S192 I. J. Radiation Oncology d Biology d Physics Volume 78, Number 3, Supplement, 2010

Purpose/Objective(s): To evaluate changes in outcome over time for men with localized prostate cancer treated with definitiveexternal beam radiation therapy (RT) over a 20-year period at a comprehensive cancer center.

Materials/Methods: We categorized 2675 men with localized prostate cancer treated at M.D. Anderson Cancer Center withdefinitive RT with or without androgen-deprivation therapy (AD) into three treatment eras: 1987-1993 (n = 722), 1994-1999(n = 828), and 2000-2007 (n = 1125). To help control for the effects of stage migration over time, patients were stratified accordingto NCCN risk group: 21% had low-risk, 40% had intermediate-risk, and 39% had high-risk disease. Biochemical Failure (BF,Phoenix definition), Local Failure (LF), Distant Failure (DF), Any Clinical Failure (CF), Prostate-Cancer Specific Survival(PCSS), and Overall Survival (OS) were calculated from end of RT and analyzed according to the Kaplan-Meier method.

Results: Median age was 68.5 years and median follow-up was 6.4 years. Significant improvements were seen over time in alloutcomes including BF, LF, DF, CF, PCSS and OS (p \ 0.001). Compared with men in the earliest treatment era, a lower pro-portion of men in the most recent treatment era had high-risk disease (30% vs. 51%) and a higher proportion received $72 Gy(99% vs. 4%) and AD (60% vs. 6%). Stratified by risk group, there were significant improvements in BF (p \ 0.001) and CF(p = 0.041) over time for all risk groups. In high-risk patients, this translated into decreased rates of DF (p = 0.010), and improvedPCSS (p = 0.028) and OS (p = 0.001). Local control was improved for intermediate- and high-risk patients (p\0.001), with a trendtoward improvement in low-risk patients (p = 0.054). Median time from BF to DF and from BF to PCS death was significantlylonger in low-risk patients (6.4 and 9.7 years) than high-risk patients (1.1 and 4.6 years, respectively). On multivariate analysis,high initial PSA (.20 ng/mL), high Gleason score (8-10), and stage T3-4 were predictive of BF, DF, and PCSS (all p values# 0.011). Dose $72 Gy, use of AD, and recent treatment era were closely correlated and predicted for improvement in rates ofBF and LF (all p values # 0.044). AD also predicted for improved PCSS (Adjusted HR 0.61; 95%CI 0.38-0.98, p = 0.039)and OS (Adjusted HR 0.65; 95%CI 0.51-0.83, p \ 0.001).

Conclusions: Over the last 20 years of prostate cancer irradiation, both BF and CF rates decreased in all risk groups, leading toimproved PCSS and OS for the highest-risk patients. These improvements may reflect use of AD, higher RT dose, adoption of PSAtesting, and advances in overall health in recent eras. In view of the long natural history of prostate cancer, additional follow-up isneeded to determine whether these same improvements are realized for patients with low- and intermediate-risk disease.

Author Disclosure: M.M. Kim, None; K.E. Hoffman, None; L.B. Levy, None; P. Master, None; S.J. Frank, None; S. Choi, None;Q.N. Nguyen, None; S.E. Mcguire, None; A.K. Lee, None; D.A. Kuban, Calypso Medical, F. Consultant/Advisory Board.

1116 Final Pathology in Patients Undergoing Radical Prostatectomy: A Correlation Study between Stereotactic

Transperineal Prostate Biopsy and Radical Prostatectomy

D. J. Conterato, M. H. Braccioforte, B. J. Moran

Prostate Cancer Foundation of Chicago, Westmont, IL

Purpose/Objective(s): Biopsy of the prostate is the most influential factor regarding prostate cancer treatment decisions. Stereo-tactic transperineal prostate biopsy (STPB) provides a comprehensive assessment of cancer extent and location due to the largenumber of systematic biopsies. The purpose of this study was to analyze patients who underwent STPB prior to radical prostatec-tomy (RP) and to correlate the pathologic findings between the two procedures.

Materials/Methods: One thousand four hundred fifty-two consecutive patients with continued rising total prostate specific an-tigen (PSA) having had a minimum of 1 (range 1-10) prior benign transrectal extended systematic sextant prostate biopsy(TRPB), underwent STPB at a single out-patient institution between April 2004 and November 2009. Median patient age, totalPSA, prostate volume and number of specimens obtained were 63.11 years, 7.9 ng/mL, 45.1 cm3 and 38 specimens, respec-tively. The prostate was divided into equal octants. Specimens were obtained according to x, y, and z coordinates from theseoctants with pathology reported accordingly. STPB yielded adenocarcinoma in 582/1452 (40%) patients. One hundred three of582 (18%) patients with positive biopsy chose to undergo RP. RP and pathologic review was performed by multiple physiciansat both community and university hospitals. Consent forms and pathologic reports were obtained in 85/103 (82.5%), of patientsand reviewed.

Results: There was a 62/85 (73%) concordance rate between Gleason score reported on STPB and final prostatectomy specimen.Gleason score increased in 13/85 (15%) while downgrading was noted in 10/85 (12%) of patients. Eighteen of 85 (21%) patientshad positive margins. There was a significant association (p = 0.000) between Gleason score and prostatectomy positive pathologicmargins where 3/6 (50%) of patients with Gleason score 8 and 4/5 (90%) of patients with Gleason score 9 had positive margins. In81 of 85 (95%) patients, STPB accurately predicted location of malignancy with prostatectomy specimen.

Conclusions: STPB is efficacious for diagnosis of non-palpable, isoechoic occult prostate malignancy as demonstrated by the highconcordance rate between biopsy and prostatectomy. It may also enhance research efforts regarding targeted therapy within theprostate gland. Furthermore, STPB may result in more reliable diagnosis with less undergrading compared to other biopsy tech-niques. Finally, histologic grade can suggest probability of positive pathologic margin. Considering this group of patients was pre-viously undiagnosed and after RP, 21% were found to have positive margins, TRPB may be inadequate for a subset of patients. Thisinformation may influence the decision making process regarding appropriate treatment options.

Author Disclosure: D.J. Conterato, None; M.H. Braccioforte, None; B.J. Moran, None.

1117 Risk of Hip and Femoral Neck Fractures Following Proton Therapy for Prostate Cancer

J. R. Valery1, B. S. Hoppe1, R. Henderson1, R. C. Nichols1, R. B. Marcus1, W. M. Mendenhall1, J. Costa2, C. Williams2, Z. Li1,

N. P. Mendenhall1

1University of Florida Proton Therapy Institute, Jacksonville, FL, 2University of Florida Shands Hospital, Jacksonville, FL

Purpose/Objective(s): Compared with IMRT, proton therapy (PT) for prostate cancer reduces the dose to the rectum and bladderat the expense of higher doses to the femoral neck. There is concern that this could lead to higher hip-fracture rates. In the presentstudy, we assessed the risk of hip fracture and hip pain in men treated with PT for prostate cancer.