A Practical Guide to Use of Publicly Available Data Sets for Observational Research in Interventional Radiology.

Observational data research studying access, utilization, cost, and outcomes of image-guided interventions using publicly available "big data" sets is growing in the interventional radiology (IR) literature. Publicly available data sets offer insight into real-world care and represent an important pillar of IR research moving forward. They offer insights into how IR procedures are being used nationally and whether they are working as intended. On the other hand, large data sources are aggregated using complex sampling frames, and their strengths and weaknesses only become apparent after extensive use. Unintentional misuse of large data sets can result in misleading or sometimes erroneous conclusions. This review introduces the most commonly used databases relevant to IR research, highlights their strengths and limitations, and provides recommendations for use. In addition, it summarizes methodologic best practices pertinent to all data sets for planning and executing scientifically rigorous and clinically relevant observational research.

Comparative effectiveness of posttreatment imaging modalities for Medicare patients with advanced head and neck cancer.

BACKGROUND: Persistent controversy exists with regard to how and when patients with head and neck cancer should undergo imaging after definitive therapy. The current study was conducted to evaluate whether the type of imaging modality used in posttreatment imaging impacts cancer-specific survival for patients with advanced head and neck squamous cell carcinoma. METHODS: A retrospective study of National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) program-Medicare-linked data in patients with an advanced stage of the 3 most common head and neck malignancies (oral cavity, oropharynx, and larynx) was conducted. Hazard ratios and 95% CIs for cancer-specific survival were estimated for patients diagnosed with any of these cancers between 2006 and 2015. RESULTS: Significant improvement with regard to cancer-specific survival was observed among patients with American Joint Committee on Cancer stage III and stage IVA laryngeal cancer who underwent positron emission tomography (PET) and/or computed tomography (CT) imaging during the first 6 months after receipt of definitive treatment (hazard ratio, 0.517; 95% CI, 0.33-0.811) compared with those who underwent CT. There was a trend toward an improvement in cancer-specific survival among patients with oral cavity or oropharyngeal malignancies who underwent PET/CT imaging, but it did not reach statistical significance. CONCLUSIONS: Compared with CT imaging, posttreatment imaging with PET was associated with improved survival in patients with advanced laryngeal carcinoma.

Ethnoracial Disparity in Hospital Survival following Transjugular Intrahepatic Portosystemic Shunt Creation for Acute Variceal Bleeding in the United States.

PURPOSE: To investigate the magnitude of racial/ethnic differences in hospital mortality after transjugular intrahepatic portosystemic shunt (TIPS) creation for acute variceal bleeding and whether hospital care processes contribute to them. METHODS: Patients aged ≥18 years undergoing TIPS creation for acute variceal bleeding in the United States (n = 10,331) were identified from 10 years (2007-2016) available in the National Inpatient Sample. Hierarchical logistic regression was used to examine the relationship between patient race and inpatient mortality, controlling for disease severity, treatment utilization, and hospital characteristics. RESULTS: A total of 6,350 (62%) patients were White, 1,780 (17%) were Hispanic, and 482 (5%) were Black. A greater proportion of Black patients were admitted to urban teaching hospitals (Black, n = 409 (85%); Hispanic, n = 1,310 (74%); and White, n = 4,802 (76%); P < .001) and liver transplant centers (Black, n = 215 (45%); Hispanic, n = 401 (23%); and White, n = 2,267 (36%); P < .001). Being Black was strongly associated with mortality (Black, 32% vs non-Black, 15%; odds ratio, 3.0 [95% confidence interval, 1.6-5.8]; P = .001), as assessed using the risk-adjusted regression model. This racial disparity disappeared in a sensitivity analysis including only patients with a maximum Child-Pugh score of 13 (odds ratio 1.2 [95% confidence interval, 0.4-3.6]; P = .68), performed to compensate for the absence of Model for End-stage Liver Disease scores. Ethnoracial differences in access to teaching hospitals, liver transplant centers, first-line endoscopy, and transfusion did not significantly contribute (P > .05) to risk-adjusted mortality. CONCLUSIONS: Black patients have a 2-fold higher inpatient mortality than non-Black patients following TIPS creation for acute variceal bleeding, possibly related to greater disease severity before the procedure.

Utility of Quantitative SPECT/CT Lymphoscintigraphy in Guiding Sentinel Lymph Node Biopsy in Head and Neck Melanoma.

PURPOSE: To investigate the use of advanced SPECT/CT quantification in guiding surgical selection of positive sentinel lymph nodes (SLNs) in head and neck melanoma. METHODS: We retrospectively reviewed data from patients with cutaneous head and neck melanoma who underwent lymphoscintigraphy with SPECT/CT prior to SLN biopsy (SLNB). Quantification of radiotracer uptake from SPECT/CT data was performed using in-house segmentation software. SLNs identified using SPECT/CT were compared to SLNs identified surgically using an intraoperative γ-probe. A radioactivity count threshold using SPECT/CT for detecting a positive SLN was calculated. RESULTS: One hundred and five patients were included. Median number of SLNs detected was 3/patient with SPECT/CT and 2/patient with intraoperative γ-probe. The hottest node identified by SPECT/CT and intraoperative γ-probe were identical in 85% of patients. All 20 histologically positive SLNs were identified by SPECT/CT and γ-probe. On follow-up, all nodal recurrences occurred at lymph node levels with the hottest node identified by SPECT/CT and either the hottest or second hottest node identified by γ-probe during SLNB. Using our data, a SPECT/CT radioactivity count threshold of 20% would eliminate the unnecessary removal of 11% of SPECT/CT identified nodes and 12% of intraoperatively detected nodes. CONCLUSION: Utilizing SPECT/CT quantification, we propose that a radioactivity count threshold can be developed to help guide the selective removal of lymph nodes in head and neck SLNB. Furthermore, the nodal level containing the hottest node identified by SPECT/CT quantification must be thoroughly investigated for SLNs and undergo careful follow-up and surveillance for recurrence.

Elderly Black Non-Hispanic Patients With Head and Neck Squamous Cell Cancer Have the Worst Survival Outcomes.

BACKGROUND: In this population study, we compared head and neck cancer (HNC) prognosis and risk factors in 2 underserved minority groups (Hispanic and Black non-Hispanic patients) with those in other racial/ethnicity groups. METHODS: In this SEER-Medicare database study in patients with HNC diagnosed in 2006 through 2015, we evaluated cancer-specific survival (CSS) between different racial/ethnic cohorts as the main outcome. Patient demographics, tumor factors, socioeconomic status, and treatments were analyzed in relation to the primary outcomes between racial/ethnic groups. RESULTS: Black non-Hispanic patients had significantly worse CSS than all other racial/ethnic groups, including Hispanic patients, in unadjusted univariate analysis (Black non-Hispanic patients: hazard ratio, 1.48; 95% CI, 1.33-1.65; Hispanic patients: hazard ratio, 1.12; 95% CI, 0.99-1.28). To investigate the association of several variables with CSS, data were stratified for multivariate analysis using forward Cox regression. This identified socioeconomic status, cancer stage, and receipt of treatment as predictive factors for the survival differences. Black non-Hispanic patients were most likely to present at a later stage (odds ratio, 1.62; 95% CI, 1.38-1.90) and to receive less treatment (odds ratio, 0.67; 95% CI, 0.55-0.81). Unmarried status, high poverty areas, increased emergency department visits, and receipt of healthcare at non-NCI/nonteaching hospitals also significantly impacted stage and treatment. CONCLUSIONS: Black non-Hispanic patients have a worse HNC prognosis than patients in all other racial/ethnic groups, including Hispanic patients. Modifiable risk factors include access to nonemergent care and prevention measures, such as tobacco cessation; presence of social support; communication barriers; and access to tertiary centers for appropriate treatment of their cancers.

Imaging at diagnosis impacts cancer-specific survival among patients with cancer of the oropharynx.

BACKGROUND: The optimal imaging for the staging of oropharyngeal cancer is not well defined. METHODS: The linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database for 2006 through 2011 was used to compare patient characteristics and hospital region by the initial imaging modality used for patients with oropharyngeal cancer. The primary outcome was 3-year cancer-specific survival (CSS). Cox proportional hazards models were adjusted for imaging, age, sex, region, education, race, American Joint Committee on Cancer stage of disease, and treatment, which were examined using backward elimination. The authors also explored how initial imaging use varied by patient characteristics and hospital region. RESULTS: A total of 1765 patients underwent initial diagnostic imaging. Of those, approximately 11.4% (202 patients) received computed tomography (CT) alone as their initial imaging modality, 5.2% (91 patients) underwent magnetic resonance imaging (MRI) without positron emission tomography (PET), and 83.3% (1472 patients) had initial imaging that included PET. The overall 3-year CSS rate for the entire population was 63.7%. In the adjusted survival models compared by initial imaging modality, patients who underwent a PET examination were found to have higher survival than those who underwent CT alone or MRI, respectively (hazard ratio, 1.337 [95% CI, 1.001-1.785; P = .0491]; and hazard ratio, 1.748 [95% CI, 1.2-2.545; P = .0036]). CONCLUSIONS: Among patients with oropharyngeal cancer, initial staging with PET imaging was associated with improved 3-year CSS compared with initial staging with MRI or CT.

SPECT/CT Adds Distinct Lymph Node Basins and Influences Radiologic Findings and Surgical Approach for Sentinel Lymph Node Biopsy in Head and Neck Melanoma.

BACKGROUND: Planar lymphoscintigraphy (PL) has a lower detection rate of sentinel lymph nodes (SLNs) in head and neck melanoma compared with other sites. We assessed situations when single-photon emission computed tomography/computed tomography (SPECT/CT) identified nodes not seen by PL. We also evaluated the impact of SPECT/CT on surgical approach and oncologic outcomes. METHODS: Patients who underwent SLN biopsy (SLNB) for head and neck melanoma with PL and SPECT/CT between November 2011 and December 2016 were included. Surgeons and radiologists completed a real-time survey inquiring about the utility of SPECT/CT. Patients were divided into two groups: patients with nodal basins identified by both PL and SPECT/CT ('PL + SPECT/CT'), and patients in whom SPECT/CT identified additional nodal basins not seen on PL ('SPECT/CT only'). Patient demographics and long-term outcomes including follow-up duration, recurrence, and survival are described. RESULTS: In the PL + SPECT/CT group, 73 (61.9%) patients were included and 45 (38.1%) patients were included in the SPECT/CT-only group. SPECT/CT added 51 basins to those seen on PL, primarily in the supraclavicular region (43.1%). Eighteen patients had positive node(s) in the PL + SPECT/CT group compared with two patients in the SPECT/CT-only group. Surgeons reported that 81% of the time, SPECT/CT influenced the location of incision for SLNB. CONCLUSIONS: SPECT/CT influences the location of incision and contributes most to identification of nodes in the supraclavicular region. It also detects additional SLN basins when compared with PL. Further studies are necessary to determine when these additional basins require sampling.

Clinical and Radiographic Predictors of Progression and Survival in Relapsed/Refractory Lymphoma Patients Receiving Anti-CD19 CAR T-cell Therapy.

INTRODUCTION: Chimeric antigen receptor (CAR) T-cell therapy has revolutionized treatment of relapsed/refractory (R/R) B-cell lymphomas, though certain patients do not respond to treatment or relapse afterwards. The purpose of this study is to determine patient variables that are predictive of response to CAR-T therapy. METHODS: We conducted a retrospective review of 59 R/R B-cell non-Hodgkin lymphoma patients who received anti-CD19 CAR T-cell therapy. Risk factors for progression free survival (PFS) and overall survival (OS) were identified and multivariate logistic regression models for PFS and OS at 1 year were created using stepwise selection. The final multivariate logistic regression models were used to estimate the area under the receiver operating curve (AUROC). RESULTS: At median follow up of 25.6 months, median overall survival was not reached, and median progression free survival was 5.7 months. Stage IV disease (odds ratio (OR) 9.335, P = .025) was identified as a predictive variable for progression at day 365 with an AUC of 0.7922 (P < .001). IPI (OR 2.828, P = .014), ALC ≥ 0.50 at collection (OR 0.183, P = .043), CRP ≥ 11 (OR 6.177, P = .019), and tocilizumab administration (OR 0.062, P = .005) as predictors for death at day 365 with an AUC 0.8626 (P < .001). CONCLUSION: Clinical variables identify R/R lymphoma patients who are at risk for progression and poor overall survival after CAR T-cell therapy. IPI, CRP, ALC, and tocilizumab administration may be predictors of survival.

Lack of Adherence to Guideline-Based Imaging Before Subsequent Radiation in Patients with Non-Small Cell Lung Cancer: Impact on Patient Outcomes.

Lung cancer is the leading cause of cancer death within the United States, yet prior studies have shown a lack of adherence to imaging and treatment guidelines in patients with lung cancer. This study evaluated the use of 18F-FDG PET/CT imaging before subsequent radiation therapy (RT) in patients with non-small cell lung cancer (NSCLC), as recommended by National Comprehensive Cancer Network guidelines, and whether the use of this imaging modality impacts cancer-specific survival. Methods: This was a retrospective study of the National Cancer Institute's Surveillance, Epidemiology, and End Results program of Medicare-linked data in patients with NSCLC. Hazard ratios and 95% CIs for overall and cancer-specific survival were estimated for patients diagnosed between 2006 and 2015 who underwent either 18F-FDG PET/CT-based or CT-based imaging before subsequent RT. Results: Significant improvement in cancer-specific survival was found in patients who underwent 18F-FDG PET/CT imaging before subsequent RT, compared with those who underwent CT (hazard ratio, 1.43 [95% CI, 1.32-1.55; P < 0.0001]). Although the National Comprehensive Cancer Network recommends 18F-FDG PET/CT before subsequent RT, 43.6% of patients were imaged with CT alone. Conclusion: Many patients with NSCLC are not being imaged according to national guidelines before subsequent RT, and this omission is associated with a lower cancer-specific survival.

Quantifying The Medical Impact of A Missed Diagnosis of Non-Small Cell Lung Cancer on Chest Imaging.

If a chest lesion is noted to have been visible on imaging conducted prior to a definitive diagnosis of non-small cell lung cancer, medico-legal action directed against those considered to have missed the initial diagnosis may ensue. Evidence-based approaches to determine the medical impact of the resulting delay are limited. This article reviews strategies for quantifying the medical impact of missed diagnoses and identifies areas for future research. If no nodal or metastatic disease is present at the time of the definitive diagnosis, the potential impact of the delay is sometimes deduced from the differing 5-year overall survival rates of the T status-associated cancer stage at each time point. However, relapse-free survival, specific lung cancer subtype, time from diagnosis and the medical condition of the patient when the evaluation is being made may also have to be considered. In the absence of T-status change, medical impact from any delay is unlikely to be significant, although the effect of changes in patient fitness on outcomes, emotional distress and lost time for the patient's preparation may be argued. When nodal or metastatic involvement is noted at the time of definitive diagnosis, arguments may be made that these did not exist at the time of the missed diagnosis. However, more nuanced calculations considering differences in the risk of spread based on T-stage at each time point would be preferable. Large datasets to inform T to N-status correlations for such calculations already exist, but data to inform T to M-status correlations are limited.

Targeting Treg-Expressed STAT3 Enhances NK-Mediated Surveillance of Metastasis and Improves Therapeutic Response in Pancreatic Adenocarcinoma.

PURPOSE: Metastasis remains a major hurdle in treating aggressive malignancies such as pancreatic ductal adenocarcinoma (PDAC). Improving response to treatment, therefore, requires a more detailed characterization of the cellular populations involved in controlling metastatic burden. EXPERIMENTAL DESIGN: PDAC patient tissue samples were subjected to RNA sequencing analysis to identify changes in immune infiltration following radiotherapy. Genetically engineered mouse strains in combination with orthotopic tumor models of PDAC were used to characterize disease progression. Flow cytometry was used to analyze tumor infiltrating, circulating, and nodal immune populations. RESULTS: We demonstrate that although radiotherapy increases the infiltration and activation of dendritic cells (DC), it also increases the infiltration of regulatory T cells (Treg) while failing to recruit natural killer (NK) and CD8 T cells in PDAC patient tissue samples. In murine orthotopic tumor models, we show that genetic and pharmacologic depletion of Tregs and NK cells enhances and attenuates response to radiotherapy, respectively. We further demonstrate that targeted inhibition of STAT3 on Tregs results in improved control of local and distant disease progression and enhanced NK-mediated immunosurveillance of metastasis. Moreover, combination treatment of STAT3 antisense oligonucleotide (ASO) and radiotherapy invigorated systemic immune activation and conferred a survival advantage in orthotopic and metastatic tumor models. Finally, we show the response to STAT3 ASO + radiotherapy treatment is dependent on NK and DC subsets. CONCLUSIONS: Our results suggest targeting Treg-mediated immunosuppression is a critical step in mediating a response to treatment, and identifying NK cells as not only a prognostic marker of improved survival, but also as an effector population that functions to combat metastasis.

Physical characteristics of 68Ga DOTATATE PET/CT affecting small lesion detectability.

BACKGROUND AND PURPOSE: 68Ga DOTATATE PET/CT protocols are similar to 18F FDG protocols despite differences in physical properties, biodistribution, and tumor uptake. The purpose of this study is to evaluate the impact of scan time (counts), and target activity on signal-to-noise ratio (SNR) in various sized targets, or lesions. To evaluate this, phantom experiments and analysis of clinical 68Ga DOTATATE PET/CT studies were performed. MATERIALS AND METHODS: 68Ga was first compared to 18F in phantom studies to evaluate recovery coefficients and SNR. 68Ga phantom studies were also acquired in list mode, and at varying target activities to evaluate the effects of acquisition time and high target concentrations on SNR in clinically relevant small (8 mm) and larger targets (≥ 12 mm). Clinical studies (n = 50) were analyzed to determine if phantom target concentrations and SNR are present in clinical 68Ga DOTATATE studies at similarly very high tumor activity concentrations (n = 159). RESULTS: In phantoms, recovery coefficient and SUVmax for 68Ga were ~87% of 18F. SNR for 68Ga was ~65% of 18F. For the 68Ga small target (8 mm) at standard T/B = 2.4, increasing scan time from 5 to 15 minutes increased SNR from < 1 to 1.6, and did not result in target identification. Increasing T/B from 2.4 to 10.9, however, dramatically increased SNR from < 1 to 22.3. Increased T/B resulted in clear visibility of the 8 mm target, even for 1-minute scans. In patients, high hepatic tumor SUVmax (27.3±29.6), resulted in high SNR (12.5±9.8). For extrahepatic tumors, high SUVmax (41.6±42.8), resulted in high SNR (43.8±49.9). CONCLUSION: Very high target or T/B, even in small targets, can offset the physical limitations of 68Ga. High target uptake and high T/B are primary factors influencing small lesion detectability.

Outcomes between intensity-modulated radiation therapy versus 3D-conformal in early stage glottic cancer.

BACKGROUND: The purpose of this study is to evaluate practice patterns and outcomes between intensity-modulated radiation therapy (IMRT) and 3D-conformal radiation (3D-CRT) in early stage glottic cancer. METHODS: The linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database was used to identify and compare patient and disease profiles, mortality, and toxicity in patients with T1-2 larynx cancer undergoing definitive radiation (RT). RESULTS: A total of 1520 patients underwent definitive radiation with 3D-CRT (n = 1309) or IMRT (n = 211). Non-white race, those with a Charlson Comorbidity Index ≥2, T2 disease, and those treated at community practices were more likely to undergo IMRT. Rates of IMRT increased from 2006 to 2015, while relative rates of 3D-CRT decreased. Two-year CSS was superior with 3D-CRT (hazard ratio [HR], 0.38; 95% confidence interval [CI], 0.22-0.65; p < 0.001). There was no difference in OS between 3D-CRT and IMRT (p = 0.119). CONCLUSIONS: Patients receiving 3D-CRT had improved CSS compared to IMRT with no difference in OS.

Survival impact of angiotensin-converting enzyme inhibitors and angiotensin II receptor antagonists in head and neck cancer.

BACKGROUND: Preclinical evidence suggests a link between the renin-angiotensin system and oncogenesis. We aimed to explore the impact of angiotensin-converting enzyme inhibitors (ACEi) and angiotensin II receptor blockers (ARB) in head and neck cancer (HNC). METHODS: Over 5000 patients were identified from the Surveillance, Epidemiology, and End Results-Medicare linked dataset and categorized according to ACEi and ARB and diagnoses of chronic kidney disease (CKD) or hypertension (HTN). Overall survival (OS) and cancer-specific survival (CSS) were compared using Cox multivariable regression (MVA), expressed as hazard ratios (HR) with 95% confidence intervals (95%CI). RESULTS: No significant MVA associations for OS or CSS were found for ACEi. Compared to patients with CKD/HTN taking ARB, those with CKD/HTN not taking ARB experienced worse OS (HR 1.28, 95%CI 1.09-1.51, p = 0.003) and CSS (HR 1.23, 95%CI 1.00-1.50, p = 0.050). CONCLUSIONS: ARB usage is associated with improved OS and CSS among HNC patients with CKD or HTN.

High Prevalence of Transjugular Intrahepatic Portosystemic Shunt Creation Without Prior Endoscopy During Acute Variceal Bleeding Hospitalization in the United States.

Current clinical guidelines by both American Association for the Study of Liver Disease and European Association for the Study of the Liver recommend endoscopy in all patients admitted with acute variceal bleeding within 12 hours of admission. Transjugular intrahepatic portosystemic shunt (TIPS) creation may be considered in patients at high risk if hemorrhage cannot be controlled endoscopically. We conducted a cross-sectional observational study to assess how frequently TIPS is created for acute variceal bleeding in the United States without preceding endoscopy. Adult patients undergoing TIPS creation for acute variceal bleeding in the United States (n = 6,297) were identified in the last 10 available years (2007-2016) of the National Inpatient Sample. Hierarchical logistic regression was used to examine the relationship between endoscopy nonutilization and hospital characteristics, controlling for patient demographics, income level, insurance type, and disease severity. Of 6,297 discharges following TIPS creation for acute variceal bleeding in the United States, 31% (n = 1,924) did not receive first-line endoscopy during the same encounter. Rates of "no endoscopy" decreased with increasing population density of the hospital county (nonmicropolitan counties 43%, n = 114; mid-size metropolitan county 35%, n = 513; and central county with >1 million population 23%, n = 527) but not by hospital teaching status (n = 1,465, 32% teaching vs. n = 430, 26% nonteaching; P = 0.10). Higher disease mortality risk (odds ratio, 0.42; 95% confidence interval, 0.22-0.80; P = 0.02) was associated with lower odds of noncompliance. Conclusion: One third of all patients undergoing TIPS creation for acute variceal bleeding in the United States do not receive first-line endoscopy during the same encounter. Patients admitted to urban hospitals are more likely to receive guideline-concordant care.

Factors Influential in the Selection of Radiology Residents in the Post-Step 1 World: A Discrete Choice Experiment.

OBJECTIVES: Reporting of United States Medical Licensing Examination Step 1 results will transition from a numerical score to a pass or fail result. We sought an objective analysis to determine changes in the relative importance of resident application attributes when numerical Step 1 results are replaced. METHODS: A discrete choice experiment was designed to model radiology resident selection and determine the relative weights of various application factors when paired with a numerical or pass or fail Step 1 result. Faculty involved in resident selection at 14 US radiology programs chose between hypothetical pairs of applicant profiles between August and November 2020. A conditional logistic regression model assessed the relative weights of the attributes, and odds ratios (ORs) were calculated. RESULTS: There were 212 participants. When a numerical Step 1 score was provided, the most influential attributes were medical school (OR: 2.35, 95% confidence interval [CI]: 2.07-2.67), Black or Hispanic race or ethnicity (OR: 2.04, 95% CI: 1.79-2.38), and Step 1 score (OR: 1.8, 95% CI: 1.69-1.95). When Step 1 was reported as pass, the applicant's medical school grew in influence (OR: 2.78, 95% CI: 2.42-3.18), and there was a significant increase in influence of Step 2 scores (OR: 1.31, 95% CI: 1.23-1.40 versus OR 1.57, 95% CI: 1.46-1.69). There was little change in the relative influence of race or ethnicity, gender, class rank, or clerkship honors. DISCUSSION: When Step 1 reporting transitions to pass or fail, medical school prestige gains outsized influence and Step 2 scores partly fill the gap left by Step 1 examination as a single metric of decisive importance in application decisions.

Ethnic Disparities in Imaging Utilization at Diagnosis of Non-Small Cell Lung Cancer.

BACKGROUND: Prior research demonstrated statistically significant racial disparities related to lung cancer treatment and outcomes. We examined differences in initial imaging and survival between blacks, Hispanics, and non-Hispanic whites. METHODS: The linked Surveillance, Epidemiology, and End Results-Medicare database between 2007 and 2015 was used to compare initial imaging modality for patients with lung cancer. Participants included 28 881 non-Hispanic whites, 3123 black, and 1907 Hispanics, patients age 66 years and older who were enrolled in Medicare fee-for-service and diagnosed with lung cancer. The primary outcome was comparison of positron emission tomography (PET) imaging with computerized tomography (CT) imaging use between groups. A secondary outcome was 12-month cancer-specific survival. Information on stage, treatment, and treatment facility was included in the analysis. Chi-square test and logistic regression were used to evaluate factors associated with imaging use. Kaplan-Meier method and Cox proportional hazards regression were used to calculate adjusted hazard ratios and survival. All statistical tests were two-sided. RESULTS: After adjusting for demographic, community, and facility characteristics, blacks were less likely to undergo PET or CT imaging at diagnosis compared with non-Hispanic whites odds ratio (OR) = 0.54 (95% confidence interval [CI] = 0.50 to 0.59; P < .001). Hispanics were also less likely to receive PET with CT imaging (OR = 0.72, 95% CI = 0.65 to 0.81; P < .001). PET with CT was associated with improved survival (HR = 0.61, 95% CI = 0.57 to 0.65; P < .001). CONCLUSIONS: Blacks and Hispanics are less likely to undergo guideline-recommended PET with CT imaging at diagnosis of lung cancer, which may partially explain differences in survival. Awareness of this issue will allow for future interventions aimed at reducing this disparity.

Evaluating Novel PET-CT Functional Parameters TLG and TMTV in Differentiating Low-grade Versus Grade 3A Follicular Lymphoma.

BACKGROUND: Follicular lymphoma (FL) grading, low-grade 1-2 (LG) versus grade 3A (3A), informs management. However, accurate grading is challenging owing to disease heterogeneity and inter-reader variability. The [18F]-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) parameter maximum standardized uptake value (SUVmax) has utility in differentiating LG from 3A FL, but the utility of novel parameters total lesion glycolysis (TLG) and total metabolic tumor volume (TMTV) is unknown. PATIENTS AND METHODS: Retrospective review of diagnostic pre-treatment PET-CTs of patients aged > 18 years with FL grades 1-3A from 2009-2017 was performed. PET-CT parameters SUVmax, TLG, and TMTV values were generated using manual (MW) and semi-automated workflows (SW). Poisson regression and receiver operating characteristic curves were used to compare PET-CT parameters between LG and 3A. RESULTS: A total of 49 patients with FL were identified: 38 LG and 11 3A. PET-CT parameters were significantly higher in 3A as compared with LG in both workflows. The cutoff values, sensitivities, and specificities were as follows: SUVmax: 10.4, 64%, and 74% in MW and 11.9, 73%, and 76% in SW; TLG: 543, 82%, and 74% in MW and 371, 73%, and 74% in SW; and TMTV: 141, 73%, and 76% in MW and 93, 64%, and 76% in SW. SUVmax had identical cutoff, sensitivity, and specificity across all 3 SWs, whereas TLG and TMTV had considerable variance across all 3 SWs. CONCLUSIONS: TLG and TMTV are comparable to SUVmax in differentiating LG versus 3A FL. Cutoffs, sensitivities, and specificities varied in MW versus SW. Novel PET-CT parameters serve as reproducible adjuncts but not replacements for biopsy in differentiating grades of FL.