https://doi.org/10.1051/epjap/2011100324
In vivo dosimetry for head and neck carcinoma: determination of target absorbed dose from entrance and exit absorbed dose measurements
1
Service de radiothérapie carcinologique, CHU Habib-Bourguiba, 3029 Sfax, Tunisia
2
Service de radiothérapie carcinologique, Institut Salah-Azaiz, Boulevard du 9-avril-Bab-Saadoun, 1006 Tunis, Tunisia
3
Service de radiophysique, Institut Gustave-Roussy, 39 rue
Camille-Desmoulins, 94805 Villejuif Cedex, France
Corresponding author: leilafarhat2002@yahoo.fr
Received:
22
August
2010
Revised:
21
December
2010
Accepted:
9
February
2011
Published online:
13
April
2011
The aims of this work were to measure the entrance and exit dose for patient treated for head and neck tumors. The target absorbed dose was determined from the exit and entrance dose measurement. Twenty patients were evaluated. The results were compared to the calculated values and the midline dose was determinate and compared with the prescribed dose. 80 entrance doses and 80 exit doses measurements were performed. The average difference from expected values was 1.93% for entrance dose (SD 1.92%) and –0.34% for exit dose (SD 4.1%). The target absorbed dose differed from prescribed dose values by 2.94% (1.97%) for the results using the Noël method and 3.34% (SD: 2.29%) with the Rizzotti method. The total uncertainty budget in the measurement of the absorbed entrance and exit dose with diode, including diode reading, correction factors and diode calibration coefficient, is determined as 3.02% (1 s). Simple in vivo dose measurements are an additional safeguard against major setup errors and calculation or transcription errors that were missed during pre-treatment chart check.
© EDP Sciences, 2011
