EPR/alanine dosimetry in LDR brachytherapy--a feasibility study.
In this study, we present the results of in vivo dosimetry, using electron paramagnetic resonance in l-alanine, performed on 13 patients treated for gynaecological cancers. The doses from (137)Cs (12 samples) and (192)Ir (one sample) brachytherapy sources were determined inside vagina. The detectors had a form of small cellulose capsules tightly filled with crystalline alanine. The positions of the detectors were reconstructed from two orthogonal radiographs. The planned doses were calculated with a computer planning system (PLATO, Nucletron). The relative deviations between planned and measured doses ranged from -23 to +14%. The mean deviation from the prescribed dose was relatively low (-5%) with SD of 10%. The main sources of differences between the measured and calculated doses were attributed to uncertainty in the determination of the detector position inside the patient's body and to uncontrolled changes in the detector position during the treatment.
Department of Physics and Biophysics, Medical University of Gdansk, Debinki 1, 80-211 Gdansk, Poland. kschult@amg.gda.pl
Katarzyna
K
Schultka
Bartlomiej
B
Ciesielski
Krystyna
K
Serkies
Tomasz
T
Sawicki
Zofia
Z
Tarnawska
Jacek
J
Jassem
D000409:Alanine / Q000737:chemistry* / Q000528:radiation effects*; D001918:Brachytherapy / Q000295:instrumentation* / Q000379:methods; D004307:Dose-Response Relationship, Radiation; D004578:Electron Spin Resonance Spectroscopy / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D008422:Materials Testing; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D011879:Radiotherapy Dosage; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000409:Alanine