Evaluation of rectal dose discrepancies between planned and in vivo dosimetry using MOSkin detector and PTW 9112 semiconductor probe during Co-60 HDR CT-based intracavitary cervix brachytherapy

Jamalludin, Z. and Jong, W. L. and Malik, R. A. and Rosenfeld, A. B. and Ung, Ngie Min (2020) Evaluation of rectal dose discrepancies between planned and in vivo dosimetry using MOSkin detector and PTW 9112 semiconductor probe during Co-60 HDR CT-based intracavitary cervix brachytherapy. Physica Medica-European Journal of Medical Physics, 69. pp. 52-60. ISSN 1120-1797, DOI https://doi.org/10.1016/j.ejmp.2019.11.025.

Full text not available from this repository.

Abstract

Purpose: Dose to the rectum during brachytherapy treatment may differ from an approved treatment plan which can be quantified with in vivo dosimetry (IVD). This study compares the planned with in vivo doses measured with MOSkin and PTW 9112 rectal probe in patients undergoing CT based HDR cervical brachytherapy with Co-60 source. Methods: Dose measurement of a standard pear-shaped plan carried out in phantom to verify the MOSkin dose measurement accuracy. With MOSkin attached to the third diode, RP3 of the PTW 9112, both detectors were inserted into patients' rectum. The RP3 and MOSkin measured doses in 18 sessions as well as the maximum measured doses from PTW 9112, RPmax in 48 sessions were compared to the planned doses. Results: Percentage dose differences Delta D (%) in phantom study for two MOSkin found to be 2.22 +/- 0.07% and 2.5 +/- 0.07%. IVD of 18 sessions resulted in Delta D(%) of - 16.3% to 14.9% with MOSkin and Delta D(%) of - 35.7% to -2.1% with RP3. In 48 sessions, RPmax, recorded Delta D(%) of -37.1% to 11.0%. MOSkin_measured doses were higher in 44.4% (8/18) sessions, while RP3_measured were lower than planned doses in all sessions. RP(max-)measured were lower in 87.5% of applications (42/47). Conclusions: The delivered doses proven to deviate from planned doses due to unavoidable shift between imaging and treatment as measured with MOSkin and PTW 9112 detectors. The integration of MOSkin on commercial PTW 9112 surface found to be feasible for rectal dose IVD during cervical HDR ICBT.

Item Type: Article
Funders: Faculty of Medicine, University of Malaya, Malaysia (PG211-2015B)
Uncontrolled Keywords: In vivo; Rectal dose; Intracavitary brachytherapy; MOSkin; PTW 9112 semiconductor
Subjects: R Medicine
Divisions: Faculty of Medicine
Depositing User: Ms Zaharah Ramly
Date Deposited: 02 Jun 2023 02:50
Last Modified: 02 Jun 2023 02:50
URI: http://eprints.um.edu.my/id/eprint/37048

Actions (login required)

View Item View Item