Biochemical Control and Toxicity after Intensity-Modulated Radiation Therapy for Prostate Cancer

Abstract

Intensity modulated radiation therapy (IMRT) has achieved widespread use for prostate cancer; however, in relation to this use, outcomes studies are still relatively sparse. We report a single-institutional experience in outcomes analysis with the use of IMRT for the primary management of prostate cancer. One hundred thirty consecutive patients with adenocarcinoma of the prostate were treated at a single institution using IMRT with curative intent. Thirty-six (28%) patients were classified as low-risk, 69 (53%) as intermediate-risk, and 25 (19%) as high-risk. The median dose prescription was 76 Gy to the planning target volume. Sixty-five (50%) patients received androgen deprivation therapy (ADT) for a median 4 months, starting 2 months prior to IMRT. Biochemical failure was defined as PSA < post-treatment nadir+2. Gastrointestinal (GI) and Genitourinary (GU) toxicity were defined by RTOG criteria. Median follow-up was 53 months. By NCCN risk category, 4-year biochemical control was 97%, 94%, and 87% for low, intermediate, and high-risk patients, respectively. Among disease factors, multivariable analysis demonstrated the strongest association between biochemical control and Gleason score < or =6 (p=0.0371). Therapy was well tolerated with no Grade 4 toxicity and limited grade 3 GI or GU toxicity. Acute Grade 3+ GI and GU toxicity rates were 0% and 2%, and maximal late Grade 3+ GI and GU toxicity rates were 5% and 6%, respectively. Late rectal toxicity was associated with higher volumes of RT to the rectum. By last follow-up late Grade 3+ toxicity was 2% for both GI and GU systems. In conclusion, patients treated with IMRT for prostate cancer have excellent rates of biochemical control and low rates of severe toxicity of treatment.

Efficacy and toxicity of intensity-modulated radiation therapy for prostate cancer in Chinese patients

“…These data were consistent with the results of IMRT series in Caucasians (Table 6). [11][12][13][14][15][16] Our study also concurred with previous reports that Asian patients with prostate cancer tended to present with more advanced or high-risk disease, as evidenced by 88% of the patients having intermediate-or unfavourable-risk disease. Nevertheless, it was evident that ethnicity differences did not influence treatment outcomes.…”

“…However, the proportion of patients experiencing grade 3 late GI complications (4%) was slightly higher than that in other relevant reports. [11][12][13][14][15][16] We therefore conducted a comprehensive multivariate analysis to identify clinical factors associated with late GI complications, and found that having an acute GI complication was an independent predictor of late GI complications. This finding was also consistent with previous reports.…”

“…Several reports on prostate cancer IMRT demonstrated encouraging biochemical control and favourable treatment-related toxicities compared to conventional techniques. [11][12][13][14][15][16] However, those studies enrolled predominantly Caucasian subjects. As there are differences in stage distribution, risk categories, and pre-treatment PSA levels in Asian patients undergoing radiotherapy, 17,18 it appeared valuable to evaluate the treatment efficacy and toxicity of prostate cancer IMRT in Asian populations.…”

Toxicity Analysis of Postoperative Image-Guided Intensity-Modulated Radiotherapy for Prostate Cancer

“…Although the use of intensity-modulated radiation therapy (IMRT) in the definitive radiotherapy setting for localized prostate cancer has been extensively studied (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21), data in the postoperative setting are more limited (22)(23)(24)(25)(26)(27)(28)(29). In part, this has been due to concerns regarding the cumulative toxicity from any form of postoperative radiotherapy.…”

Evaluation of Interfractional Movement of the Seminal Vesicle and Dose Variations with IGRT Throughout the Prostate Cancer Radiotherapy.

“…[1][2][3][4][5] Therefore, a high dose of IMRT as the standard treatment for early and locally advanced prostate cancer has been recommended recently. For patients with intermediate and high risk prostate cancer, seminal vesicles (SV) have a higher risk of invasion and are recommended to be included to the clinical target volume (CTV).…”