Comparative Analysis of Lung Perfusion Scan and SPECT/CT for the Evaluation of Functional Lung Capacity / 대한핵의학회잡지

PURPOSE: This study aimed to compare lung perfusion scan with single photon emission computed tomography/computed tomography (SPECT/CT) for the evaluation of lung function and to elucidate the most appropriate modality for the prediction of postoperative lung function in patients with lung cancer.METHODS: A total of 181 patients underwent Tc-99m macroaggregated albumin lung perfusion scan and SPECT/CT to examine the ratio of diseased lung and diseased lobe. Forty-one patients with lung cancer underwent both preoperative and postoperative pulmonary function tests within 1 month to predict postoperative pulmonary function. Predicted postoperative forced expiratory volume in 1 s (ppoFEV₁) was calculated by the % radioactivity of lung perfusion scan and SPECT, and the % volume of the residual lung, assessed on CT.RESULTS: The ratios of diseased lung as seen on lung perfusion scan and SPECT showed significant correlation, but neither modality correlated with CT. The ratios of the diseased lung and diseased lobe based on CT were higher than the ratios based on either perfusion scan or SPECT, because CT overestimated the function of the diseased area. The lobar ratio of both upper lobes was lower based on the perfusion scan than on SPECT but was higher for both lower lobes. Actual postoperative FEV₁ showed significant correlation with ppoFEV₁ based on lung perfusion SPECT and perfusion scan.CONCLUSIONS: We suggest SPECT/CT as the primary modality of choice for the assessment of the ratio of diseased lung area. Both perfusion scan and SPECT/CT can be used for the prediction of postoperative lung function.

Comparative Analysis of Lung Perfusion Scan and SPECT/CT for the Evaluation of Functional Lung Capacity / 대한핵의학회잡지

PURPOSE@#This study aimed to compare lung perfusion scan with single photon emission computed tomography/computed tomography (SPECT/CT) for the evaluation of lung function and to elucidate the most appropriate modality for the prediction of postoperative lung function in patients with lung cancer.@*METHODS@#A total of 181 patients underwent Tc-99m macroaggregated albumin lung perfusion scan and SPECT/CT to examine the ratio of diseased lung and diseased lobe. Forty-one patients with lung cancer underwent both preoperative and postoperative pulmonary function tests within 1 month to predict postoperative pulmonary function. Predicted postoperative forced expiratory volume in 1 s (ppoFEV₁) was calculated by the % radioactivity of lung perfusion scan and SPECT, and the % volume of the residual lung, assessed on CT.@*RESULTS@#The ratios of diseased lung as seen on lung perfusion scan and SPECT showed significant correlation, but neither modality correlated with CT. The ratios of the diseased lung and diseased lobe based on CT were higher than the ratios based on either perfusion scan or SPECT, because CT overestimated the function of the diseased area. The lobar ratio of both upper lobes was lower based on the perfusion scan than on SPECT but was higher for both lower lobes. Actual postoperative FEV₁ showed significant correlation with ppoFEV₁ based on lung perfusion SPECT and perfusion scan.@*CONCLUSIONS@#We suggest SPECT/CT as the primary modality of choice for the assessment of the ratio of diseased lung area. Both perfusion scan and SPECT/CT can be used for the prediction of postoperative lung function.

Unusual Contralateral Axillary Lymph Node Metastasis in a Second Primary Breast Cancer Detected by FDG PET/CT and Lymphoscintigraphy / 대한핵의학회잡지

Contralateral metastatic axillary lymph nodes in a patient with breast cancer is a rare condition. Here, we present a 55-year-old woman with a second primary breast cancer. The patient underwent ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) for staging work-up. Additionally, preoperative lymphoscintigraphy was performed to detect sentinel lymph nodes. FDG PET/CT demonstrated increased FDG uptake in the left nipple and right axillary lymph nodes. Lymphoscintigraphy identified the right axillary lymph nodes which was consistent with the FDG PET/CT findings. This case emphasizes the usefulness of FDG PET/CT and lymphoscintigraphy for identifying unpredictable contralateral axillary lymph node metastasis from a second primary breast cancer.

Unusual Horner's Syndrome in Recurrent Breast Cancer: Evaluation Using ¹⁸F-FDG PET/CT / 대한핵의학회잡지

¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is a widely used imaging modality in the initial diagnosis of cancer, treatment response evaluation and detection of recurrence. Herein, we present the case of a 39-year-old female who presented right ptosis on the follow-up of breast cancer after surgery. Clinicians suspected Horner's syndrome, and the patient underwent FDG PET/CT for the evaluation of recurrence that could cause Horner's syndrome. FDG PET/CT demonstrated a focal hypermetabolic lesion in the right cervicothoracic junction area, corresponding to the preganglionic cervical sympathetic trunk. A subsequent needle biopsy was done, and the lesion was confirmed as metastatic ductal carcinoma. In this case, we could detect the exact location of the recurring lesion that caused Horner's syndrome using FDG PET/CT.

Radioprotective Effect of Epigallocatechin-3-Gallate on Salivary Gland Dysfunction After Radioiodine Ablation in a Murine Model

OBJECTIVES: Radioiodine (RI) therapy is known to subject cellular components of salivary glands (SG) to oxidative stress leading to SG dysfunction. However, the protective effects of antioxidants on RI-induced SG damage have not been well investigated. The authors investigated the morphometric and functional effects of epigallocatechin-3-gallate (EGCG) administered prior to RI therapy and compared this with the effects of amifostine (a well-known antioxidant) in a murine model of RI sialadenitis. METHODS: Four-week-old female C57BL/6 mice (n=48) were divided into four groups; a normal control group, a RI-treated group (0.01 mCi/g mouse, orally), an EGCG and RI-treated group, and an amifostine and RI-treated group. Animals in these groups were divided into 3 subgroups and euthanized at 15, 30, and 90 days post-RI treatment. Salivary flow rates and lag times were measured, and morphologic and histologic examinations and TUNEL (terminal deoxynucleotidyl transferase biotin-dUDP nick end labeling) assays were performed. Changes in salivary (99m)Tc pertechnetate uptake and excretion were followed by single-photon emission computed tomography. RESULTS: Salivary flow rates and lag times to salivation in the EGCG or amifostine groups were better than in the RI-treated group. Histologic examinations of SGs in the EGCG or amifostine group showed more mucin-rich parenchyma and less periductal fibrosis than in the RI-treated group. Fewer apoptotic cells were observed in acini, ducts, and among endothelial cells in the EGCG or amifostine group than in the RI group. In addition, patterns of (99m)Tc pertechnetate excretion were quite different in the EGCG or amifostine group than in the RI group. CONCLUSION: EGCG supplementation before RI therapy could protect from RI-induced SG damage in a manner comparable to amifostine, and thus, offers a possible means of preventing SG damage by RI.

Current Status of Optical Imaging for Evaluating Lymph Nodes and Lymphatic System

Optical imaging techniques use visual and near infrared rays. Despite their considerably poor penetration depth, they are widely used due to their safe and intuitive properties and potential for intraoperative usage. Optical imaging techniques have been actively investigated for clinical imaging of lymph nodes and lymphatic system. This article summarizes a variety of optical tracers and techniques used for lymph node and lymphatic imaging, and reviews their clinical applications. Emerging new optical imaging techniques and their potential are also described.

Preoperative Serum Thyroglobulin as a Useful Predictive Marker to Differentiate Follicular Thyroid Cancer from Benign Nodules in Indeterminate Nodules

Indeterminate cytology results increase the number of repetitive procedure and unnecessary surgery. This study was designed to find useful and simple predictive tools to differentiate malignant thyroid nodules from indeterminate nodules. We retrospectively enrolled 164 patients who had undergone thyroid surgery as a result of indeterminate cytology in the National Cancer Center. We reviewed patients' age at diagnosis, sex, preoperative biochemical markers such as thyroglobulin (Tg), anti-Tg antibody, free T4 and TSH level, and sonographical and pathological findings, which were subjected to statistical analysis. We found several clinical and sonographical predictive factors that showed significant differences. Young age, male, preoperative high Tg level, and hypoechoic nodule on sonography all increased cancer probability significantly in multivariate analysis. With a cut-off value of 187.5 ng/mL Tg, sensitivity and specificity were 54.8% and 90.1%, respectively (AUC 0.748, P 1.7 cm, elevated serum Tg predicts the risk of malignancy; especially Tg > 70 ng/mL (odds ratio 3.245, 95% confidence interval 1.115-9.450, P = 0.038). Preoperative Tg levels had very high specificity in predicting thyroid cancer in case of suspicious follicular neoplasm. Therefore, Tg levels may be a useful marker for differentiating thyroid cancer from benign thyroid nodules in the cytological diagnosis of indeterminate nodules.

Locoregional Recurrence of Breast Conserving Surgery after Preoperative Chemotherapy in Korean Women with Locally Advanced Breast Cancer / 한국유방암학회지

PURPOSE: Preoperative chemotherapy has been used to increase the rate of breast conserving surgery (BCS) in Caucasian women. However, whether it would also increase the rate of BCS in Korean women has not been verified. The aim of this study was to determine the effectiveness of preoperative chemotherapy to make BCS possible in Korean women who have locally advanced cancer without any increase of locoregional recurrence according to operation methods (BCS vs. mastectomy). METHODS: From August 2002 to April 2005, 205 patients with stage II or III breast cancer were enrolled in a phase III randomized trial of preoperative chemotherapy. Surgeons decided on the type of surgery (mastectomy or BCS) at initial diagnosis. By randomization, patients received four cycles of either docetaxel/capecitabine or doxorubicin/cyclophosphamide followed by surgery and crossover to the other treatment as postoperative chemotherapy. RESULTS: The mean tumor size was 3.29 cm and the mean breast volume was 489 cc at diagnosis. After preoperative chemotherapy, clinical response was shown in 76.0% of the patients. Of the 71 patients planned for a mastectomy at initial diagnosis, 27 patients underwent BCS (38.0%). Clinical T stage after preoperative chemotherapy, pathologic T size and lymphatic invasion were correlated with conversion to BCS. In multivariate analysis, only lymphatic invasion showed statistical significance. Locoregional disease-free survival did not statistically differ between the two operation methods for the patients who were planned for a mastectomy at the initial exam. CONCLUSION: This study showed that preoperative chemotherapy also increased the rate of BCS, while avoiding any increase of locoregional recurrence in Korean women with locally advanced breast cancer.

Evaluation of Usefulness of Radio-iodine SPECT/CT in Differentiated Thyroid Cancer / 핵의학분자영상

PURPOSE: Localizing and differentiating a metastatic lesion of differentiated thyroid cancer (DTC) by using radio?iodine whole body scan could be difficult because a whole body scan (WBS) lacks anatomic information. This study was performed to evaluate the usefulness of radio-iodine SPECT/CT for differentiating equivocal lesions. MATERIALS AND METHODS: Among 253 patients with DTC who had undergone radio-iodine scan between February and July 2006, 26 patients were enrolled (M:F = 8:18, Age 50.7 +/- 12.5 years) in this study. The patients had abnormal uptakes in the WBSs that necessitated precise anatomical localization for differentiating between a metastatic lesion and a false-positive lesion. SPECT/CT was performed for the region with abnormal uptake in the WBS. WBS and SPECT/CT were evaluated visually. Metastases were diagnosed based on the results of the radio-iodine scan along with the results of other radiological examinations and serological tests. RESULTS: Based on the WBS images, 13 were suspected with cervical lymph node (LN) metastases in 16 patients with abnormal neck uptake, and in the 11 patients with abnormal extra-cervical uptakes, extra-cervical metastases were doubtful in all. After SPECT/CT was performed, the diagnostic results were altered for 16 patients (62%). SPECT/CT revealed that only 5 patients had cervical LN metastases, while 3 patients had extra-cervical (mediastinal) LN metastases. Overall, there was a 58% (15/26) change in diagnoses and plans for treatment due to SPECT/CT. Among 8 patients suspected with metastases on SPECT/CT, 6 patients underwent another radio-iodine therapy. In 96% (24/25) of the patients, the results of SPECT/CT corresponded with those of further radiological examinations and with other clinical information. CONCLUSION: Radio-iodine SPECT/CT images permitted the differentiation of abnormal radio-iodine uptake and improved anatomical interpretation in DTC.

Quantitative Assessment of the Radiation Exposure during Pathologic Process in the Sentinel Lymph Node Biopsy using Radioactive Colloid / 핵의학분자영상

PURPOSE: Sentinel lymph node biopsy became the standard procedure in early breast cancer surgery. Faculty members might be exposed to a trace amount of radiation. The aim of this study is to quantify the radiation exposure and verify the safety of the procedure and the facilities, especially during pathologic process. MATERIALS AND METHODS: Sentinel lymph node biopsies with Tc-99m human serum albumin were performed as routine clinical work. Exposed radiation doses were measured in pathologic technologist, nuclear medicine technologist, and nuclear medicine physician using a thermoluminescence dosimeter (TLD) during one month. We also measured the residual radioactivities or absorbed dose rates, the exposure distance and time during procedure, the radiation dose of the waste and the ambient equivalent dose of the pathology laboratory. RESULTS: Actual exposed doses were 0.21 and 0.85 (uSv/study) for the whole body and hand of pathology technologist after 47 sentinel node pathologic preparations were performed. Whole body exposed doses of nuclear medicine physician and technologist were 0.2 and 2.3 (uSv/study). According to this data and the exposure threshold of the general population (1 mSv), at least 1100 studies were allowed in pathology technologist. The calculated exposed dose rates (micro Sv/study) from residual radioactivities data were 2.47/ 22.4 micro Sv (whole body/ hand) for the surgeon; 0.22/ 0 micro Sv for operation nurse. The ambient equivalent dose of the pathology laboratory was 0.02-0.03 mR/hr. The radiation dose of the waste was less than 100 Bq/g and nearly was not detected. CONCLUSION: Pathologic procedure relating sentinel lymph node biopsy using radioactive colloid is safe in terms of the radiation safety.

Comparison of the Results for Sentinel Lymph Node Mapping in the Breast Cancer Patients using 99mTc-Antimony Trisulfide Colloid, 99mTc-Tin Colloid, and 99mTc-Human Serum Albumin / 핵의학분자영상

PURPOSE: In the breast cancer patient, lymphatic mapping and sentinel lymph node biopsy are the most important procedure for axillary lymph node staging. We aimed to compare the three radiocolloids [99mTc-antimony trisulfide colloid (ASC), 99mTc-tin colloid (TC), and 99mTc-human serum albumin (HSA)] for sentinel lymph node mapping. SUBJECTS AND METHODS: Totally, 397 patients with clinically N0 stage were enrolled. 99mTc-ASC was injected in 202 out of 397 patients, 99mTc-TC was injected in 120 patients, and 99mTc-HSA was injected in the remaining 75 patients. The sentinel lymph nodes were localized by lymphoscintigraphy and selected using intraoperative gamma probe. All sentinel lymph nodes were investigated by intraoperative pathologic consultation. The axillary lymph nodes which were harvested by the lymph node dissection were also investigated. RESULTS: The patients of each group showed similar clinical characteristics. There were no significant differences (p>0.05) in the identification rate of sentinel lymph nodes (IR), false negative rate (FNR), and negative predictive value (NPV). The axillary lymphadenectomy revealed axillary lymph node metastases in those three groups (ASC-33.2%, TC-31.7%, HSA-22.7%). The IR, FNR, and NPV were not significantly different among those groups. CONCLUSION: Those three 99mTc-labeled radiocolloids showed equivalent results in sentinel lymph node mapping of breast cancer.

Diagnostic Accuracy of 18F-FDG Positron Emission Tomography for Evaluation of Hepatocellular Carcinoma / 대한간학회지

tients were found to have HCC on follow-up. Thus, the sensitivity and specificity of 18F-FDG-PET were 65.5% and 33.3% respectively. The positive predictive value was 90.5%. The diagnostic accuracy was 62.5%. CONCLUSION: 18F-FDG-PET showed a low accuracy in diagnosis of HCC. Therefore, 18F-FDG-PET has a limited role in a staging and detection of occult HCC.

Simple Pulmonary Eosinophilia Evaluated by Means of FDG PET: the Findings of 14 Cases

OBJECTIVE: We wanted to describe the findings of simple pulmonary eosinophilia with using 18 fluorodeoxyglucose (FDG) positron emission tomography (PET). MATERIALS AND METHODS: We analysed the findings of 14 patients who underwent thoracic computed tomography (CT) and PET, and then they were subsequently proven to have simple pulmonary eosinophilia. PET studies were performed in four patients with malignancy to evaluate for cancer metastasis, and PET scans were also done in 10 healthy subjects who underwent volunteer cancer screening. The PET scans were evaluated by using the maximum standardized uptake values (SUVs). The subjects' CT findings also were reviewed and correlated with the PET findings. RESULTS: A total of 42 nodules were detected on the CT scans. There were single nodules in three patients and multiple nodules in 11 patients (mean number of nodules: 3, range: 1-10, mean diameter: 9.5 mm+/-4.7). Twelve of 42 (28.6%) nodules showed FDG uptake and their mean maximum SUV was 2.5+/-1.6 (range: 0.6-5.3). Five of six solid nodules showed FDG uptake (2.2+/-1.1, range: 0.9-3.6), six of 11 semisolid nodules showed FDG uptake (3.1+/-1.8, range: 0.6-5.3) and one of 25 pure ground-glass opacity nodule showed a maximum SUV of 0.8. The maximum SUVs of seven nodules in five patients were greater than 2.5. The maximum SUVs were significantly different according to the nodule types (p < 0.001). CONCLUSION: Simple pulmonary eosinophilia commonly causes an increase in FDG uptake. Therefore, correlation of the PET findings with the CT findings or the peripheral eosinophil counts can help physicians arrive at the correct diagnosis of simple pulmonary eosinophilia.

Automatic Interpretation of F-18-FDG Brain PET Using Artificial Neural Network: Discrimination of Medial and Lateral Temporal Lobe Epilepsy / 대한핵의학회잡지

PURPOSE: We developed a computer-aided classifier using artificial neural network (ANN) to discriminate the cerebral metabolic pattern of medial and lateral temporal lobe epilepsy (TLE). Materials and METHODS: We studied brain F-18-FDG PET images of 113 epilepsy patients sugically and pathologically proven as medial TLE (left 41, right 42) or lateral TLE (left 14, right 16). PET images were spatially transformed onto a standard template and normalized to the mean counts of cortical regions. Asymmetry indices for predefined 17 mirrored regions to hemispheric midline and those for medial and lateral temporal lobes were used as input features for ANN. ANN classifier was composed of 3 independent multi-layered perceptrons (1 for left/right lateralization and 2 for medial/lateral discrimination) and trained to interpret metabolic patterns and produce one of 4 diagnoses (L/R medial TLE or L/R lateral TLE). Randomly selected 8 images from each group were used to train the ANN classifier and remaining 81 images were used as test sets. The accuracy of the diagnosis with ANN was estimated by averaging the agreement rates of independent 50 trials and compared to that of nuclear medicine experts. RESULTS: The accuracy in lateralization was 89% by the human experts and 90% by the ANN classifier. Overall accuracy in localization of epileptogenic zones by the ANN classifier was 69%, which was comparable to that by the human experts (72%). CONCLUSION: We conclude that ANN classifier performed as well as human experts and could be potentially useful supporting tool for the differential diagnosis of TLE.

Preparation and Biodistribution of Re-188-Sulfur Colloid Suspension in Lipiodol / 대한핵의학회잡지

PURPOSE: Lipiodol is used for targeting liver cancers by administrating through the hepatic artery. In the present study, feasibility of Re-188-sulfur colloid suspension in lipiodol as a liver cancer targeting agent was investigated. MATERIALS AND METHODS: Re-188-sulfur colloid was prepared, harvested by centrifugation, washed with organic solvent and then suspended into lipiodol. Biodistribution of Re-188-sulfur colloid in normal saline and its suspension in lipiodol in mice after 1 hr of injection through the tail vein were investigated. Biodistribution and autoradiography of tumor-bearing liver was acquired after 5 min post-injection into left ventricle of the tumor-inoculated rats. RESULTS: After 1 hr of injection with Re-188-sulfur colloid suspensiob in lipiodol through the tail vein in normal mice (n=3), the uptakes in the liver and lung were 5.2+/-0.7 and 91.0+/-1.7% ID/organ, respectively. After 5 min of injection with Re-188-sulfur colloid suspention in lipiodol through the left ventricle in the tumor-inoculated rats (n=4), uptakes in the normal liver, hepatoma, and lung were 0.41+/-0.28, 1.88+/-1.57, and 1.65+/-1.54% ID/organ, respectively. And autoradiography of hepatoma showed increased uptake than normal liver tissues. CONCLUSION: Re-188-sulfur colloid suspension in lipiodol injected through the artery shows higher uptake in the hepatoma than normal liver tissue that indicates the feasibility as a new radiopharmaceutical for therapy of hepatoma.

Mitral Valve Reconstruction in Mitral Insufficiency: Intermediate-Term Results / 대한흉부외과학회지

BACKGROUND: The advantages of mitral valve reconstruction have been well established and so mitral valve reconstruction is now considered as the procedure of choice to correct mitral vlave disease. This is the report of intermediate-term results of 38 cases that performed mitral valve reconstruction for valve insufficiency(the total number of mitral valve reconstruction were 49 cases, but 11 cases that performed mitral valve replacement due to incomplete reconstruction were excluded). MATERIAL AND METHOD: From March 1991 to March 2001, 38 patients underwent mitral vlave repair due to mitral valve regurgitation with or without stenosis. Mean age was 47.6+/-14.7 years(range 15 to 70 years) : 11 were men and 27 were women. The causes of mitral valve regurgitation were degenerative in 14, rheumatic in 21, infective in 2 and the other was congenital. RESULT: According to the Carpentier's pathologic classification of mitral valve regurgitation, 3 were type I, 16 were type II and 19 were type III. Surgical procedures were annuloplasty 15, commissurotomy 19, leaflet resection and annular plication 9, chordae shortening 11, chordae transfer 5, new chordae formation 2, papillary muscle splitting 2 and vegetectomy 2. These procedures were combined in most patients. There were 2 early death and the causes of death were respiratory failure, renal failure and sepsis. There was no late death. Valve replacement was done in 6 patients after repair due to valve insufficiency or stenosis 3 weeks, 1,3,51,69,84months later respectively. These patients have been followed up from 1 to 116 months(mean 43.0 months). The mean functional class(NYHA) was 2.36 pre-operatively and improved to 1.70. CONCLUSION: In most cases of mitral valve regurgitation, mitral valve reconstruction when technically feasible is effective operation that can achieve stable functional results and low surgical and late mortality.

Reproducibility of non-invasive measurement for left ventricular contractility using gated myocardial SPECT / 대한핵의학회잡지

No abstract available.

Crossed Cerebellar Hyperperfusion on Ictal Tc-99m HMPAO Brain SPECT: Clinical Significance for Differentiation of Mesial or Lateral Temporal Lobe Epilepsy and Related Factors for Development / 대한핵의학회잡지

PURPOSE: The aim of this study was to determine whether crossed cerebellar hyperperfusion (CCH) was helpful in discriminating mesial from lateral temporal lobe epilepsy (TLE) and what other factors were related in the development of CCH on ictal brain SPECT. MATERALS AND METHODS: We conducted retrospective analysis in 59 patients with TLE (M:41, F:18; 27.4+/-7.8 years old; mesial TLE: 51, lateral TLE: 8), which was confirmed by invasive EEG and surgical outcome (Engel class I , II). All the patients underwent ictal Tc-99m HMPAO brain SPECT and their injection time from ictal EEG onset on video EEG monitoring ranged from 11 sec to 75 sec (32.6+/-19.5 sec) in 39 patients. Multiple factors including age, TLE subtype (mesial TLE or lateral TLE), propagation pattern (hyperperfusion localized to temporal lobes, spread to adjacent lobes or contralateral hemisphere) and injection time were evaluated for their relationship with CCH using multiple logistic regression analysis RESULTS: CCH was observed in 18 among 59 patients. CCH developed in 29% (15/51) of mesial TLE patients and 38% (3/8) of lateral TLE patients. CCH was associated with propagation pattern; no CCH (0/13) in patients with hyperperfusion localized to temporal lobe, 30% (7/23) in patients with propagation to adjacent lobes, 48% (11/23) to contralateral hemisphere. Multiple logistic regression analysis revealed that propagation pattern (p=0.01) and age (p=0.02) were related to the development of CCH. CONCLUSION: Crossed cerebellar hyperperfusio ictal brain SPECT did not help differentiate mesial from lateral temporal lobe epilepsy. Crossed cerebellar hyperperfusion was associated with propagation pattern of temporal lobe epilepsy and age.

Quantification of Cerebrovascular Reserve Using Tc-99m HMPAO Brain SPECT and Lassen's Algorithm / 대한핵의학회잡지

PURPOSE: For quantitative estimation of cerebrovascular reserve (CVR), we estimated the cerebral blood flow (CBF) using Lassen's nonlinearity correction algorithm and Tc-99m HMPAO brain SPECT images acquired with consecutive acquisition protocol. Using the values of CBF in basal and acetazolamide (ACZ) stress states, CBF increase was calculated. MATERALS AND METHODS: In 9 normal subjects (age: 72+/-4 years), brain SPECT was performed at basal and ACZ stress states consecutively after injection of 555 MBq and 1,110 MBq of Tc-99m HMPAO, respectively. Cerebellum was automatically extracted as reference region on basal SPECT image using threshold method. Assuming basal CBF of cerebellum as 55 ml/100 g/min, CBF was calculated for every pixel at basal states using Lassen's algorithm. Cerebellar blood flow at stress was estimated comparing counts of cerebellum at rest and ACZ stress and Lassen's algorithm. CBF of every pixel at ACZ stress state was calculated using Lassen's algorithm and ACZ cerebellar count. CVR was calculated by subtracting basal CBF from ACZ stress CBF for every pixel. The percent CVR was calculated by dividing CVR by basal CBF. The CBF and percentage CVR parametric images were generated. RESULTS: The CBF and percentage CVR parametric images were obtained successfully in all the subjects. Global mean CBF were 49.6+/-5.5 ml/100g/min and 64.4+/-10.2 ml/100g/min at basal and ACZ stress states, respectively. The increase of CBF at ACZ stress state was 14.7+/-9.6 ml/100g/min. The global mean percent CVR was 30.7% and was higher than the 13.8% calculated using count images. CONCLUSION: The blood flow at basal and ACZ stress states and cerebrovascular reserve were estimated using basal/ACZ Tc-99m-HMPAO SPECT images and Lassen's algorithm. Using these values, parametric images for blood flow and cerebrovascular reserve were generated.

Results of Radioiodine Treatment for Distant Metastases of Differentiated Thyroid Carcinoma / 대한핵의학회잡지

PURPOSE: To evaluate the effectiveness of radioiodine treatment for metastatic thyroid carcinoma, we reviewed results of radioactive iodine treatment in patients with functional lung or bone metastases. MATERIALS ANF METHODS: Of 760 patients who were treated for differentiated thyroid cancer between 1984 and 1998, we detected pulmonary metastases and bone metastases in 76 patients (10.0%) and 20 patients (2.6%), respectively. Among them, we could evaluate the effectiveness of I-131 therapy in 53 patients with lung metastases and 15 patients with bone metastases. RESULTS:Of 53 patients who received I-131 therapy with a mean cumulative dose of 26.2 GBq (1.1-84.4 GBq) for pulmonary metastases, metastatic lung lesions completely resolved in 19 patients (35.8%) and improved in 22 patients (41.5%). In 13 of 19 patients with complete remission of pulmonary metastases, the total accumulated dose of I-131 was less than 18.5 GBq. We found 43 sites of metastatic bone lesions in 15 patients with bone metastases. Of 29 lesions which received I-131 therapy, metastatic lesions improved in 14 sites (48.3%), but did not change or progress in 15 sites (51.7%) despite the I-131 therapy. Three lesions were completely cured with a combination treatment of surgery(+/- external radiotherapy) and I-131 therapy, and the other 11 lesions improved. CONCLUSION: Radioactive iodine treatment gives favorable results for pulmonary metastases. However, for bone metastases, there might be a need to use combination therapy including I-131 and surgery or external irradiation.