FDG-PET/CT appears to be a very promising method for distinguishing a viable tumour from fibrous changes, thereby avoiding unnecessary laparotomy.

FDG-PET or PET/CT contributed to establishing a final diagnosis in 84% of the 51 patients with positive PET findings and in 36% of all 118 evaluated patients with prolonged fever.

FDG-PET/CT imaging is very helpful in the search for the presence of a malignancy in patients with carcinoma of unknown primary syndrome. FDG-PET/CT is less accurate in identifying exactly the site of a primary. Discovery of a hypermetabolic lesion was associated with the worst survival rate.

Aims. To assess the practical localising value of subtraction ictal single‐photon emission computed tomography (SISCOM) coregistered with MRI and 18F‐fluorodeoxyglucose positron emission tomography (FDG‐PET) in patients with extratemporal epilepsy and normal MRI. Methods. We retrospectively studied a group of 14 patients who received surgery due to intractable epilepsy and who were shown to have focal cortical dysplasia, undetected by MRI, based on histological investigation. We coregistered preoperative SISCOM and PET images with postoperative MRI and visually determined whether the SISCOM focus, PET hypometabolic area, and cerebral cortex, exhibiting prominent abnormalities on intracranial EEG, were removed completely, incompletely, or not at all. These results and histopathological findings were compared with postoperative seizure outcome. Results. Two patients underwent one‐stage multimodal image‐guided surgery and the remaining 12 underwent long‐term invasive EEG. SISCOM findings were localised for all but 1 patient. FDG‐PET was normal in 3 subjects, 2 of whom had favourable postsurgical outcome (Engel class I and II). Complete resection of the SISCOM focus (n=3), the area of PET hypometabolism (n=2), or the cortical regions with intracranial EEG abnormalities (n=7) were predictive of favourable postsurgical outcome. Favourable outcome was also encountered in: 4 of 8 patients with incomplete resection and 1 of 2 with no resection of the SISCOM focus; 4 of 7 patients with incomplete resection and 1 of 2 with no resection of the PET hypometabolic area; and 2 of 7 patients with incomplete resection of the area corresponding to intracranial EEG abnormality. No correlation between histopathological FCD subtype and seizure outcome was observed. Conclusion. Complete resection of the dysplastic cortex localised by SISCOM, FDG‐PET or intracranial EEG is a reliable predictor of favourable postoperative seizure outcome in patients with non‐lesional extratemporal epilepsy.

The newly introduced GM-EDGE method was associated with significantly higher inter-rater agreement among physicians and higher subjective confidence in the reading. The method is easy to implement in clinical practice, especially when the perfusion phase is utilized clinically.

BACKGROUND: Low-grade gliomas (LGG) of the brain have an uncertain prognosis, as many of them show continuous growth or upgrade over the course of time. We retrospectively investigated the role of positron emission tomography with 3'-deoxy-3'-

BACKGROUND:In patients with brain atrophy, it is not easy to distinguish pathologic uptake of flutemetamol (FMM) in the gray matter from nonspecific, physiologic uptake in the white matter. In this paper we suggest an easy image processing method.

Aim:Our study aimed to evaluate the use of positron emission tomography/computed tomography (PET/CT) in the initial staging of head and neck squamous cell carcinoma (HNSCC), including assessment of local and distant spread of the disease. We also aimed to compare the accuracy of PET/CT in the evaluation of human papillomavirus (HPV) positive and HPV-negative oropharyngeal carcinoma. Material and methods:This single-center, prospective study was conducted between August 2016 and September 2021. A total of 198 patients with HNSCC who underwent PET/CT within the primary staging were included. We compared PET/CT results with histological findings. We calculated the accuracy, sensitivity, specificity, and positive and negative predictive values to assess the primary tumor, cervical lymph nodes, and distant metastases.Results:PET/CT showed a high success rate (32%) in revealing the primary site of carcinoma of unknown primary (CUP). The accuracy of PET/CT in displaying the primary tumor, cervical lymph node metastases, and distant metastases was 89.4%, 85.4%, and 87.4%, respectively. The method provided high sensitivity but lower specificity in all three areas. Specifically, PET/CT showed low specificity in the assessment of small tumors (75%), metastatic involvement of cervical lymph nodes (69.6%), and HPV-positive oropharyngeal carcinoma (55.6%). Conclusions:The high accuracy of PET/CT to identify distant metastases and whole-body staging in one diagnostic step accelerated primary staging and resulted in earlier commencement of therapy. However, it also led to an overestimation of clinical findings and thus to extensive surgical treatment, especially in patients with small tumors, metastatic involvement of cervical lymph nodes, and HPV- positive oropharyngeal carcinoma. PET/CT is also useful for CUP diagnostics.