- Email: [email protected]
737 poster Clinical results of proton and carbon radiotherapy at Hyogo
Posters
entire chamber can be done at a frequency of some kHz without dead time. The last design and the results of preliminary tests performed in Orsay are presented. 737 poster
Clinical results of proton and carbon radiotherapy at Hyogo
M. Murakami 1"2, Y. Hishikawa ~'2, K. Kagawa ~, A. Kawaguchi 1, H. Mayahara 1'2, Y. Oda 1'2, M. Abe 1 ~Hyogo Ion Beam Medical Center, Radiology, Hyogo, Japan 2Kobe University Graduate School of Medicine, Medical Imaging & Ion Beam Therapy, Kobe, Japan Background and Purpose: On April 2001, the HIBMC opened its door as the world's first institution where both proton and carbon-ion RT can be used. To investigate the effect and safety of the radiotherapy, clinical studies based on the Good Clinical Practice were undertaken. Now we started general practice of proton therapy on April 2003. In this article, we will report the results of the clinical study. Materials and Methods: Thirty patients with H&N (4), lung (5), liver (5), and prostate cancers (16) proton from May to November 2001, and another 30 patients with the H&N (19), lung (3), liver (6), and bone & soft tissue (B&S) tumors were treated by carbon from January to July 2002. Patients with radio-resistant H&N tumors including malignant melanoma, adenoid cystic carcinoma were indicated for carbon RT. Prescribed dose was 65 GyE/26Fr/7w for H&N, 80GyE/20Fr/5w for lung, 76GyE/20Fr/5w for liver, and 74GyE/37Fr/8w for prostate cancer in proton , while 57.6GyE/16Fr /4 w for H&N, 68.4GyE/9Fr/3 w for lung, 52.8GyE /8Fr/2 w for liver, and 70.4GyE/32Fr/8 w for B&S tumors in carbon. Local control within PTV (LC) and overall survival q[OS) rates at 2 year were calculated by Kaplan-Meier method with a median follow-up period of 33 months in proton and 25 months in carbon. Results: Full courses of proton/carbon consisted of 896/443 portals in each 30 patients were given exactly as scheduled without any trouble of the machine. No patients experienced severe acute or late toxicity more than Grade 3. Two patients were CR, 12 PR, and 9 NC with a response rate (RR) of 60.9% in proton, while 2 CR, 16 PR, and 12 NC with a RR of 60% in carbon. In lung cancer, one each patient in both group developed pleural dissemination without local failure. In liver cancer, 5 patients (3 in proton and 2 in carbon) occurred 2 nd hepatoma independent with initial tumor. The rate of LC/OS in the lung cancer was 100%/60% in proton and 100%/67% in carbon, and 100%/100% and 100%/83% in the liver cancer, respectively. One with prostate cancer (T2a NO, initial PSA=7.8, Gteason Score 9) developed bone metastasis 23 months after proton. In H&N cancer, local failure occurred in 6 patients (1 in proton and 5 in carbon), and distant failure in 10 (1 in proton and 9 in carbon). The rate of LC/QS in H&N cancer was 75%/75% in proton and 71%/49% in carbon, respectively. Two patients with B&S tumors were doing well over 2 years. Conclusions: Carbon is effective for histologically radioresistant tumors. From the results for lung and liver cancer, no difference in. the tumor response was found between proton and carbon. Further investigation according to individual disease is needed for appropriate choice of ions.
$319
738 poster
A Monte Carlo-based tool for proton dose verification on patient CT data
H. Szymanowski, S. Nil~, U. Oelfke DKFZ, Dept. of Medical Physics, Heidelberg, Germany For the planning of intensity-modulated proton therapy (IMPT) treatments, the dose calculation engine plays an important role not only in the assessment of the quality of the treatment plan but also in the determination of the optimised particle fluence. A crucial issue is thereby the accurate prediction of the dose while irradiating complex inhomogeneous patient geometries. In previous studies an improved method to account for tissue inhomogeneities in pencil beam algorithms was suggested, validated on relatively simple phantom geometries using Monte Carlo simulations, and finally integrated in our treatment planning system. The validation of the algorithm under real patient geometries before clinical implementation remains however an important challenge. For this purpose we are currently developing a Monte Carlo-based tool for the verification of the dose distribution within the patient delivered by IMPT treatments. This tool is based on the Monte Carlo simulation code GEANT4, and allows simulations of the delivered dose distribution on the basis of patient CT data. A software module performing the transformation of the patient CT data into a simulation-oriented geometry was implemented. This module allows the modelling of the patient geometry as a volume of homogeneous voxels filled with materials determined by using established correlations between Hounsfield numbers and biological tissue parameters. CTbased simulations in various biological tissues were successfully validated against analytical models. In particular for bony tissues the discrepancies found between the analytical predictions and the values of the relative stopping powers and the material specific scattering factors extracted from the simulations were found to be about 3.0% and 1.0% respectively. The program also includes the combination of the IMPT treatment parameters with the initial phase space. In particular standard sampling methods based on cumulative probability distributions are used to account for the intensity modulation. A last module which allows for a drastic reduction of the statistical noise inherent to Monte Carlo simulation in the dose distributions was finally implemented, based on the socalled anisotropic diffusion filtering. Our Monte Carlo-based benchmarking provides satisfactory results for proton simulations on the basis of patient CT data. Work in progress is the validation of newly developed dose calculation algorithms under complex patient geometries. 739 poster
Fast semi-analytical algorithm for pencil beam dose distributions in ion therapy
M. Hol/markj I. Gudowska, D. Belkic, A. Brahme Karolinska Institutet and Stockholm University, Medical Radiation Physics, Stockholm, Sweden The increased accuracy achievable in radiation therapy with light ions calls for improved precision in the calculation of the energy deposition distribution of narrow charged particle beams. Monte Carlo codes are precise, but also timeconsuming and are currently not very practical for the implementation into treatment-planning systems. The aim of the present work is to develop a complete parameterization
entire chamber can be done at a frequency of some kHz without dead time. The last design and the results of preliminary tests performed in Orsay are presented. 737 poster
Clinical results of proton and carbon radiotherapy at Hyogo
M. Murakami 1"2, Y. Hishikawa ~'2, K. Kagawa ~, A. Kawaguchi 1, H. Mayahara 1'2, Y. Oda 1'2, M. Abe 1 ~Hyogo Ion Beam Medical Center, Radiology, Hyogo, Japan 2Kobe University Graduate School of Medicine, Medical Imaging & Ion Beam Therapy, Kobe, Japan Background and Purpose: On April 2001, the HIBMC opened its door as the world's first institution where both proton and carbon-ion RT can be used. To investigate the effect and safety of the radiotherapy, clinical studies based on the Good Clinical Practice were undertaken. Now we started general practice of proton therapy on April 2003. In this article, we will report the results of the clinical study. Materials and Methods: Thirty patients with H&N (4), lung (5), liver (5), and prostate cancers (16) proton from May to November 2001, and another 30 patients with the H&N (19), lung (3), liver (6), and bone & soft tissue (B&S) tumors were treated by carbon from January to July 2002. Patients with radio-resistant H&N tumors including malignant melanoma, adenoid cystic carcinoma were indicated for carbon RT. Prescribed dose was 65 GyE/26Fr/7w for H&N, 80GyE/20Fr/5w for lung, 76GyE/20Fr/5w for liver, and 74GyE/37Fr/8w for prostate cancer in proton , while 57.6GyE/16Fr /4 w for H&N, 68.4GyE/9Fr/3 w for lung, 52.8GyE /8Fr/2 w for liver, and 70.4GyE/32Fr/8 w for B&S tumors in carbon. Local control within PTV (LC) and overall survival q[OS) rates at 2 year were calculated by Kaplan-Meier method with a median follow-up period of 33 months in proton and 25 months in carbon. Results: Full courses of proton/carbon consisted of 896/443 portals in each 30 patients were given exactly as scheduled without any trouble of the machine. No patients experienced severe acute or late toxicity more than Grade 3. Two patients were CR, 12 PR, and 9 NC with a response rate (RR) of 60.9% in proton, while 2 CR, 16 PR, and 12 NC with a RR of 60% in carbon. In lung cancer, one each patient in both group developed pleural dissemination without local failure. In liver cancer, 5 patients (3 in proton and 2 in carbon) occurred 2 nd hepatoma independent with initial tumor. The rate of LC/OS in the lung cancer was 100%/60% in proton and 100%/67% in carbon, and 100%/100% and 100%/83% in the liver cancer, respectively. One with prostate cancer (T2a NO, initial PSA=7.8, Gteason Score 9) developed bone metastasis 23 months after proton. In H&N cancer, local failure occurred in 6 patients (1 in proton and 5 in carbon), and distant failure in 10 (1 in proton and 9 in carbon). The rate of LC/QS in H&N cancer was 75%/75% in proton and 71%/49% in carbon, respectively. Two patients with B&S tumors were doing well over 2 years. Conclusions: Carbon is effective for histologically radioresistant tumors. From the results for lung and liver cancer, no difference in. the tumor response was found between proton and carbon. Further investigation according to individual disease is needed for appropriate choice of ions.
$319
738 poster
A Monte Carlo-based tool for proton dose verification on patient CT data
H. Szymanowski, S. Nil~, U. Oelfke DKFZ, Dept. of Medical Physics, Heidelberg, Germany For the planning of intensity-modulated proton therapy (IMPT) treatments, the dose calculation engine plays an important role not only in the assessment of the quality of the treatment plan but also in the determination of the optimised particle fluence. A crucial issue is thereby the accurate prediction of the dose while irradiating complex inhomogeneous patient geometries. In previous studies an improved method to account for tissue inhomogeneities in pencil beam algorithms was suggested, validated on relatively simple phantom geometries using Monte Carlo simulations, and finally integrated in our treatment planning system. The validation of the algorithm under real patient geometries before clinical implementation remains however an important challenge. For this purpose we are currently developing a Monte Carlo-based tool for the verification of the dose distribution within the patient delivered by IMPT treatments. This tool is based on the Monte Carlo simulation code GEANT4, and allows simulations of the delivered dose distribution on the basis of patient CT data. A software module performing the transformation of the patient CT data into a simulation-oriented geometry was implemented. This module allows the modelling of the patient geometry as a volume of homogeneous voxels filled with materials determined by using established correlations between Hounsfield numbers and biological tissue parameters. CTbased simulations in various biological tissues were successfully validated against analytical models. In particular for bony tissues the discrepancies found between the analytical predictions and the values of the relative stopping powers and the material specific scattering factors extracted from the simulations were found to be about 3.0% and 1.0% respectively. The program also includes the combination of the IMPT treatment parameters with the initial phase space. In particular standard sampling methods based on cumulative probability distributions are used to account for the intensity modulation. A last module which allows for a drastic reduction of the statistical noise inherent to Monte Carlo simulation in the dose distributions was finally implemented, based on the socalled anisotropic diffusion filtering. Our Monte Carlo-based benchmarking provides satisfactory results for proton simulations on the basis of patient CT data. Work in progress is the validation of newly developed dose calculation algorithms under complex patient geometries. 739 poster
Fast semi-analytical algorithm for pencil beam dose distributions in ion therapy
M. Hol/markj I. Gudowska, D. Belkic, A. Brahme Karolinska Institutet and Stockholm University, Medical Radiation Physics, Stockholm, Sweden The increased accuracy achievable in radiation therapy with light ions calls for improved precision in the calculation of the energy deposition distribution of narrow charged particle beams. Monte Carlo codes are precise, but also timeconsuming and are currently not very practical for the implementation into treatment-planning systems. The aim of the present work is to develop a complete parameterization