Proceedings of the 49th Annual ASTRO Meeting S113

Materials/Methods: Eligible patients were LAPC carriers, defined as clinical stage T2/T3 with Gleason score .7 and/or PSA .10ng/ml; and/or pathologic stage TxN1. All patients underwent hormonal ablation for a total of 9 months which was initiated at least 3months prior to the beginning of RT. Treatment consisted of daily three-dimensional conformal RT with concurrent paclitaxelgiven twice weekly at a dose of 30 mg/m2. Radiation was delivered at 1.8 Gy per fraction and the total dose was escalated as itfollows: 63 Gy, 66.6 Gy, 70.2 Gy, and 73.8 Gy. The latter dose was pre-determined as the last dose level for MTD, since 73.8Gy is the standard dose for hormonally ablated LABC treated with radiation alone. Radiation technique included treatment ofthe whole pelvis to 39.6 Gy using a four field box with a consecutive boost to the prostate and seminal vesicles using a six fieldconformal technique. No intensity modulated RT was used in this trial.

Results: Between January 2000 and October, 2006, 22 patients were enrolled in this IRB-approved combined modality protocol.Median age was 59 (range 48–72) and median PSA was 22.4 (range, 2.8–113). Clinical T-stages were: T1 (n = 3), T2 (n = 8), andT3 (n = 11) Five patients were pN1. One patient received prescribed RT but did not receive the first 2 doses of chemotherapy and isincluded in the analysis. All other patients received the prescribed treatment.

Initially the study was designed to treat whole pelvis followed by the boost to the prostate. The median clinical target volume forthe boost was 70 cc (range, 29–99). No grade 3 toxicities occurred at the first dose level of 63 Gy with concurrent chemotherapy.Grade 1–2 toxicities occurred at each dose level and consisted of diarrhea in 7 (32%) patients and urinary frequency in 7 (32%).

Grade 3 diarrhea was observed in 3 patients at a dose of 66.6 Gy. The protocol was then amended to first treat the prostate boostvolume, followed by treatment of the whole pelvis to 39.6 Gy. With this sequencing, no grade 3 toxicities were observed at the 70.2Gy dose level. One patient experienced grade 3 diarrhea at 73.8 Gy an additional 5 patients were treated to 73.8 Gy without grade 3toxicity, establishing the MTD for combined paclitaxel and RT at 73.8 Gy.

At a median follow up of 27 months (range, 1 to 69 months), 21 of 22 (95%) patients are alive. Six of 22 (27%) have hadrecurrence: one local, three distant, and two biochemical failures without clinical evidence of disease.

Conclusions: Concurrent bi-weekly paclitaxel (30 mg/m2) with RT is feasible and the MTD is 73.8 Gy. Early clinical results arepromising for this subset of patients with a dire prognosis.

Author Disclosure: N.J. Sanfilippo, None; S.S. Taneja, None; A. Chachoua, None; H. Lepor, None; S.C. Formenti, None.

203 Statin use and Clinical Outcomes After High Dose Radiotherapy for Prostate Cancer

A. M. Shippy1, M. S. Katz2, Y. Yamada1, D. J. Feder1, M. J. Zelefsky1

1Memorial Sloan-Kettering Cancer Center, New York, NY, 2Concord Hospital, Concord, NH

Purpose/Objective(s): Laboratory and clinical data suggest that 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, orstatins, may have anticancer activity. We investigated whether the concurrent use of statins with radiation therapy for prostate can-cer had any effect on clinical outcomes, such as biochemical, local, and distant control.

Materials/Methods: We retrospectively studied 871 men with clinical stage T1-3 prostate adenocarcinoma treated between Jan-uary 1995 and July 2000 with radiotherapy to a median dose of 81 Gy (range: 75.6–86.4 Gy). Statin use was evaluated with knowntumor-related and treatment-related predictors of clinical outcomes after radiotherapy. A total of 168 patients (19%) were on a statinat the time of diagnosis, and no patient discontinued its use during radiotherapy. PSA relapse was defined according to the nadir + 2definition. The median follow-up time for this cohort was 85 months after radiotherapy.

Results: The 5 and 10 year PSA relapse free survival for those patients on a statin were 91% and 76%, respectively compared to81% and 66%, respectively, for those not on a statin (p = 0.01). Additionally, there was a trend toward lower incidence of distantmetastases for those men on a statin (p = 0.06). Cox-regression analysis revealed that Gleason score \7 (p \ 0.001–hazard ratio(HR) 2.01), clinical stage T1-T2 (p \ 0.001–HR 2.41), and statin use (p = 0.03–HR 1.58) were associated with improved PSArelapse free survival outcomes following radiotherapy.

Conclusions: Statin use was associated with a significant improvement in PSA relapse-free survival after high dose radiotherapy,and a trend towards reduced distant metastases. Prospective randomized clinical trials are warranted to determine whether statin useoffers any clinical benefit to men undergoing radiation therapy for prostate cancer.

Author Disclosure: A.M. Shippy, None; M.S. Katz, None; Y. Yamada, None; D.J. Feder, None; M.J. Zelefsky, None.

204 A Phase III Randomized Trial to Assess the Efficacy of Intraoperative Steroid Use in Decreasing Acute

Urinary Retention Following Transperineal Radioactive Seed Implantation for Prostate Cancer

M. L. Mierzwa, W. L. Barrett, K. P. Redmond, R. Shirazi, A. Kastl

University of Cincinnati College of Medicine, Cincinnati, OH

Purpose/Objective(s): Prostate brachytherapy is a frequently employed treatment for early to intermediate stage prostate cancer.Acute urinary retention is a known potential complication of brachytherapy with prospective trials estimating 10–15% of patientsrequiring catheterization within 48 hours post-implant. In theory, post-implant edema could be reduced by using intraoperativesteroids. We conducted a prospective single institution trial randomizing patients to a single intraoperative dose of dexamethasoneversus no steroid use.

Materials/Methods: 204 patients who received I-125 interstitial brachytherapy alone as definitive treatment for low to interme-diate risk prostate cancer were randomized to receive either dexamethasone 6 mg IV in a single intraoperative dose (arm A) or nosteroids (arm B). 196 patients were evaluable. All patients completed the International Prostate Symptom Score (IPSS) prior totreatment. Patients were contacted by phone 72–96 hours after treatment, and acute urinary toxicities were reported accordingto the Common Toxicity Criteria (CTC) version 2.0. All patients received tamsulosin 0.4 mg daily on the operative day and firstpost-operative day.

Results: Between 2003–2005, 99 patients were randomized to arm A, and 97 patients to arm B at the University of Cincinnati andthe Cincinnati VA Hospital. Treatment arms were balanced with respect to pretreatment characteristics. Pretreatment clinical stages