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Radiation Safety of Receptive Anal Intercourse with Prostate Cancer Patients Treated with Low-Dose-Rate Brachytherapy
S48
Abstracts / Brachytherapy 15 (2016) S21eS204 PROSTATE SNAP ORALS (E-POSTER) Tuesday, June 28, 2016 8:00 AM - 9:00 AM
PSOR01 Presentation Time: 8:00 AM Radiation Safety of Receptive Anal Intercourse with Prostate Cancer Patients Treated with Low-DoseRate Brachytherapy Nicola J. Nasser, MD, PhD1, Gil’ad Cohen, MSc2, Lawrence T. Dauer, PhD2, Michael J. Zelefsky, MD2. 1Ziv Medical Center, Safed, Israel; 2 Memorial Sloan Kettering Cancer Center, New York, NY, USA. Purpose: Prostate low-dose-rate (LDR) brachytherapy involves implantation of radioactive seeds permanently into the prostate gland. The International Commission on Radiological Protection (ICRP) provides guidance on radiation precautions based on potential external exposures to members of the public and/or carers for prostate seed brachytherapy. During receptive anal intercourse (RAI) the penis of the partner may come in close proximity to the implanted prostate gland. Here, we estimate the potential intra-rectal dose rates in prostate cancer patients treated with LDR brachytherapy. Materials and Methods: One hundred and two patients were included in the study. At the end of the seed implantation procedure, while the patients under anesthesia in the dorsal lithotomy position a new set of ultrasound (US) images and a CT scan were obtained. The images were fused, radioactive seeds and US probe locations were determined on the CT, and prostate, bladder and rectal contours were drawn on the US for dosimetry. Dose rates (cGy/h) were calculated for the portion of the US probe spanning the prostate for several DVH parameters. Results: Twenty patients were treated with Iodine-125, and 82 patients with Palladium-103. At day 0, maximal and average dose rates per hour to the US probe for patients treated with 125I were 6.74.8cGy/hr and 2.11.3cGy/ hr, and for 103Pd were 10.34.0cGy/hr and 2.50.8cGy/hr, respectively. After 60 days, average calculated probe dose dropped to 1.0 0.6cGy/hr and 0.2 0.1cGy/hr, for 125I and 103Pd, respectively. Conclusions: During the immediate weeks after prostate seed implant, the estimated intra-rectal dose rates are higher in 103Pd compared to 125I. Both would likely exceed equivalent ICRP guidance, after limited RAI time. As 103Pd decays faster than 125I, two months after the implant, radiation exposure from 103Pd becomes lower than 125I. RAI should be avoided for 2 and 6 months after LDR brachytherapy of the prostate with 103Pd and 125I, respectively.
PSOR02 Presentation Time: 8:05 AM Long-Term Quality of Life in Prostate Cancer Patients Treated with Cesium-131 Scott M. Glaser, MD1, Ronald M. Benoit, MD2, Ryan P. Smith, MD1, Sushil Beriwal, MD1. 1Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA; 2Urology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA. Purpose: Prostate brachytherapy (PB) as monotherapy or in combination with external beam radiotherapy (EBRT) represents a curative treatment option for men with prostate cancer. Several radioactive isotopes are approved for use in prostate brachytherapy. Among these, Cesium-131 is the newest to market and has the shortest half-life, a property which gives it dosimetric advantages. Little data exists as to the long-term quality of life (QoL) in patients treated with Cs-131. Materials and Methods: We identified the first 272 patients treated at our institution with Cs-131, all of whom were treated greater than 5 years ago. Patients were treated between September 2006 and October 2010. These patients were asked to fill out an Expanded Prostate Cancer Index Composite (EPIC) QoL questionnaire and American Urological Association Symptom Score (AUASS) survey before treatment and at each of their follow-up appointments. EPIC scores were reported on a normalized scale from 0-100 (with higher score representing better QoL) for the following categories: Urinary Summary (US), Urinary Function (UF), Urinary Bother (UB), Urinary Incontinence (UI), Urinary Irritation/ Obstruction (UIO), Bowel Summary (BS), Bowel Function (BF), and Bowel Bother (BB). AUA scores were reported on a scale of 0-35 (with higher scores representing worse symptomatology). We compared patients’ EPIC and AUA scores at baseline to those at 5-yrs posttreatment. Mean scores were compared using a paired-samples t-test. Clinically significant improvement or worsening in QoL was defined as a change of 10 or more points in EPIC score or 3 or more in AUA score. Results: At 5-yrs of follow-up, 129 patients (47%) had completed both EPIC and AUA questionnaires and one additional patient completed AUA only. Of these 130 patients, median age was 65 (Interquartile range 56171), 28% had EBRT prior to PB, risk groups were: 40% low-risk; 51% intermediate-risk; 9% high-risk, and 18% received hormonal therapy. Baseline mean EPIC scores were as follows: US586.7, UF593.5, UB582.0, UI590.8, UIO585.9, BS591.5, BF592.2, BB590.8. Baseline mean AUA score was 6.9. Average changes in scores at 5-yrs were as follows: US50.30 (p50.78), UF5-1.33 (p50.20), UB51.51 (p50.28), UI5-3.25 (p50.02), UIO51.98 (p50.08), BS5-0.07 (p50.94), BF5-0.26 (p50.77), BB5-0.11 (p50.93), AUA50.18 (p50.72). The percent of patients with a clinically significant worsening of symptomatology were: US518%, UF519%, UB522%, UI524%, UIO514%, BS513%, BF516%, BB517%, AUA530%. The percent of patients with a clinically significant improvement of symptomatology were: US515%, UF514%, UB527%, UI515%, UIO521%, BS516%, BF515%, BB519%, AUA526%. Conclusions: Our results demonstrate minimal long-term urinary or bowel toxicity with Cs-131 prostate brachytherapy. There were no significant longterm differences in EPIC Urinary Summary score, EPIC Bowel Summary score, or AUA symptom score. As population-based means tend to underestimate individual effects, our conclusion is further validated by the small absolute difference in the rates of clinical improvement and worsening (!10% for all variables).
PSOR03 Presentation Time: 8:10 AM Long-Term Outcome of Magnetic Resonance Spectroscopic Image-Directed Dose-Escalation for Prostate Brachytherapy Martin T. King, MD, PhD1, Nicola J. Nasser, MD1, Nitin Mathur, MS1, Gil’ad N. Cohen, MS1, Marisa A. Kollmeier, MD1, Jasper Yuen, MD2, Xin Pei, PhD1, Yoshiya Yamada, MD1, Kristen Zakian, PhD1, Marco Zaider, PhD1,
Abstracts / Brachytherapy 15 (2016) S21eS204 PROSTATE SNAP ORALS (E-POSTER) Tuesday, June 28, 2016 8:00 AM - 9:00 AM
PSOR01 Presentation Time: 8:00 AM Radiation Safety of Receptive Anal Intercourse with Prostate Cancer Patients Treated with Low-DoseRate Brachytherapy Nicola J. Nasser, MD, PhD1, Gil’ad Cohen, MSc2, Lawrence T. Dauer, PhD2, Michael J. Zelefsky, MD2. 1Ziv Medical Center, Safed, Israel; 2 Memorial Sloan Kettering Cancer Center, New York, NY, USA. Purpose: Prostate low-dose-rate (LDR) brachytherapy involves implantation of radioactive seeds permanently into the prostate gland. The International Commission on Radiological Protection (ICRP) provides guidance on radiation precautions based on potential external exposures to members of the public and/or carers for prostate seed brachytherapy. During receptive anal intercourse (RAI) the penis of the partner may come in close proximity to the implanted prostate gland. Here, we estimate the potential intra-rectal dose rates in prostate cancer patients treated with LDR brachytherapy. Materials and Methods: One hundred and two patients were included in the study. At the end of the seed implantation procedure, while the patients under anesthesia in the dorsal lithotomy position a new set of ultrasound (US) images and a CT scan were obtained. The images were fused, radioactive seeds and US probe locations were determined on the CT, and prostate, bladder and rectal contours were drawn on the US for dosimetry. Dose rates (cGy/h) were calculated for the portion of the US probe spanning the prostate for several DVH parameters. Results: Twenty patients were treated with Iodine-125, and 82 patients with Palladium-103. At day 0, maximal and average dose rates per hour to the US probe for patients treated with 125I were 6.74.8cGy/hr and 2.11.3cGy/ hr, and for 103Pd were 10.34.0cGy/hr and 2.50.8cGy/hr, respectively. After 60 days, average calculated probe dose dropped to 1.0 0.6cGy/hr and 0.2 0.1cGy/hr, for 125I and 103Pd, respectively. Conclusions: During the immediate weeks after prostate seed implant, the estimated intra-rectal dose rates are higher in 103Pd compared to 125I. Both would likely exceed equivalent ICRP guidance, after limited RAI time. As 103Pd decays faster than 125I, two months after the implant, radiation exposure from 103Pd becomes lower than 125I. RAI should be avoided for 2 and 6 months after LDR brachytherapy of the prostate with 103Pd and 125I, respectively.
PSOR02 Presentation Time: 8:05 AM Long-Term Quality of Life in Prostate Cancer Patients Treated with Cesium-131 Scott M. Glaser, MD1, Ronald M. Benoit, MD2, Ryan P. Smith, MD1, Sushil Beriwal, MD1. 1Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, PA, USA; 2Urology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA. Purpose: Prostate brachytherapy (PB) as monotherapy or in combination with external beam radiotherapy (EBRT) represents a curative treatment option for men with prostate cancer. Several radioactive isotopes are approved for use in prostate brachytherapy. Among these, Cesium-131 is the newest to market and has the shortest half-life, a property which gives it dosimetric advantages. Little data exists as to the long-term quality of life (QoL) in patients treated with Cs-131. Materials and Methods: We identified the first 272 patients treated at our institution with Cs-131, all of whom were treated greater than 5 years ago. Patients were treated between September 2006 and October 2010. These patients were asked to fill out an Expanded Prostate Cancer Index Composite (EPIC) QoL questionnaire and American Urological Association Symptom Score (AUASS) survey before treatment and at each of their follow-up appointments. EPIC scores were reported on a normalized scale from 0-100 (with higher score representing better QoL) for the following categories: Urinary Summary (US), Urinary Function (UF), Urinary Bother (UB), Urinary Incontinence (UI), Urinary Irritation/ Obstruction (UIO), Bowel Summary (BS), Bowel Function (BF), and Bowel Bother (BB). AUA scores were reported on a scale of 0-35 (with higher scores representing worse symptomatology). We compared patients’ EPIC and AUA scores at baseline to those at 5-yrs posttreatment. Mean scores were compared using a paired-samples t-test. Clinically significant improvement or worsening in QoL was defined as a change of 10 or more points in EPIC score or 3 or more in AUA score. Results: At 5-yrs of follow-up, 129 patients (47%) had completed both EPIC and AUA questionnaires and one additional patient completed AUA only. Of these 130 patients, median age was 65 (Interquartile range 56171), 28% had EBRT prior to PB, risk groups were: 40% low-risk; 51% intermediate-risk; 9% high-risk, and 18% received hormonal therapy. Baseline mean EPIC scores were as follows: US586.7, UF593.5, UB582.0, UI590.8, UIO585.9, BS591.5, BF592.2, BB590.8. Baseline mean AUA score was 6.9. Average changes in scores at 5-yrs were as follows: US50.30 (p50.78), UF5-1.33 (p50.20), UB51.51 (p50.28), UI5-3.25 (p50.02), UIO51.98 (p50.08), BS5-0.07 (p50.94), BF5-0.26 (p50.77), BB5-0.11 (p50.93), AUA50.18 (p50.72). The percent of patients with a clinically significant worsening of symptomatology were: US518%, UF519%, UB522%, UI524%, UIO514%, BS513%, BF516%, BB517%, AUA530%. The percent of patients with a clinically significant improvement of symptomatology were: US515%, UF514%, UB527%, UI515%, UIO521%, BS516%, BF515%, BB519%, AUA526%. Conclusions: Our results demonstrate minimal long-term urinary or bowel toxicity with Cs-131 prostate brachytherapy. There were no significant longterm differences in EPIC Urinary Summary score, EPIC Bowel Summary score, or AUA symptom score. As population-based means tend to underestimate individual effects, our conclusion is further validated by the small absolute difference in the rates of clinical improvement and worsening (!10% for all variables).
PSOR03 Presentation Time: 8:10 AM Long-Term Outcome of Magnetic Resonance Spectroscopic Image-Directed Dose-Escalation for Prostate Brachytherapy Martin T. King, MD, PhD1, Nicola J. Nasser, MD1, Nitin Mathur, MS1, Gil’ad N. Cohen, MS1, Marisa A. Kollmeier, MD1, Jasper Yuen, MD2, Xin Pei, PhD1, Yoshiya Yamada, MD1, Kristen Zakian, PhD1, Marco Zaider, PhD1,