Review on the feasibility of using PRESAGE® dosimeter in various radiotherapy techniques

Author(s):  
Qurat-ul-ain Shamsi ◽  
Saeed Ahmad Buzdar ◽  
Shagufta Jabeen ◽  
Khalid Iqbal

Abstract The emergence of advanced radiotherapy techniques, such as intensity-modulated radiotherapy (IMRT), brachytherapy, conformal radiotherapy, magnetic resonance-guided radiotherapy (MRgRT), stereotactic synchrotron radiotherapy (SSRT) and microbeam radiotherapy (MRT), has increased the importance of the verification of volumetric dose distribution. The verification of dose distribution is usually done by 2D films and 3D gel dosimeters, but PRESAGE® due to its affordability, reproducibility, precision, accuracy, unique dosimetric and physical properties is considered as an effective candidate in providing 3D dose data. PRESAGE® is insensitive to oxygen contamination, machinable and can be molded to a variety of shapes and sizes. It is absorbing rather than scattering light which facilitates high-accuracy readout by optical computed tomography (OP-CT). This review focuses on the feasibility of using PRESAGE® in various complicated radiotherapy techniques by comparing its measured doses with 2D films and treatment planning system (TPS) calculated doses.

2013 ◽  
Vol 4 (1) ◽  
pp. 43-49
Author(s):  
M Jahangir Alam ◽  
Syed Md Akram Hussain ◽  
Kamila Afroj ◽  
Shyam Kishore Shrivastava

A three dimensional treatment planning system has been installed in the Oncology Center, Bangladesh. This system is based on the Anisotropic Analytical Algorithm (AAA). The aim of this study is to verify the validity of photon dose distribution which is calculated by this treatment planning system by comparing it with measured photon beam data in real water phantom. To do this verification, a quality assurance program, consisting of six tests, was performed. In this program, both the calculated output factors and dose at different conditions were compared with the measurement. As a result of that comparison, we found that the calculated output factor was in excellent agreement with the measured factors. Doses at depths beyond the depth of maximum dose calculated on-axis or off-axis in both the fields or penumbra region were found in good agreement with the measured dose under all conditions of energy, SSD and field size, for open and wedged fields. In the build up region, calculated and measured doses only agree (with a difference 2.0%) for field sizes > 5 × 5 cm2 up to 25 × 25 cm2. For smaller fields, the difference was higher than 2.0% because of the difficulty in dosimetry in that region. Dose calculation using treatment planning system based on the Anisotropic Analytical Algorithm (AAA) is accurate enough for clinical use except when calculating dose at depths above maximum dose for small field size.DOI: http://dx.doi.org/10.3329/bjmp.v4i1.14686 Bangladesh Journal of Medical Physics Vol.4 No.1 2011 43-49


2020 ◽  
Author(s):  
Yijiang Li ◽  
Han Bai ◽  
Danju Huang ◽  
Feihu Chen ◽  
Xuhong Liu ◽  
...  

Abstract Purpose: This study aimed to evaluate (1) the performance of the Auto-Planning module embedded in the Pinnacle treatment planning system (TPS) with 30 left-side breast cancer plans and (2) the dose-distance correlations between dose-based patients and overlap volume histogram-based (OVH) patients. Method: A total of 30 patients with left-side breast cancer after breast-conserving surgery were enrolled in this study. The clinical manual-planning (MP) and the Auto-Planning (AP) plans were generated by Monaco and by the Auto-Planning module in Pinnacle respectively. The geometric information between organ at risk (OAR) and planning target volume (PTV) of each patient was described by the OVH. The AP and MP plans were ranked to compare with the geometry-based patients from OVH. The Pearson product-moment correlation coefficient (R) was used to describe the correlations between dose-based patients (APs and MPs) and geometry-based patients (OVH). Dosimetric differences between MP and AP plans were evaluated with statistical analysis. Result: The correlation coefficient (mean R = 0.71) indicated that the AP plans have a high correlation with geometry-based patients from OVH, whereas the correlation coefficient (mean R = 0.48) shows a weak correlation between MP plans and geometry-based patients. For different indicators, the dose distribution of V5Gy in the ipsilateral lung (AP: mean R = 0.82; MP: mean R = 0.58) is more relevant to geometry-based patients compared to the dose distribution of in the heart (AP: mean R = 0.4; MP: mean R = 0.19). The dosimetric comparison revealed a statistically significant improvement in ipsilateral lung V5Gy and V10Gy and in the heart V5Gy of AP plans compared to MP plans. Conclusion: The overall results of AP plans were superior to MP plans. The dose distribution in AP plans was more consistent with the distance-dose relationship described by OVH. After eliminating the interference of human factors, the AP was able to provide more stable and objective plans for radiotherapy patients.


2019 ◽  
Vol 18 (03) ◽  
pp. 271-275 ◽  
Author(s):  
Roopam Srivastava ◽  
P.K. Sharma ◽  
K.J. Maria Das ◽  
Jayanand Manjhi

AbstractBackgroundThis is a prospective study to evaluate the dosimetric benefits of treatment plan adaptation for patients who had undergone repeat computed tomography (ReCT)and re-planning due to treatment-induced anatomical changes during radiotherapy.Materials and MethodsThis study involved five head and neck cancer patients who had their treatment plan modified, based on weekly thrice imaging protocol. Impact of mid-course imaging was assessed in patients using ReCT and cone beam computed tomography (CBCT)-based dose verification. Patients were imaged, apart from their initial CT, during the course of their radiation therapy with a ReCT and on board imager CBCT (Varian Medical Systems Inc., Palo Alto, CA, USA). Each CBCT/CT series was rigidly registered to the initial CT in the treatment planning system Eclipse (Varian Medical Systems Inc.) using bony landmarks. The structures were copied to the current CBCT/CT series and, where needed, manually edited slicewise. The dose distribution from the treatment plan was viewed as of the current anatomy by applying the treatment plan the CBCT/CT series, and studying the corresponding dose–volume histograms for organs at risk doses.ResultsThe reduction of parotid volumes due to weight loss was observed in all patients, which means an increase in predicted mean doses of parotid when initial CT plan was re-calculated on ReCT and CBCT (Table 1). This explains the necessity of adaptive planning. The predicted mean dose of parotid glands was increased and constraints to spinal cord and skin were exceeded, so re-planning was performed.ConclusionsThe CBCT is a useful tool to view anatomic changes in patients and get an estimate of their impact on dose distribution. Re-planning based on imaging in head and neck patients during the course of radiotherapy is mandatory to reduce side effects.


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