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Volumetric Modulated Arc Therapy (VMAT) Versus Helical Tomotherapy (HT) for Localized Prostate Cancer: Dosimetric Comparison by Using the Identical Prescription Dose to the Prostate
Poster Viewing Abstracts S375
Volume 87 Number 2S Supplement 2013 Conclusions: High-dose IMRT with intraprostatic fiducial markers is associated with a very low toxicity and with a significant lower rate of GI and GU complications compared to 3DCRT even considering the lower follow-up for the IMRT cohort. These data confirms that this technique is safe to deliver radiation dose above 80 Gy. Author Disclosure: A. Zapatero: None. F. Garcı´a-Vicente: None. C. Matı´n de Vidales: None. G. Rodriguez: None. O. Leaman: None. R. Bermudez: None. A. Cruz-Conde: None. O. Lin˜an: None. L. Perez: None. J. Torres: None.
2446 Quality of Life Impact of Treatments for Localized Prostate Cancer F. Ferrer,1 F. Guedea,1 Y. Pardo,2 M. Ferrer,2 J. Suarez,3 A. Herva´s,4 A. Marin˜o,5 I. Herruzo,6 M. Ortiz,7 and G. Sancho8; 1Institut Catala` d’Oncologia, L’Hospitalet-Barcelona, Spain, 2IMIM (Hospital del Mar Research Institute), Health Services Research Unit, Barcelona, Spain, 3 Hospital Universitari de Bellvitge, L’Hospitalet-Barcelona, Spain, 4 Hospital Ramon y Cajal, Madrid, Spain, 5Centro Oncolo´gico de Galicia, A Corun˜a, Spain, 6Hospital Regional Carlos Haya, Ma´laga, Spain, 7 Hospital Virgen del Rocı´o, Sevilla, Spain, 8Hospital de la Santa Creu i Sant Pau, Barcelona, Spain Purpose/Objective(s): All treatments in localized prostate cancer cause urinary, bowel, or sexual dysfunction with different frequency, duration, and severity. Long-term quality of life (QOL) impact of side effects per localized prostate cancer treatment has been poorly documented. The objective was to assess treatments’ QOL impact in localized prostate cancer patients who underwent radical prostatectomy, external beam radiation therapy or brachytherapy, from pre-treatment to seven years after the intervention. Materials/Methods: This is a prospective, observational study of 704 patients recruited in 10 Spanish hospitals (2003-2005), with follow-up until 7-years after treatment. The sample was composed by consecutive patients with low or intermediate risk localized prostate cancer. The surgery group underwent radical retropubic prostatectomy, and the nervesparing technique was used at the surgeon’s discretion. External-beam radiation was 3D conformal. Treatment was delivered with 1.8 Gy to 2.0 Gy daily fractions to a mean dose of 73.7 Gy (standard deviation [SD] Z 5.0) to the prostate planning target volume. In the brachytherapy group, participants received 125I, and the prescription dose was 144 Gy to the reference isodose (100%). The median dose of D90 and V100% was 158 Gy and 93%, respectively. The EPIC was administered pre-treatment and annually posttreatment and Generalized Estimating Equation (GEE) models were constructed to assess impact on Quality of Life (QOL). Results: QOL impact of brachytherapy was presented into the urinary and sexual domains, with GEE coefficients at 7 years indicating worsening of 12.5 points in incontinence, 4.4 in irritative-obstructive, and 7.6 in sexual scores (p < 0.001). Compared to brachytherapy, radical prostatectomy fared 18.9 points worse in incontinence, and 14.2 in sexual scores (p < 0.001). Conclusions: This study provides novel long-term results showing that, despite minor late changes which tend to reduce differences between treatments, brachytherapy produced the lowest QOL impact (mainly restricted to the urinary domain). Radical Prostatectomy caused considerably greater urinary incontinence and sexual dysfunction, and external radiation therapy greater bowel impact. Author Disclosure: F. Ferrer: None. F. Guedea: None. Y. Pardo: None. M. Ferrer: None. J. Suarez: None. A. Herva´s: None. A. Marin˜o: None. I. Herruzo: None. M. Ortiz: None. G. Sancho: None.
2447 Volumetric Modulated Arc Therapy (VMAT) Versus Helical Tomotherapy (HT) for Localized Prostate Cancer: Dosimetric Comparison by Using the Identical Prescription Dose to the Prostate S. Ayakawa,1 C. Sugie,2 F. Baba,3 A. Hayashi,2 K. Kosaki,1 Y. Nonogaki,1 S. Hasegawa,1 S. Tanaka,1 K. Komai,4 and Y. Shibamoto2; 1Social Insurance Chukyo Hospital, Nagoya, Japan, 2Nagoya City University
Graduate School of Medical Sciences, Nagoya, Japan, 3Nagoya City West Medical Center, Nagoya, Japan, 4Nagoya Daini Red Cross Hospital, Nagoya, Japan Purpose/Objective(s): The two modern radiation therapy techniques, VMATand HT, are the major innovations in high-precision radiation therapy. Both could provide better coverage of the planning target volume (PTV) and sparing of organs at risk (OAR) than conventional IMRT. Several planning studies have compared the two modalities, but there have been no consensus regarding the superiority of either one, except that VMAT provides shorter treatment time than HT. The discrepancies among previous studies may come from the tumor sites investigated and policies of treatment planning (i.e., which factors are prioritized). The purpose of this study was to compare the dose-volume parameters of VMAT and HT for prostate cancer by using the identical dose prescription to 95% of the PTV. Materials/Methods: Fifteen patients (T1-3N0M0) who received radical radiation therapy were selected. VMAT and HT plans were generated for each patient: plans of single-arc VMAT with 10-MV X rays were created, and HT plans with 6-MV X rays were produced. The PTV was defined as the prostate and all (for T3 stage) or a part (for T1 and T2) of the seminal vesicles plus margins. The prescription dose of the PTV was 74.8 Gy in 34 fractions, and 95% of the PTV was planned to receive over 90% of the prescription dose in both plans. The PTV D95% was set to be within 1% in the two plans. The target coverage, homogeneity index (HI), conformity index (CI), OAR dose, monitor units (MU), and treatment delivery time were compared. Wilcoxon signed rank test was used for statistical analysis. Results: VMAT and HT plans were comparable with respect to target coverage (PTV D95%, V95%, Dmax and Dmin), but VMAT produced a higher PTV D50% and Dmean. Median HI was 1.09 for VMATand 1.08 for HT (p Z 0.031). Median CI was better in VMAT (1.10) than in HT (1.27). HT showed better dose sparing to the rectum than VMAT; V70 Gy, V20 Gy, Dmax, Dmean and Dmean of Rectum-PTV (the rectum not overlapping with the PTV) were significantly lower, although there were no differences in V60 Gy and V40 Gy. On the other hand, VMAT showed better dose sparing for the bladder than HT; V70 Gy, V65 Gy, V40 Gy, V20 Gy, Dmax and Dmean were significantly lower. Median MU were 563 in VMAT and 3424 in HT. Median treatment time was 76.2 seconds in VMAT and 243.3 seconds in HT. Conclusions: Both VMAT and HT provide high quality conformal plans for localized prostate cancer. Significant differences were noted in a number of dose-volume parameters, but they were not so large. HT plans provided more homogeneous dose distribution in PTV and lower rectum doses, whereas VMAT yielded more conformable plans, lower bladder doses, and shorter treatment delivery time with smaller MU. Author Disclosure: S. Ayakawa: None. C. Sugie: None. F. Baba: None. A. Hayashi: None. K. Kosaki: None. Y. Nonogaki: None. S. Hasegawa: None. S. Tanaka: None. K. Komai: None. Y. Shibamoto: None.
2448 Suggestion for Target Volume in Salvage Radiation Therapy for Locally-Recurrent Prostate Cancer After Radical Prostatectomy J. Park, W. Park, H. Pyo, S. Park, C. Kim, B. Park, H. Choi, H. Lee, S. Jeon, and S. Seo; Samsung Medical Center, Seoul, Korea, Republic of Korea Purpose/Objective(s): Salvage radiation therapy provides long-term disease control of locally recurrent prostate cancer after radical prostatectomy. However the CTV in salvage radiation therapy remains controversial. We investigate the location of locally recurrent prostate cancer with MRI acquired before salvage radiation therapy to suggest optimal target volume in salvage radiation therapy. Materials/Methods: From January 2000 to December 2012, 283 patients received salvage radiation therapy. Among them, 113 patients had recurrent lesion on MRI acquired before salvage radiation therapy. The median time interval between radical prostatectomy and salvage radiation therapy was 23 months (range, 4-162 months). The median PSA nadir value after radical prostatectomy was 0.05 ng/mL (range, 0.01-1.30 ng/mL). The median PSA value before salvage treatment was 0.43 ng/mL (range, 0.079.73 ng/mL). Five patients had 2 recurrent lesions. We assessed the
Volume 87 Number 2S Supplement 2013 Conclusions: High-dose IMRT with intraprostatic fiducial markers is associated with a very low toxicity and with a significant lower rate of GI and GU complications compared to 3DCRT even considering the lower follow-up for the IMRT cohort. These data confirms that this technique is safe to deliver radiation dose above 80 Gy. Author Disclosure: A. Zapatero: None. F. Garcı´a-Vicente: None. C. Matı´n de Vidales: None. G. Rodriguez: None. O. Leaman: None. R. Bermudez: None. A. Cruz-Conde: None. O. Lin˜an: None. L. Perez: None. J. Torres: None.
2446 Quality of Life Impact of Treatments for Localized Prostate Cancer F. Ferrer,1 F. Guedea,1 Y. Pardo,2 M. Ferrer,2 J. Suarez,3 A. Herva´s,4 A. Marin˜o,5 I. Herruzo,6 M. Ortiz,7 and G. Sancho8; 1Institut Catala` d’Oncologia, L’Hospitalet-Barcelona, Spain, 2IMIM (Hospital del Mar Research Institute), Health Services Research Unit, Barcelona, Spain, 3 Hospital Universitari de Bellvitge, L’Hospitalet-Barcelona, Spain, 4 Hospital Ramon y Cajal, Madrid, Spain, 5Centro Oncolo´gico de Galicia, A Corun˜a, Spain, 6Hospital Regional Carlos Haya, Ma´laga, Spain, 7 Hospital Virgen del Rocı´o, Sevilla, Spain, 8Hospital de la Santa Creu i Sant Pau, Barcelona, Spain Purpose/Objective(s): All treatments in localized prostate cancer cause urinary, bowel, or sexual dysfunction with different frequency, duration, and severity. Long-term quality of life (QOL) impact of side effects per localized prostate cancer treatment has been poorly documented. The objective was to assess treatments’ QOL impact in localized prostate cancer patients who underwent radical prostatectomy, external beam radiation therapy or brachytherapy, from pre-treatment to seven years after the intervention. Materials/Methods: This is a prospective, observational study of 704 patients recruited in 10 Spanish hospitals (2003-2005), with follow-up until 7-years after treatment. The sample was composed by consecutive patients with low or intermediate risk localized prostate cancer. The surgery group underwent radical retropubic prostatectomy, and the nervesparing technique was used at the surgeon’s discretion. External-beam radiation was 3D conformal. Treatment was delivered with 1.8 Gy to 2.0 Gy daily fractions to a mean dose of 73.7 Gy (standard deviation [SD] Z 5.0) to the prostate planning target volume. In the brachytherapy group, participants received 125I, and the prescription dose was 144 Gy to the reference isodose (100%). The median dose of D90 and V100% was 158 Gy and 93%, respectively. The EPIC was administered pre-treatment and annually posttreatment and Generalized Estimating Equation (GEE) models were constructed to assess impact on Quality of Life (QOL). Results: QOL impact of brachytherapy was presented into the urinary and sexual domains, with GEE coefficients at 7 years indicating worsening of 12.5 points in incontinence, 4.4 in irritative-obstructive, and 7.6 in sexual scores (p < 0.001). Compared to brachytherapy, radical prostatectomy fared 18.9 points worse in incontinence, and 14.2 in sexual scores (p < 0.001). Conclusions: This study provides novel long-term results showing that, despite minor late changes which tend to reduce differences between treatments, brachytherapy produced the lowest QOL impact (mainly restricted to the urinary domain). Radical Prostatectomy caused considerably greater urinary incontinence and sexual dysfunction, and external radiation therapy greater bowel impact. Author Disclosure: F. Ferrer: None. F. Guedea: None. Y. Pardo: None. M. Ferrer: None. J. Suarez: None. A. Herva´s: None. A. Marin˜o: None. I. Herruzo: None. M. Ortiz: None. G. Sancho: None.
2447 Volumetric Modulated Arc Therapy (VMAT) Versus Helical Tomotherapy (HT) for Localized Prostate Cancer: Dosimetric Comparison by Using the Identical Prescription Dose to the Prostate S. Ayakawa,1 C. Sugie,2 F. Baba,3 A. Hayashi,2 K. Kosaki,1 Y. Nonogaki,1 S. Hasegawa,1 S. Tanaka,1 K. Komai,4 and Y. Shibamoto2; 1Social Insurance Chukyo Hospital, Nagoya, Japan, 2Nagoya City University
Graduate School of Medical Sciences, Nagoya, Japan, 3Nagoya City West Medical Center, Nagoya, Japan, 4Nagoya Daini Red Cross Hospital, Nagoya, Japan Purpose/Objective(s): The two modern radiation therapy techniques, VMATand HT, are the major innovations in high-precision radiation therapy. Both could provide better coverage of the planning target volume (PTV) and sparing of organs at risk (OAR) than conventional IMRT. Several planning studies have compared the two modalities, but there have been no consensus regarding the superiority of either one, except that VMAT provides shorter treatment time than HT. The discrepancies among previous studies may come from the tumor sites investigated and policies of treatment planning (i.e., which factors are prioritized). The purpose of this study was to compare the dose-volume parameters of VMAT and HT for prostate cancer by using the identical dose prescription to 95% of the PTV. Materials/Methods: Fifteen patients (T1-3N0M0) who received radical radiation therapy were selected. VMAT and HT plans were generated for each patient: plans of single-arc VMAT with 10-MV X rays were created, and HT plans with 6-MV X rays were produced. The PTV was defined as the prostate and all (for T3 stage) or a part (for T1 and T2) of the seminal vesicles plus margins. The prescription dose of the PTV was 74.8 Gy in 34 fractions, and 95% of the PTV was planned to receive over 90% of the prescription dose in both plans. The PTV D95% was set to be within 1% in the two plans. The target coverage, homogeneity index (HI), conformity index (CI), OAR dose, monitor units (MU), and treatment delivery time were compared. Wilcoxon signed rank test was used for statistical analysis. Results: VMAT and HT plans were comparable with respect to target coverage (PTV D95%, V95%, Dmax and Dmin), but VMAT produced a higher PTV D50% and Dmean. Median HI was 1.09 for VMATand 1.08 for HT (p Z 0.031). Median CI was better in VMAT (1.10) than in HT (1.27). HT showed better dose sparing to the rectum than VMAT; V70 Gy, V20 Gy, Dmax, Dmean and Dmean of Rectum-PTV (the rectum not overlapping with the PTV) were significantly lower, although there were no differences in V60 Gy and V40 Gy. On the other hand, VMAT showed better dose sparing for the bladder than HT; V70 Gy, V65 Gy, V40 Gy, V20 Gy, Dmax and Dmean were significantly lower. Median MU were 563 in VMAT and 3424 in HT. Median treatment time was 76.2 seconds in VMAT and 243.3 seconds in HT. Conclusions: Both VMAT and HT provide high quality conformal plans for localized prostate cancer. Significant differences were noted in a number of dose-volume parameters, but they were not so large. HT plans provided more homogeneous dose distribution in PTV and lower rectum doses, whereas VMAT yielded more conformable plans, lower bladder doses, and shorter treatment delivery time with smaller MU. Author Disclosure: S. Ayakawa: None. C. Sugie: None. F. Baba: None. A. Hayashi: None. K. Kosaki: None. Y. Nonogaki: None. S. Hasegawa: None. S. Tanaka: None. K. Komai: None. Y. Shibamoto: None.
2448 Suggestion for Target Volume in Salvage Radiation Therapy for Locally-Recurrent Prostate Cancer After Radical Prostatectomy J. Park, W. Park, H. Pyo, S. Park, C. Kim, B. Park, H. Choi, H. Lee, S. Jeon, and S. Seo; Samsung Medical Center, Seoul, Korea, Republic of Korea Purpose/Objective(s): Salvage radiation therapy provides long-term disease control of locally recurrent prostate cancer after radical prostatectomy. However the CTV in salvage radiation therapy remains controversial. We investigate the location of locally recurrent prostate cancer with MRI acquired before salvage radiation therapy to suggest optimal target volume in salvage radiation therapy. Materials/Methods: From January 2000 to December 2012, 283 patients received salvage radiation therapy. Among them, 113 patients had recurrent lesion on MRI acquired before salvage radiation therapy. The median time interval between radical prostatectomy and salvage radiation therapy was 23 months (range, 4-162 months). The median PSA nadir value after radical prostatectomy was 0.05 ng/mL (range, 0.01-1.30 ng/mL). The median PSA value before salvage treatment was 0.43 ng/mL (range, 0.079.73 ng/mL). Five patients had 2 recurrent lesions. We assessed the