Purpose/Objective(s): The goal of this multi-institutional study is to document the efficacy, toxicity and quality of life (QOL) outcome of HDR- like stereotactic body radiation therapy (SBRT) for low- and selected intermediate-risk prostate cancer. Accrual is complete and intermediate- term results are presented.
Materials/Methods: Between November 2007 and December 2011, 260 patients with prostate cancer (< Z T2bN0M0; 45% low-risk and 55% intermediate-risk) received SBRT under a sponsored study*. None had hormone therapy. Follow-up is 3 - 48 months (median 20 months). CTV Z prostate + 2 mm in low-risk patients, and prostate + 5 mm + proximal SV for intermediate-risk (Gleason 7 or PSA 10-20 ng/mL), reduced to 0 against rectal wall. CTV to PTV increase was zero. PTV received 38 Gy in 4 fractions (V100 >95%); heterogeneously applied and periph- erally weighted; PTV Dmax >57 Gy (“Emulating HDR”). Toxicities were assessed using CTCAE v 3.0. QOL was assessed using EPIC-26. Erectile function was defined as answer of 4 on EPIC question 9. Results: Actuarial 3-year biochemical disease-free survival (DFS) is 98.1% (Phoenix) and 98.5% (ASTRO). Actuarial 3-year local and clinical DFS is 99.6% and 98.5%, respectively. Median pre-treatment PSA of 5.15 ng/mL (range 0.4 - 19.3 ng/mL) decreased to 0.13 ng/mL (range 0.03 - 1.3 ng/mL) by 42 months. Of 171 patients with minimum 12-month follow- up, 85% and 49% had acute GU and GI toxicities, respectively; 44% and 11% had late GU and GI toxicities. The incidence of acute and late Grade 3 GU toxicities was 0.6% and 1.8%, respectively, with no acute or late Grade 3 GI toxicities. No patient had grade 4-5 toxicity. The Table shows median EPIC scores through 3 years. Patients with baseline erectile function had 60% and 81% preservation rates at 1 and 3 years, respectively.
Conclusions: In a multi-institutional setting, HDR-like SBRT for low- and selected intermediate-risk prostate cancer resulted in excellent 3-year biochemical, local and distant disease-free survival, a very low PSA nadir, and a low rate of serious acute and late GU and GI toxicities. EPIC analysis revealed a significant decrease in urinary and bowel QOL at 1 month, larger for urinary, with significant improvement in both by 6 months. Bowel QOL fully recovered, while mild to moderate urinary QOL impairment persisted for 2 years, returning to near baseline at 3 years. Sexual QOL declined through 2 years, with partial recovery at 3 years. Long-term assessment will follow as data mature.
Acknowledgment: This project was supported by NCT00643617 and Accuray, Inc.
Oral Scientific Abstract 368; Table. Baseline to 36-month EPIC Progression (* = nadir)
| Baseline | 1 mo. | 6 mo. | 1 yr. | 2 yr. | 3 yr. | |
| Domain | ||||||
| Urinary | 89.69 | 79.61* | 87.03 | 83.04 | 81.25 | 85.13 |
| Bowel | 95.31 | 87.22* | 92.09 | 90.81 | 92.20 | 95.63 |
| Sexual | 55.83 | 49.19 | 51.07 | 43.82 | 36.20* | 50.51 |
D.B. Fuller,1 G. Mardirossian,1 D. Wong,2 D. Morris,3 K. Underhill,4 C. Medbery,5 A. Peddada,6 H. McKellar,7 and J. Gray8
1Genesis Healthcare Partners, San Diego, CA, 2Fresno Community Regional Hospital, Fresno, CA, 3University of North Carolina, Chapel Hill, NC, 4Sletten Cancer Institute, Great Falls, MT, 5St. Anthony’s Hospital, Oklahoma City, OK, 6Penrose Cancer Center, Colorado Springs, CO, 7East Texas Medical Center Cancer Institute, Tyler, TX, 8Sarah Cannon Research Institute, Nashville, TN
Author Disclosure: D.B. Fuller: G. Consultant; Accuray. K. Stock; Accuray, Varian. G. Mardirossian: None. D. Wong: None. D. Morris: None. K. Underhill: None. C. Medbery: None. A. Peddada: None. H. McKellar: None. J. Gray: None.
PII: S0360-3016(12)01328-4
Reference: International Journal of Radiation Oncology, Biology, Physics 84(3), Suppl., Page S149, 1 November 2012 doi:10.1016/j.ijrobp.2012.07.384
© 2012 Published by Elsevier Inc.