Change of Therapeutic Response Classification According to Recombinant Human Thyrotropin‑Stimulated Thyroglobulin Measured at Different Time Points in Papillary Thyroid Carcinoma / 대한핵의학회잡지

Purpose@#We investigated whether response classification after total thyroidectomy and radioactive iodine (RAI) therapy could be affected by serum levels of recombinant human thyrotropin (rhTSH)-stimulated thyroglobulin (Tg) measured at different time points in a follow-up of patients with papillary thyroid carcinoma (PTC). @*Methods@#A total of 147 PTC patients underwent serum Tg measurement for response assessment 6 to 24 months after the first RAI therapy. Serum Tg levels were measured at 24 h (D1Tg) and 48–72 h (D2-3Tg) after the 2nd injection of rhTSH. Responses were classified into three categories based on serum Tg corresponding to the excellent response (ER-Tg), indeterminate response (IR-Tg), and biochemical incomplete response (BIR-Tg). The distribution pattern of response classification based on serum Tg at different time points (D1Tg vs. D2-3Tg) was compared. @*Results@#Serum D2-3Tg level was higher than D1Tg level (0.339 ng/mL vs. 0.239 ng/mL, P < 0.001). The distribution of response categories was not significantly different between D1Tg-based and D2-3Tg-based classification. However, 8 of 103 (7.8%) patients and 3 of 40 (7.5%) patients initially categorized as ER-Tg and IR-Tg based on D1Tg, respectively, were reclassified to IR-Tg and BIR-Tg based on D2-3Tg, respectively. The optimal cutoff values of D1Tg for the change of response categories were 0.557 ng/mL (from ER-Tg to IR-Tg) and 6.845 ng/mL (from IR-Tg to BIR-Tg). @*Conclusion@#D1Tg measurement was sufficient to assess the therapeutic response in most patients with low level of D1Tg. Nevertheless, D2-3Tg measurement was still necessary in the patients with D1Tg higher than a certain level as response classification based on D2-3Tg could change.

The clinical meaning of pre- and post-ablation thyroglobulin levels at first radioiodine therapy in patients with papillary thyroid cancer

Background/Aims@#This study was conducted to identify prognostic factors in patients with papillary thyroid cancer (PTC) at the time of first radioactive iodine (RAI) therapy, and to evaluate the clinical value of the thyroglobulin (Tg) increase after RAI. @*Methods@#Serum Tg was sampled prior to (pre-Tg) and 7 days after RAI (post-Tg) in 680 patients with PTC. Patients were classified into excellent response (ER), biochemical incomplete response (BCIR), structural incomplete response (SIR), and indeterminate response (IR) groups using dynamic risk stratification at 6 to 18 months after RAI therapy. @*Results@#After RAI therapy, 514 patients (75.6%) had an ER, 34 (5.0%) had a BCIR, 13 (2.0%) had an SIR, and 119 (17.5%) had an IR. Pre-Tg level was significantly different among the groups, with the highest level being in the SIR group, followed by the BCIR, IR, and ER groups. However, post-Tg levels were not different among the groups. Post-Tg level increased significantly after RAI therapy compared to the pre-Tg level (mean 13.8 ± 32.2 ng/mL vs. 2.5 ± 8.9 ng/mL). In 422 patients whose pre-Tg level was 10 ng/mL. No difference was observed in the response to therapy. Differences in RAI dose and uptake pattern were observed among the three groups. @*Conclusions@#Pre-Tg was useful as a prognostic factor in patients with PTC. In patients with low pre-Tg, increased post-Tg may reflect remnant tissue and does not help predict the prognosis.

Clinical Impact of F-18 FDG PET-CT on Biopsy Site Selection in Patients with Suspected Bone Metastasis of Unknown Primary Site / 대한핵의학회잡지

Purpose@#We investigated the clinical role of F-18 fluorodeoxyglucose (FDG) positron emission tomography-computed tomography(PET-CT) in the identification of the primary site and the selection of the optimal biopsy site in patients with suspectedbone metastasis of unknown primary site. @*Methods@#The patients with suspected bone metastasis who underwent PET-CT for evaluation of primary site were enrolled inthis study. The primary sites were identified by the histopathologic or imaging studies and were classified according to the FDGuptake positivity of the primary site. To evaluate the guiding capability of PET-CT in biopsy site selection, we statisticallyanalyzed whether the biopsy site could be affected according to the presence of extra-skeletal FDG uptake. @*Results@#Among 74 enrolled patients, 51 patients had a metastatic bone disease. The primary site was identified in 48 of 51patients (94.1%). Forty-six patients were eligible to test the association of clinical choice of biopsy site with PET positivity ofextra-skeletal lesion. The extra-skeletal biopsies were done in 42 out of 43 patients with positive extra-skeletal uptake lesions.Bone biopsies were inevitably performed in the other three patients without extra-skeletal uptake lesions. The association cameout to be significant (Fisher’s exact test, P< 0.001). @*Conclusion@#F-18 FDG PET-CT significantly contributed not only to identify the primary site but also to suggest optimal biopsysites in patients with suspected bone metastasis.

Quantitative Feasibility Evaluation of ¹¹C-Methionine Positron Emission Tomography Images in Gamma Knife Radiosurgery : Phantom-Based Study and Clinical Application

OBJECTIVE: The functional information of ¹¹C-methionine positron emission tomography (MET-PET) images can be applied for Gamma knife radiosurgery (GKR) and its image quality may affect defining the tumor. This study conducted the phantom-based evaluation for geometric accuracy and functional characteristic of diagnostic MET-PET image co-registered with stereotactic image in Leksell GammaPlan® (LGP) and also investigated clinical application of these images in metastatic brain tumors. METHODS: Two types of cylindrical acrylic phantoms fabricated in-house were used for this study : the phantom with an array-shaped axial rod insert and the phantom with different sized tube indicators. The phantoms were mounted on the stereotactic frame and scanned using computed tomography (CT), magnetic resonance imaging (MRI), and PET system. Three-dimensional coordinate values on co-registered MET-PET images were compared with those on stereotactic CT image in LGP. MET uptake values of different sized indicators inside phantom were evaluated. We also evaluated the CT and MRI co-registered stereotactic MET-PET images with MR-enhancing volume and PET-metabolic tumor volume (MTV) in 14 metastatic brain tumors. RESULTS: Imaging distortion of MET-PET was maintained stable at less than approximately 3% on mean value. There was no statistical difference in the geometric accuracy according to co-registered reference stereotactic images. In functional characteristic study for MET-PET image, the indicator on the lateral side of the phantom exhibited higher uptake than that on the medial side. This effect decreased as the size of the object increased. In 14 metastatic tumors, the median matching percentage between MR-enhancing volume and PET-MTV was 36.8% on PET/MR fusion images and 39.9% on PET/CT fusion images. CONCLUSION: The geometric accuracy of the diagnostic MET-PET co-registered with stereotactic MR in LGP is acceptable on phantom-based study. However, the MET-PET images could the limitations in providing exact stereotactic information in clinical study.

Quantitative Feasibility Evaluation of ¹¹C-Methionine Positron Emission Tomography Images in Gamma Knife Radiosurgery : Phantom-Based Study and Clinical Application

OBJECTIVE: The functional information of ¹¹C-methionine positron emission tomography (MET-PET) images can be applied for Gamma knife radiosurgery (GKR) and its image quality may affect defining the tumor. This study conducted the phantom-based evaluation for geometric accuracy and functional characteristic of diagnostic MET-PET image co-registered with stereotactic image in Leksell GammaPlan® (LGP) and also investigated clinical application of these images in metastatic brain tumors.METHODS: Two types of cylindrical acrylic phantoms fabricated in-house were used for this study : the phantom with an array-shaped axial rod insert and the phantom with different sized tube indicators. The phantoms were mounted on the stereotactic frame and scanned using computed tomography (CT), magnetic resonance imaging (MRI), and PET system. Three-dimensional coordinate values on co-registered MET-PET images were compared with those on stereotactic CT image in LGP. MET uptake values of different sized indicators inside phantom were evaluated. We also evaluated the CT and MRI co-registered stereotactic MET-PET images with MR-enhancing volume and PET-metabolic tumor volume (MTV) in 14 metastatic brain tumors.RESULTS: Imaging distortion of MET-PET was maintained stable at less than approximately 3% on mean value. There was no statistical difference in the geometric accuracy according to co-registered reference stereotactic images. In functional characteristic study for MET-PET image, the indicator on the lateral side of the phantom exhibited higher uptake than that on the medial side. This effect decreased as the size of the object increased. In 14 metastatic tumors, the median matching percentage between MR-enhancing volume and PET-MTV was 36.8% on PET/MR fusion images and 39.9% on PET/CT fusion images.CONCLUSION: The geometric accuracy of the diagnostic MET-PET co-registered with stereotactic MR in LGP is acceptable on phantom-based study. However, the MET-PET images could the limitations in providing exact stereotactic information in clinical study.

Response Prediction of Altered Thyroglobulin Levels After Radioactive Iodine Therapy Aided by Recombinant Human Thyrotropin in Patients with Differentiated Thyroid Cancer / 대한핵의학회잡지

PURPOSE@#Thyroglobulin (Tg) may be released from damaged residual thyroid tissues after radioactive iodine (RAI) therapy in patients with differentiated thyroid carcinoma (DTC). We investigated whether altered levels of serum Tg after recombinant human thyrotropin (rhTSH)-aided RAI therapy could be a prognostic marker in patients with DTC.@*METHODS@#We evaluated 68 patients who underwent RAI therapy after total thyroidectomy. Serum Tg levels were measured just before RAI administration (D0Tg) and 7 days after RAI therapy (D7Tg). Patients with a D0Tg level greater than 2.0 ng/mL were excluded to more precisely evaluate the injury effect of RAI in small remnant tissues. The ratioTg was defined as the D7Tg level divided by that on D0Tg. The therapeutic responses were classified as acceptable or non-acceptable. Finally, we investigated which clinicopathologic parameters were associated with therapeutic response.@*RESULTS@#At the follow-up examination, an acceptable response was observed in 50 patients (73.5%). Univariate analysis revealed significant differences in N stage (P = 0.003) and ratioTg (acceptable vs. non-acceptable responses, 21.9 ± 33.6 vs. 3.8 ± 6.5; P = 0.006). In multivariate analysis, only ratioTg significantly predicted an acceptable response (odds ratio 1.104; 95% confidence interval 1.005–1.213; P = 0.040). A ratioTg above 3.5 predicted an acceptable response with a sensitivity of 66.0%, specificity of 83.3%, and accuracy of 70.6% (area under the curve = 0.718; P = 0.006).@*CONCLUSIONS@#Altered levels of serum Tg after RAI therapy, calculated as the ratioTg (D7Tg/D0Tg), significantly predicted an acceptable response in patients with DTC.

Response Prediction of Altered Thyroglobulin Levels After Radioactive Iodine Therapy Aided by Recombinant Human Thyrotropin in Patients with Differentiated Thyroid Cancer / 대한핵의학회잡지

PURPOSE: Thyroglobulin (Tg) may be released from damaged residual thyroid tissues after radioactive iodine (RAI) therapy in patients with differentiated thyroid carcinoma (DTC). We investigated whether altered levels of serum Tg after recombinant human thyrotropin (rhTSH)-aided RAI therapy could be a prognostic marker in patients with DTC.METHODS: We evaluated 68 patients who underwent RAI therapy after total thyroidectomy. Serum Tg levels were measured just before RAI administration (D0Tg) and 7 days after RAI therapy (D7Tg). Patients with a D0Tg level greater than 2.0 ng/mL were excluded to more precisely evaluate the injury effect of RAI in small remnant tissues. The ratioTg was defined as the D7Tg level divided by that on D0Tg. The therapeutic responses were classified as acceptable or non-acceptable. Finally, we investigated which clinicopathologic parameters were associated with therapeutic response.RESULTS: At the follow-up examination, an acceptable response was observed in 50 patients (73.5%). Univariate analysis revealed significant differences in N stage (P = 0.003) and ratioTg (acceptable vs. non-acceptable responses, 21.9 ± 33.6 vs. 3.8 ± 6.5; P = 0.006). In multivariate analysis, only ratioTg significantly predicted an acceptable response (odds ratio 1.104; 95% confidence interval 1.005–1.213; P = 0.040). A ratioTg above 3.5 predicted an acceptable response with a sensitivity of 66.0%, specificity of 83.3%, and accuracy of 70.6% (area under the curve = 0.718; P = 0.006).CONCLUSIONS: Altered levels of serum Tg after RAI therapy, calculated as the ratioTg (D7Tg/D0Tg), significantly predicted an acceptable response in patients with DTC.

Clinical usefulness of post-operative 18F-fluorodeoxyglucose positron emission tomography-computed tomography in canine hemangiosarcoma

This report describes the usefulness of positron emission tomography-computed tomography (PET-CT) for evaluating recurrent or residual tumors following surgery. CT and 18F-fluorodeoxyglucose PET-CT were pre- and post-operatively applied to multiple masses in a dog with hemangiosarcoma. The distinction between the left subcutaneous mass and the peritoneum was clarified on pre-operative CT examination, and malignancy was suspected based on PET-CT. A recurrent or residual tumor in the left subcutaneous region was suspected on post-operative PET-CT, and confirmed through histopathologic examination.

Effect of post-reconstruction gaussian filtering on image quality and myocardial blood flow measurement with N-13 ammonia PET

In order to evaluate the effect of post-reconstruction Gaussian filtering on image quality and myocardial blood flow [MBF] measurement by dynamic N-13 ammonia positron emission tomography [PET], we compared various reconstruction and filtering methods with image characteristics. Dynamic PET images of three patients with coronary artery disease [male-female ratio of 2:1; age: 57, 53, and 76 years] were reconstructed, using filtered back projection [FBP] and ordered subset expectation maximization [OSEM] methods. OSEM reconstruction consisted of OSEM_2I, OSEM_4I, and OSEM_6I with 2, 4, and 6 iterations, respectively. The images, reconstructed and filtered by Gaussian filters of 5, 10, and 15 mm, were obtained, as well as non-filtered images. Visual analysis of image quality [IQ] was performed using a 3-grade scoring system by 2 independent readers, blinded to the reconstruction and filtering methods of stress images. Then, signal-to-noise ratio [SNR] was calculated by noise and contrast recovery [CR]. Stress and rest MBF and coronary flow reserve [CFR] were obtained for each method. IQ scores, stress and rest MBF, and CFR were compared between the methods, using Chi-square and Kruskal-Wallis tests. In the visual analysis, IQ was significantly higher by 10 mm Gaussian filtering, compared to other sizes of filter [P<0.001 for both reader]. However, no significant difference of IQ was found between FBP and various numbers of iteration in OSEM [P=0.923 and 0.855 for readers 1 and 2 respectively]. SNR was significantly higher in 10 mm Gaussian filter. There was a significant difference in stress and rest MBF between several vascular territories. However CFR was not significantly different according to various filtering methods. Post-reconstruction Gaussian filtering with a filter size of 10 mm significantly enhances the IQ of N-13 ammonia PET-CT, without changing the results of CFR calculation

Both F-18 FDG-avidity and malignant shape of cervical lymph nodes on PET/CT after total thyroidectomy predict resistance to high-dose I-131 therapy in patients with papillary thyroid cancer

Resistance of metastatic lymph nodes [LNs] to high dose I-131 therapy is associated with high morbidity in patients with differentiated thyroid cancer. We evaluated the role of F-18 FDG PET/CT in the prediction of resistance to high dose I-131 therapy in patients with papillary thyroid cancer. The subjects were 307 patients who underwent total or near total thyroidectomy followed by high dose [5.55-6.66 GBq] I-131 therapy. We divided the patients into three subgroups by visual assessment of regional LNs: FDG-avid LNs with a malignant shape on CT [PET/CT-positive group], FDG-avid LNs with a benign shape on CT [PET/CT-intermediate group] and no FDG-avid lesion [PET/CT-negative group]. We measured the maximum SUV [SUVmax] of FDG-avid LNs in each patient. The presence or absence of focal increased uptake of I-131 was evaluated by whole body scan [WBS], and was denoted as WBS-positive group or WBS-negative group, respectively. Resistance to therapy was defined as presence of thyroglobulin [Tg] in serum [Tg >/= 1.0 ng/ml] 3-6 months after I-131 therapy. Univariate and multivariate analyses were performed to determine the relationship between resistance to I-131 therapy and various clinico-pathologic variables. PET/CT-positive, intermediate, and negative groups included 20 [6.5%], 44 [14.3%] and 243 [79.2%] patients, respectively. The mean SUVmax was significantly higher in the PET/CT-positive group than that of the PET/CT-intermediate group [4.6 vs.2.7, P <0.001]. Univariate analysis revealed that the PET/CT-positive group [P <0.001], T2-4 stage [P <0.001], N1b stage [P = 0.001], lower dose [5.55 GBq] of I-131 [P <0.001], and the WBS-positive group [P = 0.029] were associated with resistance to therapy. In multivariate analysis, the PET/CT-positive group, lower dose of I-131, N1b stage, and T2-4 stage remained significant with odds ratios of 10.07 [P <0.001], 3.82 [P <0.001], 3.58 [P = 0.001], and 2.53 [P = 0.009], respectively. FDG-avidity and malignant shape of cervical LNs on pre-therapy FDG PET/CT were a strong risk factors predicting resistance to high dose I-131 therapy. A lower dose of administered I-131 [5.55 GBq] and more extensive tumors [T2-4 and N1b] were also associated with resistance to high dose I-131 therapy

Never-Smoker Lung Cancer Is Increasing

PURPOSE: Lung cancer has been the leading cause of death in South Korea since the year 2000. Adenocarcinoma became the most frequent type in the national survey of lung cancer since year 2005. MATERIALS AND METHODS: We analyzed 5,456 cases with lung cancer from 2004 to 2012 in a community cancer center. The mean age was 69.9 years, and 78.9% was male. RESULTS: Adenocarcinoma (ADC, 40.8%) was the most frequent type, followed by squamous cell carcinoma (SQC, 36.4%), small cell carcinoma (SCC, 14.8%) and non-small cell lung cancer (NSCLC) not otherwise specified (8.1%). In male patients, SQC was the most frequent type (43.5%), while ADC showed highest incidence in females (72.6%). Anatomic stage at diagnosis in NSCLC was I (10.3%), II (5.8%), IIIA (15.7%), IIIB (19.2%), and IV (49.0%). In SCC, 41.7% was in limited stage and 58.3% was diagnosed in extensive stage. The proportion of never smoker has been increased from 19.1% in 2004~2008 to 25.4% in 2009~2012. Never-smokers are more likely to be female (68.2% vs. 4.0%, p<0.001), have ADC (69.9% vs. 31.3%, p<0.001), and manifest as stage IV disease (58.5% vs. 45.2%, p<0.001), compared to smokers. Among 1,908 cases whose initial treatment was recorded, 42.5% received chemotherapy, 25.7% received radiation treatment, 20.5% received surgery and the remaining 11.3% received supportive cares only or transferred to other health care facilities. CONCLUSION: In conclusion, proportion of lung cancer in never-smoker is increasing. As screening for smokers will miss this growing population, we need to discover biomarkers to find high risk population of lung cancer.

Detection of Occult Thymoma Using Tc-99m tetrofosmin Scintigraphy / 핵의학분자영상

Tetrofosmin is a ligand that forms a lipophilic, cationic complex with Tc-99m.1) Tc-99m tetrofosmin was developed as a myocardial perfusion imaging agent and also used to depict tumors.1-3) Mediastinal tumors is also detected by Tc-99m tetrofosmin.2-5) We report a case of extracardiac mediastinal activity detected by Tc-99m tetrofosmin scintigraphy, which revealed thymoma.

Dual Lingual Thyroid Mimicking Mono-ectopic Thyroid in the Anterior View of Tc-99m Sodium Pertechnetate Thyroid Scan / 핵의학분자영상

Ectopic thyroid is not common disease and double ectopic thyroid is rare. Until January of 2008, dual ectopic thyroid has been reported only 23 cases in international literatures. Tc-99m sodium pertechnetate scan is playing an important role in the diagnosis of ectopic thyroid. In most of the cases, dual lingual thyroid tissues could be detected as two radiotracer uptake foci. We report a case of dual lingual thyroid mimicking mono-lingual thyroid in the anterior view of thyroid scan. Lateral view helped in this case to detect the dual lingual thyroid. With lateral view, the anatomical position and relationship could be examined in more detail.

Significant Mismatch between FDG Uptake and Size after Chemotherapy in a Patient with Non-small Cell Lung Cancer / 핵의학분자영상

A 75-year-old man with non-small cell lung cancer (NSCLC) underwent F-18 fluorodeoxyglucose (FDG) PET/CT for staging. PET/CT showed distant metastases to intra-abdominal lymph nodes (LNs) as well as bilateral mediastinal LNs (stage IV). He underwent PET/CT (restaging PET/CT) 1 week after the completion of first-line chemotherapy (docetaxel + carboplatin). It showed markedly increased FDG uptake in primary tumor, whereas tumor size decreased significantly, compared to prior PET/CT. This lesion was aggravated on follow-up CT 3 months after the completion of chemotherapy. Although there are several reports that FDG PET has potential to evaluate early response to chemotherapy and prognosis, there are a few cases to show mismatch between FDG uptake and size on PET/CT. Thus we report a case of NSCLC showed increased FDG uptake of primary tumor while decreased tumor size on restaging PET/CT.

Metastases to Skeletal Muscles from Non-Small Cell Lung Cancer Demonstrated by 18F-FDG PET/CT

Hematogenous metastases to skeletal muscles are extremely rare metastases that may present as painful masses in the proximal skeletal muscles. The reasons for the rarity of metastatic tumors in skeletal muscle are not clear. However, the whole body coverage and high sensitivity of 18F-FDG PET/CT make it suitable for evaluating distant metastasis. We report here the findings of 18F-FDG PET/CT in a 66-year-old female with non-small cell lung cancer (adenocarcinoma) and multiple metastases to skeletal muscles

Correlation of Pre-treatment FDG Uptake to Therapeutic Response and Relapse in Patients with Small Cell Lung Cancer / 핵의학분자영상

PURPOSE: We evaluated correlation of 18F-FDG uptakes, therapeutic response and relapse in pre-treatment 18F-FDG PET/CT in patients with SCLC. MATERIALS AND METHODS: We included 26 patients with pathologically proven small cell lung cancer. Total 102 lesions (26 lungs, 69 lymph nodes and 8 metastatic lesions) were evaluated. All patients underwent 18F-FDG PET/CT for staging. The maxSUV was used as a parameter of 18F-FDG uptake. The patients were divided into responders and non-responders according to response criteria on chest CT scan after 3 cycles of chemotherapy. We compared maxSUV between two groups by using independent t-test. To access correlation with 18F-FDG uptake and relapse, maxSUV and interval time to relapse was analyzed by correlation analysis. The cutoff value of maxSUV was evaluated by ROC curve. RESULTS: Twelve-one patients (81%) were responders and five patients were non-responders on follow-up chest CT scan. The mean maxSUV of main lung lesions in responders and non-responders were 14.15+/-3.72 and 9.17+/-2.15, respectively. The maxSUV in the responders was significantly lower than that in non-responders (p<0.05). According to ROC curve, point of cut that predicts therapeutic response was 8.98 with 100% sensitivity and 57% specificity. The correlation analysis between 18F-FDG uptakes and interval time to relapse showed a significant negative correlation (p<0.05, r=-0.757). CONCLUSION: The pre-treatment 18F-FDG uptake of responders was significantly lower than that of non-responders. Patients with high 18F-FDG uptake in pre-treatment 18F-FDG PET/CT relapse earlier.

Improved Specificity of 18F-FDG PET/CT for Lymph Node Staging of Non-Small Cell Lung Cancer Considering Calcified Lymph Node as Benign / 핵의학분자영상

PURPOSE: We evaluated the diagnostic value of 18F-FDG PET/CT (PET/CT) in lymph node staging of non-small cell lung cancer (NSCLC) considering calcification and histologic types as well as FDG uptake. MATERIALS AND METHODS: Fifty-three patients (38 men, 15 women; mean age, 62 years) with NSCLC underwent surgical resection (tumor resection and lymph node dissection) after PET/CT. After surgery, we compared PET/CT results with the biopsy results, and analyzed lymph node metastases, based on histologic types. PET diagnosis of lymph node metastasis was determined by maximum SUV (maxSUV) > 3.0, and PET/CT diagnosis was determined by maxSUV > 3.0 without lymph node calcification. RESULTS: By PET diagnosis, the sensitivity, specificity, and accuracy of overall lymph node staging were 45% (13 of 29), 91% (228 of 252), and 86% (241 of 281). Specificity was 91% in both squamous cell carcinoma and adenocarcinoma, while sensitivity was 71% in squamous cell carcinoma and 36% in adenocarcinoma. When we excluded calcified lymph node with maxSUV > 3.0 from metastasis by PET/CT diagnosis, specificity improved to 98% in squamous cell carcinoma and 97% in adenocarcinoma. The degree of improvement was not dependent on histologic types. CONCLUSION: PET/CT improved specificity of lymph node staging by reducing false positive lymph node regardless of histologic types of NSCLC.

Development and Evaluation of Classification Codes and Retrieval Program of the Interpretation of Nuclear Medicine Imaging Studies / 대한의료정보학회지

OBJECTIVE: To evaluate usefulness of the classification codes and retrieval program of the interpretation of nuclear medicine imaging studies. METHODS: We retrieved specific results of the interpretation of 3,613 nuclear medicine imaging studies from database server of the Chonnam National University Hwasun Hospital using classification code retrieval program or by searching narrative phrases using structured query language(SQL). Accuracy of the retrieved results as well as retrieval time in each group were compared. RESULTS: Retrieved results using SQL showed lower accuracy than those using classification codes. There was no delay of response or overload of network traffic whether we used either retrieval program or SQL. CONCLUSION: Retrieval of specific results from database of the interpretation of nuclear medicine imaging studies using classification codes with retrieval program was more accurate and convenient than searching narrative phrases using SQL.