个月）。毒性根据放射治疗肿瘤学组（RTOG）分级系统进行评分；通过连续直肠指检（DRE）和前列腺特异性抗原（PSA）测量评估局部控制情况。
104例患者可进行发病率评估。1或2级晚期发病率的精算2年发生率为12%（直肠8%，泌尿4%）。无患者出现3或4级晚期发病率。对100例治疗前血清PSA水平升高的患者评估了治疗反应。治疗前PSA分别>4 - 10、>10 - 20和>20时，PSA正常化的精算2年发生率分别为96%、97%和63%。PSA升高的13例患者出现局部复发（3例）、远处转移（8例）或除PSA升高外无疾病证据（2例）。
尽管肿瘤剂量为75 CGE，但副作用发生率较低，表明适形质子可向靶组织输送更高剂量的辐射，而不会增加周围正常组织的并发症。通过治疗前PSA≤20时较高的正常化精算率以及治疗区域内较低的复发率（2.8%）评估的初始肿瘤反应令人鼓舞。
