- Email: [email protected]
Long term results for treatment of prostate cancer by staging pelvic lymph node dissection and definitive irradiation using L.D.R. temporary IR192 interstitial implant and external beam radiotherapy
296
I. J. Radiation Oncology
2138
● Biology ● Physics
Volume 51, Number 3, Supplement 1, 2001
Prostate Swelling following Permanent Implants is an Artifact of the Imaging Technique
P.W. Mclaughlin1,2, V. Narayana1,2, D.D. Drake2, B.M. Miller2, D. McShan1, R.J. Winfield2, P.L. Roberson1 1 Radiation Oncology, University of Michigan, Ann Arbor, MI, 2Radiation Oncology, Providence Cancer Institute, Southfield, MI Purpose: American Brachytherapy Society guidelines recommend that post-implant dosimetry of permanent prostate implants be based on CT images. The prostate as imaged by CT has poor visualization of the apex, prostate-seminal vesicle interface, and distortion of margin due to seeds and trauma. MRI has been employed to better visualize the prostate volume. We have attempted to define the optimal technique to image the prostate after implantation using CT, and several MRI techniques (T1 -weighted, T2- weighted, and T1 fat saturation imaging sequences). Materials and Methods: 25 patients with prostate carcinoma received an implant to either 90 or 145 Gy using I-125 sources at .65 U (.5 mCi). 2 weeks post-implant, patients underwent CT followed by MRI. A foley catheter with a titanium marker was placed prior to CT and MRI to define the urethra. CT axial images were obtained at 2 mm thickness and no gap with the patient lying supine for a 145 Gy implant and prone for a 90 Gy implant. MR images were obtained in the same position as CT in 3 mm increments. MRI included axial T1, T1 fat saturated and T2 weighted images. In addition, T2 weighted coronal and sagittal images were obtained to confirm the location of the apex. Ultrasound prostate volumes obtained on the day of the implant were used to assess the swelling two weeks after the implantation procedure. Prostate volumes were outlined on all datasets. MR datasets were first registered based on aligning the urethra. The MR and CT datasets were registered by aligning both the urethra and matching the source positions. Post-implant dosimetry was performed based on identifying source positions on CT. Results: The average volume of the prostate as imaged during the ultrasound implantation was 33.0 ⫾ 12.3 cc. CT and T1 weighted prostate volumes were consistently larger (1.3 ⫾ 0.3) relative to initial ultrasound volume suggesting a significant swelling. T2 weighted prostate volumes were on average 1.02 ⫾ 0.26 times the initial ultrasound prostate. T1 and T1 fat saturation prostate volumes were 1.01 ⫾ 0.26 and 1.03 ⫾ 0.26 times the CT prostate volume, respectively. The T2 weighted images, in particular, the sagittal and coronal images allowed excellent definition of the prostate volume. Conclusion: We found that the post implant prostate volume varied with the imaging technique. CT and T1 weighted images had a poor definition of the prostate-seminal vesicle interface and the apex. Both imaging techniques showed prostate volumes on average 1.3 times the baseline ultrasound prostate volume. T2 weighted images allowed excellent apex and seminal vesicle definition. The correlation of axial, sagittal and coronal images allowed improved definition of post implant volume. T2 prostate volumes were consistently proportional to the initial ultrasound volumes. These data suggest that prostate swelling may be an artifact of the imaging technique and have important implications for post-implant dosimetry.
2139
Long Term Results for Treatment of Prostate Cancer by Staging Pelvic Lymph Node Dissection and Definitive Irradiation Using L.D.R. Temporary Ir192 Interstitial Implant and External Beam Radiotherapy
A.A. Puthawala1,2, N. Syed1,2, J.M. Cherlow1,2, S.J. Damore1,2, J.M. Perley2, J.E. Ingram2, J.E. Perley2, A. Londrc1, A. Sharma1,2 1 Radiation Oncology, Long Beach Memorial Medical Center, Long Beach, CA, 2Radiation Oncology; Urology, UCI Medical Center, Orange, CA Purpose: To evaluate long-term treatment outcome of definitive irradiation using temporary interstitial implant and limited dose of external beam radiotherapy in treatment of localized prostate cancer. Materials and Methods: Between January, 1980 and March, 1995 a total of 536 patients with biopsy-proven adenocarcinoma of the prostate, stages T1 to T3, underwent staging pelvic node dissection and brachytherapy delivering an average tumor dose of 30 Gy, supplemented by external beam radiation therapy for an additional dose of 36 Gy delivered over four weeks. 100/536 (18%) patients had pathological D1 disease. A total of 181 patients had undergone TURP prior to the treatment. Repeat prostate biopsy was performed on 132 patients ⱖ18 months posttreatment. None of the patients received neoadjuvant or adjuvant hormone therapy. Results: Long term (ⱖ 10 years) biochemical control rate according to ASTRO consensus panel ’97 was 97%, 91% and 85% for stages T1b-c, T2b-c and T3a-c, respectively. Cumulative disease free survival including biochemical (DFS) at ten and 15 years for stage T1b,c, 78%, 72%; T2a, 78%, 78%; T2b,c, 68%, 66%; and T3a-c, 45%, 45%, respectively. Cause-specific survival for the entire group at ten and 15 years was 89% and 87%, respectively. Severe complications occurred only in the early developmental phase of the study. Conclusion: In univariate analysis, the clinical stage, histologic grade, pretreatment PSA level, lymph node status, and results of repeat posttreatment biopsy were all independently significant prognostic factors. However, our study indicates that in multivariate analysis, only two factors emerged with statistical significance—the status of pelvic lymph nodes and the results of posttreatment biopsy. This signifies the importance of local tumor control to achieve ultimate cure and the importance of assessment of pelvic lymph nodes prior to definitive local therapy other than radical prostatectomy, especially in the high risk group.
2140
Prognostic Significance of Race on Biochemical Control in Patients with Localized Prostate Cancer Treated with Permanent Brachytherapy: A Matched Pair Analysis
L. Potters1, T. Torre1, C. Barnswell2, P. Fearn3, M. Kattan3 1 Department of Radiation Oncology, Memorial Slaon-Kettering at Mercy Medical Center, Rockville Centre, NY, 2 Department of Urology, Mercy Medical Center, Rockville Centre, NY, 3Department of Urology, Memorial Sloan Kettering Cancer Center, New York, NY Purpose: To evaluate PSA relapse-free survival (PSA-RFS) via a matched pair analysis between African American (AA) and White (W) men treated with permanent prostate brachytherapy (PPB) for clinically localized prostate cancer.
I. J. Radiation Oncology
2138
● Biology ● Physics
Volume 51, Number 3, Supplement 1, 2001
Prostate Swelling following Permanent Implants is an Artifact of the Imaging Technique
P.W. Mclaughlin1,2, V. Narayana1,2, D.D. Drake2, B.M. Miller2, D. McShan1, R.J. Winfield2, P.L. Roberson1 1 Radiation Oncology, University of Michigan, Ann Arbor, MI, 2Radiation Oncology, Providence Cancer Institute, Southfield, MI Purpose: American Brachytherapy Society guidelines recommend that post-implant dosimetry of permanent prostate implants be based on CT images. The prostate as imaged by CT has poor visualization of the apex, prostate-seminal vesicle interface, and distortion of margin due to seeds and trauma. MRI has been employed to better visualize the prostate volume. We have attempted to define the optimal technique to image the prostate after implantation using CT, and several MRI techniques (T1 -weighted, T2- weighted, and T1 fat saturation imaging sequences). Materials and Methods: 25 patients with prostate carcinoma received an implant to either 90 or 145 Gy using I-125 sources at .65 U (.5 mCi). 2 weeks post-implant, patients underwent CT followed by MRI. A foley catheter with a titanium marker was placed prior to CT and MRI to define the urethra. CT axial images were obtained at 2 mm thickness and no gap with the patient lying supine for a 145 Gy implant and prone for a 90 Gy implant. MR images were obtained in the same position as CT in 3 mm increments. MRI included axial T1, T1 fat saturated and T2 weighted images. In addition, T2 weighted coronal and sagittal images were obtained to confirm the location of the apex. Ultrasound prostate volumes obtained on the day of the implant were used to assess the swelling two weeks after the implantation procedure. Prostate volumes were outlined on all datasets. MR datasets were first registered based on aligning the urethra. The MR and CT datasets were registered by aligning both the urethra and matching the source positions. Post-implant dosimetry was performed based on identifying source positions on CT. Results: The average volume of the prostate as imaged during the ultrasound implantation was 33.0 ⫾ 12.3 cc. CT and T1 weighted prostate volumes were consistently larger (1.3 ⫾ 0.3) relative to initial ultrasound volume suggesting a significant swelling. T2 weighted prostate volumes were on average 1.02 ⫾ 0.26 times the initial ultrasound prostate. T1 and T1 fat saturation prostate volumes were 1.01 ⫾ 0.26 and 1.03 ⫾ 0.26 times the CT prostate volume, respectively. The T2 weighted images, in particular, the sagittal and coronal images allowed excellent definition of the prostate volume. Conclusion: We found that the post implant prostate volume varied with the imaging technique. CT and T1 weighted images had a poor definition of the prostate-seminal vesicle interface and the apex. Both imaging techniques showed prostate volumes on average 1.3 times the baseline ultrasound prostate volume. T2 weighted images allowed excellent apex and seminal vesicle definition. The correlation of axial, sagittal and coronal images allowed improved definition of post implant volume. T2 prostate volumes were consistently proportional to the initial ultrasound volumes. These data suggest that prostate swelling may be an artifact of the imaging technique and have important implications for post-implant dosimetry.
2139
Long Term Results for Treatment of Prostate Cancer by Staging Pelvic Lymph Node Dissection and Definitive Irradiation Using L.D.R. Temporary Ir192 Interstitial Implant and External Beam Radiotherapy
A.A. Puthawala1,2, N. Syed1,2, J.M. Cherlow1,2, S.J. Damore1,2, J.M. Perley2, J.E. Ingram2, J.E. Perley2, A. Londrc1, A. Sharma1,2 1 Radiation Oncology, Long Beach Memorial Medical Center, Long Beach, CA, 2Radiation Oncology; Urology, UCI Medical Center, Orange, CA Purpose: To evaluate long-term treatment outcome of definitive irradiation using temporary interstitial implant and limited dose of external beam radiotherapy in treatment of localized prostate cancer. Materials and Methods: Between January, 1980 and March, 1995 a total of 536 patients with biopsy-proven adenocarcinoma of the prostate, stages T1 to T3, underwent staging pelvic node dissection and brachytherapy delivering an average tumor dose of 30 Gy, supplemented by external beam radiation therapy for an additional dose of 36 Gy delivered over four weeks. 100/536 (18%) patients had pathological D1 disease. A total of 181 patients had undergone TURP prior to the treatment. Repeat prostate biopsy was performed on 132 patients ⱖ18 months posttreatment. None of the patients received neoadjuvant or adjuvant hormone therapy. Results: Long term (ⱖ 10 years) biochemical control rate according to ASTRO consensus panel ’97 was 97%, 91% and 85% for stages T1b-c, T2b-c and T3a-c, respectively. Cumulative disease free survival including biochemical (DFS) at ten and 15 years for stage T1b,c, 78%, 72%; T2a, 78%, 78%; T2b,c, 68%, 66%; and T3a-c, 45%, 45%, respectively. Cause-specific survival for the entire group at ten and 15 years was 89% and 87%, respectively. Severe complications occurred only in the early developmental phase of the study. Conclusion: In univariate analysis, the clinical stage, histologic grade, pretreatment PSA level, lymph node status, and results of repeat posttreatment biopsy were all independently significant prognostic factors. However, our study indicates that in multivariate analysis, only two factors emerged with statistical significance—the status of pelvic lymph nodes and the results of posttreatment biopsy. This signifies the importance of local tumor control to achieve ultimate cure and the importance of assessment of pelvic lymph nodes prior to definitive local therapy other than radical prostatectomy, especially in the high risk group.
2140
Prognostic Significance of Race on Biochemical Control in Patients with Localized Prostate Cancer Treated with Permanent Brachytherapy: A Matched Pair Analysis
L. Potters1, T. Torre1, C. Barnswell2, P. Fearn3, M. Kattan3 1 Department of Radiation Oncology, Memorial Slaon-Kettering at Mercy Medical Center, Rockville Centre, NY, 2 Department of Urology, Mercy Medical Center, Rockville Centre, NY, 3Department of Urology, Memorial Sloan Kettering Cancer Center, New York, NY Purpose: To evaluate PSA relapse-free survival (PSA-RFS) via a matched pair analysis between African American (AA) and White (W) men treated with permanent prostate brachytherapy (PPB) for clinically localized prostate cancer.