H Petra Kok1, Johannes Crezee2, Nicolaas A P Franken3, Lukas J A Stalpers2, Gerrit W Barendsen4, Arjan Bel2. 1. Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. Electronic address: H.P.Kok@amc.uva.nl. 2. Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. 3. Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Laboratory for Experimental Oncology and Radiobiology (LEXOR)/Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. 4. Laboratory for Experimental Oncology and Radiobiology (LEXOR)/Center for Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
Abstract
PURPOSE: To develop a method to quantify the therapeutic effect of radiosensitization by hyperthermia; to this end, a numerical method was proposed to convert radiation therapy dose distributions with hyperthermia to equivalent dose distributions without hyperthermia. METHODS AND MATERIALS: Clinical intensity modulated radiation therapy plans were created for 15 prostate cancer cases. To simulate a clinically relevant heterogeneous temperature distribution, hyperthermia treatment planning was performed for heating with the AMC-8 system. The temperature-dependent parameters α (Gy(-1)) and β (Gy(-2)) of the linear-quadratic model for prostate cancer were estimated from the literature. No thermal enhancement was assumed for normal tissue. The intensity modulated radiation therapy plans and temperature distributions were exported to our in-house-developed radiation therapy treatment planning system, APlan, and equivalent dose distributions without hyperthermia were calculated voxel by voxel using the linear-quadratic model. RESULTS: The planned average tumor temperatures T90, T50, and T10 in the planning target volume were 40.5°C, 41.6°C, and 42.4°C, respectively. The planned minimum, mean, and maximum radiation therapy doses were 62.9 Gy, 76.0 Gy, and 81.0 Gy, respectively. Adding hyperthermia yielded an equivalent dose distribution with an extended 95% isodose level. The equivalent minimum, mean, and maximum doses reflecting the radiosensitization by hyperthermia were 70.3 Gy, 86.3 Gy, and 93.6 Gy, respectively, for a linear increase of α with temperature. This can be considered similar to a dose escalation with a substantial increase in tumor control probability for high-risk prostate carcinoma. CONCLUSION: A model to quantify the effect of combined radiation therapy and hyperthermia in terms of equivalent dose distributions was presented. This model is particularly instructive to estimate the potential effects of interaction from different treatment modalities.
PURPOSE: To develop a method to quantify the therapeutic effect of radiosensitization by hyperthermia; to this end, a numerical method was proposed to convert radiation therapy dose distributions with hyperthermia to equivalent dose distributions without hyperthermia. METHODS AND MATERIALS: Clinical intensity modulated radiation therapy plans were created for 15 prostate cancer cases. To simulate a clinically relevant heterogeneous temperature distribution, hyperthermia treatment planning was performed for heating with the AMC-8 system. The temperature-dependent parameters α (Gy(-1)) and β (Gy(-2)) of the linear-quadratic model for prostate cancer were estimated from the literature. No thermal enhancement was assumed for normal tissue. The intensity modulated radiation therapy plans and temperature distributions were exported to our in-house-developed radiation therapy treatment planning system, APlan, and equivalent dose distributions without hyperthermia were calculated voxel by voxel using the linear-quadratic model. RESULTS: The planned average tumor temperatures T90, T50, and T10 in the planning target volume were 40.5°C, 41.6°C, and 42.4°C, respectively. The planned minimum, mean, and maximum radiation therapy doses were 62.9 Gy, 76.0 Gy, and 81.0 Gy, respectively. Adding hyperthermia yielded an equivalent dose distribution with an extended 95% isodose level. The equivalent minimum, mean, and maximum doses reflecting the radiosensitization by hyperthermia were 70.3 Gy, 86.3 Gy, and 93.6 Gy, respectively, for a linear increase of α with temperature. This can be considered similar to a dose escalation with a substantial increase in tumor control probability for high-risk prostate carcinoma. CONCLUSION: A model to quantify the effect of combined radiation therapy and hyperthermia in terms of equivalent dose distributions was presented. This model is particularly instructive to estimate the potential effects of interaction from different treatment modalities.
Authors: H Petra Kok; Erik N K Cressman; Wim Ceelen; Christopher L Brace; Robert Ivkov; Holger Grüll; Gail Ter Haar; Peter Wust; Johannes Crezee Journal: Int J Hyperthermia Date: 2020 Impact factor: 3.914
Authors: Adriana M De Mendoza; Soňa Michlíková; Johann Berger; Jens Karschau; Leoni A Kunz-Schughart; Damian D McLeod Journal: Sci Rep Date: 2021-03-09 Impact factor: 4.379
Authors: Sarah Catharina Brüningk; Jannat Ijaz; Ian Rivens; Simeon Nill; Gail Ter Haar; Uwe Oelfke Journal: Int J Hyperthermia Date: 2017-07-05 Impact factor: 3.914
Authors: J Crezee; C M van Leeuwen; A L Oei; L E van Heerden; A Bel; L J A Stalpers; P Ghadjar; N A P Franken; H P Kok Journal: Radiat Oncol Date: 2016-02-02 Impact factor: 3.481
Authors: S Brüningk; G Powathil; P Ziegenhein; J Ijaz; I Rivens; S Nill; M Chaplain; U Oelfke; G Ter Haar Journal: J R Soc Interface Date: 2018-01 Impact factor: 4.118