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EP-1326: Long term patients clinical outcome after salvage post-prostatectomy Radiation Therapy (RT)
S711 ESTRO 36 _______________________________________________________________________________________________
04/2015 were retrospectively analyzed. RT was administered using a simultaneous integrated boost (SIB) to the area at risk (37 fractions of 1.9 Gy, total dose: 70.3 Gy) being defined based on histopathological findings (T3 region, R1 region) and in a few cases according to additional diagnostic imaging information. The whole prostate bed was treated with a dose of 66.6 Gy (37 fractions of 1.8 Gy). Primary endpoints were acute and late genitourinary (GU) and gastrointestinal (GI) toxicities according to the National Cancer Institute Common Terminology Criteria version 4.0 (CTCAEv4.0). Secondary endpoints included patient reported outcome as assessed by the International Prostate Symptom Score (IPSS) and the International Consultation on Incontinence questionnaire (ICIQ), as well as biochemical recurrence defined as a prostate specific antigen (PSA) of 0.4 ng/ml and rising. Results A total of 69 patients were analyzed. Sixteen patients underwent adjuvant radiation therapy (ART) and 53 patients salvage radiation therapy (SRT), respectively. The median follow-up was 20 months (range, 8-41 months). Six (8.7%) and four (5.8%) patients experienced acute grade 2 GU and GI toxicity. Two patients (2.9%) had late grade 2 GU toxicity, whereas no late grade 2 GI nor any grade 3 acute or late GU or GI events were observed. When compared to the baseline urinary symptoms (p=1.0) and incontinence (p=0.9) were not significantly different at the end of follow-up. A total of seven patients (10.1%) experienced a biochemical recurrence with the 2-year biochemical recurrence-free survival (bRFS) being 91%. A persistant PSA ≥ 0.5 ng/ml after RP was significantly associated with decreased bRFS (p=0.028). Conclusion Risk adapted dose intensified postoperative RT is feasible and associated with favorable acute and late GU and GI toxicity rates and promising bRFS rates. EP-1326 Long term patients clinical outcome after salvage post-prostatectomy Radiation Therapy (RT) P. Pietro gabriele1, E. Elisabetta garibaldi2, A. Angelo maggio3, e. Elena delmastro4, a. Andrea galla4, s. Sara bresciani5, D. Domenico Gabriele6, M. Michele Stasi5 1 irccs-fpo candiolo cancer center, radiotherapy pedartment, candiolo turin, italy 2 irccs-fpo candiolo cancer cenetr, radiotherapy department, candiolo turin, italy 3 irccs-fpo candiolo cancer institute, medical physics, candiolo turin, italy 4 irccs-fpo candiolo cancer center, radiotherapy department, candiolo turin, italy 5 irccs-fpo candiolo cancer center, medical physics, candiolo turin, italy 6 sassari university, radiotherapy department, sassari, italy Purpose or Objective To study the outcome of patients treated for prostate cancer with salvage radiotherapy after radical surgery. Material and Methods From January 2000 to December 2015 we treated for salvage in our Institution 234 patients (44-75 ys, median 64) affected by prostate cancer operated and with biochemical/clinical recurrences. The pre surgery PSA was 9 (0.36-90) ng/mL, pathologic GS 7 (4-9) and cT1, 2, 3 and 4 were 1, 61, 137 and 1, respectively. Lymph node invasion was presented in 11 patients; the number of nodes removed was 6 (0-40) and positive margins were 64 (27 %); post-surgery PSA was 0.10 (0-2). Radiation therapy was performed with Linac from 1999 to 2009 by 3DCRT and with Tomotherapy from 2010 by IMRT-IGRT. Radiation dose were 70.2 Gy (61.6-79.2) to the prostate bed and 54 Gy (45-57.6) to the pelvis, 1.8 Gy per fraction; the pelvis
was irradiated in 46 patients (20%). 66 patients (28%) were treated during RT with hormone therapy (HT). The median time from surgery to RT was 40.7 months (range: 6-212). Results With a median FU of 117 months (17.6-303) the 10 years prostate Cancer Specific Survival was 88%; Clinical Relapse Free Survival was 67 % and Biochemical Relapse Free Survival only 36%. Cox univariate and multivariate analysis were performed and the results are the following: in multivariate analysis for Cancer Specific Survival are predictive PSA pre RT (p=0.0018; HR=1.18), PSA measured at last follow-up (p=0.0018; HR=1.04) and nodal invasion (p=0.024; HR=5.9); for Biochemical Free Survival are predictive D’Amico classification (p=0.002; HR=1.6) and cT(p=0.007; HR=1.7); for Clinical Relapse Free Survival GS(p=0.0008; HR=1.7) and last follw-up PSA(p=0.0001; HR=1.02). Conclusion In this, based on a large database, it was found that the PSA measured at last low-up was predictor of Prostate Cancer Specific and Clinical Relapse free survival while GS and D’Amico Classification were significantly independent prognostic factors of clinical relapse and Biochemical Free Survival for patients treated with postprostatectomy salvage RT. Acknowledgments: This work was supported by “5 per Mille 2009 MinisteroSalute-FPRC Onlus”. EP-1327 Decision Support System to implant a rectum spacer during prostate cancer radiotherapy Y. Van Wijk1, B. Vanneste2, S. Walsh2, S. Van der Meer3, B. Ramaekers4, W. Van Elmpt2, M. Pinkawa5, P. Lambin2 1 Maastricht university, School for Oncology and Developmental Biology, Maastricht, The Netherlands 2 MAASTRO clinic, Radio Oncology, Maastricht, The Netherlands 3 Adelante Zorggroep, Audiology, Maastricht, The Netherlands 4 Maastricht university, Heath Economics, Maastricht, The Netherlands 5 University Hospital Aachen, Michael Pinkawa, Aachen, Germany Purpose or Objective Dose escalation during external beam radiation in prostate cancer patients has been shown to improve progression free survival, but also leads to increased risk of gastrointestinal (GI) toxicity due to high radiation dose in the rectal wall. A method to reduce this dose is implantation of an implantable rectum spacer (IRS) to increase the distance between the rectal wall and the high dose region. Two commercial systems exist: hydrogel spacer (SPA) and Rectal balloon implant (RBI). In this study, a virtual IRS was developed to help identify the patients for whom it is cost-effective to implant an IRS. The research goal was to test whether this virtual IRS is a viable tool to tailor the decision of an IRS implantation to be beneficial for the specified patient. Material and Methods A virtual IRS was developed using a model based on scans of 11 patients with a RBI. This model was used to create a deformation field (i.e. virtual IRS) that was applied to scans of patients without an IRS. To test the virtual IRS, scans were used of 16 patients before and after the implantation of an IRS: 8 with a RBI, and 8 with a SPA. The real IRS scans were compared to scans with a virtual IRS. IMRT plans were made based on scans before the IRS, after IRS and with the virtual IRS, prescribing 78 Gy to the target volume. These plans were used to compare the rectum dose, the Normal Tissue Complication Probability (NTCP) for GI and the related cost-effectiveness of no IRS compared with the virtual IRS and the real IRS.
04/2015 were retrospectively analyzed. RT was administered using a simultaneous integrated boost (SIB) to the area at risk (37 fractions of 1.9 Gy, total dose: 70.3 Gy) being defined based on histopathological findings (T3 region, R1 region) and in a few cases according to additional diagnostic imaging information. The whole prostate bed was treated with a dose of 66.6 Gy (37 fractions of 1.8 Gy). Primary endpoints were acute and late genitourinary (GU) and gastrointestinal (GI) toxicities according to the National Cancer Institute Common Terminology Criteria version 4.0 (CTCAEv4.0). Secondary endpoints included patient reported outcome as assessed by the International Prostate Symptom Score (IPSS) and the International Consultation on Incontinence questionnaire (ICIQ), as well as biochemical recurrence defined as a prostate specific antigen (PSA) of 0.4 ng/ml and rising. Results A total of 69 patients were analyzed. Sixteen patients underwent adjuvant radiation therapy (ART) and 53 patients salvage radiation therapy (SRT), respectively. The median follow-up was 20 months (range, 8-41 months). Six (8.7%) and four (5.8%) patients experienced acute grade 2 GU and GI toxicity. Two patients (2.9%) had late grade 2 GU toxicity, whereas no late grade 2 GI nor any grade 3 acute or late GU or GI events were observed. When compared to the baseline urinary symptoms (p=1.0) and incontinence (p=0.9) were not significantly different at the end of follow-up. A total of seven patients (10.1%) experienced a biochemical recurrence with the 2-year biochemical recurrence-free survival (bRFS) being 91%. A persistant PSA ≥ 0.5 ng/ml after RP was significantly associated with decreased bRFS (p=0.028). Conclusion Risk adapted dose intensified postoperative RT is feasible and associated with favorable acute and late GU and GI toxicity rates and promising bRFS rates. EP-1326 Long term patients clinical outcome after salvage post-prostatectomy Radiation Therapy (RT) P. Pietro gabriele1, E. Elisabetta garibaldi2, A. Angelo maggio3, e. Elena delmastro4, a. Andrea galla4, s. Sara bresciani5, D. Domenico Gabriele6, M. Michele Stasi5 1 irccs-fpo candiolo cancer center, radiotherapy pedartment, candiolo turin, italy 2 irccs-fpo candiolo cancer cenetr, radiotherapy department, candiolo turin, italy 3 irccs-fpo candiolo cancer institute, medical physics, candiolo turin, italy 4 irccs-fpo candiolo cancer center, radiotherapy department, candiolo turin, italy 5 irccs-fpo candiolo cancer center, medical physics, candiolo turin, italy 6 sassari university, radiotherapy department, sassari, italy Purpose or Objective To study the outcome of patients treated for prostate cancer with salvage radiotherapy after radical surgery. Material and Methods From January 2000 to December 2015 we treated for salvage in our Institution 234 patients (44-75 ys, median 64) affected by prostate cancer operated and with biochemical/clinical recurrences. The pre surgery PSA was 9 (0.36-90) ng/mL, pathologic GS 7 (4-9) and cT1, 2, 3 and 4 were 1, 61, 137 and 1, respectively. Lymph node invasion was presented in 11 patients; the number of nodes removed was 6 (0-40) and positive margins were 64 (27 %); post-surgery PSA was 0.10 (0-2). Radiation therapy was performed with Linac from 1999 to 2009 by 3DCRT and with Tomotherapy from 2010 by IMRT-IGRT. Radiation dose were 70.2 Gy (61.6-79.2) to the prostate bed and 54 Gy (45-57.6) to the pelvis, 1.8 Gy per fraction; the pelvis
was irradiated in 46 patients (20%). 66 patients (28%) were treated during RT with hormone therapy (HT). The median time from surgery to RT was 40.7 months (range: 6-212). Results With a median FU of 117 months (17.6-303) the 10 years prostate Cancer Specific Survival was 88%; Clinical Relapse Free Survival was 67 % and Biochemical Relapse Free Survival only 36%. Cox univariate and multivariate analysis were performed and the results are the following: in multivariate analysis for Cancer Specific Survival are predictive PSA pre RT (p=0.0018; HR=1.18), PSA measured at last follow-up (p=0.0018; HR=1.04) and nodal invasion (p=0.024; HR=5.9); for Biochemical Free Survival are predictive D’Amico classification (p=0.002; HR=1.6) and cT(p=0.007; HR=1.7); for Clinical Relapse Free Survival GS(p=0.0008; HR=1.7) and last follw-up PSA(p=0.0001; HR=1.02). Conclusion In this, based on a large database, it was found that the PSA measured at last low-up was predictor of Prostate Cancer Specific and Clinical Relapse free survival while GS and D’Amico Classification were significantly independent prognostic factors of clinical relapse and Biochemical Free Survival for patients treated with postprostatectomy salvage RT. Acknowledgments: This work was supported by “5 per Mille 2009 MinisteroSalute-FPRC Onlus”. EP-1327 Decision Support System to implant a rectum spacer during prostate cancer radiotherapy Y. Van Wijk1, B. Vanneste2, S. Walsh2, S. Van der Meer3, B. Ramaekers4, W. Van Elmpt2, M. Pinkawa5, P. Lambin2 1 Maastricht university, School for Oncology and Developmental Biology, Maastricht, The Netherlands 2 MAASTRO clinic, Radio Oncology, Maastricht, The Netherlands 3 Adelante Zorggroep, Audiology, Maastricht, The Netherlands 4 Maastricht university, Heath Economics, Maastricht, The Netherlands 5 University Hospital Aachen, Michael Pinkawa, Aachen, Germany Purpose or Objective Dose escalation during external beam radiation in prostate cancer patients has been shown to improve progression free survival, but also leads to increased risk of gastrointestinal (GI) toxicity due to high radiation dose in the rectal wall. A method to reduce this dose is implantation of an implantable rectum spacer (IRS) to increase the distance between the rectal wall and the high dose region. Two commercial systems exist: hydrogel spacer (SPA) and Rectal balloon implant (RBI). In this study, a virtual IRS was developed to help identify the patients for whom it is cost-effective to implant an IRS. The research goal was to test whether this virtual IRS is a viable tool to tailor the decision of an IRS implantation to be beneficial for the specified patient. Material and Methods A virtual IRS was developed using a model based on scans of 11 patients with a RBI. This model was used to create a deformation field (i.e. virtual IRS) that was applied to scans of patients without an IRS. To test the virtual IRS, scans were used of 16 patients before and after the implantation of an IRS: 8 with a RBI, and 8 with a SPA. The real IRS scans were compared to scans with a virtual IRS. IMRT plans were made based on scans before the IRS, after IRS and with the virtual IRS, prescribing 78 Gy to the target volume. These plans were used to compare the rectum dose, the Normal Tissue Complication Probability (NTCP) for GI and the related cost-effectiveness of no IRS compared with the virtual IRS and the real IRS.