Prognostic value of TLR from FDG PET/CT in patients with margin-negative stage IB and IIA non-small cell lung cancer.

OBJECTIVES: To evaluate the prognostic value of TLR from PET/CT in patients with resection margin-negative stage IB and IIA non-small cell lung cancer (NSCLC) and compare high-risk factors necessitating adjuvant treatment (AT). METHODS: Consecutive FDG PET/CT scans performed for the initial staging of NSCLC stage IB and IIA were retrospectively reviewed. The maximum standardized uptake value (SUVmax) of the primary tumor and mean SUV of the liver were acquired. The tumor-to-liver SUV ratio (TLR) was also calculated. Charts were reviewed for basic patient characteristics and high-risk factors for considering AT (poor differentiation, visceral pleura invasion, vascular invasion, tumors > 4 cm, and wedge resection). Statistical analysis was performed using Cox regression analysis and the Kaplan-Meier method. RESULTS: Of the 112 patients included, 15 (13.4%) died, with a median overall survival (OS) of 43.8 months. Twenty-two patients (19.6%) exhibited recurrence, with median disease-free survival (DFS) of 36.0 months. In univariable analysis, pathology, poor differentiation, and TLR were associated with shorter DFS and OS. In multivariable analysis, TLR (hazard ratio [HR] = 1.263, p = 0.008) and differentiation (HR = 3.087, p = 0.012) were associated with shorter DFS. Also, TLR (HR = 1.422, p < 0.001) was associated with shorter OS. CONCLUSION: TLR from FDG PET/CT was an independent prognostic factor for recurrence and survival. PET parameters constitute risk factors for consideration in the decision-making for AT in margin-negative stage IB and IIA NSCLC. CLINICAL RELEVANCE STATEMENT: In this study, TLR from FDG PET/CT was an independent prognostic factor in stage IB-IIA non-small cell cancer patients. Although additional validation studies are warranted, TLR has the potential to be used to determine the need for adjuvant therapy. KEY POINTS: • High TLR is an independent poor prognostic factor in stage IB-IIA NSCLC. • Adjuvant treatment should be considered in patients with high TLR following complete tumor resection.

Second primary malignancy risk in thyroid cancer and matched patients with and without radioiodine therapy analysis from the observational health data sciences and informatics.

PURPOSE: Risk of second primary malignancy (SPM) after radioiodine (RAI) therapy has been continuously debated. The aim of this study is to identify the risk of SPM in thyroid cancer (TC) patients with RAI compared with TC patients without RAI from matched cohort. METHODS: Retrospective propensity-matched cohorts were constructed across 4 hospitals in South Korea via the Observational Health Data Science and Informatics (OHDSI), and electrical health records were converted to data of common data model. TC patients who received RAI therapy constituted the target group, whereas TC patients without RAI therapy constituted the comparative group with 1:1 propensity score matching. Hazard ratio (HR) by Cox proportional hazard model was used to estimate the risk of SPM, and meta-analysis was performed to pool the HRs. RESULTS: Among a total of 24,318 patients, 5,374 patients from each group were analyzed (mean age 48.9 and 49.2, women 79.4% and 79.5% for target and comparative group, respectively). All hazard ratios of SPM in TC patients with RAI therapy were ≤ 1 based on 95% confidence interval(CI) from full or subgroup analyses according to thyroid cancer stage, time-at-risk period, SPM subtype (hematologic or non-hematologic), and initial age (< 30 years or ≥ 30 years). The HR within the target group was not significantly higher (< 1) in patients who received over 3.7 GBq of I-131 compared with patients who received less than 3.7 GBq of I-131 based on 95% CI. CONCLUSION: There was no significant difference of the SPM risk between TC patients treated with I-131 and propensity-matched TC patients without I-131 therapy.

Analysis of PET parameters as prognosticators of survival and tumor extent in Oropharyngeal Cancer treated with surgery and postoperative radiotherapy.

BACKGROUND: Positron-emission tomography (PET) is widely used to detect malignancies, but consensus on its prognostic value in oropharyngeal cancer has not been established. The purpose of this study was to analyze the PET parameters associated with tumor extent and survival in resectable oropharyngeal cancer. METHODS: The PET parameters in oropharyngeal cancer patients with regional node metastasis who underwent surgery and postoperative radiotherapy between January 2005 and January 2019 were analyzed. We calculated the SUVmax, tumor-to-liver ratio (TLR), metabolic tumor volume (MTV, volume over SUV 2.5), and total lesion glycolysis (TLG, MTV x mean SUV) of the primary lesion and metastatic nodes. Histologic findings, patient survival, and recurrence were reviewed in the medical records. RESULTS: Fifty patients were included, and the PET parameters were extracted for 50 primary lesions and 104 nodal lesions. In the survival analysis, MTV and TLG of the primary lesions showed significant differences in overall survival (OS) and recurrence-free survival (RFS). In the multiple regression analysis, TLG of the primary lesion was associated with the depth of invasion (DOI). MTV of the nodes was a significant factor affecting extranodal extension (ENE). CONCLUSIONS: PET parameters could be related with OS, RFS, DOI of the primary tumor, and ENE. PET would be expected to be a useful diagnostic tool as a prognosticator of survival and pathologic findings in oropharyngeal cancer.

The clinical value of F-18 FDG PET/CT in differentiating malignant from benign lesions in pneumoconiosis patients.

OBJECTIVES: We reviewed PET/CT findings of pneumoconiosis and determined the ability of PET/CT to differentiate lung cancer from progressive massive fibrosis (PMF), and metastatic lymph nodes (LNs) from underlying reactive LN hyperplasia. METHODS: This was a retrospective study of patients with pneumoconiosis and suspected lung cancer. Maximum standardized uptake value (SUVmax), long- and short-axis diameters (DL and DS), ratio of DL to DS (DL/S), and Hounsfield unit (HU) from the lung mass and mediastinal LNs were measured. The cutoff values of each parameter were obtained by ROC analysis, and we evaluated the diagnostic sensitivity. RESULTS: Forty-nine pneumoconiosis patients were included. Eighty-three lung masses were detected, of which 42 were confirmed as lung cancer (23 squamous cell carcinomas, 12 adenocarcinomas, and 7 small cell carcinomas) and 41 were PMF. There were significant differences between lung cancer and PMF in terms of SUVmax, DS, DL/S, and HU (all p < 0.05). The sensitivity, specificity, and accuracy for diagnosis of lung cancer were 81.0%, 73.2%, and 77.1%, respectively, with an SUVmax cutoff value of 7.4; and 92.8%, 87.8%, and 90.4%, respectively, with a HU cutoff value of 45.5. Among the 40 LNs with available pathological results, 7 were metastatic. Metastatic LNs showed higher SUVmax, larger DS, and lower HU than benign lesions (all p < 0.05). The sensitivity, specificity, and accuracy for predicting metastatic LNs by PET/CT were 85.7%, 93.9%, and 92.5%, respectively. CONCLUSION: By applying PET and CT parameters in combination, the accuracy for differentiating malignant from benign lesions could be increased. PET/CT can play a central role in the discrimination of lung cancer and PMF. KEY POINTS: • Lung cancer showed significantly higher SUVmax than PMF. • Lung cancer showed similar D L but longer D S , resulting in a smaller D L/S than PMF. • SUVmax demonstrated additive value in differentiating lung cancer from PMF, compared with HU alone.

18F-fluorodeoxyglucose uptake of hepatocellular carcinoma as a prognostic predictor in patients with sorafenib treatment.

PURPOSE: Sorafenib, an oral multikinase inhibitor, is a recommended treatment option available for patients with Barcelona Clinic Liver Cancer (BCLC)-C stage hepatocellular carcinoma (HCC). This study aimed to evaluate the performance of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) for predicting tumour progression during sorafenib treatment. METHODS: We formed a retrospective cohort comprising patients treated with sorafenib for at least 30 days and undergoing 18F-FDG PET/CT within 1 month before treatment. For statistical analyses, the tumour-to-liver standardised uptake value (SUV) ratio (TLR) of the most hypermetabolic lesion was measured. RESULTS: Among a total of 35 patients, two obtained partial remission, and 11 showed stable disease after the first response evaluation. Patients with a TLR ≥ 2.9 (n = 17) had a median overall survival (OS) of 3.7 months after sorafenib treatment, whereas patients with a TLR < 2.9 (n = 18) had median OS of 12.2 months (P < 0.001), although the disease control rate was not significantly different between the two groups. Pretreatment TLR ≥ 2.9 (hazard ratio [HR] = 6.318, P = 0.002) and Child-Pugh class B (HR = 4.316, P = 0.044) were poor prognostic factors for OS, and a TLR ≥ 2.9 (HR = 2.911, P = 0.024) was the only poor prognostic factor for progression-free survival in a multivariate analysis. CONCLUSION: Pretreatment tumour metabolic activity assessed by 18F-FDG PET is an independent prognostic factor for survival in patients with BCLC-C stage HCC receiving sorafenib monotherapy, although it may not predict tumour response to the treatment.

The value of pre- and post-neoadjuvant chemotherapy F-18 FDG PET/CT scans in breast cancer: comparison with MRI.

Background Accurate assessment of neoadjuvant chemotherapy (NAC) response with positron emission tomography/computed tomography (PET/CT) or magnetic resonance imaging (MRI) may provide appropriate operation guidelines for individual breast cancer patients. Purpose To compare the values of PET/CT and MRI for response evaluation following NAC in breast cancer patients. Material and Methods Thirty-three consecutive patients who underwent NAC were included. PET/CT and MRI were performed before and one to four weeks after NAC. With response evaluation of PET/CT and MRI, patients with complete/partial responses on imaging studies were considered to be responders, and those showing stable/progressive disease non-responders. Peak standardized uptake value corrected for lean body mass (SULpeak) and metabolic tumor volume (MTV) were measured from PET/CT, and unidimensional diameter (1D) and tumor volume (TV) from MRI. Reduction rates for each parameter were calculated (Δ%SULpeak, Δ%MTV, Δ%1D, and Δ%TV). The pathological response for NAC as reference was evaluated after surgical resection of the remaining tumor in the breast. Results We identified 17 pathological responders and 16 non-responders. PET/CT had lower specificity and accuracy, but higher sensitivity than MRI, although no significant difference was found between PET/CT and MRI. Following NAC, there were significant differences between pathological responders and non-responders in SULpeak ( P < 0.001), MTV ( P < 0.001), 1D ( P = 0.0003), TV ( P = 0.038), Δ%SULpeak ( P = 0.001), Δ%MTV ( P < 0.001), Δ%1D ( P < 0.001), and Δ%TV ( P = 0.001). Conclusion PET/CT showed lower specificity and accuracy than MRI in evaluating responses to NAC, but both PET/CT and MRI parameters may have predictive value in distinguishing therapeutic responders and non-responders following NAC.

Clinical Significance of C-MET Overexpression and Epidermal Growth Factor Receptor Mutation in Platinum-Based Adjuvant Chemotherapy Outcome in Surgically Resected Lung Adenocarcinoma.

PURPOSE: We retrospectively assessed the role of C-MET expression and epidermal growth factor receptor (EGFR) mutation on survival following platinum-based adjuvant chemotherapy. The impact of C-MET on survival was also investigated in relation to EGFR mutation status. METHODS: We enrolled 311 patients with resected lung adenocarcinoma (high-risk stage 1B-3A), and performed immunohistochemistry (IHC) using C-MET- and mutant EGFR (EGFRmut)-specific antibodies in tissue microarrays. RESULTS: Adjuvant chemotherapy was administered to 151 patients, 96 of whom relapsed and 85 died by the end of the study. On IHC, C-MET and EGFRmut were positive in 141 (45.3 %) and 88 (28.3 %) cases, respectively. On univariate analysis, adjuvant chemotherapy prolonged relapse-free survival (RFS) and overall survival (OS) in C-MET(+) patients (RFS p = 0.035; OS p = 0.013) but not in C-MET(-) patients. On multivariate analysis, adjuvant chemotherapy was a positive independent prognostic factor in C-MET(+) (RFS p = 0.013; OS p = 0.006) but not in C-MET(-) patients. In addition, univariate analysis showed no effect of EGFRmut status on RFS and OS after chemotherapy, whereas multivariate analysis revealed that adjuvant chemotherapy increased RFS in both EGFRmut(+) and EGFRmut(-) patients [EGFRmut(+) p = 0.033; EGFRmut(-) p = 0.030]. C-MET was a negative prognostic factor for RFS (p = 0.045) and OS (p = 0.007) in the EGFRmut(-) group but not in the EGFRmut(+) group, on multivariate analysis. CONCLUSIONS: Our data indicate that patients with C-MET overexpression should be considered for adjuvant chemotherapy, and that C-MET negatively correlates with survival in patients with wild-type, but not mutant, EGFR.

18F-FDG PET/CT and histology for diagnosing recurrent/remnant tumors in head and neck cancer patients treated with radiotherapy.

OBJECTIVE: The aim of this study was to assess the diagnostic performance of fluorine-18-fluoro-2-deoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) for locoregional recurrent/residual tumor in patients with head and neck cancer (HNC) who underwent previous radiotherapy (RT). SUBJECTS AND METHODS: 18F-FDG PET/CT images from patients with HNC who previously underwent RT were retrospectively reviewed. Only cases with histological confirmation within 4 weeks of PET/CT imaging were included. Standardized uptake values were obtained for lesions and PET/CT findings were compared with histological results. RESULTS: Of 181 cases, 114 (63%) were histologically confirmed as malignant and 67 (37%) as benign. The sensitivity, specificity, and accuracy of PET/CT were 93%, 64%, and 82%, respectively. Inflammation was the most common cause of false positives and small tumor volume and low 18F-FDG avidity were the causes of false negatives. PET/CT had 100% sensitivity and 56% specificity for detecting recurrent or residual disease within 12 weeks after RT and 93% sensitivity and 64% specificity, more than 12 weeks after RT. The frequency of false positives in PET/CT images within 12 weeks of RT was similar to the results obtained 12 weeks after RT (15% vs. 14%). False positives were more frequent in PET/CT cases after two-dimensional or three-dimensional conformal RT than in those after intensity-modulated RT, although not statistically significant (15% vs. 9%, p>0.05). CONCLUSION: 18F-FDG PET/CT might aid the diagnosis of locoregional residual/recurrent tumors in patients with HNC previously treated with RT. Inflammation was the main cause of false positives regardless of the interval between RT and PET/CT, even several years after RT. Therefore, histological verification of positive PET/CT findings should be conducted during follow-up of HNC patients treated with RT.

The phase value of putamen measured by susceptibility weighted images in Parkinson's disease and in other forms of Parkinsonism: a correlation study with F18 FP-CIT PET.

BACKGROUND: Iron deposition of basal ganglia in Parkinson's disease (PD) can be measured using susceptibility weighted images (SWI) on magnetic resonance imaging (MRI). Fluoropropyl carbomethoxy-3b-4-iodophenyltropane (F18 FP-CIT) positron emission tomography (PET) has been used to differentiate Parkinsonism. PURPOSE: To compare SWI phase values in Parkinsonian syndrome and age-matched control and to correlate them with F18 FP-CIT PET. MATERIAL AND METHODS: Retrospectively, patients with Parkinsonian movement disorder (n = 62) and age-matched control (n = 16) were enrolled. Mean phase values on SWI were measured by region of interest (ROI) in putamens and caudate heads. Mean standardized uptake value (SUV) on F18 FP-CIT were measured in the same ROIs of PD (n = 40) and other forms of Parkinsonism (n = 22). A statistical analysis was performed to compare the phase values and SUVs and to correlate them between groups. RESULTS: The putaminal mean phase values were higher in Parkinsonism than in the control (P ≤ 0.001). There was no difference of phase value in caudate head among the groups. Also, the mean phase value of putamen between PD and other forms of Parkinsonism was not different. Mean SUV of F18 FP-CIT in the putamen was lower in PD than other forms of Parkinsonism (P ≤ 0.014). However, there was no significant correlation between phase values and mean SUV (P > 0.05). CONCLUSION: The putaminal phase value was higher than in Parkinsonian syndrome than in the age-matched controls. F18 FP-CIT PET/CT showed different tracer activity between PD and other forms of Parkinsonism. However, no correlation between phase and SUV values was discovered.

Total Lesion Glycolysis Using ¹8F-FDG PET/CT as a Prognostic Factor for Locally Advanced Esophageal Cancer.

Standardized uptake value (SUV), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) have been considered prognostic factors for survival in many cancers. However, their prognostic value for radiotherapy-treated squamous esophageal cancer has not been evaluated. In this study, SUV, MTV, and TLG were measured to predict their prognostic role in overall survival (OS) in 38 esophageal cancer patients who had undergone (18)F-FDG PET/CT before radiotherapy. TLG demonstrated higher sensitivity and specificity for predicting OS than MTV and SUV; and a better OS was observed in patients with low TLG compared to those with high TLG in locally advanced disease (OS, 46.9 months; 95% confidence interval [CI], 33.50-60.26 vs. 25.3 months; 95% CI, 8.37-42.28; P=0.003). Multivariate analyses in these patients determined that TLG and the use of combination chemotherapy were the independent prognostic factors for OS (hazard ratio [HR], 7.12; 95% CI, 2.038-24.857; P=0.002 and HR, 6.76; 95% CI, 2.149-21.248; P=0.001, respectively). These results suggest that TLG is an independent prognostic factor for OS and a better predictor of survival than MTV and SUV in patients with locally advanced esophageal cancer treated with radiotherapy.

CT and MR imaging findings of hepatic epithelioid hemangioendotheliomas: emphasis on single nodular type.

PURPOSE: To evaluate imaging findings of hepatic epithelioid hemangioendothelioma (HEH), with emphasis on solitary form at the initial presentation. MATERIALS AND METHODS: Ten cases of pathologically confirmed HEH were retrospectively reviewed; seven patients had CT and MR images and three had only CT images. Two radiologists assessed the followings in consensus: lesion number, size, location, presence of capsular retraction and calcification, attenuation, signal intensity, and enhancement pattern. RESULTS: Initially, HEHs manifested as a single mass (n = 5) or multiple masses (n = 5). One case demonstrated a solitary nodule at first, which subsequently transformed to multifocal nodules on serial follow-up. The maximal diameter of the lesions ranged from 1.8 to 10 cm (mean 4.2 cm). All cases showed predominant subcapsular location. Capsular retraction was seen in multinodular types, but not in solitary types. Two patients had intra-lesional calcifications. HEHs showed minimal enhancement (7/7 patients) on the hepatic arterial phase CT and rim-like enhancement (5/10 patients), minimal enhancement (2/10 patients), multilayered target enhancement (2/10 patients), and peripheral nodular enhancement (1/10 patients) on the portal venous phase CT. On MR images (n = 7), HEHs showed hypointensity on T1-weighted images and hyperintensity on T2-weighted images. Dynamic contrast-enhanced MR images revealed progressive centripetal fill-in enhancement (7/7 patients). On Gd-EOB-DTPA-enhanced hepatobiliary phase images, HEH manifested as homogeneous hypointensity (3/5 patients) and target-shaped hypointensity (2/5 patients). CONCLUSION: HEH can manifest as single nodular, multinodular, or diffuse type. Common imaging features of HEH are multiple subcapsular nodules with coalescence, capsular retraction, peripheral, and delayed enhancement. However, HEH can manifest as a solitary subcapsular mass with minimal or rim-like enhancement at early phase and progressive centripetal fill-in enhancement during dynamic phase imaging, representing early stage of HEH. A single nodular type can progress to multifocal nodular type during follow-up.

Giant cell tumor of soft tissue: a case report with emphasis on MR imaging.

Giant cell tumor of soft tissue is a rare neoplasm, histologically resembling giant cell tumor of bone. In this report, we describe a deep and solid giant cell tumor of soft tissue interpreted as a benign soft tissue tumor based on magnetic resonance (MR) findings with hypointense to intermediate signals on T2-weighted images and impeded diffusivity (water movement) on diffusion-weighted imaging (DWI), which could suggest a giant-cell-containing benign soft tissue tumor, despite the malignancy suggested by 18F-fluorodeoxyglucose positron emission tomography-computed tomography in a 35-year-old male. To our knowledge, this report introduces the first deep, solid giant cell tumor of soft tissue with MR features of a giant-cell-containing benign soft tissue tumor, despite the malignancy-mimicking findings on 18F-FDG PET-CT.

Prognostic value of preoperative 18F-FDG PET/CT for primary head and neck squamous cell carcinoma.

(18)F-FDG PET/CT is clinically useful in the initial staging and follow-up of patients with head and neck squamous cell carcinoma (HNSCC). We studied the potential prognostic significance of preoperative (18)F-FDG PET/CT in HNSCC. The medical records of 294 patients who underwent preoperative (18)F-FDG PET/CT for HNSCC were retrospectively reviewed. The median SUVmax of the primary lesions (SUVmax-p) and cervical lymph nodes (SUVmax-n) was 7.98 ± 5.04 (range 1.2-28.7) and 3.34 ± 3.70 (range 1.0-20.4), respectively. There was a significant difference between with and without recurrence in SUVmax-p (11.14 ± 5.36 vs. 6.78 ± 4.35, p < 0.001) and SUVmax-n (5.60 ± 4.22 vs. 1.75 ± 1.46, p < 0.001). The cut-off values of SUVmax-p and SUVmax-n in the context of recurrence and cancer-related death were 8.5 and 3.5. The 5-year disease-free survival of patients with SUVmax-p < 8.5 and SUVmax-n < 3.5 was 79 and 79%, respectively, whereas that of patients with SUVmax-p ≥ 8.5 and SUVmax-n ≥ 3.5 was 39 and 30 %, respectively. Multivariate analysis confirmed the significant association between 5-year disease-free survival and SUVmax-p ≥ 8.5 (hazard ratio (HR) 2.68, p < 0.001) and SUVmax-n ≥ 3.5 (HR 2.29, p = 0.007). Furthermore, SUVmax-p ≥ 8.5 (HR 3.20, p = 0.012) and SUVmax-n ≥ 3.5 (HR 2.14, p < 0.001) were associated with 5-year overall survival. (18)F-FDG PET/CT cut-off values of SUVmax-p ≥ 8.5 or SUVmax-n ≥ 3.5 are associated with a recurrence and survival in HNSCC.

18F-FDG PET/CT findings in endometrial cancer patients: the correlation between SUVmax and clinicopathologic features.

OBJECTIVE: To study 18F-FDG PET/CT findings in endometrial cancer patients, to analyze the correlation between the maximum standardized uptake value (SUVmax) and clinicopathologic tumor characteristics. MATERIAL AND METHOD: Retrospective study included 33 endometrial cancer patients who underwent pre-operative 18F-FDG PET/CT and abdominal CT or MRI from June 2005 to October 2009. Pattern of FDG uptake was classified as focal and diffuse uptake. SUVmax was measured at primary tumor in endometrial cavity and correlated with maximum tumor size, menopausal state, histological grade, depth of myometrial invasion and nodal metastasis. The diagnostic performance of 18F-FDG PET/CT was assessed for primary tumor and lymph node metastasis and correlated with those of CT/MRI. RESULTS: Sensitivity of 18F-FDG PET/CT in primary tumor detection was slightly higher, without significant difference, than that of either CT or MRI (93.9% vs. 87.9%, p = 0.625). The overall SUVmax mean ofthe primary tumor was 8.24 +/- 5.38. The focal FDG uptake pattern was more common than the diffuse uptake pattern (71.0% and 29.0%, respectively), but the SUVmax was higher in the diffuse uptake pattern (diffuse pattern 12.10 +/- 7.47 vs. focal pattern 6.66 +/- 3.33, p = 0.008). There was significant association between the SUVmax of the primary tumor and maximum tumor size (p = 0.001), but not between the SUVmax of the primary tumor and menopause state, histological grade, depth of myometrial invasion and nodal metastasis (p = 0.522, 0.622, 0.694 and 0.601, respectively). For lymph node detection, the sensitivity of 18F-FDG PET/CT were also higher without statistically significant difference, than those of CT/MRI (on patient basis; 80.0% vs. 40.0%, p = 0.500; on nodal basis 64.7% vs. 47.1%, p = 0.453, respectively). CONCLUSION: 18F-FDG PET/CThad slightly higher diagnostic sensitivity than CT/MRIin both primary tumor and lymph node detection. The finding focal uptake pattern is more common, but the diffuse uptake pattern shows higher FDG uptake. The SUVmax of primary tumors was associated with the maximum tumor size, but not associated with menopause state, histologic grade, depth of myometrial invasion and nodal metastasis.

Post-RFA Pulmonary Vein Stenosis Mimicking Lymphangitic Carcinomatosis in a Patient With History of Liposarcoma.

ABSTRACT: A 58-year-old man with resected liposarcoma exhibited persistent irregular interlobular septal thickening of lung on CT concerning lymphangitic metastasis. FDG PET/CT was positive in these foci. There was a narrowing of the pulmonary veins, which had not been seen on the imaging conducted prior to radiofrequency ablation therapy for atrial fibrillation. Lung perfusion scanning demonstrated more extensive hypoperfusion. This case highlights the diagnostic pitfalls of interstitial thickening of the lung in cancer patients. Meticulous history review and nuclear imaging helped distinguish the postablation pulmonary venous stenosis from metastatic spread to the lung interstitium.

Dosimetric Analysis of a Phase I Study of PSMA-Targeting Radiopharmaceutical Therapy With [177Lu]Ludotadipep in Patients With Metastatic Castration-Resistant Prostate Cancer.

OBJECTIVE: 177Lutetium [Lu] Ludotadipep is a novel prostate-specific membrane antigen targeting therapeutic agent with an albumin motif added to increase uptake in the tumors. We assessed the biodistribution and dosimetry of [177Lu]Ludotadipep in patients with metastatic castration-resistant prostate cancer (mCRPC). MATERIALS AND METHODS: Data from 25 patients (median age, 73 years; range, 60-90) with mCRPC from a phase I study with activity escalation design of single administration of [177Lu]Ludotadipep (1.85, 2.78, 3.70, 4.63, and 5.55 GBq) were assessed. Activity in the salivary glands, lungs, liver, kidneys, and spleen was estimated from whole-body scan and abdominal SPECT/CT images acquired at 2, 24, 48, 72, and 168 h after administration of [177Lu]Ludotadipep. Red marrow activity was calculated from blood samples obtained at 3, 10, 30, 60, and 180 min, and at 24, 48, and 72 h after administration. Organ- and tumor-based absorbed dose calculations were performed using IDAC-Dose 2.1. RESULTS: Absorbed dose coefficient (mean ± standard deviation) of normal organs was 1.17 ± 0.81 Gy/GBq for salivary glands, 0.05 ± 0.02 Gy/GBq for lungs, 0.14 ± 0.06 Gy/GBq for liver, 0.77 ± 0.28 Gy/GBq for kidneys, 0.12 ± 0.06 Gy/GBq for spleen, and 0.07 ± 0.02 Gy/GBq for red marrow. The absorbed dose coefficient of the tumors was 10.43 ± 7.77 Gy/GBq. CONCLUSION: [177Lu]Ludotadipep is expected to be safe at the dose of 3.7 GBq times 6 cycles planned for a phase II clinical trial with kidneys and bone marrow being the critical organs, and shows a high tumor absorbed dose.

18F-fluorodeoxyglucose PET/CT predicts tumour progression after transarterial chemoembolization in hepatocellular carcinoma.

PURPOSE: (18)F-FDG PET monitoring of FDG uptake may be a useful tool for assessment of the biological behaviour of hepatocellular carcinoma (HCC). We evaluated the correlation between FDG uptake on (18)F-FDG PET and clinical characteristics and prognosis. METHODS: In total, 58 HCC patients undergoing (18)F-FDG PET before transarterial chemoembolization (TACE) between May 2007 and May 2010 at Seoul St. Mary's Hospital were evaluated retrospectively. The predictive value of the ratio of maximal tumour standardized uptake value (SUV) to mean liver SUV (T(SUVmax)/L(SUVmean)) was tested. Primary endpoints were the clinical characteristics and treatment response according to T(SUVmax)/L(SUVmean). The secondary endpoint was time to progression (TTP). RESULTS: A high SUV ratio (cutoff value 1.70) correlated significantly with tumour size (≥5 cm) and serum AFP level (≥400 ng/mL). Objective response rates were significantly different between those with a ratio above (15.7 %) and those with a ratio below (66.6 %) the cutoff value (P = 0.023). Patients in the low SUV ratio group had a median TTP of 16.8 months compared with 8.1 months in the high SUV ratio group (P = 0.011). Overall survival in the high SUV ratio group was worse than in the low SUV ratio group (median 56.5 vs. 23.3 months), although the difference was not statistically significant in a multivariate analysis. CONCLUSION: Tumour metabolic activity (T(SUVmax)/L(SUVmean)), assessed by PET/CT, is an independent predictor of response to TACE in patients with intermediate-stage HCC. T(SUVmax)/L(SUVmean) can be used to predict tumour progression. Thus, (18)F-FDG PET can provide valuable information for prediction of prognosis and aid in decisions regarding treatment strategy.

Clinical Challenge of Two Competing Targetable Mutations in Non-Small-Cell Lung Cancer: A Case Report.

The development of therapeutic agents targeting products of epidermal growth factor receptor (EGFR) gene mutation and anaplastic lymphoma kinase (ALK) rearrangements has improved survival in patients with non-small-cell lung cancer. EGFR and ALK mutations are generally regarded as mutually exclusive, and the presence of one in lieu of another influences the response to targeted therapy. We herein present an interesting case following the course of progression of a patient with synchronous lung cancers with a discordant mutation profile. The importance of this modality in the follow-up of lung cancer patients is illustrated, and the therapeutic implications of coexisting oncogenic drivers are briefly discussed.

Brown fat activation demonstrated on FDG PET/CT predicts survival outcome.

PURPOSE: The purpose of this study was to compare the survival of patients with and without BAT activity on FDG PET/CT. METHODS: PET/CT exams from 3937 breast cancer patients were retrospectively reviewed for bilateral symmetric elongated FDG activity in the neck and chest, typical of BAT activation. A control group of age-matched (± 1 year) breast cancer patients who underwent PET/CT the same week was also enrolled for comparison. Kaplan-Meier curves of progression-free survival (PFS) and overall survival (OS) for BAT positive patients and the control group were calculated. Further sub-analysis was performed to account for the hormonal changes associated with menopause. RESULTS: 2.0% (80/3937) of the breast cancer patients who underwent PET/CT demonstrated BAT activation, and 80 additional patients were analyzed for comparison as the group without BAT activity. Mean follow-up was 76 months (range 1-225 months). There were 4 recurrences in the BAT group, compared to 12 in the control. The mean PFS for the BAT group was 127 months, which was significantly lower than the mean PFS of 180 months in the control (p = 0.047). Sub-analysis of premenopausal women again showed longer PFS for the BAT group (129 vs. 196 months, p = 0.095) while no difference was found in postmenopausal women (mean 102 vs. 135 months, p = 0.360). Presence of BAT activity was also a significant predictor variable for PFS on Cox regression. CONCLUSION: Patients with BAT activity showed longer progression-free survival than those without, emphasizing the need for further evaluation of its role in metabolism, treatment response, tumor microenvironment and long-term prognosis.

Prognostic impact of 18F-FDG PET/CT in pathologic stage II invasive ductal carcinoma of the breast: re-illuminating the value of PET/CT in intermediate-risk breast cancer.

BACKGROUND: The aim of this study is to investigate the impact of 18F-FDG PET/CT on prognosis of stage II invasive ductal carcinoma (IDC) of the breast primarily treated with surgery. METHODS: The clinical records of 297 consecutive IDC with preoperative PET/CT and pathologically staged II in surgery from 2013 to 2017 were retrospectively reviewed. The maximum standardized uptake value (SUVmax), peak standardized uptake value (SUVpeak), tumor-to-liver ratio (TLR), and metabolic tumor volume (MTV) were measured. Association of clinicopathologic factors (age, T stage, N stage, AJCC pathologic stage of IIA or IIB, pathologic prognostic stage, grade, hormonal receptor status, HER2 status, Ki-67, and adjuvant therapy) and PET parameters with DFS was assessed using the Cox proportional hazards model. RESULTS: There were 35 recurrences and 10 deaths at a median follow-up of 49 months (range 0.8 ~ 87.3). All PET parameters were significantly associated with DFS in univariate analysis but in multivariate analysis, SUVpeak was the only factor significantly associated with DFS (hazard ratio 2.58, 95% confidence interval 1.29-5.15, P = 0.007). In cohorts with higher values of SUVpeak or TLR, patients who received adjuvant chemotherapy had significantly superior DFS. CONCLUSION: Metabolic parameters derived from preoperative PET/CT was significantly associated with recurrence in stage II IDC primarily treated with surgery. PET/CT can be a powerful prognostic tool in conjunction with novel staging systems and current biomarkers for patients undergoing contemporary therapy. Our results urge to reconsider the currently underestimated value of PET/CT confined to diagnostic aspect and to newly recognize its prognostic impact in these intermediate-risk breast cancer.