- Email: [email protected]
Comparison between High and Low Source Activity for Permanent Seed Prostate Brachytherapy with Radioactive I125
I. J. Radiation Oncology d Biology d Physics
S344
Volume 75, Number 3, Supplement, 2009
Materials/Methods: From 1993 to 2005, 742 pts underwent postoperative RT with either ADV (n = 556, median FU 90 mos, median time to RT 3.3 mos, median RT dose 70.2 Gy, range 56-74 Gy) or SALV (n = 186, median FU 79 mos, median time to RT 29 mos, median RT dose 72 Gy, range 60-78) intent. 145/556 pts in the ADV (26%) and 22/186 (12%) in the SALV group underewent also whole-pelvis irradiation (WPRT; median dose 50.4 Gy, range 45-50.4 in both groups), as part of their treament. Overall, 171 pts (131 ADV, 40 SALV) developed late urinary RTOG Grade $2 (LG2tox) and 61 (51 ADV, 10 SALV) experienced $3 (LG3tox) (two G4) sequelae after a median of 20 and 27 mos, respectively. Pts with FU \ 12 mos were excluded. Results: In ADV group, univariate analysis indicated hypertension (HYPERT), acute G$2 toxicity (AG2tox) and WPRT as variables predictive of LG2tox, while age, HYPERT and AG2tox predicted LG3tox. In SALV cohort, only AG2tox predicted LG2tox, whereas age and RT dose were related to LG3tox. In ADV group, age # 62 years (yr) emerged as the most informative cut-off concerning risk of LG3TOX (5-yr risk 12% vs 6% for age #62 vs .62 yr, respectively, p = 0.02, log rank). On the contrary, in the SALV cohort only 1/10 pts experiencing LG3tox was younger than 70 yr. The 5-yr risk of LG3tox in the ADV group was 12% vs 7% in pts with and without HYPERT (p = 0.05), and 11% vs 6% (p = 0.02) in pts # 62 vs .62 yr old; in pts with 2, 1 or 0 of these two risk factors 5-yr LG3tox was 15% vs 11% vs 5% respectively (p = 0.01). In the SALV cohort, age .70 yr and RT doses .72 Gy predicted an increased 5-yr risk of LG3tox (8% vs 2%, p = 0.0004 and 10% vs 1%, p = 0.02, respectively). Multivariate analysis (MA) indicated as covariates independently predictive of LG2tox: AG2tox (p\0.0001) and WPRT (p = 0.02) in the ADV group, and AG2tox (p \ 0.0001) in the SALV one. Factors independently predictive of LG3tox at MA were: AG2tox (p = 0.02), HYPERT (HR 2.1, p = 0.02) and age # 62 yr (HR 2.6, p = 0.04) in the ADV group, and age . 70 yr (p = 0.02) and RT dose . 72 Gy (p = 0.02) in the SALV group. Factors not predictive of late GU tox: time to RT, hormonal therapy, diabetes, non conformal RT, finality and year of treatment (RP or RT). Conclusions: In the ADV setting, patients #62 yr old with HYPERT experienced a three-fold risk of LG3tox when compared to older ones without HYPERT. In the SALV cohort, on the contrary, age . 70 yr and RT dose . 70 Gy independently predicted LG3tox. Author Disclosure: C. Cozzarini, None; C. Fiorino, None; F. Alongi, None; G. Berardi, None; A. Bolognesi, None; S. Broggi, None; A. Deli, None; M. Pasetti, None; P. Rigatti, None; N. Di Muzio, None.
2362
Comparison between High and Low Source Activity for Permanent Seed Prostate Brachytherapy with Radioactive I125
G. Masucci, D. Donath, A. Te´treault-Laflamme, Y. Hervieux, R. Larouche, J. Bahary, D. Taussky Centre Hospitalier de l’Universite´ de Montre´al (CHUM), Montre´al, QC, Canada Purpose/Objective(s): To compare low (mostly 0.42-0.46mCi) with high source activity (mostly 0.59-0.62mCi) in I125 permanent seed brachytherapy regarding seed loss, dosimetric outcome and urinary toxicity. Materials/Methods: 199 consecutive patients with mainly low-risk prostate cancer (#T2a,Gleason score#6 and prostate-specific antigen #10) were analyzed. They were treated by intraoperative (IO) permanent seed brachytherapy alone; 144 Gy were prescribed to the prostate + 3mm. The first 105 patients were treated with seeds of lower activity (first cohort); the following 94 with higher seed activity (second cohort). The V100, V150, V200 and D90 were analyzed on the IO TRUS plan and on the CT scan 30 days after implant (CTD30). For the rectum, the V100, V150 and D5 were calculated for the last 20 patients of the first cohort and the first 22 patients of the second cohort on CTD30. Seed loss was determined 30 days after implant. Conformality and homogeneity of dose distribution was calculated using a circumferential margin of 5mm around the prostate on the IO TRUS. This annular area was divided into an anterior, posterior, left and right quadrant. Urinary toxicity was measured with the IPSS (International Prostate Symptom Score) questionnaire before the implant (baseline) and then again 1 and 4 months after. Chi Square and Mann-Whitney tests were used for statistical analysis. Results: Lower seed activity was associated with a more homogenous (lower V150 and V200) implant in the IO planning setting (p = 0.01 and p = \0.001, resp.). On CTD30, only 19.8% of patients of the second cohort had a V100 \90% and D90\140 Gy compared to 32.4% of patients of the first cohort (p = 0.056). The right lateral prostate quadrant received a higher dose in patients of the second cohort (p = 0.001). For the rectum, the V100, V150 and D5 on CTD30 showed no statistically significant difference between both groups (p = 0.325-0.516). There was no statistical difference in patients’ IPSS score between baseline and at 1 (p = 0.80) and 4 months (p = 0.259) after treatment. Absolute seed loss was significantly greater for patients treated with lower seed activity (p = 0.014). Conclusions: High seed activity resulted in a better V100 and D90 of the prostate on dosimetric evaluation 30 days after the implant and reduced seed loss. Moreover, this was not associated with an increase in urinary toxicity. Author Disclosure: G. Masucci, None; D. Donath, None; A. Te´treault-Laflamme, None; Y. Hervieux, None; R. Larouche, None; J. Bahary, None; D. Taussky, None.
2363
Proton Radiotherapy for Prostate Cancer is Not Associated with Post Treatment Testosterone Suppression 1
R. Nichols , C. G. Morris1, B. G. Hoppe1, R. H. Henderson1, R. M. Marcus1, W. M. Mendenhall1, Z. Li1, C. R. Williams2, J. A. Costa2, N. P. Mendenhall1 University of Florida Proton Therapy Institute, Jacksonville, FL, 2University of Florida / Shands Hospital Division of Urology, Jacksonville, FL
1
Purpose/Objective(s): Two independent studies of photon (x-ray) therapy for prostate cancer have demonstrated evidence of testosterone suppression after treatment. The current study was undertaken to determine if this is also the case with conformal protons. Materials/Methods: From August, 2006 to October, 2007, 173 patients with low and intermediate risk localized prostate cancer were enrolled on the PR01 (low risk) and PR02 (intermediate risk) protocols. Patients received between 78 and 82 Cobalt Gray Equivalent (CGE) at 2CGE per daily fraction to the prostate. No patient received pelvic nodal irradiation. 19 Patients were excluded from analysis who either: received androgen deprivation therapy at any time prior to radiotherapy (18); or who received androgen
S344
Volume 75, Number 3, Supplement, 2009
Materials/Methods: From 1993 to 2005, 742 pts underwent postoperative RT with either ADV (n = 556, median FU 90 mos, median time to RT 3.3 mos, median RT dose 70.2 Gy, range 56-74 Gy) or SALV (n = 186, median FU 79 mos, median time to RT 29 mos, median RT dose 72 Gy, range 60-78) intent. 145/556 pts in the ADV (26%) and 22/186 (12%) in the SALV group underewent also whole-pelvis irradiation (WPRT; median dose 50.4 Gy, range 45-50.4 in both groups), as part of their treament. Overall, 171 pts (131 ADV, 40 SALV) developed late urinary RTOG Grade $2 (LG2tox) and 61 (51 ADV, 10 SALV) experienced $3 (LG3tox) (two G4) sequelae after a median of 20 and 27 mos, respectively. Pts with FU \ 12 mos were excluded. Results: In ADV group, univariate analysis indicated hypertension (HYPERT), acute G$2 toxicity (AG2tox) and WPRT as variables predictive of LG2tox, while age, HYPERT and AG2tox predicted LG3tox. In SALV cohort, only AG2tox predicted LG2tox, whereas age and RT dose were related to LG3tox. In ADV group, age # 62 years (yr) emerged as the most informative cut-off concerning risk of LG3TOX (5-yr risk 12% vs 6% for age #62 vs .62 yr, respectively, p = 0.02, log rank). On the contrary, in the SALV cohort only 1/10 pts experiencing LG3tox was younger than 70 yr. The 5-yr risk of LG3tox in the ADV group was 12% vs 7% in pts with and without HYPERT (p = 0.05), and 11% vs 6% (p = 0.02) in pts # 62 vs .62 yr old; in pts with 2, 1 or 0 of these two risk factors 5-yr LG3tox was 15% vs 11% vs 5% respectively (p = 0.01). In the SALV cohort, age .70 yr and RT doses .72 Gy predicted an increased 5-yr risk of LG3tox (8% vs 2%, p = 0.0004 and 10% vs 1%, p = 0.02, respectively). Multivariate analysis (MA) indicated as covariates independently predictive of LG2tox: AG2tox (p\0.0001) and WPRT (p = 0.02) in the ADV group, and AG2tox (p \ 0.0001) in the SALV one. Factors independently predictive of LG3tox at MA were: AG2tox (p = 0.02), HYPERT (HR 2.1, p = 0.02) and age # 62 yr (HR 2.6, p = 0.04) in the ADV group, and age . 70 yr (p = 0.02) and RT dose . 72 Gy (p = 0.02) in the SALV group. Factors not predictive of late GU tox: time to RT, hormonal therapy, diabetes, non conformal RT, finality and year of treatment (RP or RT). Conclusions: In the ADV setting, patients #62 yr old with HYPERT experienced a three-fold risk of LG3tox when compared to older ones without HYPERT. In the SALV cohort, on the contrary, age . 70 yr and RT dose . 70 Gy independently predicted LG3tox. Author Disclosure: C. Cozzarini, None; C. Fiorino, None; F. Alongi, None; G. Berardi, None; A. Bolognesi, None; S. Broggi, None; A. Deli, None; M. Pasetti, None; P. Rigatti, None; N. Di Muzio, None.
2362
Comparison between High and Low Source Activity for Permanent Seed Prostate Brachytherapy with Radioactive I125
G. Masucci, D. Donath, A. Te´treault-Laflamme, Y. Hervieux, R. Larouche, J. Bahary, D. Taussky Centre Hospitalier de l’Universite´ de Montre´al (CHUM), Montre´al, QC, Canada Purpose/Objective(s): To compare low (mostly 0.42-0.46mCi) with high source activity (mostly 0.59-0.62mCi) in I125 permanent seed brachytherapy regarding seed loss, dosimetric outcome and urinary toxicity. Materials/Methods: 199 consecutive patients with mainly low-risk prostate cancer (#T2a,Gleason score#6 and prostate-specific antigen #10) were analyzed. They were treated by intraoperative (IO) permanent seed brachytherapy alone; 144 Gy were prescribed to the prostate + 3mm. The first 105 patients were treated with seeds of lower activity (first cohort); the following 94 with higher seed activity (second cohort). The V100, V150, V200 and D90 were analyzed on the IO TRUS plan and on the CT scan 30 days after implant (CTD30). For the rectum, the V100, V150 and D5 were calculated for the last 20 patients of the first cohort and the first 22 patients of the second cohort on CTD30. Seed loss was determined 30 days after implant. Conformality and homogeneity of dose distribution was calculated using a circumferential margin of 5mm around the prostate on the IO TRUS. This annular area was divided into an anterior, posterior, left and right quadrant. Urinary toxicity was measured with the IPSS (International Prostate Symptom Score) questionnaire before the implant (baseline) and then again 1 and 4 months after. Chi Square and Mann-Whitney tests were used for statistical analysis. Results: Lower seed activity was associated with a more homogenous (lower V150 and V200) implant in the IO planning setting (p = 0.01 and p = \0.001, resp.). On CTD30, only 19.8% of patients of the second cohort had a V100 \90% and D90\140 Gy compared to 32.4% of patients of the first cohort (p = 0.056). The right lateral prostate quadrant received a higher dose in patients of the second cohort (p = 0.001). For the rectum, the V100, V150 and D5 on CTD30 showed no statistically significant difference between both groups (p = 0.325-0.516). There was no statistical difference in patients’ IPSS score between baseline and at 1 (p = 0.80) and 4 months (p = 0.259) after treatment. Absolute seed loss was significantly greater for patients treated with lower seed activity (p = 0.014). Conclusions: High seed activity resulted in a better V100 and D90 of the prostate on dosimetric evaluation 30 days after the implant and reduced seed loss. Moreover, this was not associated with an increase in urinary toxicity. Author Disclosure: G. Masucci, None; D. Donath, None; A. Te´treault-Laflamme, None; Y. Hervieux, None; R. Larouche, None; J. Bahary, None; D. Taussky, None.
2363
Proton Radiotherapy for Prostate Cancer is Not Associated with Post Treatment Testosterone Suppression 1
R. Nichols , C. G. Morris1, B. G. Hoppe1, R. H. Henderson1, R. M. Marcus1, W. M. Mendenhall1, Z. Li1, C. R. Williams2, J. A. Costa2, N. P. Mendenhall1 University of Florida Proton Therapy Institute, Jacksonville, FL, 2University of Florida / Shands Hospital Division of Urology, Jacksonville, FL
1
Purpose/Objective(s): Two independent studies of photon (x-ray) therapy for prostate cancer have demonstrated evidence of testosterone suppression after treatment. The current study was undertaken to determine if this is also the case with conformal protons. Materials/Methods: From August, 2006 to October, 2007, 173 patients with low and intermediate risk localized prostate cancer were enrolled on the PR01 (low risk) and PR02 (intermediate risk) protocols. Patients received between 78 and 82 Cobalt Gray Equivalent (CGE) at 2CGE per daily fraction to the prostate. No patient received pelvic nodal irradiation. 19 Patients were excluded from analysis who either: received androgen deprivation therapy at any time prior to radiotherapy (18); or who received androgen