8 Target Delineation and Dose Prescription

2009 ◽  
Keyword(s):  
2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii190-ii190
Author(s):  
Daniel Ma ◽  
Zaker Rana ◽  
Sirisha Viswanatha ◽  
Louis Potters ◽  
Jenghwa Chang ◽  
...  

Abstract BACKGROUND Stereotactic radiosurgery (SRS) planning for patients with meningiomas can be confounded by difficulty in identifying the tumor boundary, especially in those who have had prior surgery. Recent data have suggested the benefit of 68Ga-DOTATATE CT/PET scans in delineation of meningioma compared to MRI alone. We propose that incorporating 68Ga-DOTATATE PET scans in addition to MRI in SRS planning will provide better target identification and tumor coverage compared to MRI alone. METHODS We reviewed patients with meningioma who had MRI and 68Ga-DOTATATE PET imaging over 12 months. Images were imported into Velocity treatment planning software and separated into two different sessions, one in which only the MRI was accessible, and a second which had the PET scan fused to the MRI. Three different users were asked to contour the residual meningioma as gross tumor volume (GTV) first with MRI alone, and then with the PET/MRI fusion. The volume of each GTV pre-and post-PET fusion was compared and a Dice index was generated. RESULTS Four patients with 6 GTV targets were identified. PET fusion identified new lesions close to the initial GTV targets in 2 patients. The first was a discontinuous dural lesion in the post-op bed. The second was a nodular dural lesion along the left high parietal convexity adjacent to a prior craniectomy and mesh duraplasty site. In the third patient, PET scan identified a greater extent of disease in the skull base. Across all observers, GTV volumes were significantly increased when PET fusion was used. The average volume (cc) increase was 111.6%±66.2%. The average Dice index was 0.58±0.17. CONCLUSION 68Ga-DOTATATE PET scan fused with MRI improved the visualization of meningiomas in patients undergoing SRS. A larger experience is needed to confirm this trend. We have begun to use DOTATATE-PET imaging regularly when imaging patients with meningiomas for SRS.


2021 ◽  
Vol 161 ◽  
pp. S874-S875
Author(s):  
S. Martin Pastor ◽  
F.A. Calvo Manuel ◽  
A. Garcia-Consuegra ◽  
J. Serrano Andreu ◽  
J. Arbizu Lostao ◽  
...  

2017 ◽  
Vol 125 (1) ◽  
pp. 113-117 ◽  
Author(s):  
Daryl Lim Joon ◽  
Adeline Lim ◽  
Michal Schneider ◽  
Chee-Yan Hiew ◽  
Nathan Lawrentschuk ◽  
...  

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1929
Author(s):  
Jiandong Zhao ◽  
Jiazhou Wang ◽  
Mingxia Cheng

Hepatocellular carcinoma (HCC) is a leading cause of cancer death in China and around the world. Tumoricidal doses of modern radiation therapy (RT) can now be safely delivered with excellent local control and minimal toxicity. Delivering adequate doses of radiation to the primary tumor, while preserving adjacent healthy organs, depends on accurate target identification. In recent years, different novel machine learning techniques, including artificial intelligence technology, have been exploited in RT with impressive results in automatic image segmentation. If the machine learning algorithms are trained on delineated contours, according to consensus contouring guidelines, it promises greatly reduced interobserver and intraobserver variability in target delineation, thus substantially improving the quality and efficiency of HCC radiotherapy. This study protocol proposes to develop a fully-automated target structure contouring system, which is based on deep neural networks trained on contours delineated according to consensus contouring guidelines in HCC radiotherapy. In addition, the study will evaluate the contouring system’s feasibility and performance during application in normal clinical operations. The study is ongoing (data analysis).


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