Complete and sustained response after peptide receptor radionuclide therapy in a 66-year-old Filipino male with metastatic pancreatic neuroendocrine tumor: A case report

@#The introduction of peptide receptor radionuclide therapy (PRRT) to the Philippines has allowed for novel approaches in the management of neuroendocrine tumors (NETs). This case report details the management of a 66-year-old Filipino man diagnosed with metastatic pancreatic NET after biopsy and staging with Ga-68 DOTATATE PET-CT. After poor response to somatostatin analogue therapy, the patient was advised to undergo PRRT. Upon completing four cycles of PRRT with Lu-177 DOTATATE, the metastatic hepatic lesions showed resolution and the pancreatic tail tumor exhibited regression, allowing the patient to undergo surgical resection of the primary tumor. On follow-up, he was declared to be in remission with good quality of life and no imaging evidence of recurrence. The case underscores the diagnostic and therapeutic utility of radiolabeled somatostatin analogues along with the importance of a multidisciplinary approach in the management of an initially unresectable metastatic pancreatic NET

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

A comparative study of different methods of estimating glomerular filtration rate in a subset of Filipinos with normal renal function

@#Kidney function is commonly quantified using the glomerular filtration rate (GFR). However, the gold standard of measuring GFR, inulin clearance, is not practical for daily clinical use. This study compares different methods of GFR estimation based on serum creatinine, plasma levels of 99mTc-diethylenetriaminepentaacetic acid (DTPA), and camera acquisition of 99mTc-DTPA uptake. Seventy-five Filipino adults between ages 20 and 35 presumed to have normal kidneys were recruited. Each subject underwent gamma camera scintigraphy using the Gates and Inoue protocols after receiving a dose of 99mTc-DTPA. Blood samples were subsequently extracted at 1 hour and 3 hours after tracer injection, and GFRs were calculated based on single- and double-plasma sampling methods (SPSM and DPSM, respectively). Serum creatinine was also measured to derive GFR using the CKD-EPI, MDRD, and CockroftGault equations. Each method was correlated with a reference standard (DPSM) based on accuracy, linear regression, bias, and precision. SPSM tends to overestimate GFR unlike the other methods evaluated, but otherwise shows the most favorable diagnostic performance among the six methods when correlated with DPSM. The Inoue method appears modestly better than the routinely utilized Gates protocol, though both methods exhibit lack of precision. The CKD-EPI formula shows similar, if not slightly superior, diagnostic properties to the MDRD and Cockroft-Gault equations, thus confirming its validity for use in this Filipino population subset. Further studies are needed, particularly involving SPSM and CKD-EPI, to determine the applicability of our findings in Filipinos with varying degrees of kidney function. It is hoped that modifications to these methods can be made that are tailor-fit to derive more accurate and population-specific GFR values.

The Emergence of Theranostics in the Philippines: Overcoming Challenges and Bringing Hope / 대한핵의학회잡지

Medical managements are becoming personalized while diseases are being understood at the molecular level. Nuclear medicine is one of the fields actively contributing to this development. In particular, theranostics, a combinatorial term for therapy and diagnostics, enables accurate imaging and subsequent targeted radionuclide treatment. Due to its high impact in healthcare, many countries have begun to offer Ga-68 PET/CTscans and Lu-177 therapies. The Philippines has followed suit through the initiative of this author and able support of the administration and staff of St. Luke's Medical Center. The Ga-68 DOTATATE and PSMA PET/CT scans became officially available in January 2018 while the first peptide receptor radionuclide therapy for neuroendocrine tumor and first PSMA radioligand therapy for prostate cancer occurred in May and June 2018, respectively. Amidst past, present, and future challenges, theranostics has emerged in the Philippines, offering hope to cancer patients in the country.

The Emergence of Theranostics in the Philippines: Overcoming Challenges and Bringing Hope / 대한핵의학회잡지

Medical managements are becoming personalized while diseases are being understood at the molecular level. Nuclear medicine is one of the fields actively contributing to this development. In particular, theranostics, a combinatorial term for therapy and diagnostics, enables accurate imaging and subsequent targeted radionuclide treatment. Due to its high impact in healthcare, many countries have begun to offer Ga-68 PET/CTscans and Lu-177 therapies. The Philippines has followed suit through the initiative of this author and able support of the administration and staff of St. Luke's Medical Center. The Ga-68 DOTATATE and PSMA PET/CT scans became officially available in January 2018 while the first peptide receptor radionuclide therapy for neuroendocrine tumor and first PSMA radioligand therapy for prostate cancer occurred in May and June 2018, respectively. Amidst past, present, and future challenges, theranostics has emerged in the Philippines, offering hope to cancer patients in the country.

Utility of radiolabeled leukocyte and bone marrow scintigraphy with SPECT/CT in the diagnostic work-up- of the painful prosthetic joint: A single-institution experience

@#In tbhe assessment of prosthetic joint pains, differentiating between aseptic loosening and infection can be challenging due to their similarities in clinical presentation and histopathology. Combined radiolabeled leukocyte and bone marrow scintigraphy and SPECT/CT is considered the most suitable nuclear imaging modality for this purpose. However, this is infrequently performed in our local setting. We present two cases where these studies were appropriately performed with different scan outcomes. The first case involved a 67-year-old male with painful right knee prosthesis and an alleged history of recurrent periprosthetic joint infection (PJI). The leukocyte tagging scan and marrow scan images were found to be congruent, which was more compatible with aseptic loosening. No emergent surgical intervention was done in our hospital, and the patient returned to this home territory for further management. The second case was a 72-year-old male with progressive pain in his left prosthetic hiip which began after surgery a year prior. Scan images were incongruent, suggestive of PJI; this was confired on joint aspiration and eventual surgical revision. Despite this imaging study's high sensitvity and high specificity, it has not been well-received in management algorihms of PJI. Collaboration between clinicans and nuclear imaging specilists is key in increasing the general use of these procedures.

The first application of Ga-68 and Lu-177 theranostics in the Philippines: A rare case of mediastinal small cell neuroendocrine carcinoma

@#A 43-year-old female with a surgically unresectable and non-secretory mediastinal small cell neuroendocrine carcinoma waws previously given the protein kinase inhibitor Everolimus with intolerable nausea and fatigue. High somatostatin receptor expression of the known tumor was seen on 68Ga-DOTATATE PET/CT scan. She was then given 6.4 GBq of 177 Lu-DOTATATE with no adverse events. A follow-up 68Ga-DOTATATE PET/CT scan three months post-treatment showerd stable DOTATATE affinity with no evidence of metastasis. this case presents an overview of peptide receptor radionuclide therapy (PRRT), especially for multidisciplinary teams in the Philippines, as 68Ga and 177 Lu theranostics is introduced in the country.

Initial experience with Gallium-68 and Lutetium-177 prostate-specific membrane antigen theranostics for prostate cancer in the Philippines: A case series

@#In the Philippines, prostate cancer is the third most common malignancy among men. Over time, it tends to recur and/or progress to metastatic castration-resistant prostate cancer, wherein conventional therapies no longer work. Taking advantage of the high expression of prostate-specific membrane antigen (PSMA) on prostate cancer cells, 68GA- and 177 Lu-PSMA theranostics provides a targeted approach to imaging and therapy. With it's availabity in our country, patients now have an appealing and accessible treatment option. In this paper, we present five cases of metastatic castration-resistant prostate cancer, who have undergone 68Ga-PSMA PET/CT scans and 177Lu-PSMA radioligand therapies in the Philippines, to showcase the usefulness of theranostics in the local setting.

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.

Role of 18F-FDG PET/CT in the diagnostic work-up of renal cell carcinoma presenting as low back pain

@#Low back pain is common among adults, but back pain secondary to a metastatic carcinoma is rare. We present a case of a 71-year-old male with low back pain who was referred for a 18F-FDG PET/CT scan due to suspicious-looking skeletal lesions on MRI. On PET/CT, multiple foci of increased FDG uptake were noted in the axial and appendicular skeleton. When correlated with a non-contrast CT stonogram done 2 months prior, an exophytic lesion in the right kidney did not show FDG update; rather, it was in the left kidney where an FDG-avid focus was seen. A concomitant bone scan revealed fewer bone lesions when compared with the PET/CT findings. Biopsies of the left renal mass and a vertebral lession were consistent with metastatic renal cell carcinoma. While not a first-line diagnostic test in the management of low back pain, 18F-FDG PET/CT scan can be valuable in cases where metasis highly suspected without a known primary carcinoma site.

SPECT-CT localization of Tc-99m methylene diphosphonate uptake in a subacute brain infarct on bone scintigraphy

Bone scan is a sensitive imaging procedure for cancer patients who are at high risk for bone metastases. Despite the high sensitivity, Tc-99m methylene diphosphonate (MDP) is not a specific tracer and its increased uptake may also be seen in extra-osseous areas. In cases where localization of extra-osseous sites of MDP uptake on planar imaging prove to be difficult, single photon emission computed tomography with computed tomography (SPECT/CT) may be useful. A known lung cancer patient was referred for whole body bone scan to detect bone metastasis. Planar images showed tracer accumulation in the left area of the head, suspicious for skull metastasis. SPECT-CT imaging of the head was done for further evaluation, which showed Tc-99m MDP uptake in the left temporoparietal lobe. Magnetic resonance imaging (MRI) of the brain was subsequently done, which showed a subacute brain infarct corresponding to the Tc-99m MDP-avid focus. Thus, SPECT-CT was helpful in proper anatomical localization of the focal Tc-99m MDP uptake in the head, which otherwise might have been easily mistaken for skull metastasis should only planar imaging was used.

Nuclear medicine in the philippines: a glance at the past, a gaze at the present, and a glimpse of the future

While the introduction of radioactive tracers in the study of metabolic pathways has been well-documented in clinical thyroidology as early as 1924, the widespread utilization in other clinical specialties has been hampered by slow developments in radiation-detecting devices and in the production of appropriate radiopharmaceuticals, in addition to the morbid fear of radiation. In the Philippines, the first radioisotope laboratory was established in 1956. Ten years later, the Philippine Society of Nuclear Medicine was formed. Through the years, challenges were overcome, foundations were laid down, growth was encouraged, friendships with other organizations were built, adjustments were made, and rules were enforced. To date, there are approximately 58 nuclear medicine centers randomly distributed from north to south of the Philippines, 7 accredited nuclear medicine training institutions, 95 board-certified nuclear medicine physicians [a few of whom are also internationally recognized], and a regionally-indexed Philippine Journal of Nuclear Medicine. Qualifying examinations for technologists were also recently instated. International relations are constantly strengthened by sending trainees abroad and accepting foreign trainees here, as well as participating in conferences and other endeavors. While the cost of putting up nuclear medicine centers in the Philippines is still prohibitive, it should not pose too much of a constraint as there are foreign and local parties willing to help. With appropriate instrumentation, targeting radiopharmaceuticals and trained human resources, nuclear medicine can indeed contribute much to health care delivery