The primary objectives of this retrospective study were to determine the cancer detection rate of PET/CT in this institution and to compare the sensitivity and specificity of low-dose PET/CT to that of PET with high-dose CT. Three hundred sixty-seven (367) patients with unremarkable history, family history of cancer, symptoms or abnormal diagnostic tests, and with follow-up studies were included. PET/CT and histopathology results were noted. Individual and overall cancer detection rates, as well as sensitivities and specificities for each subgroup, were computed. Overall cancer detection rates was 22.3%, for low-dose PET/CT was 17.9%, and for high-dose PET/CT was 24.4%. Using the chi squared test of independence, no statistically significant difference was found between the calculated sensitivities and specificities of low- and high-dose PET/CT across all patient groups. Using the Mantel-Haeaszel chi squared test, a statistically significant association between the subindication for malignancy screening and PET/CT results was established with subindications pointing to a higher suspicion for malignancy having a higher probability of detecting a malignancy. Therefore, high-dose PET/CT as a screening test would be advised for high-risk patients and low-dose PET/CT would be recommended because of its similar accuracy but lower radiation exposure.

Human ; Male ; Female ; Aged 80 and over ; Aged ; Middle Aged ; Adult ; Young Adult ; Adolescent ; Child ; Positron-Emission Tomography ; Tomography Scanners, X-Ray Computed ; neoplasms-diagnosis ; False Positive Reactions ; False Negative Reactions

PET is essential for the post-treatment assessment of lymphomas because a negative PET scan after treatment is required for a complete remission and curative outcome. Functional imaging with 18F-FDG PET enables evaluation of the early metabolic changes rather than the moprphologic changes of the lymphoma occurring later. Among 186 patients diagnosed with Hodgkin's Disease or Non-Hodgkin's Lymphoma who were referred to the PET Center in this institution from April 2002 to June 2010, 35 patients were included in this study. All 14 patients who only had end-of-chemotherapy scans without midcycle scans had no tumor recurrence on subsequent scan/s, with a median follow-up of 17.5 months. Of the remaining 21 patients, 11 patients had positive studies, 9 had negative studies and 1 had an indeterminate study of the midcycle scans. All the patients obtained similar results on the subsequent scans, excluding 5 with no follow-up scans, with median follow-ups of 13 months for the PET-positive patients and 23 months for the PET-negative patients. These results support the strong prognostic value of PET for aggressive lymphomas, whether the imaging is performed at the end of therapy or after only a few cycles of chemotherapy. PET has consistently been shown to identify positive respondents with higher survival probabilities and longer progression-free survival periods from non-responders on subsequent scans.
Human ; Male ; Female ; Aged 80 and over ; Aged ; Middle Aged ; Adult ; Young Adult ; Adolescent ; LYMPHOMA ; NEOPLASMS ; NEOPLASMS BY HISTOLOGIC TYPE

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.

Human ; Male ; Aged ; Technetium Tc 99m Medronate ; Single Photon Emission Computed Tomography Computed Tomography ; Skull ; Magnetic Resonance Imaging ; Brain ; Lung Neoplasms

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.

Human ; Male ; Aged ; Technetium Tc 99m Medronate ; Single Photon Emission Computed Tomography Computed Tomography ; Skull ; Magnetic Resonance Imaging ; Brain ; Lung Neoplasms

Hepatocellular carcinoma and metastatic colorectal carcinoma are amongst the more common causes of cancer-related mortality worldwide. Selective internal radiation therapy (SIRT) with 90y microspheres is usually indicated in patients with nonresectable status and extensive colorectal liver metastases that are refractory to chemotherapy or target therapy. Several examinations, including CT, MRI or PET, serum chemical analyses, hepatic angiography and liver-lung shunting study with Tc-99m MAA, are done to ensure appropriateness and safety of therapy. Herein, three cases (two with hepatocellular carcinoma and one with metastatic colorectal cancer), which qualified for SIRT and underwent SPECT-CT, are presented. All of them underwent the necessary pre-therapy work-ups. The CT and PET-CT scans identified the hepatic lesions. The blood tests showed nearly normal hepatic and renal functions, except for the third case with elevated bilirubin level. The hepatic angiograms revealed no significant gastrointestinal shunting. The liver-lung shunting studies computed <20% hepatopulmonary shunt fraction in all cases. One patient had >10% hepatopulmonary shunt. Together with the patient with an elevated bilirubin level, they received a reduced dose of 90Y microspheres by 20%. After SIRT, bremsstrahlung planar imaging and SPECT-CT were performed to localize the distribution of the 90y microspheres, the findings of which correlated well with the results of the pre-therapy scans. The use of SPECT-CT is recommended for better anatomic localization and functional correlation.

Human ; Female ; Middle Aged ; Carcinoma, Hepatocellular ; Neoplasms ; Adenocarcinoma ; Bilirubin ; Hematologic Tests ; Liver Neoplasms ; Microspheres ; Positron Emission Tomography Computed Tomography ; Sulfhydryl Compounds ; Technetium Tc 99m Aggregated Albumin ; Tomography, Emission-computed, Single-photon

Neuroblastoma is an embryonal tumor of children that frequently presents with metastases. Our patient is a 6-year-old girl who was diagnosed to have neuroblastoma with diffuse metastatic disease throughout the skeleton as seen in her 123I-MIBG scan in the United States. 18F-FDG PET/CT scan was done in the Philippines after chemotherapy and gene therapy, and before 131I-MIBG therapy. No additional lesions were seen on PET.  131I-MIBG was then performed and an 131I-MIBG with SPECT/CT thereafter, which showed an increase in size and extent of the lesion in the head and a decrease in number of the skeletal metastases. New 131I-MIBG-avid posterior cervical lymph nodes were also localized through SPECT/CT. For this patient, a follow-up 123I/131I-MIBG scan would be more cost-effective in assessing response to therapy. Sectional imaging may be done to obviate the need for sedation of this young patient.

Human ; Female ; Child ; 3-iodobenzylguanidine ; Fluorodeoxyglucose F18 ; Genetic Therapy ; Lymph Nodes ; Neuroblastoma ; Positron Emission Tomography Computed Tomography ; Radionuclide Imaging ; Radiopharmaceuticals

Copper dotatate CU-64 ; Gallium 68 PSMA-11 ; Gallium Radioisotopes

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.
Delivery of Health Care ; Hope ; Humans ; Neuroendocrine Tumors ; Nuclear Medicine ; Philippines ; Positron-Emission Tomography and Computed Tomography ; Prostatic Neoplasms ; Receptors, Peptide ; Theranostic Nanomedicine

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.

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.
Glomerular Filtration Rate ; Creatinine