Sergio Curto1, Hendrik Thijmen Mulder1, Bassim Aklan2, Oliver Mils3, Manfred Schmidt4, Ulf Lamprecht5, Michael Peller6, Ruediger Wessalowski3, Lars H Lindner2, Rainer Fietkau4, Daniel Zips5, Netteke van Holthe1, Martine Franckena1, Margarethus M Paulides1,7, Gerard C van Rhoon1. 1. Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands. 2. Department of Internal Medicine III, Ludwig-Maximilians University Hospital, Munich, Germany. 3. Department of Pediatric Hematology, Oncology and Clinical Immunology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany. 4. Department of Radiation Oncology, University Hospital Erlangen, Erlangen, Germany. 5. Department of Radiation Oncology, University Hospital Tübingen, Tübingen, Germany. 6. Department of Radiology, Ludwig-Maximilians University Hospital, Munich, Germany. 7. Faculty of Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
Abstract
INTRODUCTION: Within the hyperthermia community, consensus exists that clinical outcome of the treatment radiotherapy and/or chemotherapy plus hyperthermia (i.e. elevating tumor temperature to 40 - 44 °C) is related to the applied thermal dose; hence, treatment quality is crucial for the success of prospective multi-institution clinical trials. Currently, applicator quality assurance (QA) measurements are implemented independently at each institution using basic cylindrical phantoms. A multi-institution comparison of heating quality using magnetic resonance thermometry (MRT) and anatomical representative anthropomorphic phantoms provides a unique opportunity to obtain novel QA insights to facilitate multi-institution trial evaluation. OBJECTIVE: Perform a systematic QA procedure to compare the performance of MR-compatible hyperthermia systems in five institutions. METHODS AND MATERIALS: Anthropomorphic phantoms, including pelvic and spinal bones, were produced. Clinically relevant power of 600 watts was applied for ∼12 min to allow for 8 sequential MR-scans. The 3D-heating distribution, steering capabilities, and presence of off-target heating were analyzed. RESULTS: The evaluated devices show comparable heating profiles for centric and eccentric targets. The differences observed in the 3D-heating profiles are the result of variations in the exact phantom positioning and applicator characteristics, whereby positioning of the phantom followed current ESHO-QA guidelines. CONCLUSION: Anthropomorphic phantoms were used to perform QA-measurements of MR-guided hyperthermia systems operating in MR-scanners of different brands. Comparable heating profiles are shown for the five evaluated institutions. Subcentimeter differences in position substantially affected the results when evaluating the heating patterns. Integration of advanced phantoms and precise positioning in QA-guidelines should be evaluated to guarantee the best quality patient care.
INTRODUCTION: Within the hyperthermia community, consensus exists that clinical outcome of the treatment radiotherapy and/or chemotherapy plus hyperthermia (i.e. elevating tumor temperature to 40 - 44 °C) is related to the applied thermal dose; hence, treatment quality is crucial for the success of prospective multi-institution clinical trials. Currently, applicator quality assurance (QA) measurements are implemented independently at each institution using basic cylindrical phantoms. A multi-institution comparison of heating quality using magnetic resonance thermometry (MRT) and anatomical representative anthropomorphic phantoms provides a unique opportunity to obtain novel QA insights to facilitate multi-institution trial evaluation. OBJECTIVE: Perform a systematic QA procedure to compare the performance of MR-compatible hyperthermia systems in five institutions. METHODS AND MATERIALS: Anthropomorphic phantoms, including pelvic and spinal bones, were produced. Clinically relevant power of 600 watts was applied for ∼12 min to allow for 8 sequential MR-scans. The 3D-heating distribution, steering capabilities, and presence of off-target heating were analyzed. RESULTS: The evaluated devices show comparable heating profiles for centric and eccentric targets. The differences observed in the 3D-heating profiles are the result of variations in the exact phantom positioning and applicator characteristics, whereby positioning of the phantom followed current ESHO-QA guidelines. CONCLUSION: Anthropomorphic phantoms were used to perform QA-measurements of MR-guided hyperthermia systems operating in MR-scanners of different brands. Comparable heating profiles are shown for the five evaluated institutions. Subcentimeter differences in position substantially affected the results when evaluating the heating patterns. Integration of advanced phantoms and precise positioning in QA-guidelines should be evaluated to guarantee the best quality patient care.
Entities:
Keywords:
Quality assurance (QA); anthropomorphic phantom; heating patterns; magnetic resonance (MR)-guided hyperthermia; magnetic resonance thermometry (MRT)