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EP-1294: Feasibility and safety of prophylactic nodal irradiation with SIB- IMRT in high risk prostate cancer
S86 EP-1293 Computed tomography perfusion of prostate cancer before and after radiation therapy: Early experience results G.I. Boboc1, V. Donato1, M. Osimani2, A. Laghi2, A.L. Pastore3, G. Palleschi3, A. Carbone3 1 San Camillo Forlanini Hospital, Radiotherapy, Rome, Italy 2 ICOT, Radiology, Latina, Italy 3 ICOT, Urology, Latina, Italy
ESTRO 33, 2014 71 Gy for PTV1 and 56.7 Gy for PTV2. Mean dose maximum was 75.5 Gy in PTV1 and 64.8 Gy in PTV2. Gastrointestinal G3 toxicity occurred in 1 pt and G2 cystitis occurred in 2 pts.(fig 1)
Purpose/Objective: To prospectively evaluate the changes in quantitative Computed Tomography (CT) perfusion parameters in patients (pts) affected by prostate cancer and treated with externalbeam radiation therapy Materials and Methods: Between September 2011 and September 2012 we prospectively enrolled 20 pts affected by prostate cancer with Gleason Score ≥7. All pts received a diagnosis of prostatic adenocarcinoma, as determined by transperineal ultrasound-guided biopsy after preliminary clinical evaluation involving digital rectal examination and assessment of serum prostate-specific antigen (PSA) level (total PSA, free-PSA, and ratio). Three-dimensional conformal radiotherapy (3D-CRT) was used to deliver doses of 76 Gy to the prostate and seminal vesicle. Before radiation therapy all pts were treated with short-course (three-month) androgen deprivation therapy which was continued at the completion of radiotherapy due to unfavorable- risk prostate cancer. All pts enrolled underwent CT perfusion exam, before and after radiation therapy (RT). Eight contiguous 5 mm sections were acquired at 1 second intervals for 45 seconds followed by three additional scans every 10 seconds after the administration of 80 mL of iodinated contrast medium (350 mg I/mL). Prostate cancer was identified in all pts and perfusion parameters were recorded by manually defined a region of interest on tumoral areas. Using deconvolution as cinetical model, four perfusion parameters (blood volume, blood flow, mean transit time and permeability surface area product) were calculated, dividing each slice into nine square regions in order to evaluate changes after radiation therapy. Results: We obtained a statistically significant decrease of blood flow (BF) and permeability surface area product of cancerous squares (PS) (p<0,05) after RT. Both BF and PS showed the highest correlation with the response to external beam radiation therapy. Conclusions: Radiotherapy in prostate cancer seems to decrease the 'inflammatory pattern' of neo-angiogenesis (higher PS). The reported results are encouraging, and CT perfusion may be suited to monitoring prostate cancer response to radiation therapy. EP-1294 Feasibility and safety of prophylactic nodal irradiation with SIB- IMRT in high risk prostate cancer A. Leone1, D. Russo1, A. Papaleo1, E. Cavalera1, F.P. Ricci1, G. Di Paola1, V.E. Chiuri2, M. Santantonio2 1 Vito Fazzi Hospital ASL LE, Radiation Oncology, Lecce, Italy 2 Vito Fazzi Hospital ASL LE, Oncology, Lecce, Italy Purpose/Objective: Whole pelvis prophylactic irradiation in prostate cancer(PC) is still discussed because of high doses required for disease control and for its uncertain utility. However, prophylactic irradiation is recommended in patients with high risk of pelvic nodes involvement calculated on Partin nomograms. RTOG 9413 indicates pelvic irradiation in pts with high risk PC (GS 7-10 and PSA < 30 ng/ml or GS < 7 and PSA > 30 ng/ml). The aim of this paper is to evaluate feasibility and early toxicity patterns of nodal irradiation using SIB-IMRT. Materials and Methods: Between May 2008 and december 2012, in our institution 10 pts with PC demonstrate an high risk of pelvic nodal involvement. In these pts were delineated PTV1 (prostate and seminal vesicles with a margin of 10 mm in every directions and 6 mm posteriorly) and PTV2, including pelvic nodes with a 5mm-margin. Prescription doses were 70 Gy in 2.5Gy-fractions to PTV1 and 56 Gy in 2 Gy-fractions to PTV2, delivered using Serial Tomotherapy (2 pts) and VMAT (8 pts). Bladder, rectum, femoral heads and penile bulb were defined as organ at risk (OARs) and their constraints were suggested by QUANTEC (respectively V50/DT 65 Gy for bladder, V35/DT 65Gy and V50/DT 60 Gy for rectum, V40/DT 40 Gy for femoral heads,DT 52,5 Gy for penile bulb). In all pts treatment plan was obtained with Oncentra Masterplan inverse planning. Acute side effects were registered according to RTOG/EORTC criteria. Results: In all treatment plans target coverage by 95% and OARs constraints respect were required and obtained. Mean doses average was
Conclusions: Supposing an α/β of 1,5, BED in PTV1 was 80 Gy, which is considered a curative dose in PC. Moreover higher prophylactic nodal doses was prescribed, considering radiobiology of PC. Despite improvement in tumor control probability, toxicity pattern seems to be not increased, probably due to theoretical higher rectal α/β. Reduction of total fractions number to 28 (vs 40 in conventional fractionation) induced by hypofractionation represents an important issue in a Radiation Therapy Unit. EP-1295 Target motion assessment with beacon transponders during extreme hypofractionated IGRT of the prostate C. Greco1, J. Stroom1, S. Vieira1, D. Mateus2, O. Pares1, N. Pimentel1, Z. Fuks1 1 Champalimaud Foundation, Radiation Oncology, Lisboa, Portugal 2 Medical Consult / Champalimaud Foundation, Radiation Oncology, Lisboa, Portugal Purpose/Objective: Extreme hypofractionated radiation schedules may be superior to conventional fractionation schemes in the management of prostate adenocarcinoma. Safe delivery of these treatments mandates the fulfillment of strict dose/volume constraints to the adjacent normal tissues. The aim of this study is to assess the feasibility of ultra-high dose hypofractionated prostate IGRT using beacon transponder technology to measure organ motion via a catheter-based intra-urethral approach. Materials and Methods: Between July and October 2013, 10 consecutive patients with low- and intermediate-risk prostate cancer and a median age of 73 years (range 53-83) and mean CTV volume of 49 cm3 (range 3185 cm3) were included. CT/MRI fusion was used to delineate the target volume and organs-at-risk. The prescription dose was 45Gy in five fractions every other day and the location of the urethra was identified for negative dose-painting (D1cc=36Gy) to reduce treatment-related GU
ESTRO 33, 2014 71 Gy for PTV1 and 56.7 Gy for PTV2. Mean dose maximum was 75.5 Gy in PTV1 and 64.8 Gy in PTV2. Gastrointestinal G3 toxicity occurred in 1 pt and G2 cystitis occurred in 2 pts.(fig 1)
Purpose/Objective: To prospectively evaluate the changes in quantitative Computed Tomography (CT) perfusion parameters in patients (pts) affected by prostate cancer and treated with externalbeam radiation therapy Materials and Methods: Between September 2011 and September 2012 we prospectively enrolled 20 pts affected by prostate cancer with Gleason Score ≥7. All pts received a diagnosis of prostatic adenocarcinoma, as determined by transperineal ultrasound-guided biopsy after preliminary clinical evaluation involving digital rectal examination and assessment of serum prostate-specific antigen (PSA) level (total PSA, free-PSA, and ratio). Three-dimensional conformal radiotherapy (3D-CRT) was used to deliver doses of 76 Gy to the prostate and seminal vesicle. Before radiation therapy all pts were treated with short-course (three-month) androgen deprivation therapy which was continued at the completion of radiotherapy due to unfavorable- risk prostate cancer. All pts enrolled underwent CT perfusion exam, before and after radiation therapy (RT). Eight contiguous 5 mm sections were acquired at 1 second intervals for 45 seconds followed by three additional scans every 10 seconds after the administration of 80 mL of iodinated contrast medium (350 mg I/mL). Prostate cancer was identified in all pts and perfusion parameters were recorded by manually defined a region of interest on tumoral areas. Using deconvolution as cinetical model, four perfusion parameters (blood volume, blood flow, mean transit time and permeability surface area product) were calculated, dividing each slice into nine square regions in order to evaluate changes after radiation therapy. Results: We obtained a statistically significant decrease of blood flow (BF) and permeability surface area product of cancerous squares (PS) (p<0,05) after RT. Both BF and PS showed the highest correlation with the response to external beam radiation therapy. Conclusions: Radiotherapy in prostate cancer seems to decrease the 'inflammatory pattern' of neo-angiogenesis (higher PS). The reported results are encouraging, and CT perfusion may be suited to monitoring prostate cancer response to radiation therapy. EP-1294 Feasibility and safety of prophylactic nodal irradiation with SIB- IMRT in high risk prostate cancer A. Leone1, D. Russo1, A. Papaleo1, E. Cavalera1, F.P. Ricci1, G. Di Paola1, V.E. Chiuri2, M. Santantonio2 1 Vito Fazzi Hospital ASL LE, Radiation Oncology, Lecce, Italy 2 Vito Fazzi Hospital ASL LE, Oncology, Lecce, Italy Purpose/Objective: Whole pelvis prophylactic irradiation in prostate cancer(PC) is still discussed because of high doses required for disease control and for its uncertain utility. However, prophylactic irradiation is recommended in patients with high risk of pelvic nodes involvement calculated on Partin nomograms. RTOG 9413 indicates pelvic irradiation in pts with high risk PC (GS 7-10 and PSA < 30 ng/ml or GS < 7 and PSA > 30 ng/ml). The aim of this paper is to evaluate feasibility and early toxicity patterns of nodal irradiation using SIB-IMRT. Materials and Methods: Between May 2008 and december 2012, in our institution 10 pts with PC demonstrate an high risk of pelvic nodal involvement. In these pts were delineated PTV1 (prostate and seminal vesicles with a margin of 10 mm in every directions and 6 mm posteriorly) and PTV2, including pelvic nodes with a 5mm-margin. Prescription doses were 70 Gy in 2.5Gy-fractions to PTV1 and 56 Gy in 2 Gy-fractions to PTV2, delivered using Serial Tomotherapy (2 pts) and VMAT (8 pts). Bladder, rectum, femoral heads and penile bulb were defined as organ at risk (OARs) and their constraints were suggested by QUANTEC (respectively V50/DT 65 Gy for bladder, V35/DT 65Gy and V50/DT 60 Gy for rectum, V40/DT 40 Gy for femoral heads,DT 52,5 Gy for penile bulb). In all pts treatment plan was obtained with Oncentra Masterplan inverse planning. Acute side effects were registered according to RTOG/EORTC criteria. Results: In all treatment plans target coverage by 95% and OARs constraints respect were required and obtained. Mean doses average was
Conclusions: Supposing an α/β of 1,5, BED in PTV1 was 80 Gy, which is considered a curative dose in PC. Moreover higher prophylactic nodal doses was prescribed, considering radiobiology of PC. Despite improvement in tumor control probability, toxicity pattern seems to be not increased, probably due to theoretical higher rectal α/β. Reduction of total fractions number to 28 (vs 40 in conventional fractionation) induced by hypofractionation represents an important issue in a Radiation Therapy Unit. EP-1295 Target motion assessment with beacon transponders during extreme hypofractionated IGRT of the prostate C. Greco1, J. Stroom1, S. Vieira1, D. Mateus2, O. Pares1, N. Pimentel1, Z. Fuks1 1 Champalimaud Foundation, Radiation Oncology, Lisboa, Portugal 2 Medical Consult / Champalimaud Foundation, Radiation Oncology, Lisboa, Portugal Purpose/Objective: Extreme hypofractionated radiation schedules may be superior to conventional fractionation schemes in the management of prostate adenocarcinoma. Safe delivery of these treatments mandates the fulfillment of strict dose/volume constraints to the adjacent normal tissues. The aim of this study is to assess the feasibility of ultra-high dose hypofractionated prostate IGRT using beacon transponder technology to measure organ motion via a catheter-based intra-urethral approach. Materials and Methods: Between July and October 2013, 10 consecutive patients with low- and intermediate-risk prostate cancer and a median age of 73 years (range 53-83) and mean CTV volume of 49 cm3 (range 3185 cm3) were included. CT/MRI fusion was used to delineate the target volume and organs-at-risk. The prescription dose was 45Gy in five fractions every other day and the location of the urethra was identified for negative dose-painting (D1cc=36Gy) to reduce treatment-related GU