292 poster Can we accrue to “difficult” trials in brachytherapy?

292 poster Can we accrue to “difficult” trials in brachytherapy?

$126 symptoms. Only 13.8% had a grade 3 & 4 acute GU symptoms. 15% of our patients suffered of acute urinary retention, being mainly in the acute pos...

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$126

symptoms. Only 13.8% had a grade 3 & 4 acute GU symptoms. 15% of our patients suffered of acute urinary retention, being mainly in the acute post-implant phase. All were treated successfully and are being catheter free. Late grade 3 & 4 GU symptoms affected only 1.9% of our population. Regarding GI symptoms, 91.9 % of our population showed to be symptom free in the acute phase, 7.1% had grade 1 and 0.8% had grade 2 GI symptoms. Elapse time reduce GI symptoms, 95.9% of the patients being symptoms free and 4.1% had residual grade 1 at 6 months post implantation. Conclusion: Inverse planning and high activity seeds (average of 60 seeds/patient) gives a 5 year PSA failure free survival comparable with the best published series with a low toxicity profile for patients with localized prostate cancer treated with I 125 permanent prostate implant. 292 poster Can we accrue to "difficult" trials in brachytherapy?

J. Crook ~, K. Wallace 1, N. Fleshnef , M. Jewetl2 IPrincess Margaret Hospital, Radiation Oncology, Toronto, Canada 2University Health Network, Urology, Toronto, Canada Purpose: In order to improve accrual to difficult randomized trials, innovative methods are required. Trials comparing brachytherapy to another treatment option (surgery or external radiation) may not seem equivalent in a patient's mind. SPIRIT (ACOSOG Z0070* NCIC PR10: radical prostatectomy vs. brachytherapy for favourable risk prostate cancer) is a good example of such a trial. We describe the results of a program of educating patients and their families about early stage, favourable prostate cancer and their treatment options and the impact of these sessions on trial accrual. Materials and Methods: We developed a 90 minute education session for SPIRIT candidates and their families. All new prostate referrals are screened by the Clinical Research Associate (CRA) using SPIRIT criteria and eligible patients are contacted prior to their first consult at the multidisciplinary urooncology clinic and invited to a small group educational session which is held weekly. This session, facilitated by the clinical research associate (CRA), begins with the SPIRIT informed consent video followed by presentation from a patient and SPIRIT participant who describes his decision-making process. A radiation oncologist and urologist then jointly compare and contrast RP and BT and establish the rationale and purpose behind the trial. Emphasis is placed upon the clinical equipoise that exists between these modalities by the radiation oncologist and urologist. Trial-specific, but not patient-specific, questions are answered. Consult appointments are verified, patients are given a SPIRIT brochure, and CRA contact information. Results: Prior to initiating this approach, 27 eligible patients over a 3 month period were offered SPIRIT in the standard fashion by the urologist or radiation oncologist and none consented. After commencing the educational intervention, 198 patients have attended a session and 32 have consented to the trial (chi square=3.863, p<0.05). Consent rates since the launch of the evening sessions now approach 1 in 6. Conclusion: These data support the efficacy of a novel approach using a small group educational session in improving accrual to SPIRIT. They also confirm that obtaining informed consent for challenging trials involving brachytherapy is feasible. Sites open to SPIRIT but having difficulty with accrual, or new sites taking on the trial, may want to consider this method.

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293 poster 1125 re-implantation in patients with poor initial dosimetry after prostate brachytherapy

M. Keyes ~, T. Pickles ~, A. Agranovich 2, W. Kwan2, J. Morris 1 ~BC Cancer Agency, Vancouver Cancer Centre, Radiation Oncology, Vancouver BC, Canada 2BC Cancer Agency, Fraser Valley Cancer Centre, Radiation Oncology, Surrey BC, Canada Purpose: To present dosimetric and clinical parameters on 9 patients with suboptimal dosimetry after 1-125 prostate brachytherapy, who underwent a second re-implant procedure in order to improve dosimetric coverage of the prostate. Material and methods: Between July 1998 and January 2004, 1050 patients were implanted at Vancouver Cancer Centre. Low risk patients (GS< 6; PSA_< 10 and < T2a) received implant alone. Patients with prostate volume >50cc, GS 7, or PSA 1015, received 3 months of neoadjuvant hormones, brachytherapy and 3 months of adjuvant hormones. Mean V100 and D90 for entire group is 91.2% and 151 Gy. Nine pts (0.85%) have undergone a second re-implant procedure to improve dosimetric coverage of the prostate. Results: Median FU of re-implanted pts is 6 months (range 224). The pre-treatment characteristics: clinical stage, Gleason Score, iPSA, location of positive cores, IPSS, potency, use of androgen suppression, are described. Median time to reimplant is 64 days (range 54-110). Initial implant median V100 and D90 (Day 30 CT- based post implant dosimetry) are 74% (range 59-82%)and 110Gy (70-122Gy). Re-implant median V100 and D90 (Day 0 CT based post implant dosimetry) are 96% (range 90-99%) and 168Gy (range 144196Gy). Median rectal volumes receiving 100% of the dose (VR100) for the initial vs. re-implant are 1.03 vs. 1.7 cc. Short term PSA outcome is favourable, median PSA post treatment is 0.19 (range 0.17-0.62). Re-implanted patients had transient increase in IPSS scores and acute grade 2 urinary toxicity. One pt had transient worsening of the mild rectal symptoms. The acute toxicity of the re-implant procedure has been reasonably low. We describe our re-implant planning and intra-operative procedure. Conclusion: It is possible to safely add more seeds to the dosimetricaly cool area after the initial brachytherapy procedure and achieve excellent post-implant dosimetry with acceptable acute toxicity the second time around. So far, the available data on dose response in prostate brachytherapy may justify this approach. The ultimate benefits and long term toxicity of reimplantation is unknown. 294 poster CT, MRI, and CT-MRI image fusion assessment for prostate 1-125 post implant dosimetry

B. AI-Qaisieh 1, B. Carey2, J. Evans3, A. Flynn ~, D. Bottomley 4, D. Ash" ~Cookridge Hospital, Medical physics, Leeds, United Kingdom 2Cookridge Hospital, Radiology, Leeds, United Kingdom 3Cookridge Hospital, University of Leeds, Leeds, United Kingdom 4Cookridge Hospital, Radiation Oncology, Leeds, United Kingdom Purpose: (1) To validate the use of CT and MRI for post implant dosimetry (2) To quantify the uncertainty in outlining the prostate and the precision of identifying seeds on CT and MRI. Methods and materials: Sixty two patients had CT and MRI scans 53 days (average) after the implant procedure. Two experienced observers were each asked to contour the prostate margins on six patients six times at weekly intervals. To