scholarly journals A clinical implementation of in vivo dosimetry with n-type Isorad semiconductor diodes

2014 ◽  
Vol 29 (4) ◽  
pp. 313-320
Author(s):  
Laza Rutonjski ◽  
Borislava Petrovic ◽  
Milutin Baucal ◽  
Milan Teodorovic ◽  
Ozren Cudic ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Mean Value ◽  
In Vivo Dosimetry ◽  
Quality Assurance Program ◽  
Clinical Implementation ◽  
Entrance Dose ◽  
Dose Measurements ◽  
Action Levels ◽  
Radiotherapy Treatment

The study was aimed to check the radiotherapy treatment accuracy and definition of action levels during implementation of in vivo dosimetry as a part of quality assurance program. The calibration and correction factors for in vivo entrance dose measurements for six n-type Isorad semiconductor diodes were determined as recommended by the European Society for Radiotherapy and Oncology Booklet No. 5. The patients for in vivo measurements have been divided in groups, according to the treatment site/techique, in order to investigate and detect the groups where the uncertainty was larger or where a systematic error occurred. The tolerance/action levels for all groups were also defined and checked. In this study, the entrance dose measurements were performed for total of 451 treatment fields, and 338 patients over one year period. The mean value and the standard deviation for different groups were: breast +1.0% ? 2.89%(1 SD), brain, and head and neck - +0.74% ? 2.04%(1 SD), and isocentric pelvis and abdomen - +0.1% ? 2.86%(1 SD). All measurements - +0.72% ? 2.64%(1 SD). In our experience, systematic in vivo dosimetry proved to be a very useful tool for quality assurance of patient's plan and treatment, both in detecting systematic errors and for estimating the accuracy of radiotherapy treatment delivery.

Systematic in vivo dosimetry for quality assurance using diodes 2: Assessing radiotherapy techniques and developing an appropriate action protocol

2004 ◽  
Vol 4 (4) ◽  
pp. 143-154 ◽  
Author(s):  
R. Appleyard ◽  
K. Ball ◽  
F. E. Hughes ◽  
W. Kilby ◽  
R. Nicholls ◽  
...  
Keyword(s):  
Head And Neck ◽  
In Vivo Dosimetry ◽  
Entrance Dose ◽  
Treatment Category ◽  
P Type ◽  
Dose Measurements ◽  
Action Levels

Purpose: Having previously reviewed the implementation of systematic in vivo dosimetry at the Norfolk and Norwich Hospital this paper examines the results of entrance dose measurements for specific sites/techniques and determines whether different action/alert protocols are required for these different categories.Methods and materials: Entrance dose measurements using p-type diodes were analysed for the following treatment categories: Breast, head and neck in beam direction shell, abdomino-pelvic and intrathoracic. A 4% tolerance was applied.Results: Mean deviations from expected dose and proportion of measurements exceeding tolerance were: Breast: +1.15%±3.04% (1SD), 238/1073≥4%; Head and neck: +0.35%±2.20% (1SD), 21/326≥4%; Abdomino-pelvic: +0.52%±2.75% (1SD), 93/712≥4%; Intrathoracic: −0.01%±2.75% (1SD), 22/119≥4%. Significant improvements in results for breast patients were noted following the introduction of a commercial breast board. The results for abdomino-pelvic patients confirmed a substantial variation in diode response under short FSD, wedged fields at 16MV (that had not been corrected for). The statistical uncertainty in dose measurement for each treatment category was calculated in order to assist determination of appropriate tolerance levels.Conclusions: A blanket tolerance of 4% was generally too low given the extent of measurement uncertainty. The relatively high number of readings outside tolerance where identification of errors was difficult/impossible resulted in inconsistent application of the action protocol. Some widening of tolerances is likely to improve quality of procedure and treatment. Appropriate action levels are recommended for each treatment category.

In vivo dosimetry as a part of quality assurance program for breast cancer irradiation

2014 ◽  
Vol 30 ◽  
pp. e75 ◽  
Author(s):  
Laza Rutonjski ◽  
Borislava Petrović ◽  
Milutin Baucal ◽  
Milan Teodorović ◽  
Ozren Čudić ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Quality Assurance ◽  
In Vivo Dosimetry ◽  
Quality Assurance Program ◽  
Cancer Irradiation

Systematic in vivo dosimetry for quality assurance using diodes. Part 1: Experiences and results of the implementation of entrance dose measurements

2003 ◽  
Vol 3 (4) ◽  
pp. 185-196 ◽  
Author(s):  
R. Appleyard ◽  
K. Ball ◽  
F.E. Hughes ◽  
W. Kilby ◽  
S. Lassen ◽  
...  
Keyword(s):  
Calibration Procedure ◽  
In Vivo Dosimetry ◽  
Mean Deviation ◽  
Factors Affecting ◽  
Entrance Dose ◽  
Dosimetric Accuracy ◽  
Single Field ◽  
Diode System ◽  
Dose Measurements

Purpose: This paper describes our experiences of implementing systematic in vivo dosimetry at the Norfolk and Norwich Hospital and reviews the results of 2,254 entrance dose measurements made over a 17-month period.Methods and materials: Entrance dose measurements using p-type diodes were performed on all new planned patients. The calibration procedure and correction factors applied are described. A 4% tolerance was applied.Results: The results of all measurements indicated a small mean deviation from expected entrance dose of 10.77% and a standard deviation of 2.85%. 16.7% of all measurements exceeded the 4% tolerance with 9.2% exceeding a 5% level. The estimated overall errors for 578 treatments were calculated using the weighted averages of all beams. A narrower SD of 1.96% combined with only 4.8% of all treatments exceeding a 4% tolerance show that large deviations from a single field do not always translate into significant overall errors.Conclusions: Global dosimetric accuracy was within clinically acceptable limits and variations between measured and expected doses were mainly attributable to factors affecting diode reading. A number of errors in calculating deviations and the inconsistent application of the protocol suggest the need for interfacing the diode system with software control.

OSL films for in-vivo entrance dose measurements

2017 ◽  
Vol 106 ◽  
pp. 644-649 ◽  
Author(s):  
S.O. Souza ◽  
F. d'Errico ◽  
B. Azimi ◽  
A. Baldassare ◽  
A.V.S. Alves ◽  
...  
Keyword(s):  
Entrance Dose ◽  
Dose Measurements

Image-guided in vivo dosimetry for quality assurance of IMRT treatment for prostate cancer

2007 ◽  
Vol 67 (1) ◽  
pp. 288-295 ◽  
Author(s):  
Hansjoerg Wertz ◽  
Judit Boda-Heggemann ◽  
Cornelia Walter ◽  
Barbara Dobler ◽  
Sabine Mai ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Quality Assurance ◽  
In Vivo Dosimetry ◽  
Image Guided
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