scholarly journals Evaluation of Given Dose Accuracy in Radiation Therapy of Patient with Breast Cancer Using Diode In-vivo Dosimetry

2021 ◽  
Vol 14 (6) ◽  
Author(s):  
Sepideh Rasouli Farah ◽  
Ahmad Mostaar ◽  
Ahmad Ameri ◽  
Ahmad R Mafi ◽  
Robab Anbiaee
Keyword(s):  
Breast Cancer ◽  
Quality Control ◽  
Radiation Therapy ◽  
Relative Error ◽  
Arithmetic Mean ◽  
Planning System ◽  
In Vivo Dosimetry ◽  
Entrance Dose ◽  
Transfer Method

Background: The main goal of radiation therapy is to deliver the highest dose to the tumor and at the same time the lowest dose to the surrounding normal tissue. In vivo dosimetry is a quality control procedure that, instead of controlling the components separately, directly examines the dose reached to the tumor area. Objectives: In this study, the entrance, exit, and middle dose of the breast and supraclavicular area of patients with breast cancer under radiation therapy were measured and compared with calculations. Methods: In this experimental study, the entrance and exit doses of 33 patients with breast tumors treated with 6 MV and 18MV photons were measured simultaneously. The measurement was done, using p-type diodes after calibration and, then, the midpoint dose was calculated, using the transfer method and arithmetic mean method. Also, the entrance dose, exit dose, and midline dose measured with dosimeter were compared with the calculated values in the treatment planning system. Results: There was no significant difference between calculated and measured doses in the entrance, exit, and midline point in breast regions (P > 0.05), but in the supraclavicular region, a challenge was observed. The difference in entrance and midline point between calculation and measurement is not significant based on the transfer method, but there is a significant error based on the arithmetic mean method (P < 0.05). Conclusions: In vivo dosimetry by measured real given dose to the patient can perform a basic role in the quality control of the radiotherapy department. It seems in the entrance dose, the relative error is smaller but due to the smaller value of exit dose, the relative error in small values is more apparent.

In vivo dosimetry using radiochromic films during intraoperative electron beam radiation therapy in early-stage breast cancer

2003 ◽  
Vol 69 (3) ◽  
pp. 285-289 ◽  
Author(s):  
Mario Ciocca ◽  
Roberto Orecchia ◽  
Cristina Garibaldi ◽  
Elena Rondi ◽  
Alberto Luini ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Radiation Therapy ◽  
Electron Beam ◽  
Early Stage ◽  
Early Stage Breast Cancer ◽  
In Vivo Dosimetry ◽  
Beam Radiation ◽  
Radiochromic Films ◽  
Electron Beam Radiation

scholarly journals Prospective superficial EPR in-vivo dosimetry study during hypofractionated radiotherapy of breast cancer patients treated with helical tomotherapy

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Sebastian Höfel ◽  
Matteo Gandalini ◽  
Michael K. Fix ◽  
Malte Drescher ◽  
Felix Zwicker
Keyword(s):  
Breast Cancer ◽  
Total Dose ◽  
Cancer Patients ◽  
Helical Tomotherapy ◽  
Planning System ◽  
In Vivo Dosimetry ◽  
Breast Cancer Patients ◽  
Displacement Vectors ◽  
The Mean

Abstract Background In-vivo dosimetry (IVD) is a patient specific measure of quality control and safety during radiotherapy. With regard to current reporting thresholds for significant occurrences in radiotherapy defined by German regulatory authorities, the present study examines the clinical feasibility of superficial electron paramagnetic resonance (EPR) IVD of cumulative total doses applied to breast cancer patients treated with helical intensity-modulated radiotherapy (tomotherapy). Methods In total, 10 female patients with left- or right-sided breast cancer were enrolled in this prospective IVD study. Each patient received a hypofractionated whole breast irradiation. A total median dose of 42.4 Gy in 16 fractions (5 fractions per week) was prescribed to the planning target volume. The treatments were completely delivered using helical tomotherapy and daily image guidance via megavoltage CT (MVCT). For each patient, three EPR dosimeters were prepared and placed at distinct locations on the patient’s skin during the delivery of all fractions. Two dosimeters were placed next to the ipsilateral and contralateral mammilla and one dosimeter was placed ventrally to the thyroid (out-of-primary-beam). The total doses delivered to the dosimeters were readout after all fractions had been administered. The measured total dose values were compared to the planned dose values derived from the treatment planning system (TPS). Daily positional variations (displacement vectors) of the ipsilateral mammilla and of the respective dosimeter were analyzed with respect to the planned positions using the daily registered MVCT image. Results Averaged over all patients, the mean absolute dose differences between measured and planned total dose values (± standard deviation (SD)) were: 0.49 ± 0.85 Gy for the ipsilateral dosimeter, 0.17 ± 0.49 Gy for the contralateral dosimeter and -0.12 ± 0.30 Gy for the thyroid dosimeter. The mean lengths of the ipsilateral displacement vectors (± SD) averaged over all patients and fractions were: 10 ± 7 mm for the dosimeter and 8 ± 4 mm for the mammilla. Conclusion Superficial EPR IVD is suitable as additional safeguard for dose delivery during helical tomotherapy of breast cancer. Despite positional uncertainties in clinical routine, the observed dose deviations at the ipsilateral breast were on average small compared to national reporting thresholds for total dose deviations (i.e. 10%/4 Gy). EPR IVD may allow for the detection of critical dose errors during whole breast irradiations.

Characterisation and use of OSLD for in vivo dosimetry in head and neck intensity-modulated radiation therapy

2020 ◽  
pp. 1-7
Author(s):  
L. Jose Solomon Raj ◽  
Benedicta Pearlin ◽  
B. S. Timothy Peace ◽  
Rajesh Isiah ◽  
I. Rabi Raja Singh
Keyword(s):  
Radiation Therapy ◽  
Head And Neck ◽  
Dose Rate ◽  
Intensity Modulated Radiation Therapy ◽  
Rate Dependence ◽  
Planning System ◽  
Treatment Planning System ◽  
In Vivo Dosimetry ◽  
Intensity Modulated

Abstract Aim: This study reveals the characteristic nature and the use of optically stimulated luminescence dosimeters (OSLD) as an in vivo dosimetry tool for head and neck intensity-modulated radiation therapy (IMRT). Materials and methods: Calibration and characterisation of OSLD such as sensitivity, reproducibility, dose-rate dependence, beam quality dependence, output factor measurement and comparison of two bleaching techniques using halogen and compact fluorescent lamp (CFL) were initially performed. Later, eye dose measurements were performed for head and neck IMRT patients using OSLD and were compared with the corresponding dose calculated by the treatment planning system (TPS). Results: While the sensitivity was found to be within ±5%, the dose-rate dependence and reproducibility were found to be within ±3%. The OSLD showed an under-response of 3% for 15 MV and an increase in response by 5% for Co60 (1·25 MeV) when compared with the 6 MV X-ray beam. Therefore, a separate calibration for different beam energies is required. The percentage deviation of OSLD to that of TPS was found to be within ±2·77%. The OSLD has been successfully used for the in vivo dosimetry of patients who received IMRT. Hence, it is concluded that OSLDs can serve as effective dosimeters for in vivo dosimetry.

scholarly journals On the Need of In Vivo Dosimetry as Quality Control for Intraoperative Electron Radiotherapy in Breast Cancer

2020 ◽  
Vol 108 (3) ◽  
pp. e317-e318
Author(s):  
M. Molla Armada ◽  
G. Óses González ◽  
I. Alonso ◽  
X. Caparros ◽  
A. Herreros ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Quality Control ◽  
In Vivo Dosimetry ◽  
Electron Radiotherapy
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