Clinical Impact of Extranodal Metabolic Tumor Volume in 240 Diffuse Large B cell Lymphoma Patients with Extranodal Involvement.

The present study is to investigate whether extranodal (EN) metabolic tumor volume (MTV) would have a specific clinical meaning for survival in EN diffuse large B cell lymphoma (DLBCL) patients. Two hundred forty DLBCL patients with EN involvement received 18F-fluorodeoxygenase (FDG) positron emission tomography/computed tomography (PET/CT) were enrolled. Survival analysis revealed that low EN MTV (PFS [progression-free survival], HR = 0.278, 95% CI = 0.127-0.807, p = 0.001; OS [overall survival], HR = 0.320, 95% CI = 0.145-0.703, p = 0.003), low total MTV (PFS, HR = 0.194, 95% CI = 0.085-0.445, p < 0.001; OS, HR = 0.213, 95% CI = 0.092-0.491, p < 0.007), and high National Cancer Center Network-International Prognostic Index score (PFS, HR = 3.152, 95% CI = 1.732-5.734, p < 0.001; OS, HR = 2.457, 95% CI = 1.363-4.430, p = 0.003) were independently associated with survivals in the patients. Our data showed that EN MTV is a useful and novel prognostic parameter for predicting survival in DLBCL patients with EN involvement.

A risk stratification model for nodal peripheral T-cell lymphomas based on the NCCN-IPI and posttreatment Deauville score.

PURPOSE: The aim of this study was to establish a risk-stratification model integrating posttreatment metabolic response using the Deauville score and the pretreatment National Comprehensive Cancer Network-International Prognostic Index (NCCN-IPI) in nodal PTCLs. METHODS: We retrospectively analysed 326 patients with newly diagnosed nodal PTCLs between January 2005 and June 2016 and both baseline and posttreatment PET/CT data. The final model was validated using an independent prospective cohort of 79 patients. RESULTS: Posttreatment Deauville score (1/2, 3, and 4/5) and the NCCN-IPI (low, low-intermediate, high-intermediate, and high) were independently associated with progression-free survival: for the Deauville score, the hazard ratios (HRs) were 1.00 vs. 2.16 (95% CI 1.47-3.18) vs. 7.86 (5.66-10.92), P < 0.001; and for the NCCN-IPI, the HRs were 1.00 vs. 2.31 (95% CI 1.20-4.41) vs. 4.42 (2.36-8.26) vs. 7.09 (3.57-14.06), P < 0.001. Based on these results, we developed a simplified three-group risk model comprising a low-risk group (low or low-intermediate NCCN-IPI with a posttreatment Deauville score of 1 or 2, or low NCCN-IPI with a Deauville score of 3), a high-risk group (high or high-intermediate NCCN-IPI with a Deauville score of 1/2 or 3, or low-intermediate NCCN-IPI with a Deauville score of 3), and a treatment failure group (Deauville score 4 or 5). This model was significantly associated with progression-free survival (5-year, 70.3%, 31.4%, and 4.7%; P < 0.001) and overall survival (5-year, 82.1%, 45.5%, and 14.7%; P < 0.001). Similar associations were also observed in the independent validation cohort. CONCLUSION: The risk-stratification model integrating posttreatment Deauville score and pretreatment NCCN-IPI is a powerful tool for predicting treatment failure in patients with nodal PTCLs.

Correction to: a risk stratification model for nodal peripheral T-cell lymphomas based on the NCCN-IPI and posttreatment Deauville score.

Unfortunately, the original version of this article contained several errors made during final step of article production. In the results section (fourth sentence) of the Abstract, the incomplete sentence,", 31.4% in high-risk group and 4.7% in treatment failure group.

Relationships between transporter expression and the status of BRAF V600E mutation and F-18 FDG uptake in papillary thyroid carcinomas.

PURPOSE: The purpose of this study was to evaluate the expression of the glucose transporters GLUT1 and GLUT3 in papillary thyroid carcinomas (PTCs) and to elucidate their relationship with the BRAF V600E mutation and F-18 FDG uptake. MATERIALS AND METHODS: We retrospectively analyzed data of 52 PTC patients (41 women and 11 men; mean age, 52.4 ± 14.5 years). F-18 FDG PET/CT was performed preoperatively, and the maximum standardized uptake value (SUVmax) was calculated. GLUT1/GLUT3 expression was determined immunohistochemically, and the BRAF V600E mutation was detected using DNA sequencing. RESULTS: GLUT1 and GLUT3 were expressed in 82.7% (43/52) and 59.6% (31/52) PTCs, respectively. The BRAF V600E mutation was detected in 65.4% (34/52) PTCs. The odds ratio between GLUT1 expression and the BRAF V600E mutation was 5.2 (95% CI, 1.11-24.05; p < 0.05), and that between GLUT3 expression and the BRAF V600E mutation was 3.8 (95% CI, 1.14-12.53; p < 0.05). The SUVmax of PTCs was significantly higher if they carried the BRAF V600E mutation (11.3 ± 2.0, compared with 5.7 ± 1.4 for wild type BRAF tumors, Mann-Whitney test, p = 0.016). Neither GLUT1 nor GLUT3 expression was significantly associated with the SUVmax of F-18 FDG PET/CT in PTCs. CONCLUSIONS: Our findings confirmed that both GLUT1 and GLUT3 are strongly expressed by PTCs, although their expression was not significantly associated with the SUVmax of F-18 FDG PET/CT. However, GLUT1 and GLUT3 expressions were significantly associated with the presence of the BRAF V600E mutation, and the SUVmax of tumors was significantly higher in the presence of the mutated BRAF gene.

Metabolic tumor volume by positron emission tomography/computed tomography as a clinical parameter to determine therapeutic modality for early stage Hodgkin's lymphoma.

Recent studies have shown that metabolic tumor volume (MTV) by positron emission tomography/computed tomography (PET/CT) is an important prognostic parameter in patients with non-Hodgkin's lymphoma. However, it is unknown whether doxorubicin, bleomycin, vinblastine, dacarbazine (ABVD) alone in early stage Hodgkin's lymphoma would lead to similar disease control as combined modality therapy (CMT) using MTV by PET/CT. One hundred and twenty-seven patients with early stage Hodgkin's lymphoma who underwent PET/CT at diagnosis were enrolled. The MTV was delineated on PET/CT by the area ≥SUV(max), 2.5 (standardized uptake value [SUV]). Sixty-six patients received six cycles of ABVD only. The other 61 patients received CMT (involved-field radiotherapy after 4-6 cycles of ABVD). The calculated MTV cut-off value was 198 cm(3) . Clinical outcomes were compared according to several prognostic factors (i.e. age ≥50 years, male, performance status ≥2, stage II, B symptoms, ≥4 involved sites, extranodal site, large mediastinal mass, CMT, elevated erythrocyte sedimentation rate and high MTV). Older age (progression-free survival [PFS], P = 0.003; overall survival [OS], P = 0.007), B symptoms (PFS, P = 0.006; OS, P = 0.036) and high MTV (PFS, P = 0.008; OS, P = 0.007) were significant independent prognostic factors. Survival of two high MTV groups treated with ABVD only and CMT were lower than the low MTV groups (PFS, P < 0.012; OS, P < 0.045). ABVD alone was sufficient to control disease in those with low MTV status. However, survival was poor, even if the CMT was assigned a high MTV status. The MTV would be helpful for deciding the therapeutic modality in patients with early stage Hodgkin's lymphoma.

Clinical significance of metabolic tumor volume by PET/CT in stages II and III of diffuse large B cell lymphoma without extranodal site involvement.

The objective of this study was to investigate whether metabolic tumor volume (MTV) by positron emission tomography (PET) can be a potential prognostic tool when compared with Ann Arbor stage, in stages II and III nodal diffuse large B cell lymphoma (DLBCL). We evaluated 169 patients with nodal stages II and III DLBCL who underwent measurements with PET prior to rituximab combined with cyclophosphamide, adriamycin, vincristine, and prednisone (R-CHOP). Cutoff point of MTV was measured using the receiver operating characteristic (ROC) curve. During a median period of 36 months, stage II was 59.2% and III was 40.8%. Using the ROC curve, the MTV of 220 cm(3) was the cutoff value. The low MTV group (<220 cm(3)) had longer progression-free survival (PFS) and overall survival (OS), compared with the high MTV group (≥220 cm(3)) (p < 0.001, p < 0.001). Stage II patients had longer survival than those in stage III (PFS, p = 0.011; OS, p = 0.001). The high MTV group had lower PFS and OS patterns, regardless of stage, compared with the low MTV group (p < 0.001, p < 0.001). Multivariate analysis revealed an association of the high MTV group with lower PFS and OS (PFS, hazard ratio (HR) = 5.300, p < 0.001; OS, HR = 7.009, p < 0.001), but not stage III (PFS, p = 0.187; OS, p = 0.054). Assessment of MTV by PET had more potential predictive power than Ann Arbor stage in the patients that received R-CHOP.

Diagnostic Performance of F-18 FDG PET/CT Compared with CA125, HE4, and ROMA for Epithelial Ovarian Cancer.

OBJECTIVE: This study aimed to examine the diagnostic performance of F-18 fluorodeoxyglucose positron emission tomography with computed tomography (F-18 FDG PET/CT) compared with cancer antigen 125 (CA125), human epididymis protein 4 (HE4), and risk of ovarian malignancy algorithm (ROMA) score to distinguish epithelial ovarian cancer from benign tumors. METHODS: A total of 46 patients with pelvic masses, who underwent F-18 FDG PET/CT, CA125, and HE4 before surgery between January 2015 and December 2018, were included in this retrospective study. The diagnostic performance of CA125, HE4, ROMA score, and maximum standardized uptake value (SUVmax) to differentiate epithelial ovarian cancer from benign pelvic tumors was examined by receiver operating characteristic curve analysis. RESULTS: Among the 46 patients, 28 were cases of ovarian cancers and 18 were of benign. The mean values of CA125, HE4, ROMA score, and SUVmax were significantly higher in the ovarian cancer group than the benign group. In early cancer stages (stages I and II), Area under the curve for SUVmax was significantly higher than CA125 and ROMA score (0.778 for CA125, 0.753 for HE4, 0.682 for ROMA score, and 0.922 for SUVmax). CONCLUSION: SUVmax using F-18 FDG PET/CT showed a high diagnostic accuracy for differentiating epithelial ovarian cancer from benign pelvic tumors, including early stage ovarian cancer. F-18 FDG PET/CT can be a useful modality for the assessment of pelvic mass.
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Evaluating the Predictive Ability of Initial Staging F-18 FDG PET/CT for the Prognosis of Non-Hodgkin Malignant Lymphoma Patients Who Underwent Stem Cell Transplantation.

OBJECTIVES: This study aimed to determine the value of clinical prognostic factors and semiquantitative metabolic parameters from initial staging fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) in non-Hodgkin lymphoma (NHL) patients treated with stem cell transplantation (SCT). METHODS: A total of 39 malignant lymphoma patients who underwent initial staging F-18 FDG PET/CT were enrolled in this study. SUVmax, MTV_wb, and TLG_wb were measured during the initial staging PET/CT. Receiver operating characteristic curve (ROC) analysis was adopted to dichotomize continuous variables. Log-rank test and Cox proportional hazard regression analysis were used to evaluate disease-free survival (DFS) rate. RESULTS: Among the 39 patients with malignant lymphoma, 17 (43.6%) had a relapse. For several clinical factors such as age, ECOG performance score, AMC/ALC score, stages, and revised International Prognostic Index score, differences between the two dichotomized groups were statistically insignificant. In univariate analysis, DFS estimates were 71.0 ± 7.8 months and 18.0 ± 5.9 months in high-SUVmax and low-SUVmax group, respectively (P < 0.01). For MTV_wb, DFS estimates were 46.6 ± 12.4 months and 69.1 ± 8.5 months in high-MTV_wb and low-MTV_wb group, respectively (P = 0.12). For TLG_wb, DFS estimates were 65.3 ± 7.5 months and 13.7 ± 8.6 months in high-TLG_wb and low-TLG_wb group, respectively (P = 0.02). In Cox proportional hazard regression analysis, only MTV_wb showed statistical significance (HR 3.01, 95% CI 1.04-8.74, P = 0.04). CONCLUSION: In NHL patients treated with SCT, the MTV_wb of initial staging F-18 FDG PET/CT was an independent prognostic factor.

Prognostic value of positron emission tomography/computed tomography for adjuvant chemotherapy of colon cancer.

BACKGROUND: To assess the prognostic value of preoperative 18 F-fluorodeoxyglucose positron emission tomography/computed tomography in patients with high-risk stage II or stage III colon cancer who underwent FOLFOX chemotherapy. METHODS: The study included 166 patients with high-risk stage II or stage III colon cancer who received FOLFOX4 chemotherapy. Retrospective patient data were analysed including pathological stage, histology, disease-free survival (DFS) and the maximum standardized uptake value (SUVmax ) of the primary tumour on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography. The primary end point was DFS. RESULTS: There were recurrences in 29 of the 166 patients (17.4%). Measuring the area under the receiver operating characteristic curve, the cut-off value of SUVmax with maximum sensitivity and specificity was 10.95. Using the Kaplan-Meier method, the DFS of the patients categorized by SUVmax tended to differ (P = 0.055). In univariate analyses, the risk factors for DFS were age over 70 years, higher N stage and neural invasion. SUVmax ≤ 10.95 showed a tendency, but was not significant (P = 0.0604). In multivariate analyses, the risk factors for DFS were age over 70 and neural invasion. CONCLUSIONS: The results of this study suggest that high fluorodeoxyglucose uptake of the primary mass in high-risk stage II and stage III colon cancer does not significantly correlate with DFS.

Correlation of Molecular Subtypes of Invasive Ductal Carcinoma of Breast with Glucose Metabolism in FDG PET/CT: Based on the Recommendations of the St. Gallen Consensus Meeting 2013.

PURPOSE: This study aimed to investigate the relationship between the SUVmax of primary breast cancer lesions and the molecular subtypes based on the recommendations of the St. Gallen consensus meeting 2013. METHODS: Clinical records of patients who underwent F-18 FDG PET/CT for initial staging of invasive ductal carcinoma (IDC) of the breast were reviewed. A total of 183 patients were included. SUVmax was correlated with the molecular subtypes defined by the St. Gallen Consensus Meeting 2013, i.e., luminal A-like (LA), luminal B-like HER2 negative (LBHER2-), luminal B-like HER2 positive (LBHER2+), HER2 positive (HER2+), and triple negative (TN), and with the clinicohistopathologic characteristics. RESULTS: The molecular subtype was LA in 38 patients, LBHER2- in 72, LBHER2+ in 21, HER2+ in 30, and TN in 22. The mean SUVmax in the LA, LBHER2-, LBHER2+, HER2+, and TN groups were 4.5 ± 2.3, 7.2 ± 4.9, 7.2 ± 4.3, 10.2 ± 5.5, and 8.8 ± 7.1, respectively. Although SUVmax differed significantly among these subtypes (p < 0.001), the values showed a wide overlap. Optimal cut-off SUVmax to differentiate LA from LBHER2-, LBHER2+, HER2+ and TN were 5.9, 5.8, 7.5, and 10.2 respectively, with area under curve (AUC) of 0.648, 0.709, 0.833, and 0.697 respectively. The cut-off value of 5.9 yielded the highest accuracy for differentiation between the LA and non-LA subtypes, with sensitivity, specificity, and AUC of 79.4 %, 57.9 %, and 0.704 respectively. CONCLUSION: The SUVmax showed a significant correlation with the molecular subtype. Although SUVmax measurements could be used along with immunohistochemical analysis for differentiating between molecular subtypes, its application to individual patients may be limited due to the wide overlaps in SUVmax.

Increased Malignant Microcalcifications after Neoadjuvant Chemotherapy in Advanced Breast Cancer.

In patients with advanced breast cancer, most new calcifications detected on a mammogram after neoadjuvant chemotherapy are benign dystrophic calcifications, but this is not always observed. We present a patient with advanced breast cancer who had paradoxically increased malignant microcalcifications concomitant with primary tumor regression after undergoing neoadjuvant chemotherapy. After the neoadjuvant chemotherapy, the follow-up mammogram revealed that local, fine pleomorphic microcalcifications had markedly increased. Pathologically, these calcifications were ductal carcinoma in situ. We concluded that, in patients with breast cancer undergoing neoadjuvant chemotherapy, newly developed microcalcifications on follow-up mammograms should be carefully evaluated, and any suspicious malignant microcalcifications should be included in surgical excision planning.

Efficacy of Positron Emission Tomography/Computed Tomography in Gastric Mucosa-associated Lymphoid Tissue Lymphoma.

BACKGROUND/AIMS: This study evaluated the diagnostic efficacy of fluorine-18 fluorodeoxyglucose PET/CT (F-18 FDG PET/CT) for patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma and examined the association between FDG avidity and the clinical factors affecting lesions. METHODS: Among the patients diagnosed with gastric MALT lymphoma, 16 who underwent a PET/CT for gastric MALT lymphoma were semi-quantitatively and qualitatively tested for FDG avidity of lesions in the stomach. Retrospectively collected data was analyzed to investigate the clinicoradiological factors and endoscopic findings between the patients with positive F-18 FDG PET/CT scans and those with negative scans. RESULTS: Eight of the 16 patients showed FDG avidity. When comparing the size of lesions in the stomach, the patients with FDG avidity had significantly larger lesions than those without (28.8 mm vs. 15.0 mm, p=0.03). The FDG-avid group has a significantly higher rate of positive CT scans than the non-avid group (75% vs. 13%, p=0.03). According to the endoscopic finding of the lesions, FDG avidity was pronounced with 75% of the protruding tumors, and 100% of the erosive-ulcerative types, which are a type of depressed tumors. CONCLUSIONS: When gastric MALT lymphoma is large, when lesions are found using abdominal CT scans, and the macroscopic appearance of a lesion is that of a protruding tumor or erosive-ulcerative type of depressed tumor, there is a high probability that such patients may have a positive F-18 FDG PET/CT scan.

Clinical Usefulness of F-18 FDG PET/CT in Papillary Thyroid Cancer with Negative Radioiodine Scan and Elevated Thyroglobulin Level or Positive Anti-thyroglobulin Antibody.

PURPOSE: Elevated thyroglobulin (Tg) levels, along with a negative radioiodine scan, present a clinical problem for the diagnosis of recurrence in papillary thyroid cancer (PTC) patients. The purpose of this study was to assess (1) the usefulness of (18)F-fluorodeoxyglucose (F-18 FDG) positron emission tomography (PET)/computed tomography (CT) for PTC patients with negative diagnostic radioiodine scan and elevated serum Tg level or positive anti-thyroglobulin antibody (TgAb), and (2) the effect of endogenous thyroid stimulating hormone (TSH) stimulation (ETS) on detecting recurrence in these circumstances. METHODS: Eighty-four patients with negative diagnostic radioiodine scan and elevated serum Tg or positive TgAb under ETS were included. Correlation with clinicopathological features and recurrence, detectability of FDG PET/CT and cut-off value of serum Tg for recurrence in PTC patients with these circumstance were assessed. In addition, detectability of F-18 FDG PET/CT under ETS and suppression were compared. RESULTS: In Cox regression analysis, only serum Tg level was significantly associated with recurrence (P < 0.001, HR = 1.13; 95 % CI, 1.061-1.208). The cut-off level of Tg was 21.5 ng/mL (AUC, 0.919; P < 0.001) for discriminating the recurrence in the patients with positive PET/CT finding. The sensitivity, specificity, PPV, NPV, and accuracy of F-18 FDG PET/CT for detecting recurrence were 64 %, 94 %, 86 %, 81 %, and 83 %. In the analysis of F-18 FDG PET/CT under ETS, the sensitivity, specificity, PPV, NPV and accuracy was 64 %, 94 %, 88 %, 81 % and 83 %. Those under TSH suppression were 67 %, 92 %, 80 %, 85 % and 83 %. CONCLUSIONS: F-18 FDG PET/CT, although less sensitive, showed high specificity, PPV, NPV, and accuracy and therefore can be useful for the patients with negative diagnostic radioiodine scan and elevated serum Tg or positive TgAb. In addition, FDG PET/CT under ETS does not seem to have an additive role in detecting recurrence in these patients.

FDG uptake in non-small cell lung cancer is not an independent predictor of EGFR or KRAS mutation status: a retrospective analysis of 206 patients.

PURPOSE: Data in the literature regarding the use of F-FDG avidity of non-small cell lung cancer (NSCLC) as an imaging biomarker to predict the status of epidermal growth factor receptor (EGFR) mutation are conflicting. Association between KRAS mutation and FDG avidity of NSCLC on PET/CT is not well known. We assessed whether the EGFR or KRAS mutation status in NSCLC can be predicted by FDG avidity by performing several different subgroup analyses to better compare with various published results. PATIENTS AND METHODS: After obtaining institutional review board approval, we enrolled patients (1) who had FDG PET/CT performed for staging of NSCLC, (2) with EGFR and KRAS mutational status of tumor identified, and (3) without uncontrolled diabetes. Univariate and multivariate regression analyses were performed to assess the relationship between the independent clinical variables (sex, age, smoking history, tumor histology, tumor size, stage, and SUV-derived variables) and the EGFR and KRAS mutation status. Separate analyses were performed for patients with adenocarcinomas. RESULTS: There were 206 patients (age, 33-88 years; 148 male/58 female; 71 ever-smokers/135 never-smokers; 135 adenocarcinoma/71 squamous cell carcinoma; 22 stage I-II/184 stage III-IV; tumor size, 1.2-15.0 cm; SUVmax, 2.9-36.4; EGFR mutations present in 47; KRAS mutations present in 20). In multivariate analysis, sex, smoking history, histology, and tumor size were significantly associated with EGFR mutation but none of the SUV-derived variables was. Likewise, no correlation was found between the SUV-derived variables and KRAS mutation. CONCLUSIONS: Our results suggest that FDG avidity of NSCLC has no significant clinical value in predicting the EGFR or KRAS mutation status.

Comparison of sonographic and cytological diagnoses of solid thyroid nodules: Emphasis on the discordant cases.

BACKGROUND: This study aimed to assess solid thyroid nodule (STN) cases with discordant sonographic and cytological diagnoses and to compare the diagnostic indices of these modalities. METHODS: From January 2013 to December 2013, a single radiologist performed consecutive thyroid ultrasonography (US) and US-guided fine-needle aspiration (US-FNA) to diagnose 347 STNs in 347 patients. Each STN was classified into 1 of 5 categories according to the US diagnosis before US-FNA: "benign," "probably benign," "indeterminate," "suspicious for malignancy," or "malignant." We assessed cases where the sonographic and cytological STN diagnoses were discordant, using the final diagnosis as the reference standard. RESULTS: Of the 347 STNs, 279 (80.4%) had a final diagnosis confirmed. The "benign," "probably benign," and "malignant" US categories showed high concordance with the cytological diagnoses, whereas the "suspicious for malignancy" US category revealed only a 62.2% concordance rate. The prevalence of indeterminate cytology was higher in the "indeterminate" and "suspicious for malignancy" US categories than other US categories. STNs with indeterminate cytology showed a higher malignancy rate in the malignant US categories. When STNs classified into indeterminate categories from the sonographic (n = 49) and cytological (n = 18) diagnoses were excluded, the sensitivity, specificity, and accuracy of the sonographic and cytological diagnoses were 95.5 and 98.8%, 92.1 and 100%, and 93.0 and 99.6%, respectively. CONCLUSION: The "suspicious for malignancy" US category showed higher discordance with cytological diagnoses than other US categories, and the diagnostic value of US was lower than that of cytology.

False Positive Radioiodinated Metaiodobenzylguanidine ((123)I-MIBG) Uptake in Undifferentiated Adrenal Malignant Tumor.

(123)I-Metaiodobenzylguanidine ((123)I-MIBG) scintigraphy is a widely used functional imaging tool with a high degree of sensitivity and specificity in diagnosis of pheochromocytoma. However, rare cases of false positive reactions have been reported. A 67-year-old male patient was admitted with epigastric pain. Abdominal computed tomography (CT) revealed a heterogeneous left adrenal mass 6 cm in diameter; following hormone testing, (123)I-MIBG scintigraphy was performed to determine the presence of pheochromocytoma, which confirmed eccentric uptake by a large left adrenal gland mass. Chest CT and PET-CT confirmed metastatic lymphadenopathy; therefore, endobronchial ultrasound transbronchial needle aspiration was performed. Metastatic carcinoma of unknown origin was suspected from a lymph node biopsy, and surgical resection was performed for definitive diagnosis and correction of excess hormonal secretion. A final diagnosis of undifferentiated adrenal malignant tumor was rendered, instead of histologically malignant pheochromocytoma, despite the uptake of (123)I-MIBG demonstrated by scintigraphy.

Characteristics of Metastatic Mediastinal Lymph Nodes of Non-Small Cell Lung Cancer on Preoperative F-18 FDG PET/CT.

PURPOSE: The aim of this study was to evaluate the characteristics of PET and CT features of mediastinal metastatic lymph nodes on F-18 FDG PET/CT and to determine the diagnostic criteria in nodal staging of non-small cell lung cancer. METHODS: One hundred four non-small cell lung cancer patients who had preoperative F-18 FDG PET/CT were included. For quantitative analysis, the maximum SUV of the primary tumor, maximum SUV of the lymph nodes (SUVmax), size of the lymph nodes, and average Hounsfield units (aHUs) and maximum Hounsfield units (mHUs) of the lymph nodes were measured. The SUVmax, SUV ratio of the lymph node to blood pool (LN SUV/blood pool SUV), SUV ratio of the lymph node to primary tumor (LN SUV/primary tumor SUV), size, aHU, and mHU were compared between the benign and malignant lymph nodes. RESULTS: Among 372 dissected lymph node stations that were pathologically diagnosed after surgery, 49 node stations were malignant and 323 node stations benign. SUVmax, LN SUV/blood pool SUV, and size were significantly different between the malignant and benign lymph node stations (P < 0.0001). However, there was no significant difference in LN SUV/primary tumor SUV (P = 0.18), mHU (P = 0.42), and aHU (P = 0.98). Using receiver-operating characteristic curve analyses, there was no significant difference among these three variables (SUVmax, LN SUV/blood pool SUV, and size). The optimal cutoff values were 2.9 for SUVmax, 1.4 for LN SUV/blood pool SUV, and 5 mm for size. When the cutoff value of SUVmax ≥2.9 and size ≥5 mm were used in combination, the positive predictive value was 44.2 %, and the negative predictive value was 90.9 %. When we evaluated the results based on the histology of the primary tumor, the negative predictive value was 92.3 % in adenocarcinoma (cutoff values of SUVmax ≥2.3 and size ≥5 mm) and 97.2 % in squamous cell carcinoma (cutoff values of SUVmax ≥3.6 and size ≥8 mm), separately. CONCLUSIONS: In the lymph node staging of non-small cell lung cancer, SUVmax, LN SUV/blood pool SUV, and size show statistically significant differences between malignant and benign lymph nodes. These variables can be used to differentiate malignant from benign lymph nodes. The combination of the SUVmax and size of lymph node might have a good negative predictive value.

Value of 18F-FDG PET/CT for early prediction of pathologic response (by residual cancer burden criteria) of locally advanced breast cancer to neoadjuvant chemotherapy.

PURPOSE: A relatively new pathologic grading system, called residual cancer burden (RCB) criteria (0 to III), for assessing the response to neoadjuvant chemotherapy (NCT) of breast cancer has been reported to be more accurate than conventional pathologic criteria. This study assesses the value of F-FDG PET/CT in early prediction of chemotherapeutic response determined based on these criteria. PATIENTS AND METHODS: Thirty-six patients with locally advanced breast cancer underwent F-FDG PET/CT before and after the first (just before the second) cycle of NCT. Percentage changes (%△) in SUVmax, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) between F-FDG PET/CT before and after the first cycle of NCT were correlated with RCB index on pathologic specimens after the completion of NCT. RESULTS: The %△SUVmax, %△MTV, and %△TLG in the RCB 0/I group (n = 5) were all significantly larger than those in the RCB II/III group (n = 31) (82.9%, 100%, and 100% vs 45.8%, 83.2%, and 88.0%, respectively, P < 0.01). The sensitivity/specificity/accuracy of the optimal cutoff %△SUVmax, %△MTV, and %△TLG for discriminating RCB 0/I group from RCB II/III group based on the receiver operating characteristic analysis were 80.0%/96.8%/94.4%, 100%/80.6%/83.3%, and 100%/80.6%/83.3%, respectively. The area under the curve for the 3 parameters was 0.923, 0.903, and 0.884, respectively, and not statistically different. CONCLUSIONS: The %Δmetabolic parameters derived from F-FDG PET/CT studies performed before and after the first cycle of NCT in patients with locally advanced breast cancer appear to be useful in early prediction of eventual therapy response determined based on the RCB pathologic grading system.

Diagnostic Performance of Breast-Specific Gamma Imaging (BSGI) for Breast Cancer: Usefulness of Dual-Phase Imaging with (99m)Tc-sestamibi.

PURPOSE: The aim of this study was to investigate the usefulness of breast-specific gamma imaging (BSGI) with dual-phase imaging for increasing diagnostic performance and interpreter confidence. METHODS: We studied 76 consecutive patients (mean age: 49.3 years, range: 33-61 years) who received 925 MBq (25 mCi) (99m)Tc-sestamibi intravenously. Craniocaudal and mediolateral oblique planar images were acquired for all patients. Delayed images were obtained from all patients 1 h after tracer injection, except for patients with no definite abnormal uptake. All images were classified into four categories: group 1 (definite negative) = no definite abnormal uptake; group 2 (possible negative) = symmetrically diffuse and amorphous uptake; group 3 (possible positive) = asymmetrically mild and nodular uptake; group 4 (definite positive) = asymmetrically intense and nodular uptake. To evaluate diagnostic performance, the BSGI studies were classified as positive (group 3 or 4) or negative (group 1 or 2) for malignancy according to a visual analysis. The final diagnoses were derived from histopathological confirmation and/or imaging follow-up after at least 6 months (range: 6-14 months) by both ultrasonography and mammography. RESULTS: The patients' ages ranged from 33 to 61 years, with an average of 49.3 years. Thirteen patients were diagnosed with malignancy, and 63 patients were diagnosed as negative for malignancy. Using early images, 43 patients were classified as group 1, 12 as group 2, 10 as group 3 and 11 as group 4. Based on early images, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of BSGI were 77 %, 83 %, 48 %, 95 % and 82 %, respectively. Dual-phase BSGI had a sensitivity, specificity, PPV, NPV and accuracy of 69 %, 95 %, 75 %, 94 % and 91 %, respectively. The BSGI specificity was significantly higher with dual-phase imaging than with single-phase imaging (p = 0.0078), but the sensitivity did not differ significantly (p = 1.0). Based on dual-phase imaging, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of BSGI for the evaluation of US BI-RADS 4 lesions were 60 %, 86 %, 67 %, 83 % and 78 %, respectively. CONCLUSION: Dual-phase imaging in BSGI showed good diagnostic performance and would be useful for increasing interpreter diagnostic confidence, with higher specificity, positive predictive value and accuracy for breast cancer screening as well as the differential diagnosis of breast disease compared with single-phase imaging.

Clinical value of metabolic tumor volume by PET/CT in extranodal natural killer/T cell lymphoma.

This study investigated whether metabolic tumor volume (MTV) by PET/CT as indicator of extent of lymphoma burden would be a prognostic factor in stage I(E)/II(E) extranodal natural killer/T cell lymphoma (ENKTCL). Eighty patients with stage I(E)/II(E) ENKTCL in the upper aerodigestive tract underwent PET/CT at diagnosis were enrolled and 32 patients received upfront radiotherapy (RTx). MTV was measured on PET/CT images by the extranodal region above SUV, 2.5. Receiver operating curve analyses indicated that an MTV of 35.2 cm(3) was the ideal cut-off to distinguish between low and high MTV groups. Clinical outcomes were compared according to several prognostic factors (age, stage, high performance status [PS], high International Prognostic Index, elevated lactate dehydrogenase [LDH], local tumor invasiveness [LTI], high MTV and up-front RT). High PS, elevated LDH, LTI, high MTV and upfront RT were associated with survivals. In multivariate analysis, high MTV (PFS, HR=4.170, 95% CI=1.714-10.147, p=0.002; OS, HR=4.102, 95% CI=1.617-10.408, p=0.003) and up-front RT (PFS, HR=0.410, 95%CI=0.178-0.946, p=0.037; OS, HR=0.365, 95% CI=0.152-0.872, p=0.023) were significant independent prognostic factors. Upfront RTx and extent of tumor burden, as measured by the MTV, had significant prognostic value in patients with ENKTCL.