Mitigating the dilemma in dementia: A case series of the first amyloid brain PET scans in the Philippines

@#Diagnosis of Alzheimer dementia is done clinically using criteria set by different neurological associations. Inevitably, clinicians encounter cases that do not fulfill the set definitions and have to resort to supporting data to form a clinical judgment. Part of the ancillary work-up for dementia is the brain amyloid PET scan that has recently been available in the Philippines. It involves a radiopharmaceutical with high-affinity binding to amyloid plaques which for a time were thought to be central pathological finding for Alzheimer dementia. This study describes the first four amyloid PET scans in the Philippines and detail the protocol as well as interpretation of such studies. The procedure is not as simple and reproducible as one might think hence following the recommended protocol and interpretation guidelines are of utmost importance. We recommend standardization of the reporting of results for all centers that will cater to patients being worked up for dementia, which include reporting SUVRs for both whole cerebellum and cerebellar cortex. More studies are recommended to generate a local Florbetaben SUVR cutoff.

Comparison of Gallium - 68 Prostate-Specific Membrane Antigen (Ga-68 PSMA) normal tissue uptake across tumor burden groups among Filipino patients with prostate cancer

Background@#PSMA-targeted radiopharmaceuticals have been widely studied for their theragnostic role in prostate cancer and were introduced in the Philippines in 2018. The optimal administered activity of 177Lu-PSMA for targeted endoradiotherapy has not yet been established and is thought to be influenced by several factors, including tumor burden. This study investigates the effect of tumor burden on the normal tissue PSMA uptake among Filipino patients with prostate cancer using its diagnostic counterpart, 68Ga-PSMA I&T @*Methods@#One hundred four patients imaged with 68Ga-PSMA I&T PET/CT in our institution from January 2018 to May 2020 were included. Patients were visually classified into low, medium, and high tumor burden groups. Maximum and mean standardized uptake values (SUVmax and SUVmean) of the lacrimal glands, parotid glands, submandibular glands, kidneys, liver, spleen, and bone were measured and compared among tumor burden groups. @*Results and Conclusions@#68Ga-PSMA I&T uptake in the kidneys, the salivary glands, and the liver, were significantly reduced by approximately 25-50% in patients with high tumor burden. This finding supports the hypothesis that patients with higher tumor load can tolerate higher activity doses of 177Lu-PSMA for endoradiotherapy before developing significant damage to the critical organs. This may serve as a guide towards optimizing and personalizing 177Lu-PSMA I&T administered activity dose for radionuclide therapy

The Role of I-131 MIBG cardiac scintigraphy in diagnosing dementia with lewy bodies : A case report

@#The objective of this case report is to highlight the role of Iodine-131 metaiodobenzylguanidine (MIBG) cardiac scintigraphy in discriminating Dementia with Lewy Bodies (DLB) from other neurodegenerative diseases such as Alzheimer’s Disease. This patient is a known case of Parkinson’s disease and has been treated as such since 2011. However, the patient also concurrently deals with visual hallucinations and because of this, the patient’s attending neurologist wanted to rule in the diagnosis of DLB rather than AD. Hence, an I-131 MIBG cardiac scan was requested in order to support the diagnosis of DLB. The use of I-131 MIBG cardiac scintigraphy as a diagnostic tool for diagnosing Lewy Body Dementia is not prevalent and to our knowledge, this was the first time in the country that this procedure was done (December 9, 2019).

Role of Tc-99m MDP Bone Scintigraphy in the evaluation of suspected Chondrosarcoma from OIiier Disease: A rare case repor

@# OIiier disease is a rare nonhereditary disorder characterized by multiple enchondromas in which malignant changes may occur. We report the case of a 15-year-old male with Ollier disease who presented with a large mass in the left upper arm for several months. Radiography revealed hugelytic mass in the proximal half to two-thrids of the left humerus. Bone scan showed irregularly increased tracer uptake in the head to mid shaft of the left humerus that is suggestive of malignant disease. Pathology analysis demonstrated proximal humeral chondrosarcoma, grade 1. In Ollier disease, bone scan may be used for monitoring the lessions with suspicion for malignant transpormation.

Comparison of whole-body FDG-PET and bone scintigraphy in the evaluation of skeletal metastases in patients with breast cancer

An established standard imaging modality for detecting bone metastases in patients with breast cancer is through the use of 99mTc-hydroxymethylene diphosphonate (99mTc-IIDP) bone scintigraphy. It is clearly documented that sensitivity is generally high while specificity is often lower because of tracer uptake in non-malignant processes. The aim of this study is to evaluate the diagnostic performance of whole body 2-deoxy-2-[18F]-D- glucose positron emission tomography (18 F-FDG PET) and bone scintigraphy in the detection of bone metastasis in patients with breast cancer.METHODS: There were 232 consecutive patients who underwent FDG PET for breast cancer staging/restaging at our center during the study period. We included those who only had a bone scintigraphy within a month before or after the PET scan. The results of each image interpretation were compared retrospectively by an experienced nuclear medicine physician. Per-patient and per-lesion detection rates were collected. Bone metastasis slams was established on the basis of multimodality imaging and/or clinical follow-up for at least 6 months Weighted kappa was also calculated to determine agreement between the two modalities.RESULTS: Forty-seven patients were included in the study with ages ranging from 28-86 years. For the patient-based data, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 90%, 92.6%, 90%, 92.6%, and 91.5%, respectively, for FDG PET, and 95%, 44.4%, 55.9%, 92.3% and 66%, respectively,for bone scintigraphy. For the lesion-based data, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 66.4%, 90%, 94.7%, 50%, and 72.8%, respectively, for FDG PET, and 74.5%, 27%, 752%, 26.3% and 62.6%, respectively, for bone scintigraphy Agreement between the two modalities was slight.CONCLUSIONS: Overall, FDG PET shows to be as sensitive as bone scintigraphy in picking up bone metastases Furthermore, on both per patient and per lesion bases; PET was shown to be more confirmatory and more accurate with evidence of statistical significance. FDG PET and bone scintigraphy should play complementary roles in the detection of skeletal metastases.