Ko Christine, Ning Holly, Lita Elena, McNally Deborah, Wood Bradford J, Choyke Peter, Guion Peter, Smith Sharon, Krieger Axel, Camphausen Kevin, Singh Anurag K, Kaushal Aradhana
Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
Urologic Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA.
World J Oncol. 2012 Feb;3(1):16-22. doi: 10.4021/wjon436w. Epub 2012 Feb 19.
To present the early findings of a phase I clinical trial studying the use of intensity modulated radiation treatment (IMRT) to treat at risk pelvic and lower para-aortic lymph nodes in patients with high risk prostate cancer while escalating dose. Dose escalation was performed with a technique particularly aiming to limit the dose to surrounding critical structures.
A total of 12 patients were treated with an IMRT plan that delivered 45 Gy to the pelvic lymph nodes, prostate and proximal seminal vesicles. This was followed by an image guided IMRT plan that delivered 9 Gy to the prostate and seminal vesicles and then an additional 21.6 Gy delivered to the prostate for a total dose of 75.6 Gy to the prostate. Gastrointestinal (GI) and genitourinary (GU) toxicity were recorded weekly throughout treatment and in follow up (range: 20 - 49 months).
At diagnosis, median age was 64, median PSA 15.5 (range: 5 - 103) and Gleason score ranged 7 - 9. The median dose to the bladder was 52 Gy, the median dose to the rectum was 53 Gy and the median dose to the small bowel was 26 Gy. During treatment, Grade 2 GU toxicity was noted in 3/12 (25%) patients and Grade 2 GI toxicity was noted in 2/12 patients (16%). At a median follow-up of 28 months, Grade 2 late GI toxicity was seen in 1/12 (8%) and late GU in 3/12 (25%) of patients. There were no acute or late grade 3 and 4 GU or GI toxicities.
Our study shows the feasibility of using IMRT for pelvic and lower para-aortic nodal irradiation as the toxicities are low for the total dose that was delivered. This shows promise for reducing normal tissue doses, improving target control, and potentially allowing for additional dose escalation to the pelvic/lower para-aortic lymph nodes in our successive cohorts.
本研究旨在展示一项I期临床试验的早期结果，该试验采用调强放射治疗（IMRT）对高危前列腺癌患者盆腔及下腹主动脉旁淋巴结进行放疗，并逐步增加剂量。剂量递增采用了一种特别旨在限制周围关键结构剂量的技术。
共有12例患者接受了IMRT计划，该计划对盆腔淋巴结、前列腺和近端精囊给予45 Gy的剂量。随后进行图像引导的IMRT计划，对前列腺和精囊给予9 Gy的剂量，然后再对前列腺额外给予21.6 Gy的剂量，使前列腺的总剂量达到75.6 Gy。在整个治疗过程及随访期间（范围：20 - 49个月）每周记录胃肠道（GI）和泌尿生殖系统（GU）毒性反应。
诊断时，患者中位年龄为64岁，中位前列腺特异性抗原（PSA）为15.5（范围：5 - 103），Gleason评分范围为7 - 9。膀胱的中位剂量为52 Gy，直肠的中位剂量为53 Gy，小肠的中位剂量为26 Gy。治疗期间，3/12（25%）的患者出现2级GU毒性反应，2/12（16%）的患者出现2级GI毒性反应。中位随访28个月时，1/12（8%）的患者出现2级晚期GI毒性反应，3/12（25%）的患者出现晚期GU毒性反应。未出现3级和4级急性或晚期GU或GI毒性反应。
我们的研究表明，采用IMRT对盆腔及下腹主动脉旁淋巴结进行照射是可行的，因为所给予的总剂量毒性较低。这显示出在降低正常组织剂量、改善靶区控制以及在后续队列中可能允许对盆腔/下腹主动脉旁淋巴结进一步增加剂量方面具有前景。
