OBJECTIVES: Prompt gamma (PG) imaging has previously been demonstrated for use in proton range verification of a brain treatment with a homogeneous target region. In this study, the feasibility of PG imaging to detect anatomic change within a heterogeneous region is presented. METHODS: A prompt gamma camera recorded several fractions of a patient treatment to the base of skull. An evaluation CT revealed a decrease in sinus cavity filling during the treatment course. Comparison of PG profiles between measurement and simulation was performed to investigate range variations between planned and measured pencil beam spot positions. RESULTS: For one field, an average over range of 3 mm due to the anatomic change could be detected for a subset of spots traversing the sinus cavity region. The two other fields appeared less impacted by the change but predicted range variations could not be detected. These results were partially consistent with the simulations of the evaluation CT. CONCLUSION: We report the first clinical application of PG imaging that detected some of the expected small regional proton range deviations due to anatomic change in a heterogeneous region. However, several limitations exist with the technology that may limit its sensitivity to detect range deviations in heterogeneous regions. ADVANCES IN KNOWLEDGE: We report on the first detection of range variations due to anatomic change in a heterogeneous region using PGI. The results confirm the feasibility of using PG-based range verification in highly heterogeneous target regions to identify deviations from the treatment plan.
OBJECTIVES: Prompt gamma (PG) imaging has previously been demonstrated for use in proton range verification of a brain treatment with a homogeneous target region. In this study, the feasibility of PG imaging to detect anatomic change within a heterogeneous region is presented. METHODS: A prompt gamma camera recorded several fractions of a patient treatment to the base of skull. An evaluation CT revealed a decrease in sinus cavity filling during the treatment course. Comparison of PG profiles between measurement and simulation was performed to investigate range variations between planned and measured pencil beam spot positions. RESULTS: For one field, an average over range of 3 mm due to the anatomic change could be detected for a subset of spots traversing the sinus cavity region. The two other fields appeared less impacted by the change but predicted range variations could not be detected. These results were partially consistent with the simulations of the evaluation CT. CONCLUSION: We report the first clinical application of PG imaging that detected some of the expected small regional proton range deviations due to anatomic change in a heterogeneous region. However, several limitations exist with the technology that may limit its sensitivity to detect range deviations in heterogeneous regions. ADVANCES IN KNOWLEDGE: We report on the first detection of range variations due to anatomic change in a heterogeneous region using PGI. The results confirm the feasibility of using PG-based range verification in highly heterogeneous target regions to identify deviations from the treatment plan.
Authors: E Sterpin; G Janssens; J Smeets; François Vander Stappen; D Prieels; Marlen Priegnitz; Irene Perali; S Vynckier Journal: Phys Med Biol Date: 2015-06-09 Impact factor: 3.609
Authors: M Priegnitz; S Helmbrecht; G Janssens; I Perali; J Smeets; F Vander Stappen; E Sterpin; F Fiedler Journal: Phys Med Biol Date: 2015-06-09 Impact factor: 3.609
Authors: Enrique Muñoz; John Barrio; Ane Etxebeste; Pablo G Ortega; Carlos Lacasta; Josep F Oliver; Carles Solaz; Gabriela Llosá Journal: Phys Med Biol Date: 2017-08-22 Impact factor: 3.609
Authors: I Perali; A Celani; L Bombelli; C Fiorini; F Camera; E Clementel; S Henrotin; G Janssens; D Prieels; F Roellinghoff; J Smeets; F Stichelbaut; F Vander Stappen Journal: Phys Med Biol Date: 2014-09-10 Impact factor: 3.609
Authors: Yunhe Xie; El Hassane Bentefour; Guillaume Janssens; Julien Smeets; François Vander Stappen; Lucian Hotoiu; Lingshu Yin; Derek Dolney; Stephen Avery; Fionnbarr O'Grady; Damien Prieels; James McDonough; Timothy D Solberg; Robert A Lustig; Alexander Lin; Boon-Keng K Teo Journal: Int J Radiat Oncol Biol Phys Date: 2017-05-03 Impact factor: 7.038