Joo Hyun O

Johns Hopkins University, Baltimore, Maryland, United States

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Publications (27)53.17 Total impact

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    ABSTRACT: To review the F-18 FDG PET/CT findings of metastatic ovarian tumors and to determine any correlation between FDG uptake by metastatic ovarian tumors and that by the primary tumors. PET/CT performed from June 2005 to March 2011 on patients with metastatic ovarian tumors of gastrointestinal tract origin malignancies was analyzed retrospectively. The SUVmax of metastatic ovarian tumors and primary tumors, when available, was measured. Thirty-two patients were included. Of the 32 cases, 20 had metastatic tumors in bilateral ovaries and 12 had in a single ovary. The mean SUVmax of the 52 total lesions was 4.1 ± 3.1 (range 1.2-13.3), and 46 lesions showed a heterogeneous FDG uptake pattern. In 22 cases with available primary tumor SUVmax values, there was a moderate positive correlation with the SUVmax of the corresponding metastatic tumors (r = 0.559, p = 0.007). There was no significant correlation between the size and SUVmax of metastatic ovarian tumors (p = 0.128). The mean SUVmax of metastatic ovarian tumors from colorectal cancers was significantly higher than that of stomach cancers (p = 0.039). Metastatic ovarian tumors showed FDG uptake of variable intensity, depending on the primary tumor type. The FDG uptake pattern was heterogeneous by PET imaging in vast majority of the cases. When the primary tumor demonstrates a low FDG uptake, careful evaluation is necessary since the metastatic ovarian tumors may also show low FDG uptake.
    Journal of Cancer Research and Clinical Oncology 05/2015; DOI:10.1007/s00432-015-1978-2 · 3.01 Impact Factor
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    ABSTRACT: The purpose of this study was to develop a noninvasive imaging test of pancreatic exocrine function. Methods: In this pilot study, 5 healthy volunteers underwent two 60-min dynamic C-11-acetate PET studies, one before and one after intravenous secretin administration. Kinetic analysis of the pancreas was performed using a 1-compartment model and an image-derived input function. From summed images, standardized uptake values were measured from the pancreas and the liver, and the pancreas-to-liver ratio was computed. Results: The baseline k(1) and k(2) data for all 5 volunteers were consistent. After secretin stimulation, the k(1) and k(2) significantly increased (paired t test P = 0.046 and P = 0.023, respectively). In the summed PET images, the pancreas-to-liver ratio decreased (P = 0.037). Increased C-11-acetate activity was observed in the duodenum after secretin stimulation consistent with secretin-induced secretion. Conclusion: C-11-acetate PET studies with secretin stimulation show potential as a noninvasive method for assessing pancreatic exocrine function.
    Journal of Nuclear Medicine 05/2014; 55(7). DOI:10.2967/jnumed.113.135681 · 5.56 Impact Factor
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    ABSTRACT: PURPOSE Assessment of tumor response to therapy by FDG PET/CT image sets from various time points can be often tedious and time consuming, especially in complex patients with multiple lesions or subtle changes. We developed and applied an integrated color-coded PET/CT image visualization workflow incorporating the tumor uptake at two time points to allow the reader to efficiently and accurately assess the relative PET tumor response to therapy. METHOD AND MATERIALS Using MIM 5 imaging software (MIM Software TM), we analyzed FDG PET/CT image sets from two time points for 6 melanoma and 6 lymphoma cases. With technical support from MIM, we created a workflow that deformed the baseline PET and CT to the follow-up images. The SUV in each voxel of the deformed baseline PET was substracted from each voxel’s SUV in the follow-up PET. Each PET voxel was assigned a color based on its subtraction value, and the colored images were fused with the follow-up CT image set to create an anatomical view of the relative SUV changes. The colors corresponding to each subtraction value were based on a 20-color scale for positive and negative absolute and percent SUV change from baseline to follow-up. Two readers with third reader adjudication reviewed all 12 cases to determine if the response of the lesions with the greatest SUV values from baseline (max of 2 per organ) were accurately depicted by the color scale by comparing it to traditional gray-scale PET/CT visualization and ROI SUV values. RESULTS The number of lesions analyzed per patient ranged from 1 to 5 for each based on the state of the patient’s disease. The readers found that integrated PET/CT color scale images accurately depicted the approximate SUV changes for 26 of the 28 index lesions. The less clear color scale representations occurred because of small errors in the deformable registration in a lung nodule and with development of tumor necrosis. CONCLUSION The integrated color scale PET/CT tumor response image sets provides an efficient and reliable method of determining the approximate tumor SUV changes associated with disease progression or treatment response for the major index lesions in our pilot study of metastatic melanoma or lymphoma patients. CLINICAL RELEVANCE/APPLICATION Integrated color scale PET/CT representation can be a helpful aid to quickly judge and approximately quantify tumor response to therapy, especially in cases difficult to assess by current methods.
    Radiological Society of North America 2013 Scientific Assembly and Annual Meeting; 12/2013
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    ABSTRACT: PURPOSE To determine how well the different PET metrics in PET response criteria in solid tumor (PERCIST) correlate to each other for measuring fractional change before and after radioimmunotherapy. METHOD AND MATERIALS Patients with refractory or relapsed non-Hodgkin's lymphoma received Bexxar (n=35) or Zevalin (n=14) therapy. FDG PET/CT studies were obtained before the radioimmunotherapy and 12 weeks after single dose of radioimmunotherapy. Three different PERCIST metrics were measured from the baseline and the post therapy FDG PET studies: 1.) the peak standard uptake value corrected for lean body mass (SULpeak) of the single hottest tumor, 2.) the sum of up to the 5 hottest SULpeaks, and 3.) the total lesion glycolysis (TLG) of the entire tumor burden. The three PET metrics represent measurement of a single, up to the 5 hottest lesions, or the entire tumor burden. The fractional change for each PET metric was computed. (Percent change=[baseline measurement - follow-up measurement] ÷ baseline measurement.) RESULTS For patients treated with Bexxar, the percent change in a single SULpeak correlated with the change of up to 5 SULpeaks (r=0.932, p<0.001), and TLG (r=0.747, p<0.001). For patients treated with Zevalin, the correlation between percent change in a single SULpeak and up to 5 SULpeaks was (r=0.971, p<0.001), and with TLG was (r=0.807, p<0.001). CONCLUSION Tracking the single hottest SULpeak before and after radioimmunotherapy shows high correlation with both the analysis of up to the 5 hottest lesions and the entire tumor TLG, both for Bexxar and Zevalin. CLINICAL RELEVANCE/APPLICATION Measuring just the one hottest SULpeak may adequately represent the entire tumor burden, saving the time and effort that goes into measuring multiple lesions.
    Radiological Society of North America 2013 Scientific Assembly and Annual Meeting; 12/2013
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    ABSTRACT: We evaluated whether the maximum standardized uptake values (SUVmax) of primary tumor from the initial staging by (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) of patients with breast cancer could identify patients at risk for early recurrence within 2 years, particularly in comparison to the American Joint Committee on Cancer (AJCC) stage.
    12/2013; 47(4):263-267. DOI:10.1007/s13139-013-0232-6
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    ABSTRACT: PURPOSE: The aim of this study was to assess the value of dual-time point PET/CT in the differentiation of extrahepatic cholangiocarcinoma from benign stricture and the added benefits of delayed PET/CT image. PATIENTS AND METHODS: Thirty-nine patients with suspected extrahepatic biliary malignancy based on conventional imaging studies such as ultrasonography, CT, and MRI between July 2008 and December 2010 were included. All patients underwent dual-time point PET/CT scans at 1 and 2 hours after radiotracer injection. From the site of suspected malignancy, the SUVmax for both time points (SUVmax1 and SUVmax2), the percent change in SUVmax between the 2 (Δ%SUVmax) and the ratio of SUVmax1, SUVmax2, Δ%SUVmax in comparison with average SUV of right hepatic lobe (T/L ratio1, T/L ratio2, and Δ%T/L ratio) were generated. Diagnostic performances using visual assessment and various SUVmax cutoff values were analyzed in the differential diagnosis of extrahepatic cholangiocarcinoma from benign disease. PET/CT results were correlated with histological results and radiological follow-up for at least 6 months. RESULTS: Of 39 patients, the final diagnosis was cholangiocarcinoma in 34 and benign disease in 5. Between malignant and benign lesions, there were significant differences in SUVmax1 (5.43 ± 4.66 vs 2.26 ± 0.83, P = 0.003) and SUVmax2 (6.02 ± 5.26 vs 2.26 ± 0.76, P = 0.002). There was no significant difference in Δ%SUVmax, T/L ratio1, T/L ratio2, and Δ%T/L ratio. On receiver operator curve analysis, SUVmax1 with cutoff value of 2.5 demonstrated sensitivity of 97.6%, specificity of 60.0%, and accuracy of 92.3% and SUVmax2 with cutoff value of 3.1 demonstrated sensitivity of 88.2%, specificity of 100%, and accuracy of 89.7%. CONCLUSION: SUVmax from both early and delayed PET/CT scans are useful parameters in the differentiation of extrahepatic biliary malignancy from benign disease. However, there was no added benefit of delayed PET/CT in patients suspicious for extrahepatic cholangiocarcinoma.
    Clinical nuclear medicine 01/2013; DOI:10.1097/RLU.0b013e318266f402 · 2.86 Impact Factor
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    ABSTRACT: PURPOSE PET response criteria in solid tumors (PERCIST) 1.0 does not require the tumor for assessment be from the same tumor or tumor region as baseline, but requires measurement of the hottest tumor focus on each study. We examined how often the hottest tumor focus is different in location or intra-tumoral region in early follow-up FDG PET images compared to baseline. METHOD AND MATERIALS From the sarcoma alliance for research collaboration (SARC11) trial, FDG PET images obtained at baseline and 2 weeks after anti-insulin-like growth factor antibody treatment in an explanatory subset of 30 patients were evaluated by PERCIST 1.0. The site of the highest FDG uptake tumor, the intra-tumoral location of the hottest focus within the same tumor lesion (in clockwise direction or quadrant), the highest peak standard uptake value corrected for lean body mass (SULpeak) in 1 cc sphere, maximal tumor SUL (SULmax), and the relationship of SULmax voxel to SULpeak sphere were studied. RESULTS The tumor containing the highest SULpeak or SULmax changed from baseline in 8 cases. Among 22 cases with the same hottest tumor on follow-up, 6 showed change in intra-tumoral location of the hottest focus. The SULpeak sphere did not contain the SULmax in 4 out of 30 cases at baseline, and in 5 cases at follow-up. CONCLUSION The hottest tumor changed from baseline to early follow-up on FDG PET images in 27%, and the intra-tumoral location differed in 20% of the sarcoma cases. In about 15%, the SULmax voxel was not contained in the SULpeak volume of interest. CLINICAL RELEVANCE/APPLICATION It is not uncommon for the hottest tumor to differ in location at baseline and follow-up PET studies early in treatment.
    Radiological Society of North America 2012 Scientific Assembly and Annual Meeting; 11/2012
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    ABSTRACT: BACKGROUND: Standard follow up for bone recurrence has not yet been established for gastric cancer after surgical resection. The aim of this study was to investigate the incidence of and related risk factors for bone recurrence after surgical resection of gastric cancer. METHODS: A cohort of 3035 gastric cancer patients after curative resection was reviewed. We analyzed the patients who had bone scintigraphy before the surgery as well as during the follow-up period. The incidence of and the risk factors for bone recurrence after surgical resection of gastric cancer were investigated. RESULTS: In a total of 1683 patients analyzed, bone recurrence was detected in 30 patients (1.8 %). The incidence of bone recurrence was significantly higher in advanced gastric cancers than in early lesions (3.5 vs. 0.4 %, p < 0.01). The most common recurrence site was the spine, followed by pelvic bone and rib. Most patients had multiple bone metastases. The median time for recurrence was 28 months (range 4-111) from the surgery. In univariate analysis, the recurrence rate was higher in the tumors with large size, undifferentiated pathology, location in the body, and advanced stage. In multivariate analysis, lymph node metastasis (N2/N3 vs. N0/N0I) was the most predictable risk factor for bone recurrence [hazard ratio [HR] 1.44 (95% confidence interval [CI] 1.217-1.694)] and depth of invasion (T2-4 vs. T1) was also independently associated with bone recurrence. CONCLUSIONS: The incidence of bone recurrence was low after curative surgery in patients with gastric cancer. Intensive follow up with bone scintigraphy seems to be unnecessary in these patients.
    Gastric Cancer 09/2012; 16(3). DOI:10.1007/s10120-012-0193-y · 4.83 Impact Factor
  • Gastrointestinal endoscopy 09/2012; 76(5):1047-8. DOI:10.1016/j.gie.2012.07.011 · 4.90 Impact Factor
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    ABSTRACT: Purpose To assess the value of PET/CT for detecting local or distant recurrence in patients who undergo surgery for colorectal cancer (CRC) and to compare the accuracy of PET/CT to that of conventional imaging studies (CIS). Methods Tumor surveillance PET/CT scans done between March 2005 and December 2009 of disease-free patients after surgery with or without adjuvant chemotherapy for CRC were retrospectively studied. CIS (serial enhanced CT from lung base to pelvis and plain chest radiograph) were performed within 1 month of PET/CT. We excluded patients with distant metastasis on initial staging, a known recurrent tumor, and a lack of follow-up imaging. The final diagnosis was based on at least 6 months of follow-up with colonoscopy, biopsy, and serial imaging studies in combination with carcinoembryonic antigen levels. Results A total of 262 PET/CT scans of 245 patients were included. Local and distant recurrences were detected in 27 cases (10.3%). On case-based analysis, the overall sensitivity, specificity, and accuracy were 100, 97.0, and 97.3% for PET/CT and 85.1, 97.0, and 95.8% for CIS, respectively. On lesion-based analysis, PET/CT detected more lesions compared to CIS in local recurrence and lung metastasis. PET/CT and CIS detected the same number of lesions in abdominal lymph nodes, hepatic metastasis, and peritoneal carcinomatosis. PET/CT detected two more metachronous tumors than did CIS in the lung and thyroid gland. Conclusion PET/CT detected more recurrences in patients who underwent surgery for CRC than did CIS and had the additional advantage of evaluating the entire body during a single scan.
    09/2012; 46(3). DOI:10.1007/s13139-012-0145-9
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    ABSTRACT: We assessed the ability of positron emission tomography-computed tomography (PET/CT) to detect synchronous colonic pathology and determined the significance of 18F-fluorodeoxyglucose ((18)F-FDG) activity in the colon of gastric cancer patients. A total of 239 gastric cancer patients who underwent PET/CT and colonoscopy preoperatively were included. FDG uptake patterns on PET/CT were classified as (1) group A, focal; (2) group B, diffuse; and (3) group C, no uptake. The PET/CT findings were compared with the results of concurrent colonoscopy. In group A, a total of 123 polyps of >0 mm were observed. Of these, nine polyps were colonic adenocarcinomas and six were high-grade dysplasia. The incidence of colonic adenocarcinomas was significantly higher in group A than in the other two groups (p = 0.037). There was a significant correlation between SUVmax values and incidence of colonic polyps of >10 mm (r = 0.471, p = 0.04). The distribution pattern of SUVmax in polyps with adenoma (>10 mm) was less homogenous than in polyps (>10 mm) with adenocarcinoma. The focal colonic FDG uptake in PET/CT requires colonoscopic confirmation. The suspicion of colonic malignancy increased in the presence of polyps >10 mm that showed a positive correlation with the SUVmax.
    Journal of Gastrointestinal Surgery 06/2012; 16(10):1847-53. DOI:10.1007/s11605-012-1941-3 · 2.39 Impact Factor
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    ABSTRACT: Purpose To decrease the risk of recurrence or metastasis in differentiated thyroid cancer (DTC), selected patients receive radioactive iodine ablation of remnant thyroid tissue or tumor. A low iodine diet can enhance uptake of radioactive iodine. We compared the success rates of radioactive iodine ablation therapy in patients who followed two different low iodine diets (LIDs). Materials and Methods The success rates of postsurgical radioactive iodine ablation in DTC patients receiving empiric doses of 150 mCi were retrospectively reviewed. First-time radioactive iodine ablation therapy was done in 71 patients following less strict LID and 90 patients following very strict LID. Less strict LID restricted seafood, iodized salt, egg yolk, dairy products, processed meat, instant prepared meals, and multi-vitamins. Very strict LID additionally restricted rice, freshwater fish, spinach, and soybean products. Radioactive iodine ablation therapy was considered successful when follow-up 123I whole body scan was negative and stimulated serum thyroglobulin level was less than 2.0 ng/mL. Results The success rate of patients following less strict LID was 80.3% and for very strict LID 75.6%. There was no statistically significant difference in the success rates between the two LID groups (p = 0.48). Conclusions Very strict LID may not contribute to improving the success rate of initial radioactive iodine ablation therapy at the cost of great inconvenience to the patient.
    03/2012; 46(1). DOI:10.1007/s13139-011-0111-y
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    ABSTRACT: Positron emission tomography/computed tomography (PET/CT) scan has a role in the surveillance of patients with a history of thyroid carcinoma. Its efficacy after remnant ablation as far as detecting persistent or recurrent thyroid carcinoma before other surveillance methods is not known, however. In intermediate-to-high risk thyroid carcinoma patients we studied whether PET/CT scan, performed 6-12 months after the first remnant ablation, could provide more information than ultrasonography (US) and thyrotropin-stimulated serum thyroglobulin (Tg) determination with diagnostic whole-body scan (DxWBS). We studied 71 subjects with differentiated thyroid cancer (DTC) who were intermediate-to-high risk for persistent/recurrent disease and who had received PET/CT scan, US, and DxWBS simultaneously with stimulated Tg levels 6-12 months after remnant ablation. To evaluate the diagnostic efficacy of PET/CT scan, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy were calculated. Ten subjects (14%) had persistent/recurrent disease detected 6-12 months after remnant ablation. Persistence/recurrence was detected in nine (12.7%) of these patients by conventional methods, including US and DxWBS, along with stimulated Tg levels. The remaining case was detected solely by a PET/CT scan, which showed a mediastinal prevascular lesion; this was confirmed by a therapeutic WBS after additional radioiodine therapy. Among the six patients whose PET/CT scan showed positive results, five had persistent/recurrent disease. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of PET/CT scan for detecting persistent/recurrent thyroid carcinoma were 50%, 98.4%, 83.3%, 92.3%, and 91.5%, respectively. In intermediate-to-high risk patients with DTC seen 6-12 months after their first remnant ablation, there is almost no complementary role for adding a PET/CT scan to conventional follow-up methods, an US and a DxWBS simultaneously with stimulated Tg levels.
    Thyroid: official journal of the American Thyroid Association 02/2012; 22(2):157-64. DOI:10.1089/thy.2011.0177 · 3.84 Impact Factor
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    ABSTRACT: To evaluate the diagnostic accuracy of (18)F-FDG PET/CT in detection of recurrent differentiated thyroid cancer (DTC) in patients with elevated stimulated thyroglobulin (Tg) or anti-Tg antibody (Ab) levels, and negative (131)I whole body scan according to the Tg level. PET/CT images of well DTC patients who had total thyroidectomy and radioiodine ablation were included. Patients showing elevated Tg titer (≥2.0 ng/ml after TSH stimulation) or elevated anti-Tg titer (≥70.0 IU/ml) while diagnostic radioiodine scan was negative were enrolled. PET/CT was classified as positive or negative on the basis of visual interpretation. The maximum standard uptake values (SUVmax) of the suspected lesions on PET/CT were also recorded. The PET/CT findings were compared with histological or clinical follow-up results based on other imaging modalities and serum Tg/anti-Tg Ab titers. The diagnostic performance of PET/CT was compared among 4 subgroups according to the Tg level [2 ng/ml ≤ stimulated Tg (sTg) < 5 ng/ml, 5 ng/ml ≤ sTg < 10 ng/ml, 10 ng/ml ≤ sTg < 20 ng/ml, and ≥20 ng/ml]. A total of 68 PET/CT images from 60 patients were included, and histological confirmations were available in 32 images. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of PET/CT were 69.4, 66.7, 69.1, 95.6, and 17.4%, respectively. There were 3 PET/CT cases with high anti-Tg Ab level, and low (<2 ng/ml) Tg level, and all 3 were positive of recurrence. The mean SUVmax of the suspected lesions on PET/CT was 2.9 ± 4.5 (range 1.3-29.7). The sensitivity of PET/CT according to Tg levels was 28.6% when Tg was between 2 and 5, 57.1% between 5 and 10, 60.0% between 10 and 20, and 85.7% when Tg was equal to or greater than 20 ng/ml sub-groups, respectively. Diagnostic accuracy of FDG PET in radioiodine negative thyroid cancer may vary depending on serum Tg levels at imaging. (18)F-FDG PET/CT is useful in detection and localization of recurrent thyroid cancer in patients with negative diagnostic radioiodine scan despite elevated Tg greater than 20 ng/ml or high anti-Tg Ab titers. In contrast, PET/CT provides little additional information when the Tg is less than 5 ng/ml.
    Annals of Nuclear Medicine 01/2012; 26(1):26-34. DOI:10.1007/s12149-011-0536-5 · 1.51 Impact Factor
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    ABSTRACT: Purpose This study aims to examine the findings of 99mTc-diphosphonate bone scans in cancer patients with a history of HIFU treatment. Methods Bone scan images of patients with a history of HIFU treatment for primary or metastatic cancer from January 2006 to July 2010 were retrospectively reviewed. Cases of primary bone tumor or HIFU treatment reaching only the superficial soft tissue layer were excluded. Results Bone scan images of 62 patients (26 female, 36 male; mean age 57 ± 9 years) were studied. HIFU treatment was performed in the liver (n = 40), pancreas (n = 16), and breast (n = 6). Mean interval time between HIFU treatment and bone scan was 106 ± 105 days (range: 1–572 days). Of 62 scans, 43 showed diffusely decreased uptake of bone within the path of HIFU treatment: antero-axillary and/or posterior arcs of right 5th to 11th ribs in 34 cases after treatment of hepatic lesions; anterior arcs of 2nd to 5th ribs in 5 cases after treatment for breast tumors; and posterior arcs of left 9th to 11th ribs or thoraco-lumbar vertebrae in 4 cases after treatment for pancreas tumor. Of 20 patients who had bone scans more than twice, five showed recovered uptake of the radiotracer in the involved ribs in the follow-up bone scan. Conclusion Of 62 bone scans in patients with a history of HIFU treatment for primary or metastatic cancer, 69% presented diffusely decreased uptake in the bone in the path of HIFU treatment.
    12/2011; 45(4). DOI:10.1007/s13139-011-0102-z
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    ABSTRACT: Currently, there is no consensus on the necessity of repeated radioiodine therapy (RAI) in patients who show iodine uptake in the thyroid bed on a diagnostic whole-body scan (DxWBS) despite undetectable thyroglobulin (Tg) levels after remnant ablation. The present study investigated the clinical outcomes of scan-positive, Tg-negative patients (WBS+Tg-) who did or did not receive additional RAI. We retrospectively reviewed 389 differentiated thyroid carcinoma patients who underwent a total thyroidectomy and received high-dose RAI from January 2003 through December 2005. The patients were classified according to surveillance DxWBS findings and TSH-stimulated Tg levels 6 to 12 months after the initial RAI. Forty-four of the 389 patients (11.3%) showed thyroid bed uptake on a DxWBS despite negative Tg levels (WBS+Tg-). There was no difference in clinical and pathological parameters between WBS+Tg- and WBS-Tg- patients, except for an increased frequency of thyroiditis in the WBS+Tg- group. Among the 44 WBS+Tg- patients, 27 subjects were treated with additional RAI; 25 subjects showed no uptake in subsequent DxWBS. Two patients were evaluated only by ultrasonography (US) and displayed no persistent/recurrent disease. The other 17 patients received no further RAI; Eight patients and two patients showed no uptake and persistent uptake, respectively, on subsequent DxWBS. Six patients presented negative subsequent US findings, and one was lost to follow-up. Over the course of 53.2 ± 10.1 months, recurrence/persistence was suspicious in two patients in the treatment group. There were no remarkable differences in clinical outcomes between observation and treatment groups of WBS+Tg- patients. Observation without repeated RAI may be an alternative management option for WBS+Tg- patients.
    The Korean Journal of Internal Medicine 12/2010; 25(4):408-14. DOI:10.3904/kjim.2010.25.4.408
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    ABSTRACT: To evaluate the clinical significance of incidental focal prostate fluorodeoxyglucose (FDG) uptake, we reviewed 18-F-FDG positron emission tomography (PET)/CT scans from 2003 to 2007 and selected cases with focal FDG uptake in prostate. Cases of known prostate cancer were excluded. The maximum standardised uptake value (SUV(max)), site (central or peripheral) and pattern (discrete or ill-defined) of FDG uptake, calcification (present or absent) and prostate volume (<30 or ≥30 cc) were recorded. The PET/CT findings were correlated with serum prostate-specific antigen (PSA) levels, imaging studies, clinical follow-up and biopsy. Of a total of 5119 cases, 63 (1.2%) demonstrated focal FDG uptake in prostate. Eight cases were lost to follow-up. Among the 55 cases with follow-up, malignancy was confirmed by biopsy in 3 (5.4%). The three malignant cases had SUV(max) values of 3.3, 3.6 and 2.3, and all were noted in the peripheral portion of prostate; two of these cases had a discrete FDG uptake pattern, none had calcification corresponding to the FDG uptake area and one had a prostatic volume greater than 30 cc. The mean SUV(max) of 52 benign cases was 3.2 ± 1.7 and focal FDG uptake was noted in the peripheral portion in 34 (65%), 20 (38%) cases showed a discrete FDG uptake pattern, 35 (67%) were accompanied by calcification and 32 (62%) had a prostatic volume greater than 30 cc. The majority of cases demonstrating focal FDG uptake in prostate were benign and no PET/CT finding could reliably differentiate benign from malignant lesions; however, when discrete focal FDG uptake without coincidental calcification is seen, particularly in the peripheral zone of the prostate, further clinical evaluation is recommended.
    The British journal of radiology 11/2010; 83(995):915-20. DOI:10.1259/bjr/19887771 · 1.53 Impact Factor
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    ABSTRACT: The sensitivity of 18-fluorodeoxyglucose ((18)F-FDG) positron emission tomography (PET) for detecting axillary lymph node (ALN) metastases in breast cancer is reported to be low. Several studies have shown, however, that dual-time-point (18)F-FDG PET imaging provides improved accuracy in the diagnosis of certain primary tumours when compared with single-scan imaging. The purpose of this study was to assess whether the use of dual-time-point (18)F-FDG PET/CT scans could improve the diagnostic accuracy of ALN metastasis in breast cancer. The study included 171 breast cancer patients who underwent pre-operative (18)F-FDG PET/CT scans at 2 time-points, the first at 1 h after radiotracer injection and the second 3 h after injection. Where (18)F-FDG uptake was in the ALN perceptibly increased, the maximum standardised uptake values for both time-points (SUVmax1 and SUVmax2) and the retention index (RI) were calculated. Correlation between the PET/CT results and post-operative histological results was assessed. The performance of 1 h and 3 h PET/CT scans was equal, with sensitivity 60.3% and specificity 84.7%, in detecting ALN metastasis. Out of 171 patients, 60 had ALNs with increased (18)F-FDG uptake on 1 h or 3 h images. There was no significant difference in RI between the metastatic ALN-positive group and the node-negative group. The area under the receiver operating characteristic (ROC) curve for SUVmax1 was 0.90 (p<0.001) and 0.87 for SUVmax2 (p<0.001). Dual time-point imaging did not improve the overall performance of (18)F-FDG PET/CT in detecting ALN metastasis in breast cancer patients.
    The British journal of radiology 11/2010; 84(1003):593-9. DOI:10.1259/bjr/56324742 · 1.53 Impact Factor
  • Clinical nuclear medicine 06/2010; 35(6):473-4. DOI:10.1097/RLU.0b013e3181db4dc9 · 2.86 Impact Factor
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    ABSTRACT: We describe 3 cases of fat necrosis with increased FDG uptake in patients with breast cancer who underwent mastectomy and then transverse rectus abdominis myocutaneous (TRAM) flap reconstruction. PET/CT performed for restaging showed focal FDG uptake in the reconstructed breast. The FDG uptake corresponded to irregular fibrotic nodular lesions containing fat density or calcification in accompanying CT images. Subsequent ultrasound examination demonstrated ill-defined echogenic lesions with internal hypoechoic components. Fat tissue rich flap used for breast reconstruction may be injured by surgical manipulation. Abnormal FDG uptake in this setting is most likely due to fat necrosis, rather than recurrent tumor.
    Clinical nuclear medicine 04/2010; 35(4):283-5. DOI:10.1097/RLU.0b013e3181d1905a · 2.86 Impact Factor

Publication Stats

135 Citations
53.17 Total Impact Points

Institutions

  • 2014
    • Johns Hopkins University
      Baltimore, Maryland, United States
  • 2007–2012
    • Catholic University of Korea
      • Department of Radiology
      Sŏul, Seoul, South Korea