The significance of a subcentimetre 18F-FDG PET/CT pulmonary abnormality in a patient with known extrapulmonary primary malignancy can have a major impact on the clinical management of the patient. The clinician’s reliance on the semi-quantitative and qualitative PET/CT analysis of the abnormality has, at times, led to untoward diagnostic problems, given the limited spatial resolution of PET for a small volume lesion performed as part of the standard PET/CT study. This paper highlights a case each of an FDG-positive and an FDG-negative focal pulmonary abnormality in a combined PET/CT study of patients with known extrapulmonary malignancy.

An incidental finding of an intense focus of 18F-Fluorodeoxyglucose (FDG) pulmonary uptake on positron emission tomography (PET) without detectable lesions on computed tomography (CT) is highly suggestive of FDG microembolus. Its microscopic nature means it is undetectable on CT. It is an artefact attributable to 18F-FDG-tracer contamination at the injection site. This paper reports a case of a 61 year-old lady with a past history of breast carcinoma, in whom follow-up PET/CT images demonstrated an incidental intense FDG pulmonary abnormality. A follow-up PET/CT seven months later demonstrated complete resolution of the abnormality.

A malignant melanoma in the vagina is a rare entity, for which there is little evidence-based literature for guiding clinicians to understand the importance of disease staging via noninvasive imaging strategy. Conventional imaging techniques i.e. computed tomography (CT) may be suboptimal in evaluating a small volume tumour, which may lead to inaccurate staging of a loco-regional tumour. A multimodality imaging exploiting a glucose biomarker, i.e. 18 [F]FDG PET/CT, is being increasingly used for tumour staging, particularly when the other imaging modalities have failed, although its precise role in the T- staging remains to be defined. This paper reports a 51-year-old lady who presented with pervaginal bleeding for 3 months. She has no constitutional symptoms or history of bleeding tendency. Examination of the vagina revealed blood clots without discernible mucosal abnormalities. CT abdomen revealed no perceptible abnormalities aside for an asymmetry of the anterior vaginal fornices. A 18[F]-FDG PET/CT showed a focus of an FDG-avid lesion embedded in the right anterior vaginal fornix without lymphatic or distant metastasis. Histological sections of the tumour lesion confirmed the diagnosis of a primary malignant vaginal melanoma. This report documents the importance of FDG-PET/CT in delineating a small volume tumour which is imperceptible on CT imaging.

Introduction: Specific mutations in the epidermal growth factor receptor (EGFR) characterize a subgroup of nonsmall cell lung cancer (NSCLC) patients that may be highly responsive to receptor inhibitor therapy. 18F-FDG PET/CT scans can map the glucose metabolism and treatment response of NSCLC. Therefore, we aimed to assess the pattern of metabolic response and outcome of inoperable NSCLC treated with epidermal growth factor receptor (EGFR) inhibitors, using 18F-FDG PET/CT scan. Methods: A retrospective study of inoperable NSCLC patients on EGFR inhibitor treatment that were referred for wholebody18F-FDG PET/CT scans was conducted based on cases scanned from January 2011 to June 2014. Comparison was made among serial attenuation-corrected fused PET/CT images for all study patients throughout the course of their treatment. Comparison based on PERCIST criteria was categorized into 4 levels ie. complete response (CMR), partial response (PMR), stable disease (SMD), progressive metabolic disease (PMD). Results: Overall, there were 5 patients identified, mean age: 57.4 years old +/- 2.9 years; The median survival time from initiation of EGFR inhibitor treatment to death was 17 months. Two patients showed initial partial metabolic response (PMR), two had progressive metabolic disease (PMD) and one had complete metabolic response (CMR) after the initiation of treatment. The patient with initial CMR had relapse and PMD 5 months later. Majority of patients eventually succumbed to their illness. Conclusions: Wholebody18F-FDG PET/CT is able to assess metabolic treatment response of NSCLC towards EGFR inhibitor treatment.
Lung Neoplasms ; Carcinoma, Non-Small-Cell Lung

Neuroendocrine tumours (NETs) are a category of neoplasm that is characterised by its phenotypic and heterogeneity. The occurrence of this type of neoplasm in the nasal cavity and paranasal sinuses is extremely rare accounting for only 0.2-0.8% of all cancers. NET tends to expresses somatostatin receptors (SSTR) and owning to this unique characteristic, molecular imaging has been able to detect these tumours using radiolabelled somatostatin analogue agent. Gallium-68 (Ga-68) DOTATATE PET/CT is an example of SSTR imaging and has been shown to be of importance in the assessment and staging of NET. We present a case of a rare sphenoid sinus NET in a 45-year-old gentleman whom initially presented with persistent left eye pain which led to visual loss. We described the utilization of Ga-68 DOTATATE PET/CT in the diagnosis and staging of this patient which in turn dictated treatment approach.

Objective: To identify regions of the brain affected during cognitive working memory during tasks to assess attention, planning and decision making among military aviation personnel who have chronic intermittent exposure to high altitude environment. Method: A case-control study was conducted in the Universiti Putra Malaysia among eight military personnel, four of whom had chronic intermittent exposure to high altitude training. They were divided into two groups, chronic intermittent exposure group (CE) (n=4) and a control group (n=4). They underwent a task-based functional magnetic resonance imaging (fMRI) that utilised spatial working memory task to objectively evaluate the neural activation in response to the Tower of London paradigm. Each correct answer was given a score of one and the maximum achievable score was 100%. Results: A consecutive dichotomised group of CE (4/8) and control (4/8) of age-matched military aviation personnel with a mean age of 37.23±5.52 years; showed significant activation in the right middle frontal gyrus (MFG). This in turn was positively correlated with response accuracy. A significant difference in the response accuracy was noted among both the groups at p<0.05. Conclusion: At the minimum results of power analysis of this preliminary fMRI study, our group of aviation personnel who had chronic intermittent exposure to hypobaric hypoxic environment, did not have any significant decrease in cognitive function namely attention, decision-making and problem solving compared to controls during a working memory task