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H Macapinlac

Publications and source records attributed to H Macapinlac.

At least 19 recordsLinked to original sources
PubMed2002

[FGD PET in a patient with pseudofractures from osteomalacia].

We present the case of a 42 year old man, with a history of multiple fractures and generalized pain for two years. A three phase bone scan, demonstrated multiple fractures involving the ribs, both ankles and feet. After going through a battery of tests which included an FDG PET scan (to exclude an occult malignancy), the patient was diagnosed with osteomalacia and hyperparathyroidism. The FDG PET scan, demonstrated multiple foci of increased FDG uptake throughout the axial skeleton, in a pattern highly suggestive of pseudofractures, rather than osseous metastases.

Adult↗
PubMed2001

Fludeoxyglucose positron emission tomography in the diagnosis of giant cell arteritis.

We describe a case in which fludeoxyglucose F 18 positron emission tomography (PET) led directly to the diagnosis of giant cell arteritis in an elderly woman with a fever of unknown origin. The patient presented with a 3-month history of fatigue, fever, headache, visual disturbance, jaw claudication, and anemia. A computed tomographic scan showed an anterior mediastinal mass that was suspected of being malignant. A fludeoxyglucose F 18 PET scan performed for preoperative evaluation identified striking uptake of fludeoxyglucose F 18 in the walls of the entire aorta, left main coronary artery, and subclavian, carotid, and common iliac arteries bilaterally, suggestive of an arteritis, a diagnosis subsequently confirmed by the findings of an arterial biopsy. Her erythrocyte sedimentation rate was 129 mm/h. There was normalizaton of the PET scan 2 weeks following treatment with prednisolone. This case suggests that fludeoxyglucose F 18 PET contributes to the noninvasive diagnosis of giant cell arteritis, as well as to the evaluation of the extent of disease, response to therapy, and disease recurrence.

Aged↗
PubMed2000

Prospective assessment of primary rectal cancer response to preoperative radiation and chemotherapy using 18-fluorodeoxyglucose positron emission tomography.

PURPOSE: The purpose of this prospective study was to determine the ability of fluorine-18 fluorodeoxyglucose positron emission tomography to assess extent of pathologically confirmed rectal cancer response to preoperative radiation and 5-fluorouracil-based chemotherapy. METHODS: Patients with primary rectal cancer deemed eligible for preoperative radiation and 5-fluorouracil-based chemotherapy because of a clinically bulky or tethered tumor or endorectal ultrasound evidence of T3 and/or N1 were prospectively enrolled. Positron emission tomography and CT scans were obtained before preoperative radiation and 5-fluorouracil-based chemotherapy (5,040 cGy to the pelvis and 2 cycles of bolus 5-fluorouracil with leucovorin) and repeated four to five weeks after completion of radiation and 5-fluorouracil-based chemotherapy. In addition to routine pathologic staging, detailed assessment of rectal cancer response to preoperative radiation and 5-fluorouracil-based chemotherapy was performed independently by two pathologists. Positron emission tomography parameters studied included conventional measures such as standardized uptake value (average and maximum), positron emission tomography-derived tumor volume (size), and two novel parameters: visual response score and change in total lesion glycolysis. RESULTS: Of 21 patients enrolled, prospective data (pretreatment and posttreatment positron emission tomography, and complete pathologic assessment) were available on 15 patients. All 15 demonstrated pathologic response to preoperative radiation and 5-fluorouracil-based chemotherapy. This was confirmed in 100 percent of the cases by positron emission tomography compared with 78 percent (7/9) by CT. In addition, one positron emission tomography parameter (visual response score) accurately estimated the extent of pathologic response in 60 percent (9/15) of cases compared with 22 percent (2/9) of cases with CT. CONCLUSIONS: This pilot study demonstrates that fluorine-18 fluorodeoxyglucose positron emission tomography imaging adds incremental information to the preoperative assessment of patients with rectal cancer. However, further studies in a larger series of patients are needed to verify these findings and to determine the value of fluorine-18 fluorodeoxyglucose positron emission tomography in a preoperative strategy aimed at identifying patients suitable for sphincter-preserving rectal cancer surgery.

Adenocarcinoma, Mucinous↗
PubMed2000

Use of PET to monitor the response of lung cancer to radiation treatment.

Approximately 170,000 people are diagnosed with lung cancer in the United States each year. Many of these patients receive external beam radiation for treatment. Fluorine-18 2-fluoro-2-deoxy-D-glucose positron emission tomography (FDG PET) is increasingly being used in evaluating non-small cell lung cancer and may be of clinical utility in assessing response to treatment. In this report, we present FDG PET images and data from two patients who were followed with a total of eight and seven serial FDG PET scans, respectively, through the entire course of their radiation therapy. Changes in several potential response parameters are shown versus time, including lesion volume (V(FDG)) by PET, SUVav, SUVmax, and total lesion glycolysis (TLG) during the course of radiotherapy. The response parameters for patient 1 demonstrated a progressive decrease; however, the response parameters for patient 2 showed an initial decrease followed by an increase. The data presented here may suggest that the outcome of radiation therapy can be predicted by PET imaging, but this observation requires a study of additional patients.

Aged↗
PubMed2000

Prognostic value of [18F]fluorodeoxyglucose positron emission tomographic scanning in patients with thyroid cancer.

Poorly differentiated thyroid cancer lesions often lose the ability to concentrate radioactive [131I]iodine (RAI) and exhibit increased metabolic activity, as evidenced by enhanced glucose uptake. We incorporated [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) scanning into the routine follow-up of a cohort of thyroid cancer patients undergoing annual evaluations. One hundred and twenty-five patients who had previous thyroidectomies were included. They had diagnostic RAI whole body scans, serum thyroglobulin measurements, and additional imaging studies as clinically indicated. During 41 months of follow-up, 14 patients died. Univariate analysis demonstrated that survival was reduced in those with age over 45 yr, distant metastases, PET positivity, high rates of FDG uptake, and high volume of the FDG-avid disease (>125 mL). Survival did not correlate with gender, RAI uptake, initial histology, or grade. Multivariate analysis demonstrated that the single strongest predictor of survival was the volume of FDG-avid disease. The 3-yr survival probability of patients with FDG volumes of 125 mL or less was 0.96 (95% confidence interval, 0.91, 1.0) compared with 0.18 (95% confidence interval, 0.04, 0.85) in patients with FDG volume greater than 125 mL. Only 1 death (of leukemia) occurred in the PET-negative group (n = 66). Of the 10 patients with distant metastases and negative PET scans, all were alive and well. Patients over 45 yr with distant metastases that concentrate FDG are at the highest risk. Once distant metastases are discovered in patients with differentiated thyroid carcinoma, FDG-PET can identify high and low risk subsets. Subjects with a FDG volume greater than 125 mL have significantly reduced short term survival.

Adult↗
PubMed1999

Utility of 18F-FDG positron emission tomography scanning on selection of patients for resection of hepatic colorectal metastases.

BACKGROUND: Hepatectomy represents a standard and potentially curative therapy for hepatic colorectal metastases. However, up to two thirds of patients explored for resection are found to have unsuspected disease, which precludes resection. METHODS: In order to determine if 18F-FDG positron emission tomography (PET) scanning may prevent unnecessary surgery, a group of 40 patients being considered for hepatic resection but at high risk for unresectable disease by clinical criteria were subjected to whole body 18F-FDG-PET scanning. Effect on clinical outcome was evaluated. In addition, PET findings in the 25 patients who underwent resection of hepatic metastases were directly compared with the resected specimen to determine the sensitivity of 18F-FDG PET scanning in the liver. RESULTS: Findings on 18F-FDG-PET scanning influenced the clinical management in 16 patients (40%) and directly altered management in 9 cases (23%). Six patients were spared laparotomy, and 3 others had PET-directed surgery that found extrahepatic tumor and spared the patient unwarranted liver resection. In 3 cases PET missed peritoneal metastases found on laparotomy. In these cases all missed tumors were less than 1 cm in size. Out of 52 resected hepatic lesions, 18F-FDG-PET detected 37. Within the liver, sensitivity of detection was also related to size. Only 25% of hepatic lesions smaller than 1 cm were detected by PET, while 85% of lesions larger than 1 cm were detected. CONCLUSIONS: FDG-PET is best for detecting extrahepatic disease. There are few false positives, and surgeons should carefully evaluate and biopsy extrahepatic positive sites. This test should be used for patients at high risk for extrahepatic disease and should be evaluated prospectively for all patients under consideration for liver resection.

Adult↗
PubMed1999

[18F]-2-fluoro-2-deoxy-D-glucose positron emission tomography localizes residual thyroid cancer in patients with negative diagnostic (131)I whole body scans and elevated serum thyroglobulin levels.

Progressive dedifferentiation of thyroid cancer cells leads to a loss of iodine-concentrating ability, with resultant false negative, whole body radioactive iodine scans in approximately 20% of all differentiated metastatic thyroid cancer lesions. We tested the hypothesis that all metastatic thyroid cancer lesions that did not concentrate iodine, but did produce thyroglobulin (Tg), could be localized by [18F]2-fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography (PET). We performed FDG-PET on 37 patients with differentiated thyroid cancer after surgery and radioiodine ablation who had negative diagnostic 131I whole body scans during routine follow-up. Serum Tg, Tg autoantibodies, neck ultrasounds, and other clinically indicated imaging procedures were performed to detect residual disease. In those with elevated Tg levels, FDG-PET localized occult disease in 71%, was false positive in one, and was false negative in five patients. The majority of false negative FDG-PET occurred in patients with minimal cervical adenopathy. Surgical resections, biopsies, 131 therapy, and differentiation therapy were performed based on the PET results. The FDG-PET result changed the clinical management in 19 of the 37 patients. In patients with elevated Tg levels, FDG-PET had a positive predictive value of 92%. In patients with low Tg levels, FDG-PET had a negative predictive value of 93%. No FDG-PET scans were positive in stage I patients; however, they were always positive in stage IV patients with elevated Tg levels. An elevated TSH level (i.e. hypothyroidism) did not increase the ability to detect lesions. FDG-PET is able to localize residual thyroid cancer lesions in patients who have negative diagnostic 131I whole body scans and elevated Tg levels, although it was not sensitive enough to detect minimal residual disease in cervical nodes.

Adenocarcinoma, Follicular↗
PubMed1998

Mathematical model of 5-[125I]iodo-2'-deoxyuridine treatment: continuous infusion regimens for hepatic metastases.

PURPOSE: Due to the cytotoxicity of DNA-bound iodine-125, 5-[125I]Iodo-2'-deoxyuridine ([125I]IUdR), an analog of thymidine, has long been recognized as possessing therapeutic potential. In this work, the feasibility and potential effectiveness of hepatic artery infusion of [125I]IUdR is examined. METHODS: A mathematical model has been developed that simulates tumor growth and response to [125I]IUdR treatment. The model is used to examine the efficacy and potential toxicity of prolonged infusion therapy. Treatment of kinetically homogeneous tumors with potential doubling times of either 4, 5, or 6 days is simulated. Assuming uniformly distributed activity, absorbed dose estimates to the red marrow, liver and whole-body are calculated to assess the potential toxicity of treatment. RESULTS: Nine to 10 logs of tumor-cell kill over a 7- to 20-day period are predicted by the various simulations examined. The most slowly proliferating tumor was also the most difficult to eradicate. During the infusion time, tumor-cell loss consisted of two components: A plateau phase, beginning at the start of infusion and ending once the infusion time exceeded the potential doubling time of the tumor; and a rapid cell-reduction phase that was close to log-linear. Beyond the plateau phase, treatment efficacy was highly sensitive to tumor activity concentration. CONCLUSIONS: Model predictions suggest that [125I]IUdR will be highly dependent upon the potential doubling time of the tumor. Significant tumor cell kill will require infusion durations that exceed the longest potential doubling time in the tumor-cell population.

Antimetabolites, Antineoplastic↗
PubMed1998

Accuracy of FDG-PET in Gastric Cancer. Preliminary Experience.

OBJECTIVE: Currently available imaging modalities, including CT, ultrasound, and MRI are unsatisfactory in the detection of metastatic gastric cancer, especially lymph node metastases and peritoneal spread. The aim of this study is to evaluate FDG-PET in the diagnosis of primary as well as metastatic gastric cancer.METHOD: All patients (18M/5F; mean age 62, range 33-81) with gastric cancer referred for FDG-PET scan from 1/1/97 to 3/20/98 were studied. PET images of the neck, chest, and abdomen were acquired using a dedicated whole body scanner. A final diagnosis was reached in 21 patients by histology, surgical findings, or clinical follow-up.RESULTS: All but 1 primary tumor (12 out of 13) and both cases with local recurrence showed a high degree of FDG uptake, with mean SUV of 8.9 (range 4.8-17.6). The one false negative (FN) occurred in a poorly controlled diabetic with blood sugar of >400 at the time of study. Six cases with prior gastrectomy were true negative (TN) in the region of the stomach. This translates to a sensitivity of 93%, specificity of 100%, and accuracy of 95% for the primary site. In contrast, for intra-abdominal lymph node (LN) stations PET was true positive (TP) in 2, FN in 7, false positive (FP) in 1, and TN in 32, yielding a sensitivity of 22% and accuracy of 81%. PET detected only 2 out of 9 perigastric lymph node metastases. For the 8 patients in this series who had documented M1 disease, PET detected two with liver metastasis, one with colon metastasis, and one with submandibular LN. However, four cases of peritoneal spread were missed.CONCLUSION: FDG-PET is highly sensitive in detecting the primary lesion in gastric cancer and shows promise in the detection of liver and extra-abdominal metastasis. However, PET appears limited in the detection of perigastric lymphadenopathy as distinct from the primary tumor and in assessing peritoneal spread. Our preliminary assessment suggests that staging of gastric cancer with FDG-PET scanning is relatively effective at detecting distant metastatic disease and will complement standard staging methods such as laparoscopy, which are more effective at staging local nodal spread and peritoneal disease.

Journal Article↗
PubMed1997

Technetium-99m-MIBI versus fluorine-18-FDG in diffuse multiple myeloma.

Experience of scintigraphic detection of bone lesion and active bone marrow involvement of multiple myeloma, especially with sestamibi and FDG-PET scans is in evolution. We report a case of intense sestamibi uptake in bone marrow correlating with the extent of the disease, while FDG-PET scans showed activity only in areas of active disease progression associated with pain. Technetium-99m-sestamibi appears to indicate the extent of the disease, while [18F]FDG-PET scans show sites of active tumor proliferation and may be useful in directing local therapy such as radiation.

Aged↗
PubMed1996

Visualization of myocardial metastasis of carcinoid tumor by indium-111-pentetreotide.

We present a case of metastatic carcinoid tumor metastatic to the heart, presenting as ventricular arrhythmia and diagnosed by 111Inpentetreotide scintiscan despite negative endocardial biopsy. The incidence and diagnosis of carcinoid heart disease is discussed, as well as the complementary role of high-resolution anatomical images (CT, MRI) with functional images (SPECT, PET) to determine the correct diagnosis of this rare condition.

Carcinoid Heart Disease↗
PubMed1995

Diffuse Tl-201 uptake in the lungs. Etiologic classification and pattern recognition.

Diffuse Tl-201 uptake in the lungs could be because of cardiac, neoplastic, inflammatory, or interstitial lung disease. Examples from the different categories, differential diagnosis, and different patterns are presented. The authors discuss the different mechanisms of increased Tl-201 uptake in the lungs which vary according to the underlying pathology.

AIDS-Related Opportunistic Infections↗
PubMed1995

Image registration of SPECT and CT images using an external fiduciary band and three-dimensional surface fitting in metastatic thyroid cancer.

Image registration of 131I SPECT with CT scans was performed in a patient with metastatic thyroid carcinoma using an external fiduciary band and a three-dimensional surface-fitting algorithim. Areas of metastatic disease taking up 131I were accurately localized to the liver, lungs and vertebral bodies; providing information that could not be obtained by planar or SPECT images alone. Based on these findings, further invasive diagnostic procedures were not performed, therefore considerably altering management in this patient. This approach to image registration has immediate clinical utility in the registration and interpretation of SPECT studies with corresponding CT or MRI scans.

Algorithms↗
PubMed1994

Tracer imaging in lung cancer.

Lung cancer is the leading cause of death from cancer in males. Adequate staging is essential if proper treatment is to be administered. Current morphological imaging modalities are confronted with problems in the staging of lung cancer, in the evaluation of treatment response, and in establishing whether a residual mass is due to fibrosis, residual tumors or local recurrence. Nuclear medicine imaging techniques have advanced from planar gallium-67 citrate scans in the 1970s to multihead-detector single-photon emission tomography for 67Ga, Thallium-201 chloride, technetium-99m SestaMIBI, monoclonal antibodies, and octreotide compounds. Results of positron emission tomography (PET) with fluorine-18 deoxyglucose or carbon-11 methionine are very promising. PET units are now employed in centers all over the world and the recently introduced whole-body PET units will be ideal for the correct staging of malignant diseases. The current status of various nuclear medicine imaging procedures is reviewed. The problems and advantages of each scintigraphic procedure are discussed. It appears that many of the problems that confront morphological imaging will be solved by nuclear medicine techniques in the future.

Aged↗