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P067 Comparison of available dynamic techniques for elective nodal irradiation for prostate cancer patients
posters / european urology supplements 11 (2012) 191–235
number of cores at diagnosis, total number of cores at 1 yrrebiopsy, prostate volume, DRE were considered as factors potentially influencing upgrading (UPG) /upsizing (UPS). GPS was not considered (all pts had GPS = +3). Three separate endpoints were considered: (1) UPS OR UPG; (2) UPG and (3) UPS. Multivariable logistic regression (MVLR) was used to analyze correlations between variables and endpoints at first re-biopsy. Results: Statistical analysis was performed on 255pts with complete records (1 yr min f-up). 40%pts had a negative 1 yr biopsy (0 positive cores), 45pts had UPS/UPG after re-biopsy, switching to radical treatment. The endpoint “UPS OR UPG” was only related to prostate volume >60 cc (OR = 0.27, p = 0.04). When UPG (27pts) was considered separately a 3-variable model was determined (p = 0.018, AUC = 0.71): age >60 yrs (OR = 3.4, p = 0.12), PSA density (continuous variable, OR = 1.04, p = 0.16) and prostate volume >60 cc (OR = 0.17, p = 0.1). Taking UPS (18pts) as the endpoint, MLVR resulted in a 4-variable model (p = 0.03, AUC = 0.73) including: DRE (T2a vs T1c, OR = 3.03, p = 0.16), total number of cores at 1-yr re-biopsy (discrete variable, OR = 1.14, p = 0.18), age >60 yrs (OR = 0.48, p = 0.23) and max core length containing cancer >10% (OR = 3.4, p = 0.03). Conclusions: UPS is strongly related to “volume” variables, and, as a consequence, may be strongly affected by sampling. UPG is more related to PSA density. It is noteworthy as age has an opposite effect on the two endpoints (protective for UPS and risk factor for UPG) and that max core length containing cancer is highly predictive of UPS. Such analysis may generate the hypothesis that two different populations of PCa pts are subjected to drop-off from AS protocols. Biological and clinical implications deserve further studies. Supported by Fond Monzino. P067 Comparison of available dynamic techniques for elective nodal irradiation for prostate cancer patients 1 H.A. Urbanczyk ´ , L. Hawrylewicz2 , R. Kulik2 , K. Szczepanik1 , J. Ciechowicz3 . 1 MSC Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Dept. of Radiotherapy, Gliwice, Poland; 2 MSC Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Dept. of Radiotherapy Planning, Gliwice, Poland; 3 Medical University In Ł´ od´z, Computer Laboratory, Ł´ od´z, Poland
Introduction & Objectives: The few recent studies showed that regional lymph node metastases of prostate cancer (PCa) could be successfully treated. It means that role of pelvic nodes (PN) irradiation could increase in next period. A problem is rectal and bladder toxicities of this treatment. Intensity modulated dynamic irradiation techniques (DT) may potentially help to reduce treatment related side effects. The aim of study is to compare three different radiotherapy techniques: conformal (CRT), static field intensity modulated (SF IMRT) and rapid arc (RA) for elective pelvic lymph nodes irradiation. Material & Methods: We analyzed CRT, IMRT and RA plans of irradiation PN for ten patients. PTVs included PN iliac, iliac external upper then acetabulum, iliac internal and obturatory. Prescribed doses were 44 Gy/22 fractions. We compared the doses delivered to PTV rectum and bladder using dose volume histograms. The U Mann-Whitney, W Shapiro-Wilk and ANOVA rang Kruskal-Wallis tests were used for statistical analysis. Results: The median PTV doses were not statistically different in analyzed plans. The minimum doses for PTV were significantly lower in IMRT and RA plans but the differences were not clinically significant. Maximum doses were significantly higher for CRT plans. The doses calculated for rectum and bladder were statistically significantly lower for dynamic techniques in whole range of volumes and doses. SF IMRT is the most efficient technique in reducing the dose to bladder. The doses observed
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in half of the rectum and bladder volumes bladder were also statistically significant different (p = 0.002 for rectum and 0.001 for bladder). The median doses for rectum were 43.6 Gy for CRT plans, 33.5 Gy for IMRT and 37.9 Gy for RA, median doses calculated for bladder were 44 Gy for CRT, 35.6 Gy for IMRT and 39.6 Gy for RA. Conclusions: CRT does not allow to reduce the dose to organs at risk. Both DT reduce the doses to bladder and rectum while maintaining the high homogenous dose to PTV. SF IMRT is more efficient in reducing the dose to bladder than RA. SF IMRT technique seems to be better than Rapid Arc for PN irradiation. It is probably because the nodal PTVs are large and their structures are complicated. P068 Active surveillance in prostate cancer: 7 year experience C. Marenghi1 , N. Nicolai2 , T. Rancati1 , M.F. Alvisi1 , L. Bellardita1 , B. Avuzzi3 , S. Stagni2 , S. Villa3 , T. Magnani1 , N. Bedini3 , R. Salvioni2 , R. Valdagni4 . 1 Fondazione IRCCS Istituto Nazionale Dei Tumori, Prostate Cancer Program, Milan, Italy; 2 Fondazione IRCCS Istituto Nazionale Dei Tumori, Dept. of Urology, Milan, Italy; 3 Fondazione IRCCS Istituto Nazionale Dei Tumori, Dept. of Radiotherapy, Milan, Italy; 4 Fondazione IRCCS Istituto Nazionale Dei Tumori, Prostate Cancer Program and Dept. of Radiation Oncology 1, Milan, Italy Introduction & Objectives: We here present results on 7 year experience in active surveillance (AS). Material & Methods: In our Institute patients can enter 2 AS protocols: SAINT and PRIAS. The 2 protocols have some common entry criteria: initial PSA ≤10 ng/ml, DRE ≤T2 and GPS ≤3+3. SAINT requires max 20% positive cores and max 50% core involvement, while PRIAS max 2 positive cores and PSA density <0.2 ng/ml/cc. Follow-up includes in both cases PSA every 3mos, DRE every 6mos, re-biopsy after 1 yr of AS. When PSA doubling time (DT) = 3–10 yrs a yearly repeated biopsy is scheduled. Whenever during the follow-up the PSADT <3 yrs, clinical stage is >T2, the re-biopsies show more than 2 (or 20%) positive cores or GPS >3+3, change to active treatment is advised.
Results: 342 pts were enrolled in AS (February 2012): 120 SAINT and 222 PRIAS. 215/342 (62.9%) pts are still in AS (median f-up of 33 mos, range 1.5–96.1; median time in AS 22.5 mos, range 1.5–96.1): 6 pts dropped out due to comorbidities, 7 due to
number of cores at diagnosis, total number of cores at 1 yrrebiopsy, prostate volume, DRE were considered as factors potentially influencing upgrading (UPG) /upsizing (UPS). GPS was not considered (all pts had GPS = +3). Three separate endpoints were considered: (1) UPS OR UPG; (2) UPG and (3) UPS. Multivariable logistic regression (MVLR) was used to analyze correlations between variables and endpoints at first re-biopsy. Results: Statistical analysis was performed on 255pts with complete records (1 yr min f-up). 40%pts had a negative 1 yr biopsy (0 positive cores), 45pts had UPS/UPG after re-biopsy, switching to radical treatment. The endpoint “UPS OR UPG” was only related to prostate volume >60 cc (OR = 0.27, p = 0.04). When UPG (27pts) was considered separately a 3-variable model was determined (p = 0.018, AUC = 0.71): age >60 yrs (OR = 3.4, p = 0.12), PSA density (continuous variable, OR = 1.04, p = 0.16) and prostate volume >60 cc (OR = 0.17, p = 0.1). Taking UPS (18pts) as the endpoint, MLVR resulted in a 4-variable model (p = 0.03, AUC = 0.73) including: DRE (T2a vs T1c, OR = 3.03, p = 0.16), total number of cores at 1-yr re-biopsy (discrete variable, OR = 1.14, p = 0.18), age >60 yrs (OR = 0.48, p = 0.23) and max core length containing cancer >10% (OR = 3.4, p = 0.03). Conclusions: UPS is strongly related to “volume” variables, and, as a consequence, may be strongly affected by sampling. UPG is more related to PSA density. It is noteworthy as age has an opposite effect on the two endpoints (protective for UPS and risk factor for UPG) and that max core length containing cancer is highly predictive of UPS. Such analysis may generate the hypothesis that two different populations of PCa pts are subjected to drop-off from AS protocols. Biological and clinical implications deserve further studies. Supported by Fond Monzino. P067 Comparison of available dynamic techniques for elective nodal irradiation for prostate cancer patients 1 H.A. Urbanczyk ´ , L. Hawrylewicz2 , R. Kulik2 , K. Szczepanik1 , J. Ciechowicz3 . 1 MSC Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Dept. of Radiotherapy, Gliwice, Poland; 2 MSC Memorial Cancer Center and Institute of Oncology, Gliwice Branch, Dept. of Radiotherapy Planning, Gliwice, Poland; 3 Medical University In Ł´ od´z, Computer Laboratory, Ł´ od´z, Poland
Introduction & Objectives: The few recent studies showed that regional lymph node metastases of prostate cancer (PCa) could be successfully treated. It means that role of pelvic nodes (PN) irradiation could increase in next period. A problem is rectal and bladder toxicities of this treatment. Intensity modulated dynamic irradiation techniques (DT) may potentially help to reduce treatment related side effects. The aim of study is to compare three different radiotherapy techniques: conformal (CRT), static field intensity modulated (SF IMRT) and rapid arc (RA) for elective pelvic lymph nodes irradiation. Material & Methods: We analyzed CRT, IMRT and RA plans of irradiation PN for ten patients. PTVs included PN iliac, iliac external upper then acetabulum, iliac internal and obturatory. Prescribed doses were 44 Gy/22 fractions. We compared the doses delivered to PTV rectum and bladder using dose volume histograms. The U Mann-Whitney, W Shapiro-Wilk and ANOVA rang Kruskal-Wallis tests were used for statistical analysis. Results: The median PTV doses were not statistically different in analyzed plans. The minimum doses for PTV were significantly lower in IMRT and RA plans but the differences were not clinically significant. Maximum doses were significantly higher for CRT plans. The doses calculated for rectum and bladder were statistically significantly lower for dynamic techniques in whole range of volumes and doses. SF IMRT is the most efficient technique in reducing the dose to bladder. The doses observed
213
in half of the rectum and bladder volumes bladder were also statistically significant different (p = 0.002 for rectum and 0.001 for bladder). The median doses for rectum were 43.6 Gy for CRT plans, 33.5 Gy for IMRT and 37.9 Gy for RA, median doses calculated for bladder were 44 Gy for CRT, 35.6 Gy for IMRT and 39.6 Gy for RA. Conclusions: CRT does not allow to reduce the dose to organs at risk. Both DT reduce the doses to bladder and rectum while maintaining the high homogenous dose to PTV. SF IMRT is more efficient in reducing the dose to bladder than RA. SF IMRT technique seems to be better than Rapid Arc for PN irradiation. It is probably because the nodal PTVs are large and their structures are complicated. P068 Active surveillance in prostate cancer: 7 year experience C. Marenghi1 , N. Nicolai2 , T. Rancati1 , M.F. Alvisi1 , L. Bellardita1 , B. Avuzzi3 , S. Stagni2 , S. Villa3 , T. Magnani1 , N. Bedini3 , R. Salvioni2 , R. Valdagni4 . 1 Fondazione IRCCS Istituto Nazionale Dei Tumori, Prostate Cancer Program, Milan, Italy; 2 Fondazione IRCCS Istituto Nazionale Dei Tumori, Dept. of Urology, Milan, Italy; 3 Fondazione IRCCS Istituto Nazionale Dei Tumori, Dept. of Radiotherapy, Milan, Italy; 4 Fondazione IRCCS Istituto Nazionale Dei Tumori, Prostate Cancer Program and Dept. of Radiation Oncology 1, Milan, Italy Introduction & Objectives: We here present results on 7 year experience in active surveillance (AS). Material & Methods: In our Institute patients can enter 2 AS protocols: SAINT and PRIAS. The 2 protocols have some common entry criteria: initial PSA ≤10 ng/ml, DRE ≤T2 and GPS ≤3+3. SAINT requires max 20% positive cores and max 50% core involvement, while PRIAS max 2 positive cores and PSA density <0.2 ng/ml/cc. Follow-up includes in both cases PSA every 3mos, DRE every 6mos, re-biopsy after 1 yr of AS. When PSA doubling time (DT) = 3–10 yrs a yearly repeated biopsy is scheduled. Whenever during the follow-up the PSADT <3 yrs, clinical stage is >T2, the re-biopsies show more than 2 (or 20%) positive cores or GPS >3+3, change to active treatment is advised.
Results: 342 pts were enrolled in AS (February 2012): 120 SAINT and 222 PRIAS. 215/342 (62.9%) pts are still in AS (median f-up of 33 mos, range 1.5–96.1; median time in AS 22.5 mos, range 1.5–96.1): 6 pts dropped out due to comorbidities, 7 due to