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Clinical experience with Calypso-guided EBRT following seed implantation
Abstracts / Brachytherapy 7 (2008) 91e194 Group 2, although both values are within tolerance. Mean urethral dose (135 Gy 21.4 vs. 126 Gy 23.5, p 5 0.11) and rectal V100 (1.07 cc 0.7 vs. 0.89 cc 0.5, p 5 0.29) were unaffected. Conclusions: In experienced centres with an existing high standard of implant quality, it may be difficult to improve dosimetry. The incorporation of intraoperative planning into the implant procedure did not impact on the quality of prostate dosimetry, although there is evidence for a beneficial effect on urethral dose and prostate V150. Further studies will examine whether this translates into clinical benefit.
PO125 Dosimetry and 2-year potency is improved by hybrid I-125 prostate brachytherapy implant technique Jenny P. Nobes, FRCR, Sara J. Khaksar, FRCR, Stephen E.M. Langley, FRCS, Robert W. Laing, FRCR. St. Luke’s Cancer Centre, The Royal Surrey County Hospital, Guildford, Surrey, United Kingdom. Purpose: Brachytherapy (BXT) provides high dose radiation to the prostate whilst minimizing dose to surrounding tissues, although there is little comparison of the differing implant techniques that are used. This study updates the rate of potency preservation at 2 years post-implant. Methods and Materials: In January 2005 we developed a hybrid implant technique using peripheral stranded seeds and centrally-distributed loose seeds implanted via a Mick applicator. This technique allows greater precision and flexibility when implanting the apex, which is implicated in erectile dysfunction post-BXT. We previously evaluated day-1 postimplant dosimetry in a group of 30 patients undergoing this technique (Group 2). When compared to 64 patients (Group 1) undergoing the classic modified-uniform implant technique, there was a significant improvement in penile bulb dosimetry (D25 as %mPD - Group 1: 60.7 35.1, Group 2: 27.4 12.2, p!0.0001; D50 as %mPD - Group 1: 45.5 26.4, Group 2: 20.1 8.4, p!0.0001), whilst also improving prostate dosimetry (D90 - Group 1: 147 Gy 20.7, Group 2: 160.3 Gy 16.5, p!0.05; V100 - Group 1: 90.7% 5.9, Group 2: 93.4% 3.9, p!0.05). At 12 months there was an improved potency rate of 86.6% vs. 60.9%, as defined by an IIEF score >11/25. All patients were potent preimplant. For this study, we have updated erectile function data for each group at 2 years. Four patients were lost to followup in Group 1, and one from Group 2. One patient in Group 2 experienced distant failure at 18 months, received androgen deprivation therapy, and is thus excluded from this analysis. No patients received external beam radiotherapy or hormonal treatment. There was no significant difference in age or preimplant potency score between the two groups. Results: At 2 years post-implant, there is a significantly higher mean IIEF score in Group 2 (12.9 8.3 vs. 18.5 6.6, p 5 0.002). This corresponds to a potency rate of 89.3%, as compared to 61.7% in Group 1. Furthermore, there was a greater mean reduction in IIEF score from pre- to 2 years post-implant in the classically treated group ( 9.5 8.1 vs. 3.8 7.4, p 5 0.002). Neither group exhibited a significant decline in IIEF between 1 and 2 years ( 1.2 8.3 vs. 0.75 3.9, p 5 0.79). PDE5 inhibitor use was similar in each group. Conclusions: This study confirms that careful seed placement at the apex with our hybrid implant technique leads to excellent potency preservation at 2 years. Future studies will examine the influence of factors such as concurrent cardiovascular disease and diabetes, as well as longer term effects on post-treatment potency rates.
PO126 Clinical experience with Calypso-guided EBRT following seed implantation Robert K. Takamiya, M.D., Timothy P. Mate, M.D., John E. Sylvester, M.D., Stephen M. Eulau, M.D., Peter D. Grimm, D.O. Seattle Prostate Institute/Swedish Medical Center, Seattle, WA. Purpose: The combination of brachytherapy and external beam radiation therapy (EBRT) is a common prostate cancer treatment; however, these
179
patients experience a higher rate of rectal complications. The Calypso System, used for continuous prostate tracking during EBRT, is based on implanted transponders. A prior phantom study demonstrated that AC electromagnetic-based transponder function is not affected by the presence of the metallic seed casing. This study examined the clinical feasibility of concurrently placing transponders with seed implantation to localize the prostate during subsequent EBRT. The clinical objective was to enable the use of a tight rectal margin during post implant EBRT to potentially minimize rectal complications. Methods and Materials: Patients appropriate for combination therapy initially underwent a palladium seed implant. First, seeds were placed, then three transponders were inserted in the apex, base, contralateral mid gland positions in different coronal planes. Approximately six weeks later, the patients underwent EBRT with continuous Calypso localization. In the areas where prostate and rectum were in close proximity, the clinical target volume (CTV) was tightly drawn and expanded by 1 mm to create the planning target volume (PTV). Elsewhere the CTV expansion was 5 mm. EB set up was within 1 mm of isocenter and if, during beamon, the prostate moved greater than 3 mm from isocenter, the beam was interrupted and/or the patient re-positioned. Data review included transponder retention, migration, function, frequency of prostate excursions and beam interrupts. Results: There were no procedural challenges to insert the transponders immediately following seed insertion. Transponders were functional in the presence of seeds, as seen in the prior phantom study. Delivering EBRT with tight excursion constraints did not impact workflow. Conclusions: This study supports use of the Calypso technology to provide precise setup and continuous prostate localization during EBRT after seed implantation as an enabler of tight posterior treatment margins to potentially reduce rectal complications.
PO127 Treatment of T3B prostate cancer with a combination of hormonal therapy, permanent brachytherapy and external beam irradiation Vassilios M. Skouteris, M.D.1,3 Nelson N. Stone, M.D.2 Jamie A. Cesaretti, M.D.1 Richard G. Stock, M.D.1 1Radiation Oncology, Mount Sinai Hospital, New York, NY; 2Urology, Mount Sinai Hospital, New York, NY; 3 Urology, Hygeia Hospital, Athens, Maroussi, Greece. Purpose: We investigated the efficacy of a trimodality approach consisting of 9 months of hormonal therapy (HT), permanent brachytherapy (PB), and external beam radiation therapy (EBRT) in the treatment of locally advanced prostate cancer (PCa) with seminal vesicle (SV) involvement. We report the biochemical freedom from failure (bFFF), post-treatment biopsy and survival outcomes. Methods and Materials: Intermediate and high risk localized PCa patients (pts) from 2 institutions had 6 ultrasound-guided SV biopsies (SVB) for staging because they presented with PSA>10 ng/mL, Gleason>7 or Stage>T2b. 52 of them had positive SVB, negative laparoscopic pelvic lymph node dissection (n 5 48), CT and bone scan results and were treated with 3 months of HT, Pd-103 (n 5 40, 76.9%) or I-125 (n 5 12, 23.1%) real time prostate and SV seed implantation (prescription dose: 100 Gy NIST99 for Pd-103 and 107 Gy for I-125), followed 2 months later by 45 Gy of conformal EBRT. EBRT included a 1.5-cm margin around prostate and SVs. HT was continued for 6 months after the implant. During the seed implant, an intraoperative technique was used to place the SV sources so the prescription dose would cover the proximal 2/ 3rds of the SVs. Postimplant dosimetry was determined at 1 month by CT scan and reported as the biological effective dose (BED). Failure was calculated if PSAO0.2ng/mL (AUA) or by ASTRO definition and bFFF was determined by Kaplan Meier method. Comparisons were made by log rank. Of the 52 pts, 18 (34.6%) agreed to prostate/SV biopsy (12 cores) 2 years after completion of all therapy. Results: Median patient age was 70 years (range: 47e80) and median PSA was 16ng/mL (range: 4e100). Clinical stage was T1c-T2a in 7 (13.5%), T2b-c in 25 (48.1%) and T3 in 20 (38.4%). Gleason score was <6 in 15 (28.9%), 7 in 21 (40.3%) and 8e10 in 16 (30.8%). PSA was <10 in 20 (34.8%), 10.1e20 in 13 (25%), and O20 in 19 (40.2%). Median followup
PO125 Dosimetry and 2-year potency is improved by hybrid I-125 prostate brachytherapy implant technique Jenny P. Nobes, FRCR, Sara J. Khaksar, FRCR, Stephen E.M. Langley, FRCS, Robert W. Laing, FRCR. St. Luke’s Cancer Centre, The Royal Surrey County Hospital, Guildford, Surrey, United Kingdom. Purpose: Brachytherapy (BXT) provides high dose radiation to the prostate whilst minimizing dose to surrounding tissues, although there is little comparison of the differing implant techniques that are used. This study updates the rate of potency preservation at 2 years post-implant. Methods and Materials: In January 2005 we developed a hybrid implant technique using peripheral stranded seeds and centrally-distributed loose seeds implanted via a Mick applicator. This technique allows greater precision and flexibility when implanting the apex, which is implicated in erectile dysfunction post-BXT. We previously evaluated day-1 postimplant dosimetry in a group of 30 patients undergoing this technique (Group 2). When compared to 64 patients (Group 1) undergoing the classic modified-uniform implant technique, there was a significant improvement in penile bulb dosimetry (D25 as %mPD - Group 1: 60.7 35.1, Group 2: 27.4 12.2, p!0.0001; D50 as %mPD - Group 1: 45.5 26.4, Group 2: 20.1 8.4, p!0.0001), whilst also improving prostate dosimetry (D90 - Group 1: 147 Gy 20.7, Group 2: 160.3 Gy 16.5, p!0.05; V100 - Group 1: 90.7% 5.9, Group 2: 93.4% 3.9, p!0.05). At 12 months there was an improved potency rate of 86.6% vs. 60.9%, as defined by an IIEF score >11/25. All patients were potent preimplant. For this study, we have updated erectile function data for each group at 2 years. Four patients were lost to followup in Group 1, and one from Group 2. One patient in Group 2 experienced distant failure at 18 months, received androgen deprivation therapy, and is thus excluded from this analysis. No patients received external beam radiotherapy or hormonal treatment. There was no significant difference in age or preimplant potency score between the two groups. Results: At 2 years post-implant, there is a significantly higher mean IIEF score in Group 2 (12.9 8.3 vs. 18.5 6.6, p 5 0.002). This corresponds to a potency rate of 89.3%, as compared to 61.7% in Group 1. Furthermore, there was a greater mean reduction in IIEF score from pre- to 2 years post-implant in the classically treated group ( 9.5 8.1 vs. 3.8 7.4, p 5 0.002). Neither group exhibited a significant decline in IIEF between 1 and 2 years ( 1.2 8.3 vs. 0.75 3.9, p 5 0.79). PDE5 inhibitor use was similar in each group. Conclusions: This study confirms that careful seed placement at the apex with our hybrid implant technique leads to excellent potency preservation at 2 years. Future studies will examine the influence of factors such as concurrent cardiovascular disease and diabetes, as well as longer term effects on post-treatment potency rates.
PO126 Clinical experience with Calypso-guided EBRT following seed implantation Robert K. Takamiya, M.D., Timothy P. Mate, M.D., John E. Sylvester, M.D., Stephen M. Eulau, M.D., Peter D. Grimm, D.O. Seattle Prostate Institute/Swedish Medical Center, Seattle, WA. Purpose: The combination of brachytherapy and external beam radiation therapy (EBRT) is a common prostate cancer treatment; however, these
179
patients experience a higher rate of rectal complications. The Calypso System, used for continuous prostate tracking during EBRT, is based on implanted transponders. A prior phantom study demonstrated that AC electromagnetic-based transponder function is not affected by the presence of the metallic seed casing. This study examined the clinical feasibility of concurrently placing transponders with seed implantation to localize the prostate during subsequent EBRT. The clinical objective was to enable the use of a tight rectal margin during post implant EBRT to potentially minimize rectal complications. Methods and Materials: Patients appropriate for combination therapy initially underwent a palladium seed implant. First, seeds were placed, then three transponders were inserted in the apex, base, contralateral mid gland positions in different coronal planes. Approximately six weeks later, the patients underwent EBRT with continuous Calypso localization. In the areas where prostate and rectum were in close proximity, the clinical target volume (CTV) was tightly drawn and expanded by 1 mm to create the planning target volume (PTV). Elsewhere the CTV expansion was 5 mm. EB set up was within 1 mm of isocenter and if, during beamon, the prostate moved greater than 3 mm from isocenter, the beam was interrupted and/or the patient re-positioned. Data review included transponder retention, migration, function, frequency of prostate excursions and beam interrupts. Results: There were no procedural challenges to insert the transponders immediately following seed insertion. Transponders were functional in the presence of seeds, as seen in the prior phantom study. Delivering EBRT with tight excursion constraints did not impact workflow. Conclusions: This study supports use of the Calypso technology to provide precise setup and continuous prostate localization during EBRT after seed implantation as an enabler of tight posterior treatment margins to potentially reduce rectal complications.
PO127 Treatment of T3B prostate cancer with a combination of hormonal therapy, permanent brachytherapy and external beam irradiation Vassilios M. Skouteris, M.D.1,3 Nelson N. Stone, M.D.2 Jamie A. Cesaretti, M.D.1 Richard G. Stock, M.D.1 1Radiation Oncology, Mount Sinai Hospital, New York, NY; 2Urology, Mount Sinai Hospital, New York, NY; 3 Urology, Hygeia Hospital, Athens, Maroussi, Greece. Purpose: We investigated the efficacy of a trimodality approach consisting of 9 months of hormonal therapy (HT), permanent brachytherapy (PB), and external beam radiation therapy (EBRT) in the treatment of locally advanced prostate cancer (PCa) with seminal vesicle (SV) involvement. We report the biochemical freedom from failure (bFFF), post-treatment biopsy and survival outcomes. Methods and Materials: Intermediate and high risk localized PCa patients (pts) from 2 institutions had 6 ultrasound-guided SV biopsies (SVB) for staging because they presented with PSA>10 ng/mL, Gleason>7 or Stage>T2b. 52 of them had positive SVB, negative laparoscopic pelvic lymph node dissection (n 5 48), CT and bone scan results and were treated with 3 months of HT, Pd-103 (n 5 40, 76.9%) or I-125 (n 5 12, 23.1%) real time prostate and SV seed implantation (prescription dose: 100 Gy NIST99 for Pd-103 and 107 Gy for I-125), followed 2 months later by 45 Gy of conformal EBRT. EBRT included a 1.5-cm margin around prostate and SVs. HT was continued for 6 months after the implant. During the seed implant, an intraoperative technique was used to place the SV sources so the prescription dose would cover the proximal 2/ 3rds of the SVs. Postimplant dosimetry was determined at 1 month by CT scan and reported as the biological effective dose (BED). Failure was calculated if PSAO0.2ng/mL (AUA) or by ASTRO definition and bFFF was determined by Kaplan Meier method. Comparisons were made by log rank. Of the 52 pts, 18 (34.6%) agreed to prostate/SV biopsy (12 cores) 2 years after completion of all therapy. Results: Median patient age was 70 years (range: 47e80) and median PSA was 16ng/mL (range: 4e100). Clinical stage was T1c-T2a in 7 (13.5%), T2b-c in 25 (48.1%) and T3 in 20 (38.4%). Gleason score was <6 in 15 (28.9%), 7 in 21 (40.3%) and 8e10 in 16 (30.8%). PSA was <10 in 20 (34.8%), 10.1e20 in 13 (25%), and O20 in 19 (40.2%). Median followup