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Cesium-131 prostate brachytherapy: An early experience
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Abstracts / Brachytherapy 6 (2007) 77e118
Purpose: To determine the value of prostatic acid phosphatase on outcomes of patients with prostate cancer treated with external beam radiotherapy followed by brachytherapy boost. Methods and Materials: Between 1992 and 1996, 243 patients with clinically localized prostate cancer and at least one high risk feature of Gleason score >7, prostate specific antigen (PSA) >10 ng/mL, or prostatic acid phosphatase (PAP) O2.5 U/L were treated with external beam radiotherapy (EBRT) followed by brachytherapy boost. Two hundred one patients had a pretreatment serum PAP available. Patients received 41 Gy EBRT to a limited pelvic field followed 4 weeks later by Palladium-103 (Pd-103) brachytherapy boost. The prescribed minimum Pd-103 dose to the prostate was 80e90 Gy. Freedom from biochemical failure (FBF) was defined as a serum PSA <0.2 ng/mL. Cause-specific survival (CSS) was defined as time from diagnosis to death from prostate cancer. Results: Five- and 10-year overall survival rates were 93% and 70%, respectively. CSS at five and ten years was 97% and 84%, respectively. In Cox multivariate regression analysis, considering each factor as a continuous variable, the strongest predictor of biochemical control was PAP (p!0.001) followed by PSA (p 5 0.074) and Gleason score (p 5 0.34). The strongest predictor of CSS was PAP (p!0.001), followed by Gleason score (p 5 0.022) and PSA (p 5 0.27). Conclusions: In patients with high-risk localized prostate cancer treated with EBRT followed by brachytherapy boost, pretreatment serum PAP was the best predictor of cause-specific survival, above PSA and Gleason score and thus may be a more accurate indicator of micrometastatic disease.
OR-6 Presentation Time: 9:50 AM Cesium-131 prostate brachytherapy: An early experience Brian J. Moran, M.D., Michelle H. Braccioforte, B.S. Chicago Prostate Cancer Center, Westmont, IL. Purpose: This study investigates prostate specific antigen (PSA) response and acute side effects of patients undergoing low-dose-rate ultrasound-guided transperineal prostate brachytherapy (PB) with Cesium-131 seeds. Methods and Materials: Between 11/2004 and 11/2006, 104 patients, median age 61.3 years (range 44e77 years), underwent PB using Cesium-131 by a single physician at a single out-patient institution. The prescription dose was 115 Gy. Eligibility criteria were: clinical stage T1ceT2b, Gleason score <7, total PSA <20 ng/mL and prostate volume <60 cm3. PSA tests were performed prior to treatment, in addition to 1 month, 6 months and 1 year post implant. Patients completed International Prostate Symptom Score (IPSS), International Index of Erectile Function (IIEF) and Radiation Therapy Oncology Group (RTOG) toxicity surveys at various time intervals to evaluate urinary, sexual and bowel function, respectively. The IPSS symptom scale ranges from 0 to 35 with lower scores representing better outcomes. The IIEF scale ranges from 0 to 25 with higher scores representing better outcomes. Finally, the RTOG toxicity scale ranges from 0 to 5, with ‘0’ representing no morbidity and ‘5’ characterizing the most severe complications, including death. Results: Median PSA pre-implant, 1 month, 6 months and 1 year post implant were 5.1 4.5 ng/mL, 3.7 2.6 ng/mL, 1.2 0.94 ng/mL and 0.61 0.67 ng/mL, respectively. Median IPSS scores pre-implant, 2 weeks, 1 month, 4 months, 6 months and 1 year post implant were 5.0 5.7, 16 8.4, 17.0 8.4, 7.0 5.6, 7.0 5.7, 5.5 6.0, respectively. Median IIEF scores pre-implant, 1 month and 6 months postimplant were 16.0 7.4, 11.0 8.4 and 16.5 8.3, respectively. Median RTOG gastrointestinal toxicity scores 2 weeks, 1 month, 4 months and 1 year post implant were 1.0 0.68, 0.0 0.64, 0.0 0.35, 0.0 0.23, respectively. No rectal bleeding or long-term urinary retention was reported. Conclusions: PB with Cesium-131 is effective and well-tolerated; both PSA response and the acute morbidity profile are very encouraging. Continued followup of this cohort will define long-term outcomes. IsoRay Medical Inc., manufacturer of Cesium 131 seeds, provided a research grant to complete this study.
BREAST PAPER SESSION Sunday April 29, 2007 1:45 PMe2:30 PM OR-7 Presentation Time: 1:45 PM Stereotactic breast brachytherapy applied peripherally using a compression applicator and HDR Ir-192 Mark J. Rivard, Ph.D.1 Raymond J. Bricault, M.Sc.2 Christopher S. Melhus, M.Sc.1 Jessica R. Hiatt, M.Sc.3 Piran Sioshansi, Ph.D.2 David E. Wazer, M.D.1,3 1Radiation Oncology, Tufts-New England Medical Center, Boston, MA; 2Radiation Physics, Advanced Radiation Therapy, Billerica, MA; 3Radiation Oncology, Rhode Island Hospital, Providence, RI. Purpose: Breast brachytherapy has historically been applied via interstitial or intracavitary application. This approach produces conformal dose distributions through an invasive surgical procedure. By using peripherally positioned brachytherapy applicators to preferentially irradiate the lumpectomy cavity, breast brachytherapy may be applied non-invasively while minimizing critical structure doses to the skin and chest wall. A novel applicator design applies teletherapy-like beam collimation with brachytherapy dose falloff. This study aims to characterize dose rate distributions through application of this surface applicator, and compare these results to current standard-of-care treatment techniques. Methods and Materials: Treatment using the ART applicator positions the breast within two mammography paddles under slight compression to mimic the diagnostic geometry and fix the skin:source separation distance. Applicator diameters ranged from 5e7 cm, and use a W-alloy collimator with a conventional HDR Ir-192 source. Skin separations ranged from 3 to 7 cm. Dose rate distributions and skin dose relative to target dose were assessed using Monte Carlo (MC) methods and experimental techniques (ionization chambers and radiographic film). Using the MCNPv5 geometry package, the breast was modeled as a 16 cm diameter right cylinder with thicknesses of 3e7 cm in 0.5 cm increments. Dose rate was calculated in annular voxels 1 mm thick in 1mm radial increments from 0.1 to 7.9 cm. Measurements were performed in a rectilinear acrylic phantom using a parallel plate ionization chamber to minimize dose gradient volume averaging in the depth direction. Radiographic film was positioned at various depths for direct comparison with the MC dose profile, and to confirm cylindrical symmetry. Results: There was good beam uniformity within the collimated region. Surface and midplane collimation provided a factor of 8 and 5 attenuation, respectively. Ionization chamber measurements and MCderived dose falloff agreed within 2%. Film measurements and MCderived relative dose profiles agreed within 6%. Ratios of skin/target dose ranged from 0.5 to 1.1 over the wide range of applicator sizes and breast separations. For a typical 6 cm diameter applicator and 5 cm separation, the skin/target dose ratio was 0.74 with V50 !50% and CTV DHI 5 1.00. Teletherapy and balloon APBI have DHIs of 0.95 and 0.70, respectively. Conclusions: Compared to the capabilities of other treatment modalities, the dose distributions, CTV DHIs, and normal tissue sparing are superior with this non-invasive approach. The applicator was provided to Tufts-NEMC and RIH for free on a temporary basis to assess its dosimetric and clinical potential.
OR-8 Presentation Time: 1:54 PM Dosimetric comparison of three radiation sources used in balloon-based breast brachytherapy John J. Munro, Ph.D.1 David C. Medich, Ph.D.2 1SPECMed LLC, St. Rose, LA; 2Radiation Laboratory, Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA. Purpose: We report a dosimetric comparison of three radiation sources used for balloon-based accelerated partial breast irradiation: 192Iridium (SPECMed M19), 169Ytterbium (SPECMed M46), and X-ray (Xoft S700 Axxent).
Abstracts / Brachytherapy 6 (2007) 77e118
Purpose: To determine the value of prostatic acid phosphatase on outcomes of patients with prostate cancer treated with external beam radiotherapy followed by brachytherapy boost. Methods and Materials: Between 1992 and 1996, 243 patients with clinically localized prostate cancer and at least one high risk feature of Gleason score >7, prostate specific antigen (PSA) >10 ng/mL, or prostatic acid phosphatase (PAP) O2.5 U/L were treated with external beam radiotherapy (EBRT) followed by brachytherapy boost. Two hundred one patients had a pretreatment serum PAP available. Patients received 41 Gy EBRT to a limited pelvic field followed 4 weeks later by Palladium-103 (Pd-103) brachytherapy boost. The prescribed minimum Pd-103 dose to the prostate was 80e90 Gy. Freedom from biochemical failure (FBF) was defined as a serum PSA <0.2 ng/mL. Cause-specific survival (CSS) was defined as time from diagnosis to death from prostate cancer. Results: Five- and 10-year overall survival rates were 93% and 70%, respectively. CSS at five and ten years was 97% and 84%, respectively. In Cox multivariate regression analysis, considering each factor as a continuous variable, the strongest predictor of biochemical control was PAP (p!0.001) followed by PSA (p 5 0.074) and Gleason score (p 5 0.34). The strongest predictor of CSS was PAP (p!0.001), followed by Gleason score (p 5 0.022) and PSA (p 5 0.27). Conclusions: In patients with high-risk localized prostate cancer treated with EBRT followed by brachytherapy boost, pretreatment serum PAP was the best predictor of cause-specific survival, above PSA and Gleason score and thus may be a more accurate indicator of micrometastatic disease.
OR-6 Presentation Time: 9:50 AM Cesium-131 prostate brachytherapy: An early experience Brian J. Moran, M.D., Michelle H. Braccioforte, B.S. Chicago Prostate Cancer Center, Westmont, IL. Purpose: This study investigates prostate specific antigen (PSA) response and acute side effects of patients undergoing low-dose-rate ultrasound-guided transperineal prostate brachytherapy (PB) with Cesium-131 seeds. Methods and Materials: Between 11/2004 and 11/2006, 104 patients, median age 61.3 years (range 44e77 years), underwent PB using Cesium-131 by a single physician at a single out-patient institution. The prescription dose was 115 Gy. Eligibility criteria were: clinical stage T1ceT2b, Gleason score <7, total PSA <20 ng/mL and prostate volume <60 cm3. PSA tests were performed prior to treatment, in addition to 1 month, 6 months and 1 year post implant. Patients completed International Prostate Symptom Score (IPSS), International Index of Erectile Function (IIEF) and Radiation Therapy Oncology Group (RTOG) toxicity surveys at various time intervals to evaluate urinary, sexual and bowel function, respectively. The IPSS symptom scale ranges from 0 to 35 with lower scores representing better outcomes. The IIEF scale ranges from 0 to 25 with higher scores representing better outcomes. Finally, the RTOG toxicity scale ranges from 0 to 5, with ‘0’ representing no morbidity and ‘5’ characterizing the most severe complications, including death. Results: Median PSA pre-implant, 1 month, 6 months and 1 year post implant were 5.1 4.5 ng/mL, 3.7 2.6 ng/mL, 1.2 0.94 ng/mL and 0.61 0.67 ng/mL, respectively. Median IPSS scores pre-implant, 2 weeks, 1 month, 4 months, 6 months and 1 year post implant were 5.0 5.7, 16 8.4, 17.0 8.4, 7.0 5.6, 7.0 5.7, 5.5 6.0, respectively. Median IIEF scores pre-implant, 1 month and 6 months postimplant were 16.0 7.4, 11.0 8.4 and 16.5 8.3, respectively. Median RTOG gastrointestinal toxicity scores 2 weeks, 1 month, 4 months and 1 year post implant were 1.0 0.68, 0.0 0.64, 0.0 0.35, 0.0 0.23, respectively. No rectal bleeding or long-term urinary retention was reported. Conclusions: PB with Cesium-131 is effective and well-tolerated; both PSA response and the acute morbidity profile are very encouraging. Continued followup of this cohort will define long-term outcomes. IsoRay Medical Inc., manufacturer of Cesium 131 seeds, provided a research grant to complete this study.
BREAST PAPER SESSION Sunday April 29, 2007 1:45 PMe2:30 PM OR-7 Presentation Time: 1:45 PM Stereotactic breast brachytherapy applied peripherally using a compression applicator and HDR Ir-192 Mark J. Rivard, Ph.D.1 Raymond J. Bricault, M.Sc.2 Christopher S. Melhus, M.Sc.1 Jessica R. Hiatt, M.Sc.3 Piran Sioshansi, Ph.D.2 David E. Wazer, M.D.1,3 1Radiation Oncology, Tufts-New England Medical Center, Boston, MA; 2Radiation Physics, Advanced Radiation Therapy, Billerica, MA; 3Radiation Oncology, Rhode Island Hospital, Providence, RI. Purpose: Breast brachytherapy has historically been applied via interstitial or intracavitary application. This approach produces conformal dose distributions through an invasive surgical procedure. By using peripherally positioned brachytherapy applicators to preferentially irradiate the lumpectomy cavity, breast brachytherapy may be applied non-invasively while minimizing critical structure doses to the skin and chest wall. A novel applicator design applies teletherapy-like beam collimation with brachytherapy dose falloff. This study aims to characterize dose rate distributions through application of this surface applicator, and compare these results to current standard-of-care treatment techniques. Methods and Materials: Treatment using the ART applicator positions the breast within two mammography paddles under slight compression to mimic the diagnostic geometry and fix the skin:source separation distance. Applicator diameters ranged from 5e7 cm, and use a W-alloy collimator with a conventional HDR Ir-192 source. Skin separations ranged from 3 to 7 cm. Dose rate distributions and skin dose relative to target dose were assessed using Monte Carlo (MC) methods and experimental techniques (ionization chambers and radiographic film). Using the MCNPv5 geometry package, the breast was modeled as a 16 cm diameter right cylinder with thicknesses of 3e7 cm in 0.5 cm increments. Dose rate was calculated in annular voxels 1 mm thick in 1mm radial increments from 0.1 to 7.9 cm. Measurements were performed in a rectilinear acrylic phantom using a parallel plate ionization chamber to minimize dose gradient volume averaging in the depth direction. Radiographic film was positioned at various depths for direct comparison with the MC dose profile, and to confirm cylindrical symmetry. Results: There was good beam uniformity within the collimated region. Surface and midplane collimation provided a factor of 8 and 5 attenuation, respectively. Ionization chamber measurements and MCderived dose falloff agreed within 2%. Film measurements and MCderived relative dose profiles agreed within 6%. Ratios of skin/target dose ranged from 0.5 to 1.1 over the wide range of applicator sizes and breast separations. For a typical 6 cm diameter applicator and 5 cm separation, the skin/target dose ratio was 0.74 with V50 !50% and CTV DHI 5 1.00. Teletherapy and balloon APBI have DHIs of 0.95 and 0.70, respectively. Conclusions: Compared to the capabilities of other treatment modalities, the dose distributions, CTV DHIs, and normal tissue sparing are superior with this non-invasive approach. The applicator was provided to Tufts-NEMC and RIH for free on a temporary basis to assess its dosimetric and clinical potential.
OR-8 Presentation Time: 1:54 PM Dosimetric comparison of three radiation sources used in balloon-based breast brachytherapy John J. Munro, Ph.D.1 David C. Medich, Ph.D.2 1SPECMed LLC, St. Rose, LA; 2Radiation Laboratory, Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA. Purpose: We report a dosimetric comparison of three radiation sources used for balloon-based accelerated partial breast irradiation: 192Iridium (SPECMed M19), 169Ytterbium (SPECMed M46), and X-ray (Xoft S700 Axxent).