- •Improving a bleeding detector for PMMA applicators with minimum visual impact.
- •The developed detector avoids the asymmetry in detection when the applicator is tilted.
- •The conditioning circuit features high sensitivity and low-noise.
- •A minimum fluid depth of 0.5 cm can be detected with a linear behaviour.
- •The detector features: low-cost and easily integration into the applicator.
The aim of this work is to improve the potential bleeding detection during intraoperative radiotherapy with linac polymethyl methacrylate applicators (PMMA), based on one previously developed. The improvements carried out have been focused on: i) minimizing the impact of the detector on the visual through the plastic applicators and ii) avoiding the asymmetry in the detection capability when the applicator is tilted.
Simulations have been made to select the geometry that provides a reduced visual impact on the applicator as well as allowing an independent response with the tilting angle of the applicator. A low-noise circuit for signal conditioning has been developed. Measurements have been made on three setups: 10 cm, 7 cm and 4 cm applicator diameters, 0° and 45° tilted.
The detector has a visibility through the applicator greater than 50%. Due to the geometry, optimal detection is ensured regardless of its orientation when the applicator is tilted. It is possible to detect the presence of fluid well below the typical perturbing fluid depth established by the clinic (1–1.5 cm).
The detector can distinguish the presence of around 0.5 cm of fluid depth while showing a high visual field through the PMMA applicators and providing a measure that does not depend on the detector orientation when the applicator is tilted. The prototype is ready for its industrialization by embedding it into the applicator for clinical use. The detector would have a significant impact on both the quality assurance and the outcome of the treatment.
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- Intraoperative radiation therapy. First part: Rationale and techniques.Crit Rev Oncol Hematol. 2006; 59: 106-115https://doi.org/10.1016/j.critrevonc.2005.11.004
- Intra-operative radiotherapy (IORT) in pancreatic cancer: joint analysis of the ISIORT-Europe experience.Radiother Oncol. 2009; 91: 54-59https://doi.org/10.1016/j.radonc.2008.07.020
- Results of European pooled analysis of IORT-containing multimodality treatment for locally advanced rectal cancer: adjuvant chemotherapy prevents local recurrence rather than distant metastases.Ann Oncol. 2010; 21: 1279-1284https://doi.org/10.1093/annonc/mdp501
- Radiotherapy and surgery-an indispensable duo in the treatment of retroperitoneal sarcoma.Cancer. 2011; 117: 4355-4364https://doi.org/10.1002/cncr.26071
- Combined modality therapy including intraoperative electron irradiation for locally recurrent colorectal cancer.Int J Radiat Oncol Biol Phys. 2011; 79: 143-150https://doi.org/10.1016/j.ijrobp.2009.10.046
- Intraoperative radiation therapy for colon and rectal cancers: a clinical review.Radiat Oncol. 2017; 12: 1-8https://doi.org/10.1186/s13014-016-0752-1
- Intraoperative radiation therapy (IORT) in soft-tissue sarcoma.Radiat Oncol. 2017; 12: 1-13https://doi.org/10.1186/s13014-016-0751-2
- Intraoperative radiotherapy in gynaecological and genito-urinary malignancies: focus on endometrial, cervical, renal, bladder and prostate cancers.Radiat Oncol. 2017; 12https://doi.org/10.1186/s13014-016-0748-x
- Breast intraoperative electron radiotherapy: image-based setup verification and in-vivo dosimetry.Phys Medica. 2019; 60: 37-43https://doi.org/10.1016/j.ejmp.2019.03.017
- Intraoperative irradiation: precision medicine for quality cancer control promotion.Radiat Oncol. 2017; 12: 1-5https://doi.org/10.1186/s13014-017-0764-5
- Defining action levels for in vivo dosimetry in intraoperative electron radiotherapy.Technol Cancer Res Treat. 2015; 15: 453-459https://doi.org/10.1177/1533034615588196
- Detector for monitoring potential bleeding during electron intraoperative radiotherapy.Phys Medica. 2019; 57: 95-99https://doi.org/10.1016/j.ejmp.2018.12.010
LIAC HWL Mobile Ioert Accelerator n.d. https://www.soiort.com/products/liac-hwl/ (accessed October 26, 2018).
- Design and dosimetry characteristics of a commercial applicator system for intra-operative electron beam therapy utilizing ELEKTA Precise accelerator.J Appl Clin Med Phys. 2010; 11: 57-69https://doi.org/10.1120/jacmp.v11i4.3244
- Intraoperative irradiation. Techniques and results.2th ed. Springer, 2011
COMSOL. Introduction to COMSOL Multiphysics 2015. http://cdn.comsol.com/documentation/220.127.116.11/IntroductionToCOMSOLMultiphysics.pdf.
Published online: August 29, 2019
Accepted: August 23, 2019
Received in revised form: July 22, 2019
Received: June 4, 2019
© 2019 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.