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PO-1035: Comparison of permanent 125-I seeds implants with two different techniques in 500 cases of prostate cancer
S158 regarding risk factors. Prior TURP was more frequent in the HDR2 group (p=0.003). Results: Median Follow-up is 3.7 years (range, 2-6) . Rectal Toxicity grade ³ 2 were HDR4=9.3% and HDR2=13.0% (p=ns) and grade ³ 3 HDR4=1.6% and HDR2=2.2% (p=ns). Urinary toxicity grade ³ 2 were HDR4=17.5% and HDR2=34.8% (p=0.01) and grade ³ 3 HDR4=4.9% and HDR2=10.9% (p=ns). Six-year PSA RFS for HDR4 and HDR2 protocols were 83.1% and 88.7% (p=ns). Conclusions: HDR4 and HDR2 Protocols produce similar results at the intermediate time point of 6 years although survival curves tend to separate out with time and this difference might be significant in the near future. HDR2 patients have more grade ³ 2 urinary events that can be partly explained by a higher number of prior TURP. Urinary constraints will be further refined in the ongoing HDR2 protocol. PO-1034 Optimal source distribution for focal boosts using high dose rate (HDR) brachytherapy alone in prostate cancer P. Dankulchai1, R. Alonzi1, G. Lowe1, J. Burnley1, A. Padhani2, P. Hoskin1 1 Mount Vernon Cancer Centre, Radiotherapy Department, Middlesex, United Kingdom 2 Paul Strickland Scanner Centre, Mount Vernon Cancer Centre, Middlesex, United Kingdom Purpose/Objective: To investigate the optimal distribution of sources using high dose rate brachytherapy to deliver a focal boost to a dominant lesion within the whole prostate gland of based on multi-parametric magnetic resonance imaging (MRI). Materials and Methods: Sixteen patients with prostate cancer underwent multi-parametric MRI for diagnosis with demonstration of a dominant lesion. The entire prostate gland was outlined to define the clinical target volume of the prostate (CTV1), and the dominant lesion(s) based on the functional MRI was contoured as CTV of boost area (CTV2). These were then expanded with a 3 mm margin excluding the rectum to form the planning target volume (PTV) from the respective CTV. This is shown in figure 1A. Two dosimetric models and parameters were compared in each case. The model A used 10mm intervals between all needles, and the model B used additional needles at 5mm intervals between each needle for the boost area as shown in figure 1B and 1C. PTV2 was prescribed to 21Gy with the aim that 95% of the prescription volume received this dose. 15Gy to 95% of the PTV non-boost volume was also defined. Based on the dose volume histograms, a conformity index (CI), a modified healthy tissues conformity index (mHTCI), a conformation number (CN), and a conformal index (COIN) have been defined in evaluating treatment plan conformality to PTV2.
Figure 1: The drawing of contouring is shown as 1A. The light blue line is CTV1, the dark blue line is PTV1, the red line is CTV2, and the orange line is PTV2. The example of the dose distribution of between 1 cm interval (Model A) and 0.5 cm interval between each needle for boost area (Model B) are shown as 1B, and 1C, respectively. Results: Three of thirty-two plans did not achieve the plan objectives. These three plans were in the model A. A higher median urethral volume was seen in the 'unsuccessful' group (2.7cc, and 1.9cc, respectively, pvalue=0.12). The conformity indices of the model B were also better than that of the model A as shown in table 1. Table 1:Treatment plan evaluation by the Conformity Index (CI), modified Healthy TissueConformity Index (mHTCI), Conformation Number (CN), and Conformal Index (COIN). Conclusions: Focal monotherapy based on functional MRI is feasible. Optimal dosimetry can be achieved by individualizing the needle positions using 5mm spacing rather than 10mm spacing within the boost volume. A larger urethral volume may have an adverse effect on this distribution. Formal clinical evaluation of this approach is required and is currently underway.
ESTRO 33, 2014 PO-1035 Comparison of permanent 125-I seeds implants with two different techniques in 500 cases of prostate cancer J.L. Guinot1, J.V. Ricós2, M.I. Tortajada1, M.A. Santos1, J. Perez1, A. Martos1, C. Guardino3, V. De los Dolores3, V. González3, J. Casanova2 1 Fundación Instituto Valenciano de Oncologia, Department of Radiation Oncology, Valencia, Spain 2 Fundación Instituto Valenciano de Oncologia, Department of Urology, Valencia, Spain 3 Fundación Instituto Valenciano de Oncologia, Department of Medical Physics, Valencia, Spain Purpose/Objective: To compare the experience of 500 consecutive implants with 125-I seeds for intracapsular prostate carcinoma by two different techniques: Fixed stranded seeds with RapidStrand™ and preplanning system, in front of real-time and Bard Pro-Link system™ (a method that allows to link seeds at any distance between them) Materials and Methods: From Dec 2002 to Oct 2007 we have performed 250 implants with LDR brachytherapy with RapidStrand™ and preplanning system and from Nov 2007 to Dec 2010, 266 with real-time and Bard ProLink system™. Nine patients were lost and twelve were excluded. In each group mean age was 68 and 66 respectively, PSA was 7.3 and 7.2 (PSA was under 10 in 87 and 85%). T1-T2a was the stage in 98 and 94%, and Gleason=<6 in 96 and 86%. Low risk cases (EORTC) were 81and 71%. The prescribed dose was 145 Gy to the prostate volume. 108 Gy plus EBRT46 Gy was given to intermediate risk cases in 26%of the first group and 73% of the second group. Hormonal treatment was given to 42 and 28%. Biochemical failure(BF) was defined according to Phoenix criteria. Results: With a median follow-upof 48 and 47 months respectively, 14 patients in the first group and 7 patients in the second one showed a BF. Actuarial PSA relapse-free survival at 5 years increased from 91% to 97.2%, (low risk from 92 to 97.2%, intermediate risk from 86 to 97.1%). Patients with PSA >10 showed an improvement from 81% to 93.8%, and cases with PSA <10 from 92 to 97.6%. Hormonal treatment had no influence in BF. Rectal complications were G1-2 in17.6 and 5.2% respectively. A urinary catheter was necessary in 6.9 and 9.6%,and urethral resection in 1.9 and 4.4% at long term. In one patient of the second group a cistectomy was required to treat a microbladder four years later. Sexual function was conserved in about 60% in both cases. The dosimetry with a postoperative CT planning at 1 month improved from a mean V100 of 89 to 93% and a D90 of 143 Gy to 157 Gy when using real-time and Bard Pro-Link system™. When dosimetry was done at the end of the implant with ultrasound control in the real-time group, mean V100 was 97% and D90 171 Gy. Conclusions: The outcome of patients with low risk prostate carcinoma treated with I-125 seed is very good with very low complications rate. Real-time approach and Bard Pro-Link system™ allows a more exact seed implantation, better dosimetry and better results with similar complications rate. In the intermediate risk group a combined treatment with EBRT plus this second technique yields the best results PO-1036 Intraoperative HDR brachytherapy and external beam radiotherapy for prostate cancer: long-term outcomes R. Galalae MD PhD1, N. Brüske1, F. Geiger2, F.A. Siebert3, P. Jiang3, B. Kimmig1, J. Dunst3 1 Christian-Albrechts-University, Medical Faculty, Kiel, Germany 2 University Hospital Schleswig-Holstein, Department of General Pediatrics, Kiel, Germany 3 University Hospital Schleswig-Holstein, Department of Radiotherapy, Kiel, Germany Purpose/Objective: Long-term results of our well known specific method were previously published and showed excellent outcomes. The aim of this study was to evaluate the 5-year results of our protocol 3 (since introduction of intraoperative technique in 2003). Materials and Methods: Interstitial image-guided, intraoperative planned High-Dose-Rate (HDR) brachytherapy was used to escalate the dose in addition to small pelvis conformal external beam radiotherapy (EBRT) to a total EQD2 (biological equivalent Dose 2 Gy per fraction) of 80.9 Gy in CTV2 (entire prostate), and 127.25 Gy in CTV1 (peripheral zone) estimating α/β=3. Total dose and daily fractionation remained unchanged to predecessor protocols 1 and 2. The first consecutive treated 98 patients were analyzed and the endpoints overall survival, cancer-specific survival, local recurrence/distant metastases rates, and biochemical control rate according to ASTRO and Phoenix definitions were calculated by using the Kaplan-Meier method, and the log-rank test in univariate analyses.
Figure 1: The drawing of contouring is shown as 1A. The light blue line is CTV1, the dark blue line is PTV1, the red line is CTV2, and the orange line is PTV2. The example of the dose distribution of between 1 cm interval (Model A) and 0.5 cm interval between each needle for boost area (Model B) are shown as 1B, and 1C, respectively. Results: Three of thirty-two plans did not achieve the plan objectives. These three plans were in the model A. A higher median urethral volume was seen in the 'unsuccessful' group (2.7cc, and 1.9cc, respectively, pvalue=0.12). The conformity indices of the model B were also better than that of the model A as shown in table 1. Table 1:Treatment plan evaluation by the Conformity Index (CI), modified Healthy TissueConformity Index (mHTCI), Conformation Number (CN), and Conformal Index (COIN). Conclusions: Focal monotherapy based on functional MRI is feasible. Optimal dosimetry can be achieved by individualizing the needle positions using 5mm spacing rather than 10mm spacing within the boost volume. A larger urethral volume may have an adverse effect on this distribution. Formal clinical evaluation of this approach is required and is currently underway.
ESTRO 33, 2014 PO-1035 Comparison of permanent 125-I seeds implants with two different techniques in 500 cases of prostate cancer J.L. Guinot1, J.V. Ricós2, M.I. Tortajada1, M.A. Santos1, J. Perez1, A. Martos1, C. Guardino3, V. De los Dolores3, V. González3, J. Casanova2 1 Fundación Instituto Valenciano de Oncologia, Department of Radiation Oncology, Valencia, Spain 2 Fundación Instituto Valenciano de Oncologia, Department of Urology, Valencia, Spain 3 Fundación Instituto Valenciano de Oncologia, Department of Medical Physics, Valencia, Spain Purpose/Objective: To compare the experience of 500 consecutive implants with 125-I seeds for intracapsular prostate carcinoma by two different techniques: Fixed stranded seeds with RapidStrand™ and preplanning system, in front of real-time and Bard Pro-Link system™ (a method that allows to link seeds at any distance between them) Materials and Methods: From Dec 2002 to Oct 2007 we have performed 250 implants with LDR brachytherapy with RapidStrand™ and preplanning system and from Nov 2007 to Dec 2010, 266 with real-time and Bard ProLink system™. Nine patients were lost and twelve were excluded. In each group mean age was 68 and 66 respectively, PSA was 7.3 and 7.2 (PSA was under 10 in 87 and 85%). T1-T2a was the stage in 98 and 94%, and Gleason=<6 in 96 and 86%. Low risk cases (EORTC) were 81and 71%. The prescribed dose was 145 Gy to the prostate volume. 108 Gy plus EBRT46 Gy was given to intermediate risk cases in 26%of the first group and 73% of the second group. Hormonal treatment was given to 42 and 28%. Biochemical failure(BF) was defined according to Phoenix criteria. Results: With a median follow-upof 48 and 47 months respectively, 14 patients in the first group and 7 patients in the second one showed a BF. Actuarial PSA relapse-free survival at 5 years increased from 91% to 97.2%, (low risk from 92 to 97.2%, intermediate risk from 86 to 97.1%). Patients with PSA >10 showed an improvement from 81% to 93.8%, and cases with PSA <10 from 92 to 97.6%. Hormonal treatment had no influence in BF. Rectal complications were G1-2 in17.6 and 5.2% respectively. A urinary catheter was necessary in 6.9 and 9.6%,and urethral resection in 1.9 and 4.4% at long term. In one patient of the second group a cistectomy was required to treat a microbladder four years later. Sexual function was conserved in about 60% in both cases. The dosimetry with a postoperative CT planning at 1 month improved from a mean V100 of 89 to 93% and a D90 of 143 Gy to 157 Gy when using real-time and Bard Pro-Link system™. When dosimetry was done at the end of the implant with ultrasound control in the real-time group, mean V100 was 97% and D90 171 Gy. Conclusions: The outcome of patients with low risk prostate carcinoma treated with I-125 seed is very good with very low complications rate. Real-time approach and Bard Pro-Link system™ allows a more exact seed implantation, better dosimetry and better results with similar complications rate. In the intermediate risk group a combined treatment with EBRT plus this second technique yields the best results PO-1036 Intraoperative HDR brachytherapy and external beam radiotherapy for prostate cancer: long-term outcomes R. Galalae MD PhD1, N. Brüske1, F. Geiger2, F.A. Siebert3, P. Jiang3, B. Kimmig1, J. Dunst3 1 Christian-Albrechts-University, Medical Faculty, Kiel, Germany 2 University Hospital Schleswig-Holstein, Department of General Pediatrics, Kiel, Germany 3 University Hospital Schleswig-Holstein, Department of Radiotherapy, Kiel, Germany Purpose/Objective: Long-term results of our well known specific method were previously published and showed excellent outcomes. The aim of this study was to evaluate the 5-year results of our protocol 3 (since introduction of intraoperative technique in 2003). Materials and Methods: Interstitial image-guided, intraoperative planned High-Dose-Rate (HDR) brachytherapy was used to escalate the dose in addition to small pelvis conformal external beam radiotherapy (EBRT) to a total EQD2 (biological equivalent Dose 2 Gy per fraction) of 80.9 Gy in CTV2 (entire prostate), and 127.25 Gy in CTV1 (peripheral zone) estimating α/β=3. Total dose and daily fractionation remained unchanged to predecessor protocols 1 and 2. The first consecutive treated 98 patients were analyzed and the endpoints overall survival, cancer-specific survival, local recurrence/distant metastases rates, and biochemical control rate according to ASTRO and Phoenix definitions were calculated by using the Kaplan-Meier method, and the log-rank test in univariate analyses.