Social Determinants of Health Framework to Identify and Reduce Barriers to Imaging in Marginalized Communities.

Social determinants of health (SDOH) are conditions influencing individuals' health based on their environment of birth, living, working, and aging. Addressing SDOH is crucial for promoting health equity and reducing health outcome disparities. For conditions such as stroke and cancer screening where imaging is central to diagnosis and management, access to high-quality medical imaging is necessary. This article applies a previously described structural framework characterizing the impact of SDOH on patients who require imaging for their clinical indications. SDOH factors can be broadly categorized into five sectors: economic stability, education access and quality, neighborhood and built environment, social and community context, and health care access and quality. As patients navigate the health care system, they experience barriers at each step, which are significantly influenced by SDOH factors. Marginalized communities are prone to disparities due to the inability to complete the required diagnostic or screening imaging work-up. This article highlights SDOH that disproportionately affect marginalized communities, using stroke and cancer as examples of disease processes where imaging is needed for care. Potential strategies to mitigate these disparities include dedicating resources for clinical care coordinators, transportation, language assistance, and financial hardship subsidies. Last, various national and international health initiatives are tackling SDOH and fostering health equity.

Intelligent imaging: Applications of machine learning and deep learning in radiology.

Artificial intelligence (AI) in radiology is transforming medical image analysis. While applications in triaging for priority reporting and radiomic feature analysis have been widely reported, perhaps the most important applications lie in noise reduction, image optimization following dose reduction strategies, image reconstruction direct from projection data and generation of pseudo-CT for attenuation correction. There are common beneficial applications, and potential risks, between human radiology and veterinary radiology. Artificial intelligence may see recrafting of some responsibilities but offers AI augmentation of human driven systems. The redundancy afforded by human augmentation of AI and AI autonomy are not on the horizon, but rather are already here.

The deep radiomic analytics pipeline.

Radiomics refers to the process of extracting useful imaging features from radiological data. Conventional radiomics like standard uptake value, intensity histograms, or phase images involve hand-crafted (manual) or automated regions of interest (computer generated), however, artificial intelligence (AI) segmentation (AI-augmented radiomics) has recently emerged. Radiomic feature extraction extends image insights beyond simply data quantitation and provides additional insights to aid semantic reporting. Deeper layers of a convolutional neural network produce more abstract radiomic features that are referred to as deep radiomics. The application of radiomics in veterinary radiology is already firmly entrenched using hand-crafted and automated computer-generated radiomic features in X-ray, nuclear medicine, CT, ultrasound, and MRI. There is an opportunity for veterinary radiology to capitalize on advances in AI, machine learning, and deep learning to enrich imaging interpretation using deep radiomic feature extraction. This manuscript aims to provide a general understanding of radiomics and deep radiomics, and to arm readers with the vernacular to progress discussion and development of deep radiomics in veterinary imaging.

Reclassifying patients with early-stage Hodgkin lymphoma based on functional radiographic markers at presentation.

The presence of bulky disease in Hodgkin lymphoma (HL), traditionally defined with a 1-dimensional measurement, can change a patient's risk grouping and thus the treatment approach. We hypothesized that 3-dimensional measurements of disease burden obtained from baseline 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) scans, such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG), would more accurately risk-stratify patients. To test this hypothesis, we reviewed pretreatment PET-CT scans of patients with stage I-II HL treated at our institution between 2003 and 2013. Disease was delineated on prechemotherapy PET-CT scans by 2 methods: (1) manual contouring and (2) subthresholding of these contours to give the tumor volume with standardized uptake value ≥2.5. MTV and TLG were extracted from the threshold volumes (MTVt, TLGt) and from the manually contoured soft-tissue volumes. At a median follow-up of 4.96 years for the 267 patients evaluated, 27 patients were diagnosed with relapsed or refractory disease and 12 died. Both MTVt and TLGt were highly correlated with freedom from progression and were dichotomized with 80th percentile cutoff values of 268 and 1703, respectively. Consideration of MTV and TLG enabled restratification of early unfavorable HL patients as having low- and high-risk disease. We conclude that MTV and TLG provide a potential measure of tumor burden to aid in risk stratification of early unfavorable HL patients.

Early-stage Hodgkin lymphoma outcomes after combined modality therapy according to the post-chemotherapy 5-point score: can residual pet-positive disease be cured with radiotherapy alone?

Early-stage classical Hodgkin lymphoma (HL) patients are evaluated by an end-of-chemotherapy positron emission tomography-computed tomography (eoc-PET-CT) after doxorubicin, bleomycin, vinblastine and dacarbazine (ABVD) and before radiation therapy (RT). We determined freedom from progression (FFP) in patients treated with ABVD and RT according to the eoc-PET-CT 5-point score (5PS). Secondarily, we assessed whether patients with a positive eoc-PET-CT (5PS of 4-5) can be cured with RT alone. The cohort comprised 174 patients treated for stage I-II HL with ABVD and RT alone. ABVD was given with a median of four cycles and RT with a median dose of 30·6 Gy. Five-year FFP was 97%. Five-year FFP was 100% (0 relapses/98 patients) for patients with a 5PS of 1-2, 97% (2/65) for a 5PS of 3, 83% (1/8) for a 5PS of 4, and 67% (1/3) for a 5PS of 5 (P < 0·001). Patients with positive eoc-PET-CT scans who were selected for salvage RT alone had experienced a very good partial response to ABVD. Risk factors for recurrence in this subgroup included a small reduction in tumour size and a 'bounce' in ≥1 PET-CT parameter (reduction then rise from interim to final scan). Thus, a positive eoc-PET-CT is associated with inferior FFP; however, appropriately selected patients can be cured with RT alone.

Refining prognosis in patients with hepatocellular carcinoma through incorporation of metabolic imaging biomarkers.

PURPOSE: 18F-fluorodeoxyglucose positron emission tomopraphy/computed tomography (FDGPET/CT) has been proven to be useful for imaging many types of cancer; however, its role is not well defined in hepatocellular carcinoma (HCC). We assessed the prognostic value of metabolic imaging biomarkers as established by baseline pretreatment FDG PET/CT in patients with HCC. METHODS: We retrospectively analyzed the records of patients with HCC who underwent FDG PET/CT before initial treatment from May 2013 through May 2014. Four PET/CT parameters were measured: maximum standardized uptake value (SUVmax), total lesion glycolysis (TLG), metabolic tumor volume (MTV), and tumor-to-normal-liver SUV ratio (TNR). Optimal cut-off values for the PET/CT parameters to stratify patients in terms of overall survival (OS) were determined. Multivariate analysis was performed to determine whether the PET/CT parameters could add to the prognostic value of the Cancer of the Liver Italian Program (CLIP) scoring system and the Barcelona-Clinic Liver Cancer (BCLC) staging system. RESULTS: The analysis included 56 patients. Univariate analysis of the association between OS and continuous variables, including the PET/CT parameters SUVmax, TLG, tumor size, total bilirubin level, and alkaline phosphatase level were significant predictors of OS. SUVmax ≥ 11.7, TLG ≥ 1,341, MTV ≥ 230 mL, and TNR ≥ 4.8 were identified as cut-off values. Multivariate analysis revealed that SUVmax ≥ 11.7 and TNR ≥ 4.8 were independent factors predicting a poor prognosis in both the CLIP scoring system and the BCLC staging system, as was TLG in the BCLC staging system. CONCLUSION: Pretreatment FDG PET/CT in patients with HCC can add to the prognostic value of standard clinical measures. Incorporation of imaging biomarkers derived from FDG PET/CT into HCC staging systems should be considered.

Factors affecting (223)Ra therapy: clinical experience after 532 cycles from a single institution.

PURPOSE: The aim of this study was to identify baseline features that predict outcome in (223)Ra therapy. METHODS: We retrospectively reviewed 110 patients with metastatic castration-resistant prostate cancer treated with (223)Ra. End points were overall survival (OS), progression-free survival (PFS), bone event-free survival (BeFS), and bone marrow failure (BMF). The following parameters were evaluated prior to the first (223)Ra cycle: serum levels of hemoglobin (Hb), prostate-specific antigen (PSA), alkaline phosphatase (ALP), Eastern Cooperative Oncology Group (ECOG) status, pain score, use of chemotherapy, and external beam radiation therapy (EBRT). During/after (223)Ra we evaluated: the total number of radium cycles (RaTot), the PSA doubling time (PSADT), and the use of chemotherapy, EBRT, abiraterone, and enzalutamide. RESULTS: A significant reduction of ALP (p < 0.001) and pain score (p = 0.041) occurred throughout the (223) Ra cycles. The risk of progression was associated with declining ECOG status [hazard ratio (HR) = 3.79; p < 0.001] and decrease in PSADT (HR = 8.22; p < 0.001). RaTot, ALP, initial ECOG status, initial pain score, and use of abiraterone were associated with OS (p ≤ 0.008), PFS (p ≤ 0.003), and BeFS (p ≤ 0.020). RaTot, ALP, initial ECOG status, and initial pain score were significantly associated with BMF (p ≤ 0.001) as well as Hb (p < 0.001) and EBRT (p = 0.009). On multivariable analysis, only RaTot and abiraterone remained significantly associated with OS (p < 0.001; p = 0.033, respectively), PFS (p < 0.001; p = 0.041, respectively), and BeFS (p < 0.001; p = 0.019, respectively). Additionally, RaTot (p = 0.027) and EBRT (p = 0.013) remained significantly associated with BMF. CONCLUSION: Concomitant use of abiraterone and (223)Ra seems to have a beneficial effect, while the EBRT may increase the risk of BMF.

Assessment of Sequential PET/MRI in Comparison With PET/CT of Pediatric Lymphoma: A Prospective Study.

OBJECTIVE: The objective of our study was to compare the diagnostic performance of sequential (18)F-FDG PET/MRI (PET/MRI) and (18)F-FDG PET/CT (PET/CT) in a pediatric cohort with lymphoma for lesion detection, lesion classification, and disease staging; quantification of FDG uptake; and radiation dose. SUBJECTS AND METHODS: For this prospective study of 25 pediatric patients with lymphoma, 40 PET/CT and PET/MRI examinations were performed after a single-injection dual-time-point imaging protocol. Lesions detected, lesion classification, Ann Arbor stage, and radiation dose were tabulated for each examination, and statistical evaluations were performed to compare the modalities. Quantification of standardized uptake values (SUVs) was performed for all lesions. All available examinations and clinical history were used as the reference standard. RESULTS: No statistically significant differences between PET/MRI and PET/CT were observed in lesion detection rates, lesion classification, or Ann Arbor staging. Fifty-four regions of focal uptake were observed on PET/MRI compared with 55 on PET/CT. Both modalities accurately classified 82% of the lesions relative to the reference standard. Disease staging based on PET/MRI was correct for 35 of the 40 studies, and disease staging based on PET/CT was correct for 35 of the 40 studies; there was substantial agreement between the modalities for disease staging (κ = 0.684; p < 0.001). PET SUVs were strongly correlated between PET/CT and PET/MRI (ρ > 0.72), although PET/MRI showed systematically lower SUV measurements. PET/MRI offered an average 45% reduction in radiation dose relative to PET/CT. CONCLUSION: In a pediatric cohort with lymphoma, sequential PET/MRI showed lesion detection, lesion classification, and Ann Arbor staging comparable to PET/CT. PET/MRI quantification of FDG uptake strongly correlated with PET/CT, but the SUVs were not interchangeable. PET/MRI significantly reduced radiation exposure and is a promising new alternative in the care of pediatric lymphoma patients.

Fat-Containing Hypermetabolic Masses on FDG PET/CT: A Spectrum of Benign and Malignant Conditions.

OBJECTIVE: This article focuses on identifying the imaging appearances of hypermetabolic fatty masses and masslike lesions on PET/CT and understanding the diagnostic challenges radiologists may face while interpreting findings of these lesions on PET/CT. This article provides an approach to aid in the diagnosis of these lesions and the appropriate management of patients. CONCLUSION: Both malignant and benign fat-containing masses and masslike lesions can show hypermetabolic activity on PET/CT. Although the differential diagnosis is broad, clinical history, anatomic location, and knowledge of anatomic variants and imaging features can help radiologists avoid misinterpretation of benign fatty lesions as malignancy.

Non-Small Cell Lung Cancer, Version 6.2015.

These NCCN Guidelines Insights focus on recent updates to the 2015 NCCN Guidelines for Non-Small Cell Lung Cancer (NSCLC). Appropriate targeted therapy is very effective in patients with advanced NSCLC who have specific genetic alterations. Therefore, it is important to test tumor tissue from patients with advanced NSCLC to determine whether they have genetic alterations that make them candidates for specific targeted therapies. These NCCN Guidelines Insights describe the different testing methods currently available for determining whether patients have genetic alterations in the 2 most commonly actionable genetic alterations, notably anaplastic lymphoma kinase (ALK) gene rearrangements and sensitizing epidermal growth factor receptor (EGFR) mutations.

Rectal Cancer, Version 2.2015.

The NCCN Guidelines for Rectal Cancer begin with the clinical presentation of the patient to the primary care physician or gastroenterologist and address diagnosis, pathologic staging, surgical management, perioperative treatment, posttreatment surveillance, management of recurrent and metastatic disease, and survivorship. The NCCN Rectal Cancer Panel meets at least annually to review comments from reviewers within their institutions, examine relevant new data from publications and abstracts, and reevaluate and update their recommendations. These NCCN Guidelines Insights summarize major discussion points from the 2015 NCCN Rectal Cancer Panel meeting. Major discussion topics this year were perioperative therapy options and surveillance for patients with stage I through III disease.

Comparison of Standardized Uptake Values in Normal Structures Between PET/CT and PET/MRI in a Tertiary Pediatric Hospital: A Prospective Study.

OBJECTIVE: The purpose of this study was to compare standardized uptake values (SUVs) of normal tissues using MR attenuation-corrected versus CT attenuation-corrected (18)F-FDG PET in a pediatric population. SUBJECTS AND METHODS: Thirty-five patients (21 boys; mean age, 13.3 years) referred for 47 PET/CT scans were recruited to undergo PET/MRI. MR attenuation correction was performed using an automated three-segment model. ROIs were drawn over nine normal structures to estimate SUV(min), SUV(mean), and SUV(max). Pearson rank correlation coefficients were calculated to compare SUVs obtained from MR and CT attenuation correction. In nine patients who underwent multiple PET/MRI studies, coefficients of variance and intraclass correlation coefficients were calculated to evaluate intrapatient SUV(max) variation. RESULTS: Mean (± SD) time to imaging after FDG injection was 108 ± 17 minutes for PET/CT and 61 ± 6 minutes for PET/MRI. PET/MRI SUVs in all tissues were lower than those for PET/CT (mean difference, -28.9% ± 31.1%; p < 0.05). Very high or high correlation between PET/MRI and PET/CT SUV(max) was found in brain (r = 0.72), myocardium (r = 0.95), and bone marrow (r = 0.85) (p < 0.001). Moderate correlation was found in liver (r = 0.54), fat (r = 0.41), mean blood pool (r = 0.40), and psoas muscle (r = 0.38) (p < 0.01). Weak correlation was found in lung (r = 0.12) and iliacus muscle (r = 0.12). Compared with PET/CT, PET/MRI systematically undermeasured SUV. In nine patients who underwent multiple PET/MRI examinations, moderate or strong agreement was found in the SUV(max) of six of nine tissues, similar to the corresponding PET/CT examinations. CONCLUSION: Our study showed overall high correlation for SUV measurements obtained from MR attenuation correction compared with CT attenuation correction, although PET/MRI underestimated SUV compared with PET/CT. SUVs measured from PET/MRI indicated good intrapatient reliability.

Qualitative FDG PET Image Assessment Using Automated Three-Segment MR Attenuation Correction Versus CT Attenuation Correction in a Tertiary Pediatric Hospital: A Prospective Study.

OBJECTIVE: The purpose of this study was to systematically evaluate the diagnostic quality of (18)F-FDG PET images generated using MR attenuation correction (MRAC) compared with those images generated using CT attenuation correction (CTAC) in a pediatric population. SUBJECTS AND METHODS: Forty-two patients (mean age, 12.8 years; percentage who were male, 57%) who were referred for 62 indicated whole-body PET/CT studies were prospectively recruited to undergo PET/MRI examinations during the same clinic visit in which PET/CT was performed. MRAC was performed using an automatic three-segment model. Three nuclear radiologists scored the diagnostic quality of the PET images generated by MRAC and CTAC using a Likert scale (range of scores, 1-5). Images graded with a score of 1-3 were considered clinically unacceptable, whereas images with a score of 4-5 were considered clinically acceptable. A Wilcoxon signed-rank test was used to compare differences in the grading of PET/MRI and PET/CT images. The Fisher exact test was used to evaluate potential differences in clinically acceptable image quality and the presence of artifact. Fleiss kappa statistics were used to examine interobserver agreement. RESULTS: There was no statistically significant difference in the proportion of PET images generated with MRAC and CTAC for which image quality was considered clinically acceptable. A total of 3.9% of PET assessments generated with MRAC were of unacceptable image quality, compared with 2.2% of PET images generated with CTAC. Two of the three radiologists who reviewed the PET images reported the presence of artifacts more often on MRAC-derived images, and they graded the mean quality of these images 0.48 and 0.29 points lower on the 5-point Likert scale than they graded the mean quality of CTAC-derived images (p < 0.0001). Interobserver agreement was fair (κ = 0.39). CONCLUSION: The diagnostic quality of PET images obtained from a pediatric population with the use of an automatic three-segmentation MRAC method was comparable to that of PET images obtained with the use of CTAC.

The acetabular fossa hot spot on 18F-FDG PET/CT: epidemiology, natural history, and proposed etiology.

OBJECTIVE: To describe a benign focus of increased activity in the acetabular fossa (the acetabular fossa hot spot, AFHS) on (18) F-FDG PET/CT that can mimic a neoplasm. MATERIALS AND METHODS: (18)F-FDG PET/CT images from four patient populations were examined. Group 1 (n = 13) was collected from a search of radiology reports and used to define the AFHS and for hypothesis generation. Group 2 (n = 1,150) was used for prevalence of AFHS. Group 3 (n = 1,213) had PET/CT and MRI pelvis within a week of each other and was used to correlate metabolic and anatomic findings. Group 4 (n = 100) was used to generate the control group. Data were collected on demographics, common comorbidities, underlying cancer diagnosis and status, and hip symptoms. RESULTS: Prevalence of AFHS was 0.36 % (95 % CI 0.10-0.91 %). None progressed to malignancy or was associated with cancer status. The majority (71 %) were on the left, and 6 % were bilateral. Mean SUVmax of the AFHS was 4.8 (range, 2.7-7.8). Male patients were more likely to have the AFHS (OR = 8.69, 95 % CI 1.88-40.13). There was no difference with respect to other collected data, including hip symptoms. Average minimum duration of AFHS was 346 days (range, 50-1,010 days). Readers did not detect corresponding hip abnormalities on MRIs. CONCLUSIONS: AFHS is a benign finding that may be caused by subclinical ligamentum teres injury, focal synovitis, or degeneration of acetabular fossa fat. Despite uncertainty regarding its etiology, recognition of AFHS as a benign finding can prevent morbidity associated with unnecessary biopsy or initiation of therapy.

Impact of initial PET/CT staging in terms of clinical stage, management plan, and prognosis in 592 patients with non-small-cell lung cancer.

PURPOSE: Our objective was to determine the impact of initial (18)F-FDG PET/CT (PET/CT) staging on clinical stage and the management plan and the prognostic value of PET/CT in patients with non-small-cell lung cancer (NSCLC). METHODS: We retrospectively reviewed the records of 592 patients with NSCLC who were referred to The University of Texas MD Anderson Cancer Center during 2002/2011 and had both PET/CT and conventional CT for initial staging. Clinical stages and management plans were compared between PET/CT and CT. The impact of PET/CT on management plans was considered medium/high when PET/CT changed the planned treatment modality or treatment intent. PET/CT and CT stages were compared with all-cause mortality and survival rates. We also assessed potential prognostic factors for progression-free survival (PFS) and overall survival (OS). RESULTS: PET/CT changed the stage in 170 patients (28.7 %; 16.4 % upstaged, 12.3 % downstaged). PET/CT had a medium/high impact on the management plan in 220 patients (37.2 %). PFS and OS were significantly worse in patients with upstaged disease than in patients with no change in stage (median PFS 29.0 vs. 53.8 months, P < 0.001; median OS:64.7 vs. 115.9 months, P = 0.006). PFS and OS were significantly worse in patients with medium/high impact of PET/CT than in patients with no/low impact of PET/CT (median PFS 24.7 vs. 60.6 months, P < 0.001; median OS 64.7 vs. 115.9 months, P < 0.001). In multivariate analysis, a medium/high impact of PET/CT was an independent predictor of worse PFS (hazard ratio, HR, 1.73; 95 % CI 1.30 - 2.29; P = 0.0002) and OS (HR 1.84; 95 % CI 1.26 - 2.69; P = 0.002). CONCLUSION: Initial PET/CT staging not only impacts stage and management plan but also has prognostic value.

Colon cancer, version 3.2014.

The NCCN Guidelines for Colon Cancer address diagnosis, pathologic staging, surgical management, perioperative treatment, posttreatment surveillance, management of recurrent and metastatic disease,and survivorship. This portion of the guidelines focuses on the use of systemic therapy in metastatic disease. The management of metastatic colorectal cancer involves a continuum of care in which patients are exposed sequentially to a variety of active agents, either in combinations or as single agents. Choice of therapy is based on the goals of treatment, the type and timing of prior therapy, the different efficacy and toxicity profiles of the drugs, the mutational status of the tumor, and patient preference.

Non-small cell lung cancer, version 1.2015.

This selection from the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Non-Small Cell Lung Cancer (NSCLC) focuses on the principles of radiation therapy (RT), which include the following: (1) general principles for early-stage, locally advanced, and advanced/metastatic NSCLC; (2) target volumes, prescription doses, and normal tissue dose constraints for early-stage, locally advanced, and advanced/palliative RT; and (3) RT simulation, planning, and delivery. Treatment recommendations should be made by a multidisciplinary team, including board-certified radiation oncologists who perform lung cancer RT as a prominent part of their practice.

Prostate cancer, version 2.2014.

Prostate cancer has surpassed lung cancer as the most common cancer in men in the United States. The NCCN Guidelines for Prostate Cancer provide multidisciplinary recommendations on the clinical management of patients with prostate cancer based on clinical evidence and expert consensus. NCCN Panel guidance on treatment decisions for patients with localized disease is represented in this version. Significant updates for early disease include distinction between active surveillance and observation, a new section on principles of imaging, and revisions to radiation recommendations. The full version of these guidelines, including treatment of patients with advanced disease, can be found online at the NCCN website.

Bone-seeking radiopharmaceuticals as targeted agents of osteosarcoma: samarium-153-EDTMP and radium-223.

Osteosarcoma is a cancer characterized by formation of bone by malignant cells. Routine bone scan imaging with Tc-99m-MDP is done at diagnosis to evaluate primary tumor uptake and check for bone metastases. At time of relapse the Tc-99m-MDP bone scan also provides a specific means to assess formation of bone by malignant osteosarcoma cells and the potential for bone-seeking radiopharmaceuticals to deliver radioactivity directly into osteoblastic osteosarcoma lesions. This chapter will review and compare a bone-seeking radiopharmaceutical that emits beta-particles, samarium-153-EDTMP, with an alpha-particle emitter, radium-223. The charged alpha particles from radium-223 have far more mass and energy than beta particles (electrons) from Sm-153-EDTMP. Because radium-223 has less marrow toxicity and more radiobiological effectiveness, especially if inside the bone forming cancer cell than samarium-153-EDTMP, radium-223 may have greater potential to become widely used against osteosarcoma as a targeted therapy. Radium-223 also has more potential to be used with chemotherapy against osteosarcoma and bone metastases. Because osteosarcoma makes bone and radium-223 acts like calcium, this radiopharmaceutical could possibly become a new targeted means to achieve safe and effective reduction of tumor burden as well as facilitate better surgery and/or radiotherapy for difficult to resect large, or metastatic tumors.