- Email: [email protected]
Development of computer tools for validation of treatment plans according to RTOG, QUANTEC and SFRO criteria
e144
Abstracts / Physica Medica 30 (2014) e123ee145
Chemin de Baigne-Pieds CS 80005 84918 Avignon Cedex 9, France; 907 Voie l'Occitane 31670 Labege Cedex, France
b
TRAD
Introduction: The aim of this work is to assess the performances of a new dosimeter for electron in-vivo dosimetry: Dosi-MeV®. Dosimetric accuracy is evaluated by dose measurements in a phantom and patients. Materials and methods: The Dosi-Secure® system (TRAD) consists of a wireless tactile reader, a mosfet dosimeter, and an associated soft. This system allows the traceability of each patient during the radiotherapy session. The electron patch of Dosi-Secure®: Dosi-MeV® is based on the technology of Dosi-Patch® photon but is smaller. Dose performances are characterized for a 6MeV electron beam. Detector is placed on the surface of a water equivalent phantom. Repeatability and reproductibility is investigated. Influences of the field size, SSD, angular incidence and debit rate are evaluated. Measurements are compared to the dose measured with an ionization chamber (IC) placed at entrance dose (dmax). The device accuracy, in clinical use is assessed by measurements beams on patients. Results are compared with the dmax obtained with the Treatment Planning System (TPS). Results: The dose reproducibility and repeatability of the dosimeter is correct with a variation coefficient of 0.36% and 0.62%. The accuracy as a function of field size is ±2% from 4x4cm2 to 14x14cm2. The agreement between IC and dosimeter is ±3% for varying SSD and angular incidence. Any difference with dose rate is observed. All of clinical beam measurements on patient have a deviation 5% compared to the TPS except the 3X3 field. Conclusion: This study shows that the Dosi-MeV® responds like an IC. For patients the Dosi-MeV® has an accuracy of ±5% and the utilization of the lower fields than 4X4cm2 should be corrected. Further characterization with different electron beam energies and in vivo measurements are in progress.
http://dx.doi.org/10.1016/j.ejmp.2014.10.072
P-43. FROM CONFORMAL EBRT TO VMAT: AMIENS CTHE HYBRID EXPERIENCE S. Demko Centre de Traitements Des Hautes Energies d'Amiens (CTHE Amiens), Institut de Canc erologie Amiens Picardie, 5 All ee des Pays-Bas, 80090 Amiens, France Introduction: Private Centre dealing with ± 850 patients year-round in conformal EBRT exclusively. After implementing simplified IMRT breast treatment successfully (40% of our patients), the desire to move quickly towards IGRT, IMRT and VMAT grew. After months of consultations and evaluations, material was selected and the timetable validated: Exactrac and dMLC installation in December 2012, first IGRT patient in March 2013, IPlan installation with HybridArc in May 2013 for a first HybridArc’s prostate patient in December 2013. Material and methods: 2 Clinac2100C MLC120 millenium AS500/IAS3 upgrated by dynamic dMLC licence and Exactrac 6.2 repositioning kV system. ARIA10, TPS ISOgray reinforced by IPlan and its HybridArc option to combine dynamic arc and IMRT fixed fields. Octavius4D and its 2Darray729 and the VeriSoft 6 analysis/comparison software. The organs are outlined in ISOgray then exported with their CT to IPlan. Exactrac started in March 2013 and its use spread gradually to all locations. Training IPlan/HybridArc in June 2013, reference’s measurement was made in August 2013. With the help of 7Sigma society we prepared specific QC and validated IPlan for a series of simple, complex and modulated field as well as simple, dynamic and hybrid arc respectively in solid water and in the Octavius4D with the 2Darray and analyzed with VeriSoft. The pelvis and mainly prostate was the most appropriate location to begin. Results: Dynamic test results of sweep gap and picket fence revealed a very stable and repeatable dMLC (±1%). IPlan was validated with very good results (±2%). The HybridArc test plans shows also good repeatable agreement ( 95% points respect g<1 for 3%/3mm criteria). First HybridArc patient’s treatment could start. Dosimetry criteria have always been respected for 70 patients treated since and averaged 98% of the points controlled in Octavius4D passes these criteria!
Conclusion: After a year of Exactrac’use and 3 months of HybridArc (50% of prostate, the remainder being pelvis and metastases) we are sure to have very precise repositioning for all locations and effective complex treatments. HybridArc techniques are great alternative system adaptable on any existing system equipped with a dynamic multileaves.
http://dx.doi.org/10.1016/j.ejmp.2014.10.073
P-44. DEVELOPMENT OF COMPUTER TOOLS FOR VALIDATION OF TREATMENT PLANS ACCORDING TO RTOG, QUANTEC AND SFRO CRITERIA D. Nguyen, V. Benoit, F. Josserand Pietri, S. Fafi, G. Largeron, E. Daera, M. Khodri Orlam Villeurbanne-Macon, France Purpose/objective(s): The evaluation, approval and review of treatment plans in radiotherapy can be automated and standardized using modern computer technology. The aim of this work is to develop software for automatic verification of respect dose volumes constraints based on the validation of QUANTEC, RTOG and SFRO protocol criteria. Materials/methods: In this study, we present a program for the quantitative evaluation of treatment plans that combines Java and XML. JAVA code and libraries are implemented to calculate the dosimetric parameters. These are then used to implement the various protocols validations using XML files. The steps are to export the dose volume histogram calculated by the treatment planning system (EclipseV10 - Varian); then import it into a new database (MongoDB) via the import module. Just by doing a search (by id or name of the patient), select the plan and start the calculation. The program performs the requested tests and displays the results in green if the constraints are met, red otherwise. Results: For standard treatment, we were able to implement constraints doses volumes QUANTEC, RTOG, and SFRO. For lung SBRT treatments, RTOG 0813 was successfully implemented. The consistency and coverage of target volumes indexes were configured. The accuracy and efficiency of the program were evaluated by comparing the results with those recorded manually. A slight difference of about 0.25% volume or 0.3 Gy dose between the program and the manual reading was observed. For indices CI (100%), CI (50%) and the dose at 2 cm, there are minimal differences between the two methods. Nevertheless, the evaluation time is reduced by 10-20 min to 2 min using this program. Conclusion: This software effectively checks the quality of the plan and is useful for guiding dosimetrists, physicists in planning and physicians in the evaluation and approval of plans, and clinical review. keywords: QUANTEC; RTOG; SFRO http://dx.doi.org/10.1016/j.ejmp.2014.10.074
P-45. DETERMINATION OF THE OPTIMAL PLANNING PARAMETERS (PITCH, MF AND FW) FOR LIMB SARCOMA TREATED WITH TOMOTHERAPY: A PRELIMINARY STUDY H. Bouhours, P. Meyer, C. Niederst, D. Jarnet, N. Dehaynin, M. Gantier, D. Karamanoukian D epartement de Radioth erapie - Unit e de Physique, Centre de Lutte Contre le Cancer Paul Strauss, Strasbourg, France Introduction: During helical tomotherapy planning, the right choice of the Field Width (FW), Modulation Factor (MF) and pitch is essential in order to reach the best dosimetric quality/treatment time compromise. In 2005, Kissick et al.1 calculated optimal pitches of 0.86/n, with n an integer, that made consensus among the physicists. More recently, these optimal values were questioned by Chen et al.2 who proposed other pitch values, particularly when PTV off-axis lateral distance becomes significant. Method and materials: This preliminary study consists in analyzing 48 tomotherapy treatment plans calculated for one patient treated for an arm, with a PTV located 20 cm off-axis. These plans are calculated for the combination of 2 FW (2.5 and 5 cm), 6 pitches (0.215, 0.287, 0.43, low, medium and high) and 4 MF (1.5, 2, 2.5 and 3). “Low”, “medium” and “high” stand for the 3 corresponding “off-axis” pitches given in the work by Chen et al.2, that depend on the PTV off-axis distance and the FW.
Abstracts / Physica Medica 30 (2014) e123ee145
Chemin de Baigne-Pieds CS 80005 84918 Avignon Cedex 9, France; 907 Voie l'Occitane 31670 Labege Cedex, France
b
TRAD
Introduction: The aim of this work is to assess the performances of a new dosimeter for electron in-vivo dosimetry: Dosi-MeV®. Dosimetric accuracy is evaluated by dose measurements in a phantom and patients. Materials and methods: The Dosi-Secure® system (TRAD) consists of a wireless tactile reader, a mosfet dosimeter, and an associated soft. This system allows the traceability of each patient during the radiotherapy session. The electron patch of Dosi-Secure®: Dosi-MeV® is based on the technology of Dosi-Patch® photon but is smaller. Dose performances are characterized for a 6MeV electron beam. Detector is placed on the surface of a water equivalent phantom. Repeatability and reproductibility is investigated. Influences of the field size, SSD, angular incidence and debit rate are evaluated. Measurements are compared to the dose measured with an ionization chamber (IC) placed at entrance dose (dmax). The device accuracy, in clinical use is assessed by measurements beams on patients. Results are compared with the dmax obtained with the Treatment Planning System (TPS). Results: The dose reproducibility and repeatability of the dosimeter is correct with a variation coefficient of 0.36% and 0.62%. The accuracy as a function of field size is ±2% from 4x4cm2 to 14x14cm2. The agreement between IC and dosimeter is ±3% for varying SSD and angular incidence. Any difference with dose rate is observed. All of clinical beam measurements on patient have a deviation 5% compared to the TPS except the 3X3 field. Conclusion: This study shows that the Dosi-MeV® responds like an IC. For patients the Dosi-MeV® has an accuracy of ±5% and the utilization of the lower fields than 4X4cm2 should be corrected. Further characterization with different electron beam energies and in vivo measurements are in progress.
http://dx.doi.org/10.1016/j.ejmp.2014.10.072
P-43. FROM CONFORMAL EBRT TO VMAT: AMIENS CTHE HYBRID EXPERIENCE S. Demko Centre de Traitements Des Hautes Energies d'Amiens (CTHE Amiens), Institut de Canc erologie Amiens Picardie, 5 All ee des Pays-Bas, 80090 Amiens, France Introduction: Private Centre dealing with ± 850 patients year-round in conformal EBRT exclusively. After implementing simplified IMRT breast treatment successfully (40% of our patients), the desire to move quickly towards IGRT, IMRT and VMAT grew. After months of consultations and evaluations, material was selected and the timetable validated: Exactrac and dMLC installation in December 2012, first IGRT patient in March 2013, IPlan installation with HybridArc in May 2013 for a first HybridArc’s prostate patient in December 2013. Material and methods: 2 Clinac2100C MLC120 millenium AS500/IAS3 upgrated by dynamic dMLC licence and Exactrac 6.2 repositioning kV system. ARIA10, TPS ISOgray reinforced by IPlan and its HybridArc option to combine dynamic arc and IMRT fixed fields. Octavius4D and its 2Darray729 and the VeriSoft 6 analysis/comparison software. The organs are outlined in ISOgray then exported with their CT to IPlan. Exactrac started in March 2013 and its use spread gradually to all locations. Training IPlan/HybridArc in June 2013, reference’s measurement was made in August 2013. With the help of 7Sigma society we prepared specific QC and validated IPlan for a series of simple, complex and modulated field as well as simple, dynamic and hybrid arc respectively in solid water and in the Octavius4D with the 2Darray and analyzed with VeriSoft. The pelvis and mainly prostate was the most appropriate location to begin. Results: Dynamic test results of sweep gap and picket fence revealed a very stable and repeatable dMLC (±1%). IPlan was validated with very good results (±2%). The HybridArc test plans shows also good repeatable agreement ( 95% points respect g<1 for 3%/3mm criteria). First HybridArc patient’s treatment could start. Dosimetry criteria have always been respected for 70 patients treated since and averaged 98% of the points controlled in Octavius4D passes these criteria!
Conclusion: After a year of Exactrac’use and 3 months of HybridArc (50% of prostate, the remainder being pelvis and metastases) we are sure to have very precise repositioning for all locations and effective complex treatments. HybridArc techniques are great alternative system adaptable on any existing system equipped with a dynamic multileaves.
http://dx.doi.org/10.1016/j.ejmp.2014.10.073
P-44. DEVELOPMENT OF COMPUTER TOOLS FOR VALIDATION OF TREATMENT PLANS ACCORDING TO RTOG, QUANTEC AND SFRO CRITERIA D. Nguyen, V. Benoit, F. Josserand Pietri, S. Fafi, G. Largeron, E. Daera, M. Khodri Orlam Villeurbanne-Macon, France Purpose/objective(s): The evaluation, approval and review of treatment plans in radiotherapy can be automated and standardized using modern computer technology. The aim of this work is to develop software for automatic verification of respect dose volumes constraints based on the validation of QUANTEC, RTOG and SFRO protocol criteria. Materials/methods: In this study, we present a program for the quantitative evaluation of treatment plans that combines Java and XML. JAVA code and libraries are implemented to calculate the dosimetric parameters. These are then used to implement the various protocols validations using XML files. The steps are to export the dose volume histogram calculated by the treatment planning system (EclipseV10 - Varian); then import it into a new database (MongoDB) via the import module. Just by doing a search (by id or name of the patient), select the plan and start the calculation. The program performs the requested tests and displays the results in green if the constraints are met, red otherwise. Results: For standard treatment, we were able to implement constraints doses volumes QUANTEC, RTOG, and SFRO. For lung SBRT treatments, RTOG 0813 was successfully implemented. The consistency and coverage of target volumes indexes were configured. The accuracy and efficiency of the program were evaluated by comparing the results with those recorded manually. A slight difference of about 0.25% volume or 0.3 Gy dose between the program and the manual reading was observed. For indices CI (100%), CI (50%) and the dose at 2 cm, there are minimal differences between the two methods. Nevertheless, the evaluation time is reduced by 10-20 min to 2 min using this program. Conclusion: This software effectively checks the quality of the plan and is useful for guiding dosimetrists, physicists in planning and physicians in the evaluation and approval of plans, and clinical review. keywords: QUANTEC; RTOG; SFRO http://dx.doi.org/10.1016/j.ejmp.2014.10.074
P-45. DETERMINATION OF THE OPTIMAL PLANNING PARAMETERS (PITCH, MF AND FW) FOR LIMB SARCOMA TREATED WITH TOMOTHERAPY: A PRELIMINARY STUDY H. Bouhours, P. Meyer, C. Niederst, D. Jarnet, N. Dehaynin, M. Gantier, D. Karamanoukian D epartement de Radioth erapie - Unit e de Physique, Centre de Lutte Contre le Cancer Paul Strauss, Strasbourg, France Introduction: During helical tomotherapy planning, the right choice of the Field Width (FW), Modulation Factor (MF) and pitch is essential in order to reach the best dosimetric quality/treatment time compromise. In 2005, Kissick et al.1 calculated optimal pitches of 0.86/n, with n an integer, that made consensus among the physicists. More recently, these optimal values were questioned by Chen et al.2 who proposed other pitch values, particularly when PTV off-axis lateral distance becomes significant. Method and materials: This preliminary study consists in analyzing 48 tomotherapy treatment plans calculated for one patient treated for an arm, with a PTV located 20 cm off-axis. These plans are calculated for the combination of 2 FW (2.5 and 5 cm), 6 pitches (0.215, 0.287, 0.43, low, medium and high) and 4 MF (1.5, 2, 2.5 and 3). “Low”, “medium” and “high” stand for the 3 corresponding “off-axis” pitches given in the work by Chen et al.2, that depend on the PTV off-axis distance and the FW.