Publications by authors named "Shyama U Tetar"
Article Synopsis
- Intra-fraction motion management is crucial for the accuracy of Stereotactic Ablative Radiotherapy (SABR), and this study evaluated the effectiveness of automatic tumor segmentation in MR-guided radiotherapy compared to manual delineation.
- Twenty patients with either thoracic or abdominal tumors were analyzed using a combination of experienced observers' manual delineations and four different algorithms for automatic tumor contouring, assessing accuracy through various geometrical analysis metrics.
- Results showed that the automatic segmentation algorithms achieved excellent agreement with manual contours, demonstrating high reliability and accuracy, thereby supporting the use of DIR-based auto-contouring in MRgRT for precise treatment delivery.
Magnetic resonance-guided radiotherapy with daily plan adaptation for intermediate- and high-risk prostate cancer is time and labor intensive. Fifty adapted plans with 3 mm planning target volume (PTV)-margin were compared with non-adapted plans using 3 or 5 mm margins. Adequate (V95% ≥ 95%) prostate coverage was achieved in 49 fractions with 5 mm PTV without plan adaptation, however, coverage of the seminal vesicles (SV) was insufficient in 15 of 50 fractions.
View Article and Find Full Text PDFNovel magnetic-resonance-guided radiotherapy (MRgRT) permits real-time soft-tissue visualization, respiratory-gated delivery with minimal safety margins, and time-consuming daily plan re-optimisation. We report on early clinical outcomes of MRgRT and routine plan re-optimization for large primary renal cell cancer (RCC). Thirty-six patients were treated with MRgRT in 40 Gy/5 fractions.
View Article and Find Full Text PDFBackground: The recent introduction of magnetic resonance-guided radiation therapy (MRgRT) has allowed improved treatment planning and delivery of stereotactic body radiotherapy (SBRT) in prostate cancer (PC). The health-related quality of life (HRQoL) outcomes using this novel approach are important in shared decision making for patients.
Objective: To report HRQoL using both patient- and clinician-reported outcomes at 1 yr following stereotactic MRgRT for patients with localized PC.
Article Synopsis
- Stereotactic body radiation therapy (SBRT) is increasingly used for localized prostate cancer, but there are concerns about potential gastrointestinal (GI) and genitourinary (GU) toxicities from intensive radiation methods.
- A phase 2 study involving 101 patients aimed to assess early GI and GU toxicity after administering SBRT using Magnetic Resonance guided Radiation Therapy (MRgRT), which allows for more precise treatment delivery and adaptive planning.
- The results showed that early GU toxicity was at 23.8% and GI toxicity was at 5%, with no instances of grade 3 GI toxicity, highlighting a lower incidence of early adverse effects due to the precision offered by MRgRT.
Background And Purpose: Magnetic resonance-guided radiation therapy (MRgRT) has recently become available in clinical practice and is expected to expand significantly in coming years. MRgRT offers marker-less continuous imaging during treatment delivery, use of small clinical target volume (CTV) to planning target volume (PTV) margins, and finally the option to perform daily plan re-optimization.
Materials And Methods: A total of 140 patients (700 fractions) have been treated with MRgRT and online plan adaptation for localized prostate cancer since early 2016.
Background: Volumetric-modulated arc therapy (VMAT) delivery for stereotactic ablative radiotherapy (SABR) of multiple lung tumors allows for faster treatments. We report on clinical outcomes and describe a general approach for treatment planning.
Material And Methods: Patients undergoing multi iso-center VMAT-based SABR for ≥2 lung lesions between 2009 and 2014 were identified from the VU University Medical Center and London Health Sciences Centre.