Researchers from Fox Chase Cancer Center have reported that IMRT (intensity-modulated radiation therapy) produces the same clinical outcomes as 125-I brachytherapy for localized low-risk prostate cancer but with less acute and chronic toxicities. The details of this study appeared in an early online publication in the International Journal of Radiation Oncology Biology Physics on January 17, 2008.¹

Men with localized low-risk prostate cancer have three basic choices for treatment: radical prostatectomy, external beam radiation therapy, or brachytherapy. Less well studied options include cryotherapy and high-intensity ultrasound. There have been no randomized trials comparing the three main treatment choices, but the general consensus is that all three treatment modalities produce similar treatment results, though they may have differing patterns of toxicity. There continue to be improvements and refinements in each of these treatment modalities. For instance, radical prostatectomy is increasingly being performed with robotic techniques, radiation therapy in increasingly being performed with IMRT techniques, and there are a variety of brachytherapy techniques with or without external beam radiation therapy.

The current study evaluated the toxicities of 374 low-risk patients with localized prostate cancer treated between 1998 and 2004. The median follow-up of this group of patients was 43 months. Two-hundred sixteen patients were treated with IMRT and 158 with brachytherapy. This was not a randomized trial, and each patient selected the mode of therapy. Patients who selected IMRT were older, had more symptoms, were more likely to have had prior transurethral resection, and had larger prostate volumes. Patients treated with IMRT had less acute and chronic GI and GU toxicities. For example, three-year grade 2 or higher GU toxicities were 3.5% following IMRT and 9.2% following brachytherapy. At four years of follow-up, 99.5% of IMRT patients had not had a biochemical relapse compared with 93.5% for brachytherapy (p=0.09). These authors concluded that IMRT and brachytherapy were equally effective but that IMRT was less toxic.

Comments: Although this was not a randomized trial, patients in the IMRT group appeared to be higher risk for toxicity and possibly relapse. The IMRT group did better despite being at higher risk for complications, which makes the results remarkable. However, it will still be difficult for the average patient with low-risk prostate cancer to determine what the optimal therapy really is.

Related News:

Surgery May Be Best Treatment for Early Prostate Cancer in Younger Patients (10/15/2007)

Cryosurgery Effective for Localized Prostate Cancer (8/29/2007)

High Intensity Ultrasound for the Treatment of Localized Prostate Cancer to be Studied in the US (5/31/2007)

Randomized Trial Indicates that Cryosurgery is Equivalent to Radiation Therapy for Prostate Cancer (5/30/2007)

Functional Outcomes of Robotic Prostatectomy Similar to Conventional Prostatectomy (5/29/2007)

Quality of Life after Different Treatment for Localized Prostate Cancer Evaluated (5/18/2007)

Calypso System Effective for Monitoring Radiotherapy of Prostate Gland (3/9/2007)

Quality of Life: Brachytherapy vs. Surgery for Localized Prostate Cancer (2/27/2007)

Brachytherapy Plus External-Beam Radiation Therapy Provides Impressive Long-Term Results for Early Prostate Cancer (1/22/2007)

Good Long-Term Results Reported for High Dose Intensity Modulated Radiation Therapy for Prostate Cancer (9/12/2006)

Reference:

¹ Eade TN, Horwitz EM, Ruth K, et al. A comparison of acute and chronic toxicity for men with low-risk prostate cancer treated with intensity-modulated radiation theapy or (125)I permanent implant. International Journal of Radiation Oncology Biology Physics [early online publication]. January 17, 2008.