Premium
SU‐FF‐T‐390: In‐Vivo Prostate Brachytherapy Absorbed Dose Measurements
Author(s) -
Gueye P,
Velasco C,
Keppel C,
Murphy B,
Sinesi C
Publication year - 2009
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.3181871
Subject(s) - dosimetry , imaging phantom , nuclear medicine , reproducibility , brachytherapy , materials science , prostate , absorbed dose , photomultiplier , dose profile , biomedical engineering , thermoluminescent dosimetry , optics , detector , medicine , radiation therapy , physics , chemistry , thermoluminescent dosimeter , radiology , chromatography , dosimeter , cancer
Purpose: In‐vivo prostate brachytherapy absorbed dosimetry detector using scintillating fibers. Method and Materials: Five pairs of 85.5 ± 0.05 cm long blue shifted scintillating fibers (model BCF‐10) with 1 mm 2 cross sectional area were placed in a mixture of gelatin (368.6 ± 0.5 grams) and water (3.78 ± 0.025 liters) to measured the absorbed dose delivered by a 12 Ci 192 Ir HDR source. The fibers were held by a 7 × 7 cm 2 template grid and optically connected to a 16‐channel multianode photomultiplier tube (Hamamatsu, model H6568). Each pair consisted of one fiber 4 mm shorter than the other one to extract the dose by the subtraction method. A dose atlas was used for radiation delivered to the phantom. The plans followed delivered 5 and 7 Gy to a point located 2.0 centimeters away from the central dwelling positions. A total of 32 data points were acquired in a plan to assess the linearity and reproducibility of the measurements. Results: Reproducibility of the data was found to be within 5% and the overall accuracy of the system estimated to be ±5.5%. The linearity of the data for all 7 measured dose values (ranging from 0.6 to 7 Gy), gives a slope of 312 counts/Gy with a 1.4% relative deviation. Conclusion: This work indicates the possibility of measuring in real‐time the dose effectively delivered to a biological system during prostate brachytherapy treatments. The availability of commercially thin (150 μm) scintillating fibers opens the capability of using such system during clinical treatments (by embedding the fibers within the catheters) with the advantage of performing real‐time adjustment of the dose delivery.