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.

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.

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.

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.

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.

Reviewing RECIST in the Era of Prolonged and Targeted Therapy.

Accurate assessment of disease response is the foundation of therapeutic trails, which is why the Response Evaluation Criteria in Solid Tumors (RECIST) serve as an international standard that investigators can utilize when examining patient outcomes. Nine years after the initial RECIST criteria were released, an update, RECIST 1.1, was published to improve on the initial criteria and address technologic advancements in imaging. Since then, advancements in both standard clinical and trial practices, combined with improvements in our understanding of cancer biology, have resulted in the identification of a number of limitations of the current RECIST 1.1, either in lack of clear guidance with regard to its best application or in potential benefit of capturing imaging-related data beyond standard categorical response details. As several of these situations reflect the consequences of prolonged control of metastatic disease by using targeted therapies, thoracic oncology has generated many of the key scenarios requiring elucidation and/or improvements. This article specifically examines current controversies in the interpretation and/or optimal utilization of RECIST 1.1, focusing on examples from thoracic oncology, and makes proposals, where possible, on how best to address these issues. These situations include addressing central nervous system versus extra-central nervous system response and progression, depth of response, oligoprogression versus polyprogression, continuation of systemic therapy after use of a local ablative therapy, and the impact of fluctuations in measurements bridging partial response and stable disease categories during prolonged therapy.

Pseudolesions Impersonating Osseous Tumor Involvement on Both Contrast Enhanced CT and FDG PET/CT.

A 27-year-old man with stage IV-B Hodgkin's lymphoma status post autologous peripheral stem cell transplant in 2015 with complete response, presented in 2017 with increasing back pain. Restaging contrast enhanced CT demonstrated left brachiocephalic vein occlusion with peripheral nodular high density areas within C7-T2 vertebral bodies with corresponding radiotracer uptake on same day PET/CT. No matching lesion was seen on noncontrast CT. Findings were consistent with pooling of contrast and radiotracer within vertebral venous plexus collaterals at the cervicothoracic junction secondary to brachiocephalic vein occlusion. Repeat PET/CT with contralateral injection of radiotracer and MRI confirmed absence of osseous lymphomatous involvement.

Detection of oligoprogressive disease in oncogene-addicted non-small cell lung cancer using PET/CT versus CT in patients receiving a tyrosine kinase inhibitor.

OBJECTIVES: In oncogene-addicted non-small cell lung cancer (NSCLC), oligoprogressive disease (OPD) can be treated with local ablative therapy (LAT) to prolong benefit from tyrosine kinase inhibitors (TKIs). A comparison of PET/CT vs. CT for the detection of OPD at first extra central nervous system (eCNS) progression was performed to determine which modality was more sensitive for OPD detection. MATERIALS AND METHODS: Patients with metastatic EGFR-MT, ALK + or ROS-1+ NSCLC on a relevant TKI from 2010 to 2016 were identified. Scan methodology at first eCNS progression (index scan) was noted and progression was categorized as OPD (≤ 4 lesions) or non-OPD (> 4 lesions). RESULTS: Of the 67 analyzable patients (EGFR-MT = 37, ALK+ = 28, ROS1+ = 2), OPD was detected in 81.3% (26/32) by PET/CT vs. 68.6% (24/35) by CT (p = 0.363). Of these, 17/26(65.4%) in PET/CT and 5/24(20.8%) in CT group had LAT (p = 0.004). Among patients receiving an alternate modality scan within 6 weeks of the index scan that showed first eCNS progression, 91.7% (11/12) had CT prior to index PET/CT, 75% (6/8) had post-index PET/CT showing further progression, whereas 0% (0/5) had post-index CT showing further progression. Time to progression (TTP), Post-progression TKI benefit (TTP2) and overall survival (OS) were longer in the PET/CT-detected group (p = 0.001, p = 0.032, and p = 0.01, respectively). In both PET/CT (N = 26) and CT-detected (N = 24) OPD subgroups, TTP2 and OS were longer in those that received LAT (65.4% [17/26] and 20.8% [5/24]) versus those that did not, although the difference was not statistically significant. CONCLUSION: PET/CT demonstrated a non-significant trend to detect more eCNS OPD and a significantly higher rate of OPD suitable for LAT than CT. Peri-progression alternate modality scans were also consistent with PET/CT being more sensitive. A prospective randomized study is required to assess the long-term impact of PET/CT vs CT in oncogene-addicted NSCLC patients on TKI therapy.