Scintillating fiber based in-vivo dose monitoring system to the rectum in proton therapy of prostate cancer: A Geant4 Monte Carlo simulation
Purpose: To construct a dose monitoring system based on an endorectal balloon coupled to thin scintillating fibers to study the dose to the rectum in proton therapy of prostate cancer.
Method: A Geant4 Monte Carlo toolkit was used to simulate the proton therapy of prostate cancer, with an endorectal balloon and a set of scintillating fibers for immobilization and dosimetry measurements, respectively.
Results: A linear response of the fibers to the dose delivered was observed to within less than 2%. Results obtained show that fibers close to the prostate recorded higher dose, with the closest fiber recording about one-third of the dose to the target. A 1/r2 (r is defined as center-to-center distance between the prostate and the fibers) decrease was observed as one goes toward the frontal and distal regions. A very low dose was recorded by the fibers beneath the balloon which is a clear indication that the overall volume of the rectal wall that is exposed to a higher dose is relatively minimized. Further analysis showed a relatively linear relationship between the dose to the target and the dose to the top fibers (total 17), with a slope of (-0.07 ± 0.07) at large number of events per degree of rotation of the modulator wheel (i.e., dose).
Conclusion: Thin (1 mm × 1 mm), long (1 m) scintillating fibers were found to be ideal for real time in-vivo dose measurement to the rectum during proton therapy of prostate cancer. The linear response of the fibers to the dose delivered makes them good candidates as dosimeters. With thorough calibration and the ability to define a good correlation between the dose to the target and the dose to the fibers, such dosimeters can be used for real time dose verification to the target.
Cite this article as: Tesfamicael BY, Avery S, Gueye P, Lyons D, Mahesh M. Scintillating fiber based in-vivo dose monitoring system to the rectum in proton therapy of prostate cancer: A Geant4 Monte Carlo simulation. Int J Cancer Ther Oncol 2014; 2(2):02024.
American Cancer Society. Cancer Facts and Figures 2013. American Cancer Society, Atlanta, GA.
Crawford ED. Epidemiology of prostate cancer. Urology 2003; 62:3-12.
Gronberg H. Prostate cancer epidemiology. Lancet 2003; 361:859-64.
Cartwright LE, Suchowerska N, Yin Y, et al. Dose mapping of the rectal wall during brachytherapy with an array of scintillating dosimeters. Med Phys 2010; 37:2247-55.
Mazeron R, Bajard A, Montbarbon X, et al. Permanent 125I-seed prostate brachytherapy: early prostate specific antigen value as a predictor of PSA bounce occurrence. Radiat Oncol 2012; 7:46.
Nag S, Beyer D, Friedland J, et al. American Brachytherapy Society (ABS) recommendations for transperineal permanent brachytherapy of prostate cancer. Int J Radiation Oncology Biol Phys 1999; 44:789-99.
Porter AT, Blasko JC, Grimm PD, et al. Brachytherapy for prostate cancer. CA Cancer J Clin 1995; 45:165-78.
Hong TS, Ritter MA, Tome WA, Harari PM. Intensity-modulated radiation therapy: emerging cancer treatment technology. Br J Cancer 2005; 92:1819-24.
Zelefsky MJ, Fuks Z, Leibel SA. Intensity-modulated radiation therapy for prostate cancer. Semin Radiat Oncol 2002; 12:229-37.
Ezzell GA, Galvin JM, Low D, et al. Guidance document on delivery, treatment planning, and clinical implementation of IMRT: report of the IMRT Subcommittee of the AAPM Radiation Therapy Committee. Med Phys 2003; 30:2089-115.
Zelefsky MJ, Fuks Z, Happersett L, et al. Clinical experience with intensity modulated radiation therapy (IMRT) in prostate cancer. Radiother Oncol 2000; 55:241-9.
Cahlon O, Hunt M, Zelefsky MJ. Intensity-modulated radiation therapy: supportive data for prostate cancer. Semin Radiat Oncol 2008; 18:48-57.
Huang E, Dong L, Chandra A, et al. Intrafraction prostate motion during IMRT for prostate cancer. Int J Radiat Oncol Biol Phys 2002; 53:261-8.
Slater JD, Rossi CJ Jr, Yonemoto LT, et al. Proton therapy for prostate cancer: the initial Loma Linda university experience. Int J Radiat Oncol Biol Phys 2004; 59:348-52.
Slater JD, Rossi CJ Jr, Yonemoto LT, et al. Conformal proton therapy for early-stage prostate cancer. Urology 1999; 53:978-84.
Moyers MF, Pouliot J, Orton CG. Point/Counterpoint. Proton therapy is the radiation treatment modality for prostate cancer. Med Phys 2007; 34:375-8.
Slater JD, Yonemoto LT, Rossi CJ Jr, et al. Conformal proton therapy for prostate canrcinoma. Int J Rad Oncl Biol Phys 1998; 42:299-304.
Ulmer W. Notes of the editorial board on the role of medical physics in radiotherapy. Int J Cancer Ther Oncol 2013;1(1):01014.
Rana S, Singh H. Impact of heterogeneities on lateral penumbra in uniform scanning proton therapy. Int J Cancer Ther Oncol 2013; 1(2):01026.
Wachter S, Gerstner N, Dorner D, et al. The influence of a rectal balloon tube as internal immobilization device on variations of volumes and dose volume histograms during treatment course of conformal radiotherapy for prostate cancer. Int J Radiat Oncol Biol Phys 2002; 52:91-100.
Adamson J, Wu Q. Prostate intrafraction motion assessed by simultaneous kilovoltage fluoroscopy at megavoltage delivery I: clinical observations and pattern analysis. Int J Radiat Oncol Biol Phys 2010; 78:1563-70.
McGary JE, Teh BS, Butler EB, Grant W 3rd. Prostate immobilization using a rectal balloon. J Appl Clin Med Phys 2002; 3:6-11.
Cho JH, Lee CG, Kang DR, et al. Positional reproducibility and effects of a rectal balloon in prostate cancer radiotherapy. J Korean Med Sci 2009; 24:894-903.
Ciernik IF, Baumert BG, Egli P, et al. On-line correction of beam portals in the treatment of prostate cancer using an endorectal balloon device. Radiother Oncol 2002; 65:39-45.
Archambault L, Briere TM, Pönisch F, et al. Toward a real-time in vivo dosimetry system using plastic scintillation detectors. Int J Radiat Oncol Biol Phys 2010; 78:280-7.
Hardcastle N, Cutajar DL, Metcalfe PE, et al. In vivo real-time rectal wall dosimetry for prostate radiotherapy. Phys Med Biol 2010; 55:3859-71.
Agostinelli S, et al., Geant4 – A simulation toolkit. Nuclear Instruments and Methods in Physics Research 2003; A506:250-303.
Allison J, et al., Geant4 developments and applications, IEEE Transactions on Nuclear Science 2006; 53:270-278.
Knoll GF. Radiation Detection and Measurement. John Wiley & Sons Inc New York, 2000.
Beddar AS, Mackie TR, Attix FH. Water-equivalent plastic scintillation detectors for high-energy beam dosimetry: I. physical characteristics and theoretical considerations. Phys Med Biol 1992; 37:1883-900.
Smith DL, Polk RG, and Miller TG. Measurement of the response of several organic scintillators to electrons, protons and deuterons. Nucl Instrum Meth 1968; 64:157-66.
Beddar AS, Mackie TR, Attix FH. Water-equivalent plastic scintillation detectors for high-energy beam dosimetry: II. Properties and measurements. Phys Med Biol 1992; 37:1901-13.
Gooding TJ and Pugh HG. The response of plastic scintillators to high-energy particles. Nucl Instrum Meth 1960; 7:189-92.
Cirrone GAP, Cuttone G, Guatelli S, Lo Nigro S, Mascialino B. Implementation of a new monte carlo simulation tool for the development of a proton therapy beam line and verification of the related dose distributions. IEEE Trans. Nucl Sci 2005; 52:262-5.
NIST physical measurements laboratory. Available from http://physics.nist.gov/PhysRefData/Star/Text/ASTAR.html. [Accessed date: 10/29/2012]
Available from http://www.hamptonproton.org/ [Accessed date: 02/03/2014]
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