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A Pilot Study of Intraoperative Dynamic Dosimetry Using Registered Ultrasound and Fluoroscopy (RUF) for Permanent Prostate Brachytherapy
I. J. Radiation Oncology d Biology d Physics
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Volume 69, Number 3, Supplement, 2007
A Phase II Trial of Trilogy-Based Prostate SBRT: Initial Report of Favorable Acute Toxicity Outcomes
C. A. Mantz1, E. Fernandez2, S. Harrison1, I. Zucker1 1
21st Century Oncology, Fort Myers, FL, 221st Century Oncology, Plantation, FL
Purpose/Objective(s): Prostate stereotactic body radiation therapy (SBRT) offers a means of delivering high radiobiologic doses similar to either brachytherapy or dose-escalated external radiotherapy. However, SBRT holds potential advantages over these other modalities in that neither an operative procedure nor a protracted treatment course is needed. We describe acute toxicity outcomes in this initial report of an IRB-approved phase II trial utilizing the Varian Trilogy system in delivering prostate SBRT. Materials/Methods: A total of 22 patients have been treated to date with SBRT. Protocol inclusion criteria required all of the following parameters: clinical stage T1c–T2a, PSA\10 ng/ml, GS 6 or less, prostate volume\60 cc, and IPSS voiding score\18. A total dose of 36.25 Gy was prescribed to the prostate in 5 fractions of 7.25 Gy each on an every other day schedule. The SBRT PTV was created by a 3-mm uniform expansion of the prostate volume, and the prescription isodose line was selected such that point dose maxima of 50%, 85%, and 100% for the femoral heads, rectum, and bladder, respectively, were not exceeded. The NCI CTCAE v3.0 was used to assess urinary and rectal toxicity during treatment and then at 1, 3, 6, 9, and 12 months after treatment. Acute toxicity was defined as occurring during treatment or within 30 days of treatment completion. Studied urinary toxicities included dysuria/spasms, retention, hematuria/cystitis, frequency/urgency, and incontinence. Studied rectal toxicities included diarrhea, proctitis, and hematochezia. Results: Eighteen patients have been followed for at least one month. During treatment, 3 patients reported dysuria, 5 reported urinary hesitancy, and 11 reported urinary frequency/urgency. At one month, 1 patient reported continued dysuria and hesitancy, and 4 patients reported continued frequency/urgency. All urinary symptoms were grade 1 and required no additional medication or other intervention. During treatment, 5 patients reported diarrhea, and 2 reported proctitis. At one month, 1 patient reported continued proctitis. All rectal symptoms were grade 1 with the exception of a single patient who experienced continued proctitis and required topical steroid therapy for relief. Among those patients followed for 3 months post-treatment or greater, all returned to baseline urinary and rectal function. Multivariate analysis demonstrated no clinical or dosimetric parameters predictive of acute toxicity. Conclusions: Prostate SBRT utilizing Varian Trilogy offers high radiobiologic dose therapy with favorable acute urinary and rectal toxicity. Further followup will be needed to confirm these early toxicity results and provide meaningful disease control outcomes. Author Disclosure: C.A. Mantz, None; E. Fernandez, None; S. Harrison, None; I. Zucker, None.
2237
A Pilot Study of Intraoperative Dynamic Dosimetry Using Registered Ultrasound and Fluoroscopy (RUF) for Permanent Prostate Brachytherapy
D. Y. Song1, A. Deguet2, A. Jain2, E. Armour1, Y. Le1, I. Iordachita2, J. Blevins3, E. C. Burdette3, G. Fichtinger1 1 The Johns Hopkins University School of Medicine, Baltimore, MD, 2The Johns Hopkins University Whiting School of Engineering, Baltimore, MD, 3Acoustic MedSystems, Urbana-Champaign, IL
Purpose/Objective(s): The ability to perform dynamic intraoperative dosimetry during permanent prostate implants is expected to result in improved clinical outcomes. Currently available brachytherapy techniques do not allow robust identification of seed positions intraoperatively in a standard clinical setup. Materials/Methods: A pilot study was performed to test the feasibility and intraoperative function of a system of registered ultrasound and fluoroscopy (RUF). In contrast to prior approaches, we perform dynamic intra-operative dosimetry without major modification to the conventional setup, employing a transrectal ultrasound and C-arm as available to most practitioners. A noninvasive, radio-opaque fiducial was utilized to facilitate three-dimensional reconstruction of seed positions relative to prostate using C-arm fluoroscopy (Fig. 1). Four non-coplanar X-ray images were used for reconstruction. The 3-dimensional coordinates of the segmented seeds are calculated upon resolving the correspondence of seeds in the C-arm images, by formalizing seed-matching as a network-flow problem (1). Calculated seed positions were imported into the treatment planning software, allowing for visualization of actual dosimetry during the case. Based on this updated dosimetric information, the treatment plan and/or total number of seeds were modified prior to completion of the procedure. Post-implant CT was performed on the day of implantation. Seed positions as identified on CT were compared to final seed positions identified intraoperatively by RUF. Results: Five patients were treated with permanent palladium source brachytherapy using RUF. C-arm images were obtained and RUF calculation of seed positions was performed 3 times during each case, and subsequent seed placement modified as determined by physician judgment. A total of 54–84 seeds were placed; seed counts identified by RUF matched the number of seeds actually placed. Based on RUF data, 3–10 seeds were added to the original treatment plan to alter areas of visualized underdosing. Day 0 CT dose-volume histogram data are as follows: prostate D90 of 100–135%, V100 of 88.3–99.6% (in the patient with V100 of 88.3%, RUF indicated a small area of underdosage but all available seeds had been utilized), urethral D50 of 95–120%, urethral D10 of 105–150%, and rectal R100 of 0.0–0.3 cc. Conclusions: RUF is achievable and feasible for use in a standard intraoperative setting, without major alteration of normal clinical setup. These pilot results indicate satisfactory performance with positive dosimetric outcomes. A follow-up Phase II study is planned. 1. Jain et al. Med Phys, 32:3475–92, 2005.
Proceedings of the 49th Annual ASTRO Meeting
Author Disclosure: D.Y. Song, None; A. Deguet, None; A. Jain, None; E. Armour, None; Y. Le, None; I. Iordachita, None; J. Blevins, Acoustic MedSystems, A. Employment; E.C. Burdette, Acoustic MedSystems, E. Ownership Interest; G. Fichtinger, None.
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Long-Term Outcome of a Moderate-Hypofractionated Intensity Modulated Radiation Therapy (IMRT) (77GY at 2.2GY per Fraction) Approach Utilizing Immobilization Rectal Balloon for Localized Prostate Cancer
B. S. Teh1,2, W. Mai2, J. McGary1,2, M. Smiedala1, A. C. Paulino1,2, W. Grant1,2, E. B. Butler1 1
The Methodist Hospital, Houston, TX, 2Baylor College of Medicine, Houston, TX
Purpose/Objective(s): To assess long-term biochemical control and toxicity rates in patients with localized prostate cancer treated with a moderately hypofractionated IMRT approach. Materials/Methods: The study includes a total of 596 patients treated with full course IMRT (NOMOS system), utilizing a moderately hypofractionated schedule, i.e. mean dose of 7680 cGy at 2.19 cGy per fraction over 35 fractions. IMRT was not used as a boost approach. All patients were treated in the prone position, immobilized using a Vac-Lok bag and carrier-box system. Rectal balloon inflated with 100 cc of air was used for prostate gland immobilization during daily treatment. High-risk patients also received two years and four months of androgen deprivative therapy. Median follow-up was 48 months (3.7 months to 110 months). Biochemical failures were study endpoints, using both the first ASTRO consensus (1996)1 ‘‘three consecutive rise after a nadir’’ definition (F-bRFS) and the second ASTRO consensus (2005)2 ‘‘nadir + 2 ng/ml’’ definition (S-bRFS). RTOG scoring system was used to assess toxicity. Results: The 5-year F-bRFS and S-bRFS rates were 92.3% and 92.8% for all cases respectively. For low, intermediate and high risk categories, the 5-year F-bRFS were 95.9%, 94.1% and 79.9%. The corresponding 5-year S-bRFS were 97.4%, 92.9% and 81.9%, respectively. Pre-treatment PSA, Gleason combined score and clinical stage predict both F-bRFS and S-bRFS. $ grade 2 and $ grade 3 GI toxicities at 5 years were 8.5% and 1.2% respectively. $ grade 2 and $ grade 3 GU toxicities at 5 years were 9.4% and 1.1%. Conclusions: With a median follow-up of 48 months, the long-term results after moderate dose hypofractionation IMRT are excellent. Late GI and GU toxicities are acceptable. This may be an alternative dose escalation schedule in the treatment of localized prostate cancer. 1. Int J Radiat Oncol Biol Phys. 1997;37 (5):1035–1041. 2. Int J Radiat Oncol Biol Phys. 2006;65 (4):965–974. (Supported by a research grant from the Methodist Hospital Research Institute). Author Disclosure: B.S. Teh, None; W. Mai, None; J. McGary, None; M. Smiedala, None; A.C. Paulino, None; W. Grant, None; E.B. Butler, None.
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Volume 69, Number 3, Supplement, 2007
A Phase II Trial of Trilogy-Based Prostate SBRT: Initial Report of Favorable Acute Toxicity Outcomes
C. A. Mantz1, E. Fernandez2, S. Harrison1, I. Zucker1 1
21st Century Oncology, Fort Myers, FL, 221st Century Oncology, Plantation, FL
Purpose/Objective(s): Prostate stereotactic body radiation therapy (SBRT) offers a means of delivering high radiobiologic doses similar to either brachytherapy or dose-escalated external radiotherapy. However, SBRT holds potential advantages over these other modalities in that neither an operative procedure nor a protracted treatment course is needed. We describe acute toxicity outcomes in this initial report of an IRB-approved phase II trial utilizing the Varian Trilogy system in delivering prostate SBRT. Materials/Methods: A total of 22 patients have been treated to date with SBRT. Protocol inclusion criteria required all of the following parameters: clinical stage T1c–T2a, PSA\10 ng/ml, GS 6 or less, prostate volume\60 cc, and IPSS voiding score\18. A total dose of 36.25 Gy was prescribed to the prostate in 5 fractions of 7.25 Gy each on an every other day schedule. The SBRT PTV was created by a 3-mm uniform expansion of the prostate volume, and the prescription isodose line was selected such that point dose maxima of 50%, 85%, and 100% for the femoral heads, rectum, and bladder, respectively, were not exceeded. The NCI CTCAE v3.0 was used to assess urinary and rectal toxicity during treatment and then at 1, 3, 6, 9, and 12 months after treatment. Acute toxicity was defined as occurring during treatment or within 30 days of treatment completion. Studied urinary toxicities included dysuria/spasms, retention, hematuria/cystitis, frequency/urgency, and incontinence. Studied rectal toxicities included diarrhea, proctitis, and hematochezia. Results: Eighteen patients have been followed for at least one month. During treatment, 3 patients reported dysuria, 5 reported urinary hesitancy, and 11 reported urinary frequency/urgency. At one month, 1 patient reported continued dysuria and hesitancy, and 4 patients reported continued frequency/urgency. All urinary symptoms were grade 1 and required no additional medication or other intervention. During treatment, 5 patients reported diarrhea, and 2 reported proctitis. At one month, 1 patient reported continued proctitis. All rectal symptoms were grade 1 with the exception of a single patient who experienced continued proctitis and required topical steroid therapy for relief. Among those patients followed for 3 months post-treatment or greater, all returned to baseline urinary and rectal function. Multivariate analysis demonstrated no clinical or dosimetric parameters predictive of acute toxicity. Conclusions: Prostate SBRT utilizing Varian Trilogy offers high radiobiologic dose therapy with favorable acute urinary and rectal toxicity. Further followup will be needed to confirm these early toxicity results and provide meaningful disease control outcomes. Author Disclosure: C.A. Mantz, None; E. Fernandez, None; S. Harrison, None; I. Zucker, None.
2237
A Pilot Study of Intraoperative Dynamic Dosimetry Using Registered Ultrasound and Fluoroscopy (RUF) for Permanent Prostate Brachytherapy
D. Y. Song1, A. Deguet2, A. Jain2, E. Armour1, Y. Le1, I. Iordachita2, J. Blevins3, E. C. Burdette3, G. Fichtinger1 1 The Johns Hopkins University School of Medicine, Baltimore, MD, 2The Johns Hopkins University Whiting School of Engineering, Baltimore, MD, 3Acoustic MedSystems, Urbana-Champaign, IL
Purpose/Objective(s): The ability to perform dynamic intraoperative dosimetry during permanent prostate implants is expected to result in improved clinical outcomes. Currently available brachytherapy techniques do not allow robust identification of seed positions intraoperatively in a standard clinical setup. Materials/Methods: A pilot study was performed to test the feasibility and intraoperative function of a system of registered ultrasound and fluoroscopy (RUF). In contrast to prior approaches, we perform dynamic intra-operative dosimetry without major modification to the conventional setup, employing a transrectal ultrasound and C-arm as available to most practitioners. A noninvasive, radio-opaque fiducial was utilized to facilitate three-dimensional reconstruction of seed positions relative to prostate using C-arm fluoroscopy (Fig. 1). Four non-coplanar X-ray images were used for reconstruction. The 3-dimensional coordinates of the segmented seeds are calculated upon resolving the correspondence of seeds in the C-arm images, by formalizing seed-matching as a network-flow problem (1). Calculated seed positions were imported into the treatment planning software, allowing for visualization of actual dosimetry during the case. Based on this updated dosimetric information, the treatment plan and/or total number of seeds were modified prior to completion of the procedure. Post-implant CT was performed on the day of implantation. Seed positions as identified on CT were compared to final seed positions identified intraoperatively by RUF. Results: Five patients were treated with permanent palladium source brachytherapy using RUF. C-arm images were obtained and RUF calculation of seed positions was performed 3 times during each case, and subsequent seed placement modified as determined by physician judgment. A total of 54–84 seeds were placed; seed counts identified by RUF matched the number of seeds actually placed. Based on RUF data, 3–10 seeds were added to the original treatment plan to alter areas of visualized underdosing. Day 0 CT dose-volume histogram data are as follows: prostate D90 of 100–135%, V100 of 88.3–99.6% (in the patient with V100 of 88.3%, RUF indicated a small area of underdosage but all available seeds had been utilized), urethral D50 of 95–120%, urethral D10 of 105–150%, and rectal R100 of 0.0–0.3 cc. Conclusions: RUF is achievable and feasible for use in a standard intraoperative setting, without major alteration of normal clinical setup. These pilot results indicate satisfactory performance with positive dosimetric outcomes. A follow-up Phase II study is planned. 1. Jain et al. Med Phys, 32:3475–92, 2005.
Proceedings of the 49th Annual ASTRO Meeting
Author Disclosure: D.Y. Song, None; A. Deguet, None; A. Jain, None; E. Armour, None; Y. Le, None; I. Iordachita, None; J. Blevins, Acoustic MedSystems, A. Employment; E.C. Burdette, Acoustic MedSystems, E. Ownership Interest; G. Fichtinger, None.
2238
Long-Term Outcome of a Moderate-Hypofractionated Intensity Modulated Radiation Therapy (IMRT) (77GY at 2.2GY per Fraction) Approach Utilizing Immobilization Rectal Balloon for Localized Prostate Cancer
B. S. Teh1,2, W. Mai2, J. McGary1,2, M. Smiedala1, A. C. Paulino1,2, W. Grant1,2, E. B. Butler1 1
The Methodist Hospital, Houston, TX, 2Baylor College of Medicine, Houston, TX
Purpose/Objective(s): To assess long-term biochemical control and toxicity rates in patients with localized prostate cancer treated with a moderately hypofractionated IMRT approach. Materials/Methods: The study includes a total of 596 patients treated with full course IMRT (NOMOS system), utilizing a moderately hypofractionated schedule, i.e. mean dose of 7680 cGy at 2.19 cGy per fraction over 35 fractions. IMRT was not used as a boost approach. All patients were treated in the prone position, immobilized using a Vac-Lok bag and carrier-box system. Rectal balloon inflated with 100 cc of air was used for prostate gland immobilization during daily treatment. High-risk patients also received two years and four months of androgen deprivative therapy. Median follow-up was 48 months (3.7 months to 110 months). Biochemical failures were study endpoints, using both the first ASTRO consensus (1996)1 ‘‘three consecutive rise after a nadir’’ definition (F-bRFS) and the second ASTRO consensus (2005)2 ‘‘nadir + 2 ng/ml’’ definition (S-bRFS). RTOG scoring system was used to assess toxicity. Results: The 5-year F-bRFS and S-bRFS rates were 92.3% and 92.8% for all cases respectively. For low, intermediate and high risk categories, the 5-year F-bRFS were 95.9%, 94.1% and 79.9%. The corresponding 5-year S-bRFS were 97.4%, 92.9% and 81.9%, respectively. Pre-treatment PSA, Gleason combined score and clinical stage predict both F-bRFS and S-bRFS. $ grade 2 and $ grade 3 GI toxicities at 5 years were 8.5% and 1.2% respectively. $ grade 2 and $ grade 3 GU toxicities at 5 years were 9.4% and 1.1%. Conclusions: With a median follow-up of 48 months, the long-term results after moderate dose hypofractionation IMRT are excellent. Late GI and GU toxicities are acceptable. This may be an alternative dose escalation schedule in the treatment of localized prostate cancer. 1. Int J Radiat Oncol Biol Phys. 1997;37 (5):1035–1041. 2. Int J Radiat Oncol Biol Phys. 2006;65 (4):965–974. (Supported by a research grant from the Methodist Hospital Research Institute). Author Disclosure: B.S. Teh, None; W. Mai, None; J. McGary, None; M. Smiedala, None; A.C. Paulino, None; W. Grant, None; E.B. Butler, None.
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