Applications of MOSkin dosimeters for quality assurance in gynecological HDR brachytherapy: An in-phantom feasibility study. (November 2017)

• Record Type: Journal Article
• Authors: Romanyukha, Anna A.; Carrara, Mauro; Tenconi, Chiara; Mazzeo, Davide; Rossi, Giulio; Borroni, Marta; Pignoli, Emanuele; Cerrotta, Annamaria; Cutajar, Dean; Petasecca, Marco; Lerch, Michael; Bucci, Joseph; Rosenfeld, Anatoly B.
• Is Part Of: Radiation measurements. Volume 106(2017:Nov.)
• Page Start: 399
• Page End: 404
• Publication Date: 2017-11
• Subjects: In vivo dosimetry -- HDR brachytherapy -- MOSFET -- Gynecological brachytherapy; Nuclear emulsions -- Periodicals; Particle tracks (Nuclear physics) -- Periodicals; Thermoluminescence -- Periodicals; Cosmic rays -- Periodicals; Radiation -- Measurement -- Periodicals; Radiometry -- Periodicals; Radiation Monitoring -- Periodicals; Émulsions nucléaires -- Périodiques; Particules (Physique nucléaire) -- Traces -- Périodiques; Thermoluminescence -- Périodiques; Rayonnement cosmique -- Périodiques; Radiométrie -- Périodiques; 539.77
• DOI: 10.1016/j.radmeas.2016.12.010
• Languages: English
• ISSNs: 1350-4487

Abstract

Abstract: In vivo dosimetry (IVD) is an excellent mode of treatment verification and detection of possible overexposures. A feasibility study was conducted to evaluate a proposed IVD procedure for gynecological HDR brachytherapy procedure quality assurance. MO Skin dosimeters were selected due to their small size and capability of measuring steep dose gradients, such as those relevant in HDR brachytherapy procedures. Two in-phantom experiments measuring dose with MO Skin s at the position simulating the rectal wall were conducted employing a cylindrical single channel applicator and a multichannel applicator. Three MO Skin s were incorporated onto a rectal catheter, which was then attached to the applicator, separated by a small wooden plaque, simulating the vaginal to rectal wall distance and fixing catheter position. This setup was inserted into a water phantom and three treatment plans prescribing 300 cGy to 3 different targets were assigned with various dose distributions. Each treatment was administered three times, and doses measured by the MO Skin s were recorded. Doses measured by the MO Skin s were within 5% of the dose determined by the treatment planning system (TPS), ranging between 208 and 332 cGy, depending on dosimeter position on the rectal catheter. The overall average dose difference between measured and TPS values was 2.09% ± 1.15% (ranging between 0.83 and 4.27%, with measured values always higher than TPS dose), subdivided in 1.40 ± 0.37% and 2.79 ± 1.27% for single and multichannel applicator experiments, respectively. An overall dose agreement between the TPS and measured values, detector reproducibility, and practicality of the rectal catheter demonstrated the suitability of the proposed method for in vivo real time QA purposes in gynecological HDR brachytherapy. Highlights: Feasibility study for IVD procedure in gynecological HDR brachytherapy. Single channel and multichannel applicator doses monitored using MO Skin dosimeters. Dose discrepancies between measured and treatment planning system doses evaluated. Proposed method found to be suitable for IVD use.