after seed implantation and was continued for 1 year. The changes in the ... treatment for preventing radiation-induced acute urinary symptoms. Moreover ...
Abstracts / Brachytherapy 13 (2014) S15eS126 patients undergoing iodine-125 prostate brachytherapy. The patients were randomly grouped and received either tamsulosin or silodosin. The therapeutic dosages of tamusulosin and silodosin administered to the patients were 0.2 mg/day and 8 mg/day, respectively. This study included 70 patients between June 2006 and November 2011: 34 and 36 patients in the tamsulosin and silodosin groups, respectively. No significant differences in the pretreatment variables of the 70 patients were observed between both the groups. The a1 -blocker treatment was initiated 1 day after seed implantation and was continued for 1 year. The changes in the total International Prostate Symptom Score (IPSS), Quality of Life (QOL) index score, uroflowmetry (UFM) results, and residual urine (RU) values were estimated during the study (1, 3, 6, and 12 months). Results: The median total IPSS at 1 month after prostate brachytherapy in the tamsulosin and silodosin groups were 17.6 and 18.9, respectively. Significant increases in IPSS within the 2 groups were observed at 1-3 months following prostate brachytherapy. Moreover, IPSS improved at 6 months and recovered to baseline at 12 months. No significant differences were observed in the changes of total IPSS, QOL index score, Qmax, and RU values in both the groups. Conclusions: Thus, this study indicates that a1 -blockers are a potential treatment for preventing radiation-induced acute urinary symptoms. Moreover, tamsulosin and silodosin may have an almost similar effect in patients with radiation-induced urinary toxicity.
PO78 Is It Necessary to Perform Post-Implant Dosimetric Analysis in LowDose-Rate Brachytherapy for Prostate Cancer? A Quality Assurance Assessment Talha Shaikh, MD, Karen Ruth, MS, Nicholas G. Zaorsky, MD, David Y. Chen, MD, Richard E. Greenberg, MD, Jinsheng Li, PhD, Kevin Crawford, BS, Eric M. Horwitz, MD. Fox Chase Cancer Center, Philadelphia, PA. Purpose: To determine if computerized tomography (CT)/magnetic resonance imaging (MRI)-based day 0 (d0) dosimetry is a meaningful predictor of d21 dosimetry in low-dose-rate brachytherapy (LDR-BT) for localized prostate cancer (PCa). Materials and Methods: We performed a retrospective analysis of men with localized (T1-2 N0 M0/X), low/intermediate-risk prostate cancer treated with LDR-BT for PCa from 2003-2012 at a National Cancer Institute-designated cancer center. All men underwent an intra-operative transrectal ultrasound to generate a real-time LDR-BT plan with customized needle positions and seed-spacer sequences. The primary dose (D) constraint was O 145 Gy prescribed to 90% of the prostate volume (D90 O 145 Gy); a secondary constraint was that the volume (V) of the prostate receive O 90% of the prescription dose (V100 O 90%). CT/MRIfusion was used for post-implant dosimetry at d0 and d21. Paired t-tests were used to compare change in D or V at the time points. Logistic regression was used to construct receiver operating characteristic (ROC) curves for achieving each constraint at d21, based on d0 D90 and V100 as continuous variables. Youden’s index was used to determine D and V cut-points which maximized equally weighted sensitivity and specificity. Results: Two hundred seventy eight men were evaluated. In assessment of dose prescriptions, from d0 to d21, mean D90 increased from 133 to 150 Gy, and mean V100 increased from 85% to 91%. For patients who met the D90 O 145 Gy constraint at d0, 90% maintained this constraint at d21; of those below the D90 constraint at d0, 46% had an increase to D90 O 145 Gy at d21. Similarly, for patients who met the V100 O 90% at d0, 83% maintained this level at d21; of those below the V100 constraint at d0, 47% had an increase to V100 O 90% at d21. The optimal cut-point for d0 D90 was 135 Gy with 84% of these patients maintaining a d21 D90 O 145 Gy. For d0 V100, the optimal cut-point was 87%, with 83% of these patients maintaining a d21 V100 O 90%. Conclusions: Meeting dosimetric constraints on d0 does not obviate d21 dosimetric analysis in men receiving LDR-BT for PCa. Constraints used for dose prescriptions on d0 are not ideal predictors of d21 dosimetry.
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PO79 What Does a PSA Bounce Look Like? A Numerical and Graphical Description of the Bounce Phenomenon in 592 Patients Treated with I-125 Prostate Brachytherapy Daniel R. Zwahlen, MD, MBA1, Philipp Boutellier, Medical Student2, Kaspar Rufibach, PhD3, Leonhard Held, PhD2, Jeremy L. Millar, MBChB, FRANZCR4. 1Radiation Oncology, Kantonsspital Graubuenden, Chur, Switzerland; 2Institute for Social and Preventive Medicine, Division of Biostatistics, University of Zurich, Zurich, Switzerland; 3F. Hoffmann-La Roche AG, Basel, Switzerland; 4The Alfred, The William Buckland Radiotherapy Centre, Monash University, Melbourne, Australia. Purpose: To describe the prostate-specific antigen (PSA) bounce phenomenon graphically and numerically in patients with low-risk prostate cancer treated with iodine-125 seed brachytherapy (BT). To identify common graphical patterns of PSA bounces and analyze predictability for biochemical (BF) or clinical failure (CF). Materials and Methods: Dataset consisted of 704 men treated with BT between 12/1998 and 6/2010. No minimal followup time was required. A PSA-bounce was defined as increase $ 0.2 ng/mL above initial nadir followed by a spontaneous return to or below initial nadir. BF was defined using the Phoenix definition (nadir þ2 ng/mL). Results: 592 patients were eligible for analysis. 217 patients presented with a PSA bounce. Of these, 177 patients had one bounce and 40 had multiple bounces. The key median bounce characteristics were magnitude of 0.5 ng/ ml (0.2-8.8), duration of 18.5 months (4.6-68.9) and time to onset from BT of 15.7 months (5.5-72.0) for all 217 first bounces and 0.4 ng/mL (0.2-10.6), 17.5 months (4.7-68.8) and 19.0 months (5.5-74.9, p ! 0.0001) for all 47 multiple bounces. Assessing patients with bounces exceeding threshold for BF (28 patients) and comparing them to patients with BF at the end of followup (23 patients) or CF (10 patients), time to BF from BT (medians 18.7, 37.1 and 41.1 months, respectively), time to BF from nadir (medians 10.1, 24.1 and 24.8 months, respectively) and PSA velocity from nadir to date of BF (medians 0.26, 0.12 and 0.20 ng/mL/month, respectively) were found to be significantly different (p 5 0.0028, p 5 0.0009 and p 5 0.0029, respectively). Conclusions: The PSA bounce phenomenon presented a considerable variety when illustrated graphically. This variety might be caused by multifactorial origin of bounces. A graphical approach did not seem to help in the case of a rising PSA level after BT to discriminate a benign bounce from recurrent disease. Time to BF from BT accounted for the most reliable difference between a bounce exceeding the threshold for BF and a PSA rise ending in BF or CF.
PO80 Interstitial Prostate Brachytherapy Outcomes (1992-2002): Sexual Function Following Molecular Image-Guided Therapy Shree Agrawal, BS1, Deborah A. Kaminsky, RPh1, Bryan J. Traughber, MD1, Tarun K. Podder, PhD1, Robert Abouassaly, MD2, Lee Ponsky, MD2,
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Valdir Colussi, PhD , Robert Vinkler, RTT , April Deters, RTT1, Mitchell Machtay, MD1, Rodney J. Ellis, MD1. 1Radiation Oncology, University Hospitals Seidman Cancer Center, Cleveland, OH; 2Urology, University Hospitals Case Medical Center, Cleveland, OH. Purpose: To evaluate sexual health outcomes following interstitial brachytherapy seed implant with and without external beam radiation therapy (EBRT) in sexually active men treated for localized prostate cancer using molecular image-guided radiation therapy. Materials and Methods: We retrospectively reviewed prostate brachytherapy patients treated from 12/1999 to 12/2002 at a single institution by a single treating physician (RJE). The current study represents subset analysis of previously published 10-year actuarial prospective outcomes in 239 consecutive patients treated by prostate seed implant (PSI) with or without EBRT using molecular image guided treatment planning. PSI prescription doses were either 145/110 Gy (Iodine-125) or 125/100 Gy (Palladium-103) for PSI-alone/(PSIþEBRT). A typical peripheral loading treatment technique was used, with dose escalation to regions of the prostate identified as having focal uptake of Indium-111 labeled prostate specific membrane antigen (capromab pendetide) on SPECT/CT scans. Dose escalation (more than 150% of prescribed dose) was achieved by placing additional seeds during PSI. Minimal margins were contoured at prostate regions showing no involvement on SPECT/CT (e.g. uninvolved tissue surrounding the neurovascular bundles). In patients receiving neoadjuvant hormone ablation therapy, treatment began prior to PSI (typical range 1-6 months). We now analyze late toxicity outcomes for patients having completed sexual health inventory for men (SHIM) questionnaires at baseline (limited to only those reporting to be sexually active pretreatment) and having late post treatment SHIM followup. Retrospective data collection was performed by electronic and/or paper chart review with IRB approval. We classified erectile dysfunction (ED) by SHIM range: SHIM #7 (Severe ED), SHIM 9-21 (Moderate to Mild ED) versus SHIMO21 (No ED). Results: We identified 40 patients (16.7%) from the larger series with SHIM reported at baseline and having late followup, with median followup of 52.2 months (range 35.5-150.5). Presenting characteristics for this subset analysis included clinical stage (T1c-T3a, Nx, M0); PSA $10 (n55, 12.5%) and !10 (n535, 87.5%); Gleason sum #6 (n524, 60%), 7 (n515, 37.5%) and $8 (n51, 2.5%); median age 62.1 years (range 41.575.1); National Comprehensive Care NetworkÒ risk category low(n520, 50%), intermediate- (n515, 37.5%) and high-risk (n55 12.5%) group stratification. Twenty-five patients were treated by PSI-alone and 15 with PSIþEBRT. The number (n, %) patients reporting SHIM symptoms before therapy at baseline by SHIM category were: Severe ED (1, 2.5%), Moderate to Mild ED (4, 10%) versus No ED (35, 87.5%). For the 35 patients reporting No ED at baseline, 12 (34.3%) went on to report Severe ED, 12 (34.3%) Moderate to Mild ED and 11 (31.4%) reported No ED at last SHIM followup. For the 4 patients reporting Moderate to Mild ED at baseline, 2 reported Severe ED, 1 Mild to Moderate ED and 1 No ED at the time of last followup. There was no change in SHIM score for the single patient reporting Severe ED pretreatment. Older age at last SHIM report was found directly related to the incidence of ED symptoms. Conclusions: Late toxicity assessment found that sexual function was maintained in a third of patients reporting no erectile dysfunction prior to radiation therapy for primary treatment of localized prostate cancer using advanced imaging to plan treatment. Molecular image guided dose escalation may be useful in conformal therapies for men seeking to minimize treatment related morbidity and preserve sexual function. Additional studies are warranted to further evaluate the use of functional imaging in prostate cancer management.
PO81 Combining Multi-Modality Imaging and Transperineal Mapping Biopsy to Guide the Focal Application of Low-Dose-Rate Brachytherapy for Prostate Cancer: An Ethics Approved Pilot Study S. Sara Mahdavi, PhD1, W. James Morris, FRCPC1, Septimiu E. Salcudean, PhD2, Silvia D. Chang, MD3, Piotr Kozlowski, PhD2, Ingrid T.
Spadinger, PhD1. 1BCCA - Vancouver Center, Vancouver, BC, Canada; 2 University of British Columbia, Vancouver, BC, Canada; 3Vancouver General Hospital, Vancouver, BC, Canada. Purpose: Whole-gland treatment for prostate cancer, be it radical prostatectomy or radiation therapy, adversely affects quality of life, particularly in the sexual and urinary-function domains. The only accepted alternative for favorable risk cancers is active surveillance (AS). However, an evidence-based consensus defining disease progression and the need for timely radical therapy is lacking. Other drawbacks of AS include the infection risk associated with multiple trans-rectal biopsies and the psychological stress an untreated cancer may provoke, given the unpredictable nature of the disease. Recent technical advances have stimulated research into focal therapy (FT), a potential third alternative for appropriately selected patients. However, the widespread adoption of FT is held back by two major limitations: Firstly, standard trans-rectal biopsy is unsuitable for directing focal therapy due to suboptimal sampling and a lack of precision guidance. Secondly, due to substantial sparing of healthy prostate tissue, post-treatment PSA values are no longer reliable for validating treatment efficacy. This work is aimed at overcoming the first of these limitations with the ultimate goal of establishing FT based on low-dose-rate brachytherapy (LDRB) as an option for selected men with favorable risk disease. In this pilot study we plan to: 1) explore the correlations between prostate cancer, as mapped by TTMB (see below), and multi-modal imaging. 2) determine if FT has less impact on QOL than whole-gland LDRB. Materials and Methods: Eligibility criteria at entry include Gleason score #3þ4 in any one core, #2 cores positive from one lobe, clinical stage #T2a, and iPSA #10ng/mL. Consented participants initially undergo imaging including C11-Choline PET/CT, a 3-Tesla, multiparametric (mp) MRI (T2W, DWI, DCE), MR elastography (MRE), and trans-rectal ultrasound elastography (TRUS-E). After imaging, a transperineal template mapping biopsy (TTMB) is performed with the subject under general or spinal anaesthesia. TTMB combines a custom template with TRUS image guidance. The pitch of TTMB cores is specified to allow the creation of a 3D cancer map with a probability of !0.05 of missing a tumor of $8 mm across (assuming a spherical shape). Subjects in which TTMB yields #4 positive cores (each with GS #3þ4) within a single lobe and spanning not more than two adjacent sectors (apex, mid-gland and base), will be offered FT in addition to the option of continuing on AS or selecting one of the conventional radical treatments. For patients electing FT, the planning target volume (PTV) is considered as the location of every positive core with a radius equal to the biopsy pitch and the height determined by the prevalence of cancer throughout the core, to which a 5mm margin is
Figure 1. Schematic of the focal LDR brachytherapy procedure. Upon eligibility the patient proceeds to multi-parametric MRI (mpMRI), MR elastography (MRE) and PET/CT. If eligible, in one session, trans-rectal ultrasound (TRUS), TRUS elastography (TRUS-E) and transperineal 3D template guided pathological mapping biopsy (TTMB) will be performed. If focal therapy is chosen, a treatment plan will be created based on TTMB results and after treatment, follow-up will proceed as indicated.
