Toward a Real-Time In Vivo Dosimetry System Using Plastic Scintillation Detectors

Journal Article · Wed Sep 01 00:00:00 EDT 2010 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2009.11.025· OSTI ID:21451153

Archambault, Louis; Briere, Tina M; Poenisch, Falk ^[1]; Beaulieu, Luc ^[2]; Kuban, Deborah A; Lee, Andrew ^[3]; Beddar, Sam ^[1]

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1. Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)
2. Departement de Radio-oncologie, Centre Hospitalier Universitaire de Quebec, Quebec, QC (Canada)
3. Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

Purpose: In the present study, we have presented and validated a plastic scintillation detector (PSD) system designed for real-time multiprobe in vivo measurements. Methods and Materials: The PSDs were built with a dose-sensitive volume of 0.4 mm{sup 3}. The PSDs were assembled into modular detector patches, each containing five closely packed PSDs. Continuous dose readings were performed every 150 ms, with a gap between consecutive readings of <0.3 ms. We first studied the effect of electron multiplication. We then assessed system performance in acrylic and anthropomorphic pelvic phantoms. Results: The PSDs were compatible with clinical rectal balloons and were easily inserted into the anthropomorphic phantom. With an electron multiplication average gain factor of 40, a twofold increase in the signal/noise ratio was observed, making near real-time dosimetry feasible. Under calibration conditions, the PSDs agreed with the ion chamber measurements to 0.08%. Precision, evaluated as a function of the total dose delivered, ranged from 2.3% at 2 cGy to 0.4% at 200 cGy. Conclusion: Real-time PSD measurements are highly accurate and precise. These PSDs can be mounted onto rectal balloons, transforming these clinical devices into in vivo dose detectors without modifying current clinical practice. Real-time monitoring of the dose delivered near the rectum during prostate radiotherapy should help radiation oncologists protect this sensitive normal structure.

• OSTI ID: 21451153
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Vol. 78, Issue 1; Other Information: DOI: 10.1016/j.ijrobp.2009.11.025; PII: S0360-3016(09)03566-4; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
DOSIMETRY
IN VIVO
MONITORING
PLASTIC SCINTILLATION DETECTORS
PROSTATE
RADIOTHERAPY
REAL TIME SYSTEMS
RECTUM
BODY
DIGESTIVE SYSTEM
GASTROINTESTINAL TRACT
GLANDS
INTESTINES
LARGE INTESTINE
MALE GENITALS
MEASURING INSTRUMENTS
MEDICINE
NUCLEAR MEDICINE
ORGANS
RADIATION DETECTORS
RADIOLOGY
SCINTILLATION COUNTERS
SOLID SCINTILLATION DETECTORS
THERAPY