Quantitative Bone SPECT/CT of Central Cartilaginous Bone Tumors: Relationship between SUVmax and Radiodensity in Hounsfield Unit.

(1) Background: it is challenging to determine the accurate grades of cartilaginous bone tumors. Using bone single photon emission computed tomography (SPECT)/computed tomography (CT), maximum standardized uptake value (SUVmax) was found to be significantly associated with different grades of cartilaginous bone tumor. The inquiry focused on the effect of the tumor matrix on SUVmax. (2) Methods: a total of 65 patients from 2017 to 2022 with central cartilaginous bone tumors, including enchondromas and low-to-intermediate grade chondrosarcomas, who had undergone bone SPECT/CT were retrospectively enrolled. The SUVmax was recorded and any aggressive CT findings of cartilaginous bone tumor and Hounsfield units (HU) of the chondroid matrix as mean, minimum, maximum, and standard deviation (SD) were reviewed on CT scans. Pearson's correlation analysis was performed to determine the relationship between CT features and SUVmax. Subgroup analysis was also performed between the benign group (enchondroma) and the malignant group (grade 1 and 2 chondrosarcoma) for comparison of HU values and SUVmax. (3) Results: a significant negative correlation between SUVmax and HU measurements, including HUmax, HUmean, and HUSD, was found. The subgroup analysis showed significantly higher SUVmax in the malignant group, with more frequent CT aggressive features, and significantly lower HUSD in the malignant group than in the benign group. (4) Conclusions: it was observed that higher SUVmax and lower HUSD were associated with a higher probability of having a low-to-intermediate chondrosarcoma with aggressive features and a less calcified tumor matrix.

Atypical Layering of FDG in Pleural Effusion.

ABSTRACT: Radiopharmaceuticals can accumulate in malignant or nonmalignant pleural effusion on γ and PET imaging, and effusion shows a pattern of diffusely or focally increased activity. Herein, we report atypical layering of FDG in pleural effusion on PET/CT of 3 patients with metastatic gynecological cancer.

SPECT/CT Radiomics for Differentiating between Enchondroma and Grade I Chondrosarcoma.

This study was performed to assess the value of SPECT/CT radiomics parameters in differentiating enchondroma and atypical cartilaginous tumors (ACTs) located in the long bones. Quantitative HDP SPECT/CT data of 49 patients with enchondromas or ACTs in the long bones were retrospectively reviewed. Patients were randomly split into training (n = 32) and test (n = 17) data, and SPECT/CT radiomics parameters were extracted. In training data, LASSO was employed for feature reduction. Selected parameters were compared with classic quantitative parameters for the prediction of diagnosis. Significant parameters from training data were again tested in the test data. A total of 12 (37.5%) and 6 (35.2%) patients were diagnosed as ACTs in training and test data, respectively. LASSO regression selected two radiomics features, zone-length non-uniformity for zone (ZLNUGLZLM) and coarseness for neighborhood grey-level difference (CoarsenessNGLDM). Multivariate analysis revealed higher ZLNUGLZLM as the only significant independent factor for the prediction of ACTs, with sensitivity and specificity of 85.0% and 58.3%, respectively, with a cut-off value of 191.26. In test data, higher ZLNUGLZLM was again associated with the diagnosis of ACTs, with sensitivity and specificity of 83.3% and 90.9%, respectively. HDP SPECT/CT radiomics may provide added value for differentiating between enchondromas and ACTs.

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.

Comparison of FDG PET/CT and Bone Marrow Biopsy Results in Patients with Diffuse Large B Cell Lymphoma with Subgroup Analysis of PET Radiomics.

Whether FDG PET/CT can replace bone marrow biopsy (BMBx) is undecided in patients with diffuse large B cell lymphoma (DLBCL). We compared the visual PET findings and PET radiomic features, with BMBx results. A total of 328 patients were included; 269 (82%) were PET-negative and 59 (18%) were PET-positive for bone lesions on visual assessment. A fair degree of agreement was present between PET and BMBx findings (ĸ = 0.362, p < 0.001). Bone involvement on PET/CT lead to stage IV in 12 patients, despite no other evidence of extranodal lesion. Of 35 discordant PET-positive and BMBx-negative cases, 22 (63%) had discrete bone uptake on PET/CT. A total of 144 patients were eligible for radiomic analysis, and two grey-level zone-length matrix derived parameters obtained from the iliac crests showed a trend for higher values in the BMBx-positive group compared to the BMBx-negative group (mean 436.6 ± 449.0 versus 227.2 ± 137.8, unadjusted p = 0.037 for high grey-level zone emphasis; mean 308.8 ± 394.4 versus 135.7 ± 97.2, unadjusted p = 0.048 for short-zone high grey-level emphasis), but statistical significance was not found after multiple comparison correction. Visual FDG PET/CT assessment and BMBx results were discordant in 17% of patients with newly diagnosed DLBCL, and the two tests are complementary in the evaluation of bone involvement.

Paradoxical Cerebral Perfusion in Parkinson's Disease Patients with Orthostatic Hypotension: A Dual-Phase 18F-Florbetaben Positron Emission Tomography Study.

BACKGROUND: Orthostatic hypotension (OH) may antedate Parkinson's disease (PD) or be found in early stages of the disease. OH may induce a PD brain to chronic hypotensive insults. 18F-Florbetaben (18F-FBB) tracer has a high first-pass influx rate and can be used with positron emission tomography (PET) as a surrogate marker for early- and late-phase evaluation of cerebral perfusion and cerebral amyloidosis, respectively. OBJECTIVE: In this study, we evaluated whether 18F-FBB uptake in the early- and late-phases of PD was related to OH. This study manipulated the imaging modality to illustrate the physiology of cerebral flow with OH in PD (PD + OH). METHODS: A group of 73 early-stage PD patients was evaluated with a head-up tilt-test and 18F-FBB PET imaging. The cognitive status was assessed by a comprehensive battery of neuropsychological tests. PET images were normalized, and both early- and late-phase standardized uptake value ratios (SUVRs) of pre-specified regions were obtained. The associations between regional SUVRs and OH and cognitive status were analyzed. RESULTS: Twenty (27.4%) participants had OH. Thirteen (17.8%) patients were interpreted as having amyloid pathology based on regional 18F-FBB uptake. Early-phase SUVRs were higher in specific brain regions of PD + OH patients than those without OH. However, late-phase SUVRs did not differ between the groups. The early-phase SUVRs were not influenced by amyloid burden or by interaction between amyloid and orthostatic hypotension. Cognitive functions were not disparate when PD + OH patients were contrasted with non-OH patients in this study. CONCLUSION: Cerebral blood flow was elevated in patients with early PD + OH. This finding suggests augmented cerebral perfusion in PD + OH might be a compensatory regulation in response to chronic OH.

Serum CYFRA 21.1 Level Predicts Disease Course in Thyroid Cancer with Distant Metastasis.

BACKGROUND: Serum Cyfra 21.1, the soluble fragment of CK19, has been used as a prognostic tumor marker in various cancers, indicating poor tumor differentiation and increased metastasis. METHODS: We analyzed the serum Cyfra 21.1 level in 51 consecutive patients with thyroid cancer manifesting distant metastasis treated with prior total thyroidectomy. Serum Cyfra 21.1 levels of 26 thyroid cancer patients without metastasis and 50 healthy individuals were used for comparison. RESULTS: Higher serum Cyfra 21.1 levels were detected in thyroid cancer patients with distant metastasis compared with healthy subjects and thyroid cancer patients without metastasis (p = 0.012). Serum Cyfra 21.1 levels were significantly increased in patients with positive BRAF V600E mutation (p = 0.019), undergoing Tyrosine Kinase Inhibitor (TKI) therapy (p = 0.008), with radioiodine-refractory status (p = 0.047), and in disease progression compared with those manifesting stable disease (p = 0.007). In progressive disease with undetectable or unmonitored thyroglobulin because of thyroglobulin antibody, serum Cyfra 21.1 was useful as a biomarker for follow-up of disease course. CONCLUSION: Serum Cyfra 21.1 in thyroid cancer patients might represent an alternative biomarker predicting tumor progression, especially in cases not associated with serum Tg levels.

Prognostic value of tumor metabolic imaging phenotype by FDG PET radiomics in HNSCC.

OBJECTIVE: Tumor metabolic phenotype can be assessed with integrated image pattern analysis of 18F-fluoro-deoxy-glucose (FDG) Positron Emission Tomography/Computed Tomography (PET/CT), called radiomics. This study was performed to assess the prognostic value of radiomics PET parameters in head and neck squamous cell carcinoma (HNSCC) patients. METHODS: 18F-fluoro-deoxy-glucose (FDG) PET/CT data of 215 patients from HNSCC collection free database in The Cancer Imaging Archive (TCIA), and 122 patients in Seoul St. Mary's Hospital with baseline FDG PET/CT for locally advanced HNSCC were reviewed. Data from TCIA database were used as a training cohort, and data from Seoul St. Mary's Hospital as a validation cohort. With the training cohort, primary tumors were segmented by Nestles' adaptive thresholding method. Segmental tumors in PET images were preprocessed using relative resampling of 64 bins. Forty-two PET parameters, including conventional parameters and texture parameters, were measured. Binary groups of homogeneous imaging phenotypes, clustered by K-means method, were compared for overall survival (OS) and disease-free survival (DFS) by log-rank test. Selected individual radiomics parameters were tested along with clinical factors, including age and sex, by Cox-regression test for OS and DFS, and the significant parameters were tested with multivariate analysis. Significant parameters on multivariate analysis were again tested with multivariate analysis in the validation cohort. RESULTS: A total of 119 patients, 70 from training, and 49 from validation cohort, were included in the study. The median follow-up period was 62 and 52 months for the training and the validation cohort, respectively. In the training cohort. binary groups with different metabolic radiomics phenotypes showed significant difference in OS (p = 0.036), and borderline difference in DFS (p = 0.086). Gray-Level Non-Uniformity for zone (GLNUGLZLM) was the most significant prognostic factor for both OS (hazard ratio [HR] 3.1, 95% confidence interval [CI] 1.4-7.3, p = 0.008) and DFS (HR 4.5, CI 1.3-16, p = 0.020). Multivariate analysis revealed GLNUGLZLM as an independent prognostic factor for OS (HR 3.7, 95% CI 1.1-7.5, p = 0.032). GLNUGLZLM remained as an independent prognostic factor in the validation cohort (HR 14.8. 95% CI 3.3-66, p < 0.001). CONCLUSIONS: Baseline FDG PET radiomics contain risk information for survival prognosis in HNSCC patients. The metabolic heterogeneity parameter, GLNUGLZLM, may assist clinicians in patient risk assessment as a feasible prognostic factor.

Direct combustion of waste oil in domestic stove by an internal heat re-circulation atomization technology: Emission and performance analysis.

Direct use of waste oil as fuel to meet the residential energy demands, is very attractive due to its potentials to decrease fossil fuel consumption, reduce pollution and increase sustainability. This paper uses a domestic stove with an internal heat re-circulation and self-atomization technology to burn yellow waste cooking oil (WCO-1), brown waste cooking oil (WCO-2) and waste lubricant oil (WLO). Emission factors (EFs), energy efficiency and modified combustion efficiency (MCE) of this combined fuel/stove system were determined under space-heating and cooking modes. The results showed that EFs of CO, PM2.5, total 16 PAHs and corresponding toxic equivalent quantity (TEQ) values ranged from 2.18 × 103 to 4.90 × 103 mg/MJnet, 16.36-69.40 mg/MJnet, 2.39-12.93 µg/MJnet and 0.16-0.92 µg of TEQ/MJnet. WCO-1 was verified to be the cleanest fuel with the highest energy efficiency (85.3 ± 3.3% and 90.4 ± 2.2%) and lowest emission levels, such as NO (53.75 ± 2.62 and 37.09 ± 5.41 mg/MJnet), NO2 (82.40 ± 3.96 and 56.87 ± 8.29 mg/MJnet) and PM2.5 (20.94 ± 6.55 and 16.35 ± 5.06 mg/MJnet) compared to WCO-2 and WLO. The estimated total cost of using waste oil for each household in winter was much cheaper than some current available clean energy means, including only USD$ 400 of stove price and USD$ 250/ton of fuel per year. It is a promising candidate choice for replacing low-quality solid fuels in rural China and 2.62 million rural households would achieve environmental and economic benefits if promoting direct combustion of waste oil for daily heating and cooking.

FDG PET/CT response in diffuse large B-cell lymphoma: Reader variability and association with clinical outcome.

F-18-fluoro-2-deoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is essential for monitoring response to treatment in patients with diffuse large B-cell lymphoma (DLBCL) and qualitative interpretation is commonly applied in clinical practice. We aimed to evaluate the interobserver agreements of qualitative PET/CT response in patients with DLBCL and the predictive value of PET/CT results for clinical outcome.PET/CT images were obtained for patients with DLBCL 3 times: at baseline, after 3 cycles of first-line chemotherapy (interim), and after completion of chemotherapy. Two nuclear medicine physicians (with 3 and 8 years of experience with PET/CT) retrospectively assessed response to chemotherapy blinded to the clinical outcome using International Harmonization Project (IHP) criteria and Deauville 5-point score. The associations between PET/CT results and progression-free survival (PFS) and overall survival (OS) were assessed using Cox regression analysis.A total of 112 PET/CT images were included from 59 patients with DLBCL (36 male, 23 female; mean age 53 ±â€Š14 years). Using the IHP criteria, interobserver agreement was substantial (Cohen κ = 0.76) with absolute agreement consistency of 89%. Using the Deauville score, interobserver agreement was moderate (Cohen weighted κ = 0.54) and absolute consistency was 62%. The most common cause of disagreements was discordant interpretation of residual tumor uptake. With median follow-up period of 60 months, estimated 5-year PFS and OS were 81% and 92%, respectively. Neither interim nor posttreatment PET/CT results by both readers were significantly associated with PFS. Interim PET/CT result by the more experienced reader using Deauville score was a significant factor for OS (P = 0.019).Moderate-to-substantial interobserver agreement was observed for response assessments according to qualitative PET/CT criteria, and interim PET/CT result could predict OS in patients with DLBCL. Further studies are necessary to further standardize the PET/CT-based response criteria for more consistent interpretation.

Correlation of Consecutive Serum Thyroglobulin Levels During Hormone Withdrawal and Failure of Initial Radioiodine Ablation in Thyroid Cancer Patients.

OBJECTIVE: The aim of this study was to evaluate the value of thyroglobulin (Tg) kinetics during preparation of radioiodine ablation for prediction of initial radioiodine ablation failure in thyroid cancer patients. METHODS: Thyroid cancer patients after total thyroidectomy who underwent radioiodine ablation with 3-4 weeks of hormone withdrawal between May 2011 and January 2012 were included. Consecutive serum Tg levels 5-10 days before ablation (Tg1) and on the day of ablation (Tg2) were obtained. The difference between Tg1 and Tg2 (ΔTg), daily change rate of Tg (ΔTg/day) and Tg doubling time (Tg-DT) were calculated. Success of initial ablation was determined by the results of the follow-up ultrasonography, diagnostic radioiodine scan and stimulated Tg level after 6 to 20 months. RESULTS: A total of 143 patients were included. Failed ablation was reported in 52 patients. Tg2 higher than 5.6 ng/ml and Tg-DT shorter than 4.2 days were significantly related to a high risk of ablation failure. ΔTg and ΔTg/day did not show significant correlation with ablation failure. CONCLUSIONS: Thyroglobulin kinetics on consecutive blood sampling during hormone withdrawal may be helpful in predicting patients with higher risk of treatment failure of initial radioiodine ablation therapy in thyroid cancer patients.

Significance of Incidental Nasopharyngeal Uptake on (18)F-FDG PET/CT: Patterns of Benign/Physiologic Uptake and Differentiation from Malignancy.

PURPOSE: The purpose of this study was to assess the significance of incidental nasopharyngeal uptake on 18F-FDG PET/CT and to identify image patterns useful in the differentiation between benign or physiologic activity and nasopharyngeal carcinoma. METHODS: We retrospectively reviewed medical records of patients with nasopharyngeal uptakes on 18F-FDG PET/CT scans taken between January 2010 and July 2011. Patients with head and neck cancer, other metastatic head and neck lesions, or lymphoma were excluded. Total 177 patients were enrolled (Group A). PET images were reviewed for patterns of nasopharyngeal FDG uptake, presence/absence of cervical lymph node uptake and pattern of cervical node uptake. Diagnostic confirmation was made by pathology or clinical and radiological follow-up for 1 year or longer. Furthermore, initial PET/CT images of 48 patients with nasopharyngeal carcinoma (Group B) were reviewed for comparison with PET/CT images of Group A patients. RESULTS: All nasopharyngeal uptakes in Group A were confirmed to be benign. Group B showed significantly more intense FDG uptake (SUVmax of Group A 3.9 ± 1.4 vs. Group B 10.4 ± 4.6, p<0.001). and asymmetric nasopharyngeal uptake (asymmetric uptake of Group A 67.8% vs. Group B 89.6%). When SUVmax of 6.0 was used as cut off for detection of malignant nasopharyngeal uptake, the area under the ROC curve was 0.93 (95% confidence interval, 0.88-0.98), with a sensitivity of 88.1% and a specificity of 91.7%. Metastatic nodes in Group B showed higher SUVmax (Group A 2.3 ± 0.6 vs. Group B 7.1 ± 4.0, p<0.001) and larger size (short axis of Group A 5.3 ± 2.0 mm vs. Group B 13.1 ± 4.7 mm, p<0.001) than benign nodes of Group A. The majority of Group B cases demonstrated retropharyngeal lymph node uptake (70.8%), compared to only 2 cases in Group A. CONCLUSIONS: In patients without a history of underlying malignancy involving head and neck, incidental nasopharyngeal uptake on PET/CT does not indicate malignancy. However, if the nasopharyngeal uptake is intense (SUVmax≥6.0) or concomitant retropharyngeal lymph node uptake is present, the possibility of a malignant condition should be considered.

The Value of F-18 FDG PET for Planning Treatment and Detecting Recurrence in Malignant Salivary Gland Tumors: Comparison with Conventional Imaging Studies.

PURPOSE: To assess the value of F-18 FDG PET/CT for detecting cervical lymph node (LN) metastasis and recurrence, as well as planning treatment, and to compare the accuracy of PET/CT with conventional imaging studies (CIS) in patients with malignant salivary gland tumor (SGT). METHODS: Staging and follow-up PET/CT for SGT were retrospectively reviewed. Enhanced CT and/or MRI of the neck were performed within 1 month of PET/CT. Final diagnosis was based on histology from cervical LN dissection and biopsy or a minimum 6 months of clinical and imaging follow-up. We compared the performance of PET/CT in initial cervical LN staging and recurrence detection with that of CIS. RESULTS: A total of 184 PET/CT exams of 66 patients were included, and 34 initial staging and 150 surveillance PET/CT exams were performed. The initial cervical LN detection sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 60.9 %, 89.2 %, 84.0 %, 56.0 %, and 91.0 % for visual analysis on PET/CT, 39.1 %, 95.0 %, 84.8 %, 64.3 %, and 87.4 % for semiquantitative analysis on PET/CT, and and 43.5 %, 94.1 %, 84.8 %, 62.5 %, and 88.1 % for CIS. The sensitivity of visual analysis on PET/CT was significantly higher than that of semiquantitative analysis on PET/CT and CIS (p = 0.0009 and 0.0086). In 5 of 34 initial staging patients (14.7 %), the treatment plan was changed from curative surgery to palliative therapy. The performance of follow-up PET/CT showed no significant difference compared with CIS. CONCLUSION: PET/CT showed comparable performance with CIS for cervical LNs staging. Initial PET/CT changed treatment plans in 14.7 % of patients. However, PET/CT offered no additional advantage for detecting locoregional recurrence.