68Ga-DOTANOC PET/CT for Screening and Surveillance of Von Hippel-Lindau (VHL) disease.

Purpose: Hereditary tumor syndrome Von Hippel-Lindau (VHL) disease is characterized by various benign and malignant tumors that are known to express somatostatin receptors (SSTR). We evaluated the role of 68Ga-DOTANOC PET/CT scan in patients with positive germline mutation of the VHL gene, presented initially or on follow-up, for the detection of recurrent or synchronous/metachronous lesions. Methods: Fourteen patients (8 males; 6 females) with mean age 30 ± 9.86 years were retrospectively analyzed, were tested positive for VHL on gene dosage analysis, and underwent 68 Ga-DOTANOC PET/CT scan for disease evaluation. The number and site of lesions were determined. The tracer uptake was analyzed semi-quantitatively by calculating the maximum standardized uptake values (SUVmax) of lesion. Results: Four of the 14 patients underwent scan for initial diagnosis as baseline, 6 patients for post-therapy disease status, and 4 patients for initial diagnosis as well as follow-up evaluation of the disease. A total of 67 lesions were detected in 14 patients. The sites of lesions were cerebellar/vertebral/spinal (17; mean SUVmax = 7.85); pancreatic neuroendocrine tumor (NET) (11; mean SUVmax = 20.64); retina (3; mean SUVmax = 10.46); pheochromocytoma (10; mean SUVmax = 16.32); paragangliomas (3; mean SUVmax = 10.65); pancreatic cyst (9; mean SUVmax = 2.54); and renal cyst (8; mean SUVmax = 1.56) and miscellaneous lesions constituted 6 lesions. Conclusion: Our results show that 68 Ga-DOTANOC PET/CT may be a useful modality for screening and follow-up of associated tumors in patients with germline gene mutation for VHL. It can be used as a one-stop imaging modality for VHL patients and may substitute for separate radiological investigations, making it more convenient for patients in terms of time and cost.

Air! Places We Not Ought to See It: Incidentally Detected Spontaneous Pneumomediastinum Complicated by Cervical Emphysema on Positron Emission Tomography/Computed Tomography.

Spontaneous pneumomediastinum is a rare condition, characterized by the presence of air in the mediastinum without any apparent precipitating cause. It is mainly a radiological diagnosis. The onus of differentiating between secondary and spontaneous pneumomediastinum lies on a thorough workup. In addition to etiology, complications such as tension pneumomediastinum, cervical emphysema, and pneumorachis. When present, must be diagnosed promptly. Spontaneous pneumomediastinum is a benign condition which is usually managed conservatively. Although not routinely seen on positron emission tomography/computed tomography, when present, they must be picked up and reported accurately to guide appropriate management of the patient.