Dose Assessment of the Rectum during Brachytherapy of the Cervix Using Gafchromic Films

2017 ◽  
pp. 651-659
Author(s):  
J. Avevor ◽  
S. N. A Tagoe ◽  
J. H. Amuasi ◽  
J. J. Fletcher ◽  
I. Shirazu
Keyword(s):  
Treatment Planning ◽  
Maximum Dose ◽  
Dose Assessment ◽  
Planning System ◽  
Treatment Planning System ◽  
In Vivo Dosimetry ◽  
Intracavitary Brachytherapy ◽  
Gafchromic Films ◽  
System Verification ◽  
The Mean

Internal radiation therapy, refers to as brachytherapy, involve putting a source of radiation with high photon in or near a cancerous tissues. The type of brachytherapy used most often to treat cervical cancer is known as intracavitary brachytherapy. Unfortunately however, the radiation source placed in the cervix irradiate the normal tissues of rectum and other nearby organs during intracavitary brachytherapy of the cervix treatment. This high doses received by parts of the rectum is a concern for clinicians and the general public. The aim of this study is to assess the dose delivered to the rectum using Gafchromic films and compare it with the optimized dose calculated by the Brachy Prowess 4.60 Treatment Planning System (TPS) reports for empirical validation and system verification. Fletcher suite applicators were used to perform thirty (30) different clinical insertions on the constructed cervix phantom and results evaluated. The mean difference between the doses calculated by the TPS and the doses measured by the Gafchromic film for the rectum at the distance of 0.5cm from the edges of the film was 23.1% (range -42.42 to +40.41). At a distance of 1.5cm for the rectum the mean was 22.5% (range -49.45 to +46.48). The TPS calculated maximum dose was typically higher than the measured maximum dose. However, in some cases, the measured doses were found to be higher than the doses calculated by the TPS. This is due to positional inaccuracies of the sources during treatment planning. It is recommended that in vivo dosimetry should be performed in addition to computation.

Dose assessment to the Bladder during Intracavitary Brachytherapy of the Cervix using Gafchromic films

2017 ◽  
pp. 97-105
Author(s):  
J. Avevor ◽  
S. N. A. Tagoe ◽  
J. H. Amuasi ◽  
J. J. Fletcher ◽  
I. Shirazu
Keyword(s):  
Treatment Planning ◽  
Maximum Dose ◽  
Mean Difference ◽  
Planning System ◽  
Treatment Planning System ◽  
In Vivo Dosimetry ◽  
Intracavitary Brachytherapy ◽  
Gafchromic Films ◽  
System Verification ◽  
The Mean

Intracavitary brachytherapy procedures are used for cervical cancer treatment, by the insertion of radioactive implants directly into the diseased tissues. During the treatment process, the bladder together with surrounding tissues are exposed to radiations. Clinical complications do results from high doses received by parts of the bladder during intracavitary brachytherapy of the cervix. The aim of this study is to assess the dose delivered to the bladder using Gafchromic films and compare it with the optimized dose calculated by the Brachy Prowess 4.60 Treatment Planning System (TPS) reports for empirical validation and system verification. Fletcher suite applicators were used to perform thirty (30) different clinical insertions on the constructed cervix phantom and results evaluated. The mean difference between the doses calculated by the TPS and the doses measured by the Gafchromic film for the bladder at the distance of 0.5cm from the edge of the film was 16.3 % (range -35.33 to +39.37). At a distance of 1.5cm for the bladder, the mean difference was 19.4% (range -49.48 to +30.39). The TPS calculated maximum dose was typically higher than the measured maximum dose. However, in some cases, the measured doses were found to be higher than the doses calculated by the TPS. This is due to positional inaccuracies of the sources during treatment planning. It is recommended that in vivo dosimetry be performed in addition to computation.

scholarly journals Dose assessment in high dose rate brachytherapy with cobalt-60 source for cervical cancer treatment: a phantom study

2020 ◽  
Vol 26 (4) ◽  
pp. 243-250
Author(s):  
Bright Kwadwo Bour ◽  
Stephen Inkoom ◽  
Samuel Nii Adu Tagoe ◽  
John Humphrey Amuasi ◽  
Evans Sasu ◽  
...  
Keyword(s):  
Dose Rate ◽  
Treatment Planning ◽  
High Dose Rate ◽  
Dose Assessment ◽  
Planning System ◽  
Treatment Planning System ◽  
Intracavitary Brachytherapy ◽  
High Dose ◽  
Dose Delivery ◽  
High Dose Rate Brachytherapy

AbstractTransition from low dose rate brachytherapy to high dose rate brachytherapy at our department necessitated the performance of dose verification test, which served as an end-to-end quality assurance procedure to verify and validate dose delivery in intracavitary brachytherapy of the cervix and the vaginal walls based on the Manchester system. An in-house water phantom was designed and constructed from Perspex sheets to represent the cervix region of a standard adult patient. The phantom was used to verify the whole dose delivery chain such as calibration of the cobalt-60 source in use, applicator, and source localization method, the output of treatment planning with dedicated treatment planning system, and actual dose delivery process. Since the above factors would influence the final dose delivered, doses were measured with calibrated gafchromic EBT3 films at various points within the in-house phantom for a number of clinical implants that were used to treat a patient based on departmental protocol. The measured doses were compared to those of the treatment planning system. The discrepancies between measured doses and their corresponding calculated doses obtained with the treatment planning system ranged from -29.67 to 40.34% (mean of ±13.27%). These compared similarly to other studies.

scholarly journals Quality Assurance of Dose Distribution of Photon Beam Planning by Anisotropic Analytical Algorithm (AAA)

2013 ◽  
Vol 4 (1) ◽  
pp. 43-49
Author(s):  
M Jahangir Alam ◽  
Syed Md Akram Hussain ◽  
Kamila Afroj ◽  
Shyam Kishore Shrivastava
Keyword(s):  
Quality Assurance ◽  
Treatment Planning ◽  
Dose Distribution ◽  
Maximum Dose ◽  
Photon Beam ◽  
Field Size ◽  
Planning System ◽  
Treatment Planning System ◽  
Anisotropic Analytical Algorithm ◽  
Analytical Algorithm

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

scholarly journals DVH Prediction for VMAT in NPC with GRU-RNN: An Improved Method by Considering Biological Effects

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yongdong Zhuang ◽  
Yaoqin Xie ◽  
Luhua Wang ◽  
Shaomin Huang ◽  
Li-Xin Chen ◽  
...  
Keyword(s):  
Treatment Planning ◽  
Prediction Accuracy ◽  
Maximum Dose ◽  
Biological Effects ◽  
Patient Data ◽  
Planning System ◽  
Treatment Planning System ◽  
Rank Test ◽  
Least Squares Regression ◽  
Medical Systems

Purpose. A recurrent neural network (RNN) and its variants such as gated recurrent unit-based RNN (GRU-RNN) were found to be very suitable for dose-volume histogram (DVH) prediction in our previously published work. Using the dosimetric information generated by nonmodulated beams of different orientations, the GRU-RNN model was capable of accurate DVH prediction for nasopharyngeal carcinoma (NPC) treatment planning. On the basis of our previous work, we proposed an improved approach and aimed to further improve the DVH prediction accuracy as well as study the feasibility of applying the proposed method to relatively small-size patient data. Methods. Eighty NPC volumetric modulated arc therapy (VMAT) plans with local IRB’s approval in recent two years were retrospectively and randomly selected in this study. All these original plans were created using the Eclipse treatment planning system (V13.5, Varian Medical Systems, USA) with ≥95% of PGTVnx receiving the prescribed doses of 70 Gy, ≥95% of PGTVnd receiving 66 Gy, and ≥95% of PTV receiving 60 Gy. Among them, fifty plans were used to train the DVH prediction model, and the remaining were used for testing. On the basis of our previously published work, we simplified the 3-layer GRU-RNN model to a single-layer model and further trained every organ at risk (OAR) separately with an OAR-specific equivalent uniform dose- (EUD-) based loss function. Results. The results of linear least squares regression obtained by the new proposed method showed the excellent agreements between the predictions and the original plans with the correlation coefficient r = 0.976 and 0.968 for EUD results and maximum dose results, respectively, and the coefficient r of our previously published method was 0.957 and 0.946, respectively. The Wilcoxon signed-rank test results between the proposed and the previous work showed that the proposed method could significantly improve the EUD prediction accuracy for the brainstem, spinal cord, and temporal lobes with a p value < 0.01. Conclusions. The accuracy of DVH prediction achieved in different OARs showed the great improvements compared to the previous works, and more importantly, the effectiveness and robustness showed by the simplified GRU-RNN trained from relatively small-size DVH samples, fully demonstrated the feasibility of applying the proposed method to small-size patient data. Excellent agreements in both EUD results and maximum dose results between the predictions and original plans indicated the application prospect in a physically and biologically related (or a mixture of both) model for treatment planning.

scholarly journals Using beam profile inflection point in process of treatment planning system verification

2021 ◽  
Author(s):  
Jacek Wendykier ◽  
Aleksandra Grządziel ◽  
Barbara Bekman ◽  
Marcin Bieniasiewicz ◽  
Adam Bekman ◽  
...  
Keyword(s):  
Treatment Planning ◽  
Inflection Point ◽  
Beam Profile ◽  
Planning System ◽  
Treatment Planning System ◽  
System Verification

scholarly journals Correlation between Isotherms and Isodoses in Breast Cancer Radiotherapy—First Study

2021 ◽  
Vol 18 (2) ◽  
pp. 619
Author(s):  
Dominika Plaza ◽  
Agnieszka Baic ◽  
Barbara Lange ◽  
Agata Stanek ◽  
Krzysztof Ślosarek ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Treatment Planning ◽  
Treatment Plan ◽  
The Body ◽  
Planning System ◽  
Treatment Planning System ◽  
Breast Cancer Radiotherapy ◽  
The Mean ◽  
Radiotherapy Treatment ◽  
Tumor Area

The study is focused on correlation of isotherms derived from thermal images with an isodoses describing treatment plan for patients with breast cancer treated by radiotherapy. The irradiated area covered the part of the body after mastectomy. The study included patients diagnosed with breast cancer who were qualified for radiotherapy treatment. All patients were monitored during each treatment week during the entire radiotherapy process. The measurements were made under strictly defined conditions. In the treatment planning system (TPS), the specific plan was created for each patient. Spatial dose distribution in the patient’s body was obtained and presented by the isodoses (lines connecting points with the same dose values). The following areas from the treatment planning system were plotted on the thermograms: target (tumor area) and isodose: 45 Gy, 40 Gy, 30 Gy, 20 Gy and 10 Gy. The obtained results indicated a high correlation between magnitude of the dose represented as the isodose and the temperature of the treated skin. Moreover, preliminary analysis showed a repeatable increase of the mean temperature in the irradiated area during the treatment.

scholarly journals CT and MRI Image Fusion Reproducibility and Dose Assessment on Treatment Planning System

2014 ◽  
Vol 24 (6) ◽  
pp. 191-196
Author(s):  
Jae-Hyock Choi ◽  
Cheol-Soo Park ◽  
Jeong-Min Seo ◽  
Jae-Hwan Cho ◽  
Cheon-Woong Choi
Keyword(s):  
Image Fusion ◽  
Treatment Planning ◽  
Dose Assessment ◽  
Planning System ◽  
Treatment Planning System ◽  
Mri Image ◽  
Ct And Mri

SU-E-T-258: Commissioning of a Commercial Treatment Planning System Verification Software Package

2013 ◽  
Vol 40 (6Part14) ◽  
pp. 263-264 ◽  
Author(s):  
C Nelson ◽  
S Davidson ◽  
B Mason ◽  
S Kirsner
Keyword(s):  
Treatment Planning ◽  
Software Package ◽  
Planning System ◽  
Treatment Planning System ◽  
System Verification

Comparison of an in-house developed monitor unit double-check program for 3D conformal radiation therapy and treatment planning system verification

2019 ◽  
Vol 18 (03) ◽  
pp. 251-261
Author(s):  
Noureddine Slassi ◽  
Hmad Ouabi ◽  
Naïma El Khayati
Keyword(s):  
Radiation Therapy ◽  
Treatment Planning ◽  
Accurate Determination ◽  
Planning System ◽  
Treatment Planning System ◽  
Monitor Unit ◽  
Conformal Radiation Therapy ◽  
Water Phantom ◽  
3D Conformal Radiation Therapy ◽  
System Verification

AbstractAimThe treatment planning system (TPS) plays a key role in radiotherapy treatments; it is responsible for the accurate determination of the monitor unit (MU) needed to be delivered to treat a patient with cancer. The main goal of radiotherapy is to sterilise the tumour; however, any imprecise dose delivered could lead to deadly consequences. The TPS has a quality assurance tool, an independent program to double check the MU, evaluate patient plan correctness and search for any potential error.Materials and methodsIn this work, a comparison was carried out between a MU calculated by TPS and an independent in-house-developed monitor unit calculation program (MUCP). The program, written in Cplusplus (C++ Object-Oriented), requires a database of several measured quantities and uses a recently developed physically based method for field equivalence calculation. The ROOT CERN data analysis library has been used to establish fit functions, to extend MUCP use to a variety of photon beams. This study presents a new approach to checking MU correctness calculated by the TPS for a water-like tissue equivalent medium, using our MUCP, as the majority of previous studies on the MU independent checks were based on the Clarkson method. To evaluate each irradiated region, four calculation points corresponding to relative depths under the water phantom were tested for several symmetric, asymmetric, irregular symmetric and asymmetric field cases. A comparison of MU for each radiation fields from readings of the TPS and the MUCP was undertaken.ResultsA satisfactory agreement has been obtained and within the required standards (3%). Additional experimental measurements of dose deposited in a water phantom showed a deviation of &lt;1·6%.FindingsThe MUCP is a useful tool for basic and complex MU verification for 3D conformal radiation therapy plans.

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