Hybrid PET/MRI-based delineation of gross tumor volume in head and neck cancer and tumor parameter analysis

Abstract

Delineating GTV on hybrid PET/MRIs is feasible, and aTL, the threshold boundary of BTV, was correlated inversely with the SUVmax.

Evaluation of Hybrid PET/MRI for Gross Tumor Volume (GTV) Delineation in Liver Cancer Radiotherapy

“…Studies of other tumor locations (e.g., esophagus, lung, pancreas, head and neck) have shown that the additional biological information of PET has an effect on the variation in the GTV during radiation therapy, can reduce the risk of positioning error and in uence the normal tissue dose-volume histogram and the calculation of probability values in corresponding normal tissue [15,16,17]. Ma, J. T. et al [18] showed that GTV contouring based on hybrid PET/MRI for head and neck cancers is feasible and may provide improved accuracy. In their study, GTV VIS and GTV FUS were larger than GTV MRI with the use of hybrid PET/MRI images, which was similar to our ndings, but tumor site determinations were different.…”

“…We consider that this may be related to the imaging limitations of 18 F-FDG PET in liver cancer. Unlike in lung cancer patients, 18 F-FDG PET has already been established to play a role in the application of target volume contouring [21]. In addition, the artifacts caused by tumor location, anatomical boundaries, clinical situations, and patient cooperation during examination have a great impact on the quality of the contouring [22,23].…”

“…The hybrid PET/MR images were acquired from a 3D PET/MRI scanner. All patients received an intravenous injection of 18 F-FDG (0.8-1.0 mCi/kg) 50-60 min before PET image acquisition. In addition, a six-hour fast and bladder emptying were required prior to PET scanning.…”

“…At present, computed tomography (CT) and magnetic resonance imaging (MRI) are the best imaging modalities for detecting and characterizing liver tumors, and are widely used in target volume delineation [4]. CT or MRI alone can show the anatomical features of the tumor but not the biological behavior, while 18 F-FDG PET images can re ect the glycolytic metabolic behavior of the tumor. In addition to its widespread use in the diagnoses, staging, therapeutic evaluation, and posttreatment surveillance of patients with liver cancer [5,6,7], 18 F-uorodeoxyglucose positron emission tomography ( 18 F-FDG PET) has recently increasingly been used in the delineation of target volumes for radiotherapy.…”

“…CT or MRI alone can show the anatomical features of the tumor but not the biological behavior, while 18 F-FDG PET images can re ect the glycolytic metabolic behavior of the tumor. In addition to its widespread use in the diagnoses, staging, therapeutic evaluation, and posttreatment surveillance of patients with liver cancer [5,6,7], 18 F-uorodeoxyglucose positron emission tomography ( 18 F-FDG PET) has recently increasingly been used in the delineation of target volumes for radiotherapy. The major disadvantages of PET/CT are the relatively high radiation exposure from the two components and the relatively low spatial resolution of PET data.…”