scholarly journals Online Magnetic Resonance-Guided Radiotherapy (oMRgRT) for Gynecological Cancers

2021 ◽  
Vol 11 ◽  
Author(s):  
Lorraine Portelance ◽  
Stefanie Corradini ◽  
Beth Erickson ◽  
Susan Lalondrelle ◽  
Kyle Padgett ◽  
...  
Keyword(s):  
At Risk ◽  
Radiation Therapy ◽  
Magnetic Resonance ◽  
Treatment Planning ◽  
Organs At Risk ◽  
Locally Advanced ◽  
Tumor Control ◽  
Gynecological Cancers ◽  
Contrast Resolution ◽  
Cancer Management

Radiation therapy (RT) is increasingly being used in gynecological cancer management. RT delivered with curative or palliative intent can be administered alone or combined with chemotherapy or surgery. Advanced treatment planning and delivery techniques such as intensity-modulated radiation therapy, including volumetric modulated arc therapy, and image-guided adaptive brachytherapy allow for highly conformal radiation dose delivery leading to improved tumor control rates and less treatment toxicity. Quality on-board imaging that provides accurate visualization of target and surrounding organs at risk is a critical feature of these advanced techniques. As soft tissue contrast resolution is superior with magnetic resonance imaging (MRI) compared to other imaging modalities, MRI has been used increasingly to delineate tumor from adjacent soft tissues and organs at risk from initial diagnosis to tumor response evaluation. Gynecological cancers often have poor contrast resolution compared to the surrounding tissues on computed tomography scan, and consequently the benefit of MRI is high. One example is in management of locally advanced cervix cancer where adaptive MRI guidance has been broadly implemented for adaptive brachytherapy. The role of MRI for external beam RT is also steadily increasing. MRI information is being used for treatment planning, predicting, and monitoring position shifts and accounting for tissue deformation and target regression during treatment. The recent clinical introduction of online MRI-guided radiation therapy (oMRgRT) could be the next step in high-precision RT. This technology provides a tool to take full advantage of MRI not only at the time of initial treatment planning but as well as for daily position verification and online plan adaptation. Cervical, endometrial, vaginal, and oligometastatic ovarian cancers are being treated on MRI linear accelerator systems throughout the world. This review summarizes the current state, early experience, ongoing trials, and future directions of oMRgRT in the management of gynecological cancers.

scholarly journals Advantages of 3D-CT Based Conformal Radiotherapy Treatment Planning Over 2D Conventional Tera Six Planning for Cervical Cancer Treatment at Ocean Road Cancer Institute

2020 ◽  
Vol 8 (1) ◽  
pp. 59-68
Author(s):  
Khamis Amour ◽  
Dr. Khamza Maunda ◽  
Dr. Mohamed Mazunga ◽  
Dr. Peane Maleka ◽  
Professor Peter Msaki
Keyword(s):  
Cervical Cancer ◽  
At Risk ◽  
Radiation Therapy ◽  
Cancer Patients ◽  
Treatment Planning ◽  
Organs At Risk ◽  
Planning System ◽  
External Beam Radiation ◽  
Treatment Planning System ◽  
3D Ct

Although External Beam Radiation Therapy (EBRT) is essential tool for the radiation therapy of cervical cancer; only one cancer institute in Tanzania performs 3-Dimensional Conformal Radiation Therapy (3DCRT) Computed Tomography (CT)-based planning. To identify benefits and advantages of 3D-CRT over 2D- conventional radiation therapy (2D-CRT), dosimetric parameters for tumor targets and organs at risk (OARs) were compared between these modalities for 23 cervical cancer patients. 11 cervical cancer patients were CT scanned after proper positioning and immobilization and transferred to Eclipse Treatment Planning System (TPS) for dose planning. The remaining 12 curative intent patients were planned using 2D-CRT system and treatment times were calculated for each patient. From the CT based planning, the minimum dose (D min), maximum dose (D max) and mean dose (D mean) to Planning Target Volume (PTV) and organs at risk (OAR), were compared for each plan. On average, the optimized maximum doses for bladder, rectum, femoral heads, PTV and Gross Tumor Volume (GTV) were 46.56 Gy, 42.65 Gy, 28.76 Gy, 48.56 Gy and 48.53 Gy. For 2D-concentional planning, the dose rate was 75.75 cGy/min and the average treatment time was 1.6075 minutes. This study confirms that 3D CT-based planning is a good choice in the treatment protocol for carcinoma cervix as it delivered a highly homogeneous and conformal plan with superior dose coverage to PTV and better OARs sparing.

scholarly journals An Automated Workflow to Improve Efficiency in Radiation Therapy Treatment Planning by Prioritizing Organs at Risk

2020 ◽  
Vol 5 (6) ◽  
pp. 1324-1333
Author(s):  
Eric Aliotta ◽  
Hamidreza Nourzadeh ◽  
Wookjin Choi ◽  
Victor Gabriel Leandro Alves ◽  
Jeffrey V. Siebers
Keyword(s):  
At Risk ◽  
Radiation Therapy ◽  
Treatment Planning ◽  
Organs At Risk ◽  
Improve Efficiency ◽  
Radiation Therapy Treatment Planning ◽  
Therapy Treatment

scholarly journals Tumor Control Probability (TCP) and Normal Tissue Complication Probability (NTCP) in Mono and Dual-isocentric Techniques of Breast Cancer Radiation Therapy

2021 ◽  
pp. 192-202
Author(s):  
Kaveh Shirani Tak Abi ◽  
Sediqeh Habibian ◽  
Marzieh Salimi ◽  
Ahmad Shakeri ◽  
Mohammad Mehdi Mojahed ◽  
...  
Keyword(s):  
Breast Cancer ◽  
At Risk ◽  
Radiation Therapy ◽  
Normal Tissue ◽  
Maximum Dose ◽  
Organs At Risk ◽  
Normal Tissue Complication Probability ◽  
The Other ◽  
Tumor Control ◽  
Tumor Control Probability

Background: Nowadays, radiation therapy plays an important role in the treatment of breast cancer. The important point is the optimal control of the tumor along with the protection of organs at risk. This study aims to investigate and compare the radiobiological factors of the tumor and organs at risk in two different radiation therapy techniques of breast cancer.Methods: Ten left-sided breast cancer patients with breast-conservative surgery were selected for this study. Three-dimensional treatment planning was performed using CT scan images of the patients using PCRT 3D software. Two different tangential external beam techniques were compared: first, dual-isocentric technique (DIT) with two isocentre, one on the breast tissue, and the other one on the supraclavicular lymph nodes and second, a mono-isocentric technique (MIT) with one isocentre at the intersection of the tangential and the supraclavicular field. The total prescribed dose was 5000 cGy per 25 fractions. Dose-volume histograms (DVHs), Tumor control probability (TCP), and normal tissue complication probability (NTCP) curves were used to compare the dosimetric and radiobiological parameters of the tissues in the prementioned techniques. Results: The results showed that the maximum doses in planning target volume (PTV) with mean values of 109% and 110% in the SI and DIT were not significantly different in both techniques and that they were indeed at the optimum level based on the RTOG 1005 protocol. The dose homogeneity index in MMIT was more than that in DIT, while the conformity index and the mean TCP did not show a significant difference in the two techniques. Furthermore, minimum, mean, and maximum dose in the lung and the probability of pneumonitis decreased in MIT. On the other hand, the maximum dose, the dose of 33%, 66%, and 100% of the heart, and the probability of pericarditis in MIT were lower than the figure in DIT. Conclusion: Due to the absence of hot spots at the intersection of tangential and supraclavicular fields and the reduction of mechanical movements of the coach and collimator in MIT, the superiority of this method was confirmed.

Sign in / Sign up

Export Citation Format

Share Document