Optimal Margin Selection and the Resultant Impact on Organs-at-Risk in Stereotactic Body Radiation Therapy of Liver Tumors

2018 ◽  
Vol 102 (3) ◽  
pp. e517
Author(s):  
H. Saleh ◽  
M.A. Thompson ◽  
J. Xu ◽  
K.S. Qamar ◽  
K. Kauweloa
Keyword(s):  
At Risk ◽  
Radiation Therapy ◽  
Stereotactic Body Radiation Therapy ◽  
Liver Tumors ◽  
Organs At Risk ◽  
Stereotactic Body Radiation

scholarly journals Adrenal Stereotactic Body Radiation Therapy: The Effects of a Full and Empty Stomach on Radiation Dose to Organs at Risk

2021 ◽  
Author(s):  
Osamu Tanaka ◽  
Takuya Taniguchi ◽  
Kousei Ono ◽  
Shuto Nakaya ◽  
Takuji Kiryu ◽  
...  
Keyword(s):  
At Risk ◽  
Radiation Therapy ◽  
Stereotactic Body Radiation Therapy ◽  
Organs At Risk ◽  
Left Kidney ◽  
Empty Stomach ◽  
Full Group ◽  
Left Adrenal Gland ◽  
Stereotactic Body Radiation ◽  
Organ At Risk

Abstract BackgroundStereotactic Body Radiation Therapy (SBRT) has been reported to be curative in the treatment of oligometastases to the adrenal glands. However, the adrenals are surrounded by radiation-sensitive organs. We performed an Organ at Risk (OAR) analysis for SBRT to the left adrenal gland based on gastric state.Patients and MethodsTwenty random stomachs were divided into “empty” or “full” groups of 10 each based on size. The PTV dose was 54 Gy/6 fx and D 95 coverage of PTV(CTV) (the dose to 95% of the PTV volume). ResultsThe gastric OAR dose in the empty group was significantly lower than the full group. The OAR dose to the left kidney in the empty group was significantly higher than in the full group.ConclusionThe smaller the stomach size, the lower the dose to the stomach. It is therefore better to perform SBRT on patients with an empty stomach.

scholarly journals A Collimator Setting Optimization Algorithm for Dual-Arc Volumetric Modulated Arc Therapy in Pancreas Stereotactic Body Radiation Therapy

2019 ◽  
Vol 18 ◽  
pp. 153303381987076 ◽  
Author(s):  
Xinyi Li ◽  
Jackie Wu ◽  
Manisha Palta ◽  
You Zhang ◽  
Yang Sheng ◽  
...  
Keyword(s):  
At Risk ◽  
Radiation Therapy ◽  
Optimization Algorithm ◽  
Stereotactic Body Radiation Therapy ◽  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Target Dose ◽  
Stereotactic Body Radiation ◽  
Complexity Score ◽  
Arc Therapy

Purpose: To optimize collimator setting to improve dosimetric quality of pancreas volumetric modulated arc therapy plan for stereotactic body radiation therapy. Materials and Methods: Fifty-five volumetric modulated arc therapy cases in stereotactic body radiation therapy of pancreas were retrospectively included in this study with internal review board approval. Different from the routine practice of initializing collimator settings with a template, the proposed algorithm simultaneously optimizes the collimator angles and jaw positions that are customized to the patient geometry. Specifically, this algorithm includes 2 key steps: (1) an iterative optimization algorithm via simulated annealing that generates a set of potential collimator settings from 39 cases with pancreas stereotactic body radiation therapy, and (2) a multi-leaf collimator modulation scoring system that makes the final decision of the optimal collimator settings (collimator angles and jaw positions) based on organs at risk sparing criteria. For validation, the other 16 cases with pancreas stereotactic body radiation therapy were analyzed. Two plans were generated for each validation case, with one plan optimized using the proposed algorithm ( Planopt) and the other plan with the template setting ( Planconv). Each plan was optimized with 2 full arcs and the same set of constraints for the same case. Dosimetric results were analyzed and compared, including target dose coverage, conformity, organs at risk maximum dose, and modulation complexity score. All results were tested by Wilcoxon signed rank tests, and the statistical significance level was set to .05. Results: Both plan groups had comparable target dose coverage and mean doses of all organs at risk. However, organs at risk (stomach, duodenum, large/small bowel) maximum dose sparing ( D0.1 cc and D0.03 cc) was improved in Planopt compared to Planconv. Planopt also showed lower modulation complexity score, which suggests better capability of handling complex shape and sparing organs at risk . Conclusions: The proposed collimator settings optimization algorithm successfully improved dosimetric performance for dual-arc pancreas volumetric modulated arc therapy plans in stereotactic body radiation therapy of pancreas. This algorithm has the capability of immediate clinical application.

scholarly journals Strategies to Mitigate Toxicities From Stereotactic Body Radiation Therapy for Spine Metastases

Neurosurgery ◽  
2019 ◽  
Vol 85 (6) ◽  
pp. 729-740 ◽  
Author(s):  
Stephanie K Schaub ◽  
Yolanda D Tseng ◽  
Eric L Chang ◽  
Arjun Sahgal ◽  
Rajiv Saigal ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Stereotactic Body Radiation Therapy ◽  
De Novo ◽  
Organs At Risk ◽  
Performance Status ◽  
Compression Fracture ◽  
Neurological Dysfunction ◽  
External Beam Radiation ◽  
Beam Radiation ◽  
Stereotactic Body Radiation

Abstract Improvements in systemic therapy are translating into more patients living longer with metastatic disease. Bone is the most common site of metastasis, where spinal lesions can result in significant pain impacting quality of life and possible neurological dysfunction resulting in a decline in performance status. Stereotactic body radiation therapy (SBRT) of the spine has emerged as a promising technique to provide durable local control, palliation of symptoms, control of oligoprogressive sites of disease, and possibly augment the immune response. SBRT achieves this by delivering highly conformal radiation therapy to allow for dose escalation due to a steep dose gradient from the planning target volume to nearby critical organs at risk. In our review, we provide an in-depth review and expert commentary regarding seminal literature that defined clinically meaningful toxicity endpoints with actionable dosimetric limits and/or clinical management strategies to mitigate toxicity potentially attributable to SBRT of the spine. We placed a spotlight on radiation myelopathy (de novo, reirradiation after conventional external beam radiation therapy or salvage after an initial course of spinal SBRT), plexopathy, vertebral compression fracture, pain flare, esophageal toxicity, myositis, and safety regarding combination with concurrent targeted or immune therapies.

Impact of lung tumor motion on dose delivered to organ at risk in lung stereotactic body radiation therapy

2020 ◽  
Vol 9 (3-4) ◽  
pp. 191-198
Author(s):  
Milovan Savanovic ◽  
Bojan Strbac ◽  
Drazan Jaros ◽  
Dejan Cazic ◽  
Jean Noel Foulquier
Keyword(s):  
At Risk ◽  
Radiation Therapy ◽  
Stereotactic Body Radiation Therapy ◽  
Lung Tumor ◽  
Tumor Motion ◽  
Stereotactic Body Radiation ◽  
Organ At Risk
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