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Salvage Low-Dose-Rate 125Iodine Partial Prostate Brachytherapy after Dose-Escalated External Beam Radiotherapy
Abstracts / Brachytherapy 13 (2014) S15eS126 types, seed strength did not influence the relative rectal dose changes with rectal separation in the source strength ranges studied (two tailed probability p50.23). Conclusions: Irrespective of the seed type, reduction in rectal separation is associated with increase in rectal dose. Changes in rectal separations in the 2 to 6mm range due to edema resolution or seed displacement will result in higher magnitude of rectal dose changes from planned for Pd-103 seed implants compared to I-125 or Cs-131 seed types, due to higher radial dose function of Pd-103 seed. Clinically, the potential for larger variation in planned rectal dose with prostatic edema resolution should be considered while implanting Pd-103 seeds in the close proximity of rectum.
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Although there was no bF in the 5-ARI group compared to 3.8% in the control group, this was not statistically significant (p50.37 Fisher’s Exact Test and p50.30 Log Rank test). This could be due to a significantly longer (p5!0.001) followup in the control group (mean 46.8 vs. 33.4 months). The last PSA in patients without any bF between both groups was not significantly different (p50.83, mean 0.32 vs. 0.28 ng/mL) but the time to nadir was much shorter (p!0.001) for patients in the 5-ARI group (mean 25.4 months SD14.2 vs. 40.4 months SD 17.5). In the 5-ARI group there was a trend (p50.084) towards less PSA bounces (18.4% vs. 31.8%, RR50.48, 95% CI 0.223-1.047). IPSS within the first year between the two groups were not different (p50.5-0.9). Conclusions: Our data suggest that short-term 5-ARI use potentiates the effect of PB. The PSA bounce rate has nearly halved and there was a shorter time to PSA nadir and so far no recurrence has occurred in patients with a 5-ARI. Urinary symptoms were not different within the first year.
PO61 Salvage Low-Dose-Rate 125Iodine Partial Prostate Brachytherapy after Dose-Escalated External Beam Radiotherapy Lynn Chang, MD1, Mark K. Buyyounouski, MD2. 1Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA; 2Radiation Oncology, Stanford University, Stanford, CA.
Figure 1. Rectal Dose vs. Rectal Separation: A Dosimetric Study from a Single I-125. Cs-131 and Pd-103 Seed.
PO60 5-Alpha-Reductase Inhibitors in Combination with Permanent Seed Prostate Brachytherapy Daniel Taussky, MD1, Vimal Krishnan, MSc2, Guila Delouya, MD1. 1 Radiation Oncology, University of Montreal, Montreal, QC, Canada; 2 University of Montreal, Montreal, QC, Canada. Purpose: A combination of permanent seed brachytherapy (PB) with 5alpha-reductase inhibitors (5-ARI) has the potential benefit of increasing the efficacy of radiation through its antiandrogen effect. We investigated the effect of a combination of 5-ARI and PB on biochemical control and urinary symptoms post-PB. Materials and Methods: We identified 49 patients from our database of 850 patients treated with at least 1 month of 5-ARI before PB with I125 between 2005 - 2011 and with a minimum followup of 2 years. Median time (range) of a 5-ARI before PB was 3 months (1-12) and median treatment duration after PB was 1 months (1-7). All patients had either low risk or low-tier intermediate risk prostate cancer. A 5-ARI was most commonly prescribed because of either the waiting period for PB was judged too long by the patient or physician, to reduce prostate volume for an easier implant or for urinary symptoms pre-PB. Patients were seen 1 month after PB and if urinary symptoms were judged as reasonable, the 5-ARI was stopped at that time. Patients taking a 5-ARI were compared to 236 patients randomly chosen amongst those who did not receive any 5-ARI. IPS scores and biochemical control data was collected at 1-4-months intervals for the first year. Biochemical failure (bF) was defined as nadir þ2. Both groups were compared using T-test or Fisher’s Exact Test. Results: Pre-treatment PSA was significantly lower (p50.017) in the 5-ARI group (mean55.1ng/mL) than in the control group (6.1ng/mL). Prostate volume at the time of PB was similar (38.9 cc for 5-ARI vs. 37.5 cc, p50.43) as well as the IPSS baseline score (4.45 vs. 4.53, p50.91).
Purpose: To report outcomes on 5 patients treated with salvage partial lowdose-rate (LDR) 125iodine (125I) permanent prostate seed brachytherapy (BT) for biopsy proven locally persistent prostate cancer following failure of dose-escalated external beam radiotherapy (EBRT). Materials and Methods: A retrospective review of the Fox Chase Cancer Center prostate cancer database identified five patients treated with salvage partial LDR 125I seed implant for locally persistent disease following doseescalated EBRT. All patients had post-EBRT biopsies confirming unilateral locally persistent prostate cancer. Pre-treatment, EBRT and BT details and post-treatment characteristics were documented and assessed. Results: The median followup post-implant was 41 months. All five patients exhibited low acute genitourinary and gastrointestinal toxicities. Increased erectile dysfunction was noted in three patients. There were no biochemical failures following salvage LDR 125I seed BT to date, with a median post-salvage PSA of 0.4 ng/mL. Conclusions: In carefully selected patients with local persistence of disease, partial LDR 125I permanent prostate seed implant appears to be a feasible option for salvage local therapy with an acceptable toxicity profile. Further study is needed to determine long-term results of this approach.
PO62 Toxicity Associated with High-Dose-Rate Monotherapy for Prostate Cancer Robyn Banerjee, MD1, D. Jeffrey Demanes, MD2, Sang-June Park, PhD2, Sherif Gamal, MSc3, Alexander Rodgers, BSc4, Julia M. Fallon, BSc2, Mitchell Kamrava, MD2. 1Oncology, University of Calgary, Calgary, AB, Canada; 2Radiation Oncology, University of California Los Angeles, Los Angeles, CA; 3Clinical Oncology and Nuclear Medicine, Mansoura University Hospital, Mansoura, Egypt; 4University of California Los Angeles, Los Angeles, CA. Purpose: High-dose-rate (HDR) monotherapy is associated with favorable outcomes and low toxicity for the treatment of favorable risk group prostate cancer. Given multiple treatment choices associated with excellent disease control, comparing adverse effects is key to patient and physician decision making. Detailed HDR toxicity analyses, however, are few. In this study we prospectively assessed toxicities in a recent cohort of HDR monotherapy patients using several validated symptom scoring instruments. Materials and Methods: Toxicity analysis was carried out on 52 consecutive patients treated between March 2010 and February 2012. HDR monotherapy was delivered in two separate implants, 1 week apart,
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Although there was no bF in the 5-ARI group compared to 3.8% in the control group, this was not statistically significant (p50.37 Fisher’s Exact Test and p50.30 Log Rank test). This could be due to a significantly longer (p5!0.001) followup in the control group (mean 46.8 vs. 33.4 months). The last PSA in patients without any bF between both groups was not significantly different (p50.83, mean 0.32 vs. 0.28 ng/mL) but the time to nadir was much shorter (p!0.001) for patients in the 5-ARI group (mean 25.4 months SD14.2 vs. 40.4 months SD 17.5). In the 5-ARI group there was a trend (p50.084) towards less PSA bounces (18.4% vs. 31.8%, RR50.48, 95% CI 0.223-1.047). IPSS within the first year between the two groups were not different (p50.5-0.9). Conclusions: Our data suggest that short-term 5-ARI use potentiates the effect of PB. The PSA bounce rate has nearly halved and there was a shorter time to PSA nadir and so far no recurrence has occurred in patients with a 5-ARI. Urinary symptoms were not different within the first year.
PO61 Salvage Low-Dose-Rate 125Iodine Partial Prostate Brachytherapy after Dose-Escalated External Beam Radiotherapy Lynn Chang, MD1, Mark K. Buyyounouski, MD2. 1Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA; 2Radiation Oncology, Stanford University, Stanford, CA.
Figure 1. Rectal Dose vs. Rectal Separation: A Dosimetric Study from a Single I-125. Cs-131 and Pd-103 Seed.
PO60 5-Alpha-Reductase Inhibitors in Combination with Permanent Seed Prostate Brachytherapy Daniel Taussky, MD1, Vimal Krishnan, MSc2, Guila Delouya, MD1. 1 Radiation Oncology, University of Montreal, Montreal, QC, Canada; 2 University of Montreal, Montreal, QC, Canada. Purpose: A combination of permanent seed brachytherapy (PB) with 5alpha-reductase inhibitors (5-ARI) has the potential benefit of increasing the efficacy of radiation through its antiandrogen effect. We investigated the effect of a combination of 5-ARI and PB on biochemical control and urinary symptoms post-PB. Materials and Methods: We identified 49 patients from our database of 850 patients treated with at least 1 month of 5-ARI before PB with I125 between 2005 - 2011 and with a minimum followup of 2 years. Median time (range) of a 5-ARI before PB was 3 months (1-12) and median treatment duration after PB was 1 months (1-7). All patients had either low risk or low-tier intermediate risk prostate cancer. A 5-ARI was most commonly prescribed because of either the waiting period for PB was judged too long by the patient or physician, to reduce prostate volume for an easier implant or for urinary symptoms pre-PB. Patients were seen 1 month after PB and if urinary symptoms were judged as reasonable, the 5-ARI was stopped at that time. Patients taking a 5-ARI were compared to 236 patients randomly chosen amongst those who did not receive any 5-ARI. IPS scores and biochemical control data was collected at 1-4-months intervals for the first year. Biochemical failure (bF) was defined as nadir þ2. Both groups were compared using T-test or Fisher’s Exact Test. Results: Pre-treatment PSA was significantly lower (p50.017) in the 5-ARI group (mean55.1ng/mL) than in the control group (6.1ng/mL). Prostate volume at the time of PB was similar (38.9 cc for 5-ARI vs. 37.5 cc, p50.43) as well as the IPSS baseline score (4.45 vs. 4.53, p50.91).
Purpose: To report outcomes on 5 patients treated with salvage partial lowdose-rate (LDR) 125iodine (125I) permanent prostate seed brachytherapy (BT) for biopsy proven locally persistent prostate cancer following failure of dose-escalated external beam radiotherapy (EBRT). Materials and Methods: A retrospective review of the Fox Chase Cancer Center prostate cancer database identified five patients treated with salvage partial LDR 125I seed implant for locally persistent disease following doseescalated EBRT. All patients had post-EBRT biopsies confirming unilateral locally persistent prostate cancer. Pre-treatment, EBRT and BT details and post-treatment characteristics were documented and assessed. Results: The median followup post-implant was 41 months. All five patients exhibited low acute genitourinary and gastrointestinal toxicities. Increased erectile dysfunction was noted in three patients. There were no biochemical failures following salvage LDR 125I seed BT to date, with a median post-salvage PSA of 0.4 ng/mL. Conclusions: In carefully selected patients with local persistence of disease, partial LDR 125I permanent prostate seed implant appears to be a feasible option for salvage local therapy with an acceptable toxicity profile. Further study is needed to determine long-term results of this approach.
PO62 Toxicity Associated with High-Dose-Rate Monotherapy for Prostate Cancer Robyn Banerjee, MD1, D. Jeffrey Demanes, MD2, Sang-June Park, PhD2, Sherif Gamal, MSc3, Alexander Rodgers, BSc4, Julia M. Fallon, BSc2, Mitchell Kamrava, MD2. 1Oncology, University of Calgary, Calgary, AB, Canada; 2Radiation Oncology, University of California Los Angeles, Los Angeles, CA; 3Clinical Oncology and Nuclear Medicine, Mansoura University Hospital, Mansoura, Egypt; 4University of California Los Angeles, Los Angeles, CA. Purpose: High-dose-rate (HDR) monotherapy is associated with favorable outcomes and low toxicity for the treatment of favorable risk group prostate cancer. Given multiple treatment choices associated with excellent disease control, comparing adverse effects is key to patient and physician decision making. Detailed HDR toxicity analyses, however, are few. In this study we prospectively assessed toxicities in a recent cohort of HDR monotherapy patients using several validated symptom scoring instruments. Materials and Methods: Toxicity analysis was carried out on 52 consecutive patients treated between March 2010 and February 2012. HDR monotherapy was delivered in two separate implants, 1 week apart,