Myeloid Sarcoma: A Primer for Radiologists.

ABSTRACT: Myeloid sarcoma (MS) is a rare extramedullary neoplasm that can present in association with acute myeloid leukemia, most commonly in children younger than 15 years. This unique extramedullary malignancy may involve a variety of different organ systems and can present following, preceding, simultaneous with, or in insolation to acute myeloid leukemia. Common areas of extramedullary involvement include soft tissues, bones, lymph nodes, and the peritoneum. Imaging plays a critical role in the diagnosis and management of MS, with commonly used modalities including positron emission tomography-computed tomography, magnetic resonance imaging, computerized tomography, and ultrasound. The purpose of this review article is to provide radiologists with a comprehensive guide summarizing the relevant imaging and clinical features of MS, with emphasis on the role of imaging in the diagnosis, treatment, and follow-up of patients with MS. The relevant pathophysiology, epidemiology, clinical presentations, and differential diagnosis of MS will be reviewed. The relevance of different imaging modalities in diagnosis, monitoring of treatment response, and assessment of treatment-related complications will also be outlined. Through summarizing these topics, this review article aims to provide radiologists with a guide for understanding the existing knowledge of MS in the literature and the current role of imaging in the management of this unique malignancy.

Imaging-based Toxicity and Response Pattern Assessment Following CAR T-Cell Therapy.

Background Chimeric antigen receptor (CAR) T-cell immunotherapy is increasingly used for refractory lymphoma but may lead to cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Imaging may assist in clinical management. Associations between CRS or ICANS grade and imaging findings remain not fully established. Purpose To determine associations between imaging findings and clinical grade of CRS or ICANS, evaluate response patterns, and assess imaging use following CAR T-cell treatment. Materials and Methods Patients with refractory B-cell lymphoma who received CAR T-cell infusion between 2018 and 2020 at a single center were analyzed retrospectively. Clinical CRS or ICANS toxicity grade was assessed using American Society for Transplantation and Cellular Therapy, or ASTCT, consensus grading. Thoracic and head images (radiographs, CT scans, MRI scans) were evaluated. Associations between imaging findings and clinical CRS or ICANS grade were analyzed. Wilcoxon signed-rank and χ2 tests were used to assess associations between thoracic imaging findings, clinical CRS toxicity grade, and imaging-based response. Response to therapy was evaluated according to Deauville five-point scale criteria. Results A total of 38 patients (mean age ± standard deviation, 59 years ± 10; 23 men) who received CAR T-cell infusion were included. Of these, 24 (63% [95% CI: 48, 79]) and 11 (29% [95% CI: 14, 44]) experienced clinical grade 1 or higher CRS and ICANS, respectively. Patients with grade 2 or higher CRS were more likely to have thoracic images with abnormal findings (10 of 14 patients [71%; 95% CI: 47, 96] vs five of 24 patients [21%; 95% CI: 4, 37]; P = .002) and more likely to have imaging evidence of pleural effusions (five of 14 [36%; 95% CI: 10, 62] vs two of 24 [8.3%; 95% CI: 0, 20]; P = .04) and atelectasis (eight of 14 [57%; 95% CI: 30, 84] vs six of 24 [25%; 95% CI: 7, 43]; P = .048). Positive imaging findings were identified in three of seven patients (43%) with grade 2 or higher ICANS who underwent neuroimaging. The best treatment response included 20 of 36 patients (56% [95% CI: 39, 72]) with complete response, seven of 36 (19% [95% CI: 6, 33]) with partial response, one of 36 (2.8% [95% CI: 0, 8]) with stable disease, and eight of 36 (22% [95% CI: 8, 36]) with progressive disease. Conclusion Thoracic imaging findings, including pleural effusions and atelectasis, correlated with cytokine release syndrome grade following chimeric antigen receptor (CAR) T-cell infusion. CAR T-cell therapy yielded high response rates. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Langer in this issue.

Comparative Performance of Whole-Body MRI and FDG PET/CT in Evaluation of Multiple Myeloma Treatment Response: Systematic Review and Meta-Analysis.

BACKGROUND. Traditional approaches for evaluating multiple myeloma (MM) treatment response have low sensitivity for residual disease. Recent studies highlight the utility of whole-body MRI or FDG PET/CT in evaluating treatment response, with increasing emphasis on DWI. OBJECTIVE. This systematic review was conducted to assess the diagnostic accuracy of whole-body MRI and FDG PET/CT for MM treatment response assessment. EVIDENCE ACQUISITION. Studies in which whole-body MRI or FDG PET/CT was used to evaluate MM treatment response were identified through search of the PubMed and EMBASE databases through June 30, 2021. Pooled sensitivity and specificity for detecting response were calculated by bivariate modeling. The diagnostic performances of whole-body MRI and FDG PET/CT were compared. Subgroup analyses were conducted to assess studies comparing the modalities and studies in which whole-body MRI included DWI. EVIDENCE SYNTHESIS. Twelve studies comprising 373 patients were included: six evaluated both modalities, four evaluated whole-body MRI only, and two evaluated FDG PET/CT only. Of studies of MRI, five included DWI. Pooled sensitivity and specificity were 87% (95% CI, 75-93%) and 57% (95% CI, 37-76%) for whole-body MRI versus 64% (95% CI, 45-79%) and 82% (95% CI, 75-88%) for FDG PET/CT (sensitivity, p = .29; specificity, p = .01). For studies directly comparing the modalities, pooled sensitivity and specificity were 90% (95% CI, 80-100%) and 56% (95% CI, 44-68%) for whole-body MRI versus 66% (95% CI, 47-85%) and 81% (95% CI, 72-90%) for FDG PET/CT (sensitivity, p = .18; specificity, p < .001). Sensitivity and specificity were 93% (95% CI, 75-98%) and 57% (95% CI, 21-87%) for DWI versus 74% (95% CI, 60-85%) and 56% (95% CI, 38-73%) for whole-body MRI without DWI (sensitivity, p = .27; specificity, p = .99). The AUC values were 0.84 for whole-body MRI, 0.83 for FDG PET/CT, and 0.92 for DWI. CONCLUSION. FDG PET/CT had significantly higher specificity, and whole-body MRI had higher sensitivity (though nonsignificant). DWI may contribute to the high sensitivity of whole-body MRI. CLINICAL IMPACT. The results of this meta-analysis suggest potential complementary roles of whole-body MRI and FDG PET/CT in assessment of MM treatment response. Future studies should explore their combination through PET/MRI.

Clinically Significant Prostate Cancer Detection After a Negative Prebiopsy MRI Examination: Comparison of Biparametric Versus Multiparametric MRI.

BACKGROUND. The frequency of clinically significant prostate cancer (csPCa) following negative biparametric MRI (bpMRI) and multiparametric MRI (mpMRI) has not been well investigated in direct comparative studies. OBJECTIVE. The purposes of this study were to compare the frequency of csPCa after negative prebiopsy bpMRI and mpMRI and to evaluate factors predictive of csPCa in the two cohorts. METHODS. This retrospective study included 232 men (mean age, 64.5 years) with negative bpMRI from August 2017 to March 2020 and 193 men (mean age, 69.0 years) with negative mpMRI from January 2018 to December 2018. PI-RADS category 1 or 2 was defined as negative. The study institution offered bpMRI as a low-cost self-pay option for patients without insurer coverage of prebiospy mpMRI. Patient characteristics and subsequent biopsy results were recorded. CsPCa was defined as Gleason score of 3 + 4 or greater. Multivariable regression analyses were performed to identify independent predictors of csPCa. The AUC of PSA density (PSAD) for csPCA was computed, and the diagnostic performance of PSAD was assessed at a clinically established threshold of 0.15 ng/mL2. RESULTS. Systematic biopsy was performed after negative bpMRI for 41.4% (96/232) of patients and after negative mpMRI for 30.5% (59/193) (p = .02). Among those undergoing biopsy, csPCa was present in 15.6% (15/96) in the bpMRI cohort versus 13.6% (8/59) in the mpMRI cohort (p = .69). The NPV for csPCa was 84% (81/96) for bpMRI and 86% (51/59) for mpMRI. In multivariable analyses, independent predictors of csPCa included smaller prostate volume (OR, 0.27; p < .001) and greater PSAD (OR, 3.09; p < .001). In multivariable models, bpMRI (compared with mpMRI) was not independently predictive of csPCa (p > .05). PSAD had an AUC for csPCa of 0.71 (95% CI, 0.56-0.87) in the bpMRI cohort versus 0.68 (95% CI, 0.42-0.93) in the mpMRI cohort. For detecting csPCa, a PSAD threshold of 0.15 ng/mL2 had NPV of 90% and PPV of 28%, in the bpMRI cohort versus NPV of 92% and PPV of 44% in the mpMRI cohort. CONCLUSION. The frequencies of csPCa were not significantly different at systematic biopsy performed after negative bpMRI and mpMRI examinations. PSAD had similar diagnostic utility for csPCa in the two cohorts. CLINICAL IMPACT. Either bpMRI or mpMRI, in combination with PSAD measurement, can help avoid negative prostate biopsies.

A Decade of Success in Melanoma Immunotherapy and Targeted Therapy: What Every Radiologist Should Know.

ABSTRACT: Treatment strategies for malignant melanoma have rapidly evolved over the past decade. Because of its propensity to develop advanced stage and metastatic disease, melanoma has contributed to the majority of mortalities among patients with skin cancer. The development of novel therapeutics such as immunotherapy and targeted molecular therapies has revolutionized the treatment of patients with advanced stage and metastatic malignant melanoma. Immune checkpoint inhibitors, BRAF/MEK inhibitors, and other revolutionary therapies have demonstrated remarkable success in the treatment of this common malignancy. Along with these advancements in systemic therapies, imaging has continued to play a critical role in the diagnosis and follow-up of patients with malignant melanoma. As the use of these novel therapies continues to expand, knowledge of the evolving therapeutic landscape of melanoma is becoming critical for radiologists. In this review, we provide a primer for radiologists outlining the evolution of immunotherapy and targeted therapy in the treatment of melanoma. We discuss the critical role of imaging in evaluation of treatment response, including a summary of current imaging response guidelines. Last, we summarize the essential role of imaging in the evaluation of potential adverse events seen in patients with malignant melanoma undergoing treatment with immune checkpoint inhibitors.

CAR T-Cell Therapy: An Update for Radiologists.

Chimeric antigen receptor-engineered (CAR) T-cell therapy is a promising novel immunotherapy that has the potential to revolutionize cancer treatment. Four CAR T-cell therapies have received FDA approval within the last 5 years, and the role of CAR T cells is anticipated to continue to evolve and expand. However, various aspects of CAR T-cell therapies remain poorly understood, and the therapies are associated with severe side effects, including cytokine release syndrome and immune effector cell-associated neurotoxicity, which require prompt diagnosis and intervention. The purposes of this review are to describe the role of imaging in diagnosing and monitoring toxicities from CAR T-cell therapies and explore the use of various imaging techniques, including PET/CT with novel radiotracers, to predict and assess treatment response and adverse effects. It is important for radiologists to recognize the imaging findings associated with each syndrome and to recognize the typical and atypical treatment response patterns associated with CAR T-cell therapy. Given the expected increase in use of CAR T cells in the near future, radiologists should familiarize themselves with the imaging findings encountered in these novel therapies so that they can provide comprehensive and up-to-date guidance for clinical management.

Role of Key Guidelines in an Era of Precision Oncology: A Primer for the Radiologist.

OBJECTIVE. The purpose of this article is to familiarize radiologists with the evidence-based imaging guidelines of major oncologic societies and organizations and to discuss approaches to effective implementation of the most recent guidelines in daily radiology practice. CONCLUSION. In an era of precision oncology, radiologists in practice and radiologists in training are key stakeholders in multidisciplinary care, and their awareness and understanding of society guidelines is critically important.

Cancer Clinical Trials: What Every Radiologist Wants to Know but Is Afraid to Ask.

OBJECTIVE. The purpose of this article is to provide radiologists with a guide to the fundamental principles of oncology clinical trials. The review summarizes the evolution and structure of modern clinical trials with an emphasis on the relevance of clinical trials in the field of oncologic imaging. CONCLUSION. Understanding the structure and clinical relevance of modern clinical trials is beneficial for radiologists in the field of oncologic imaging.

Findings on Chest CT Performed in the Emergency Department in Patients Receiving Immune Checkpoint Inhibitor Therapy: Single-Institution 8-Year Experience in 136 Patients.

BACKGROUND. Patients undergoing immune checkpoint inhibitor (ICI) therapy may present to the emergency department (ED) with a wide range of immune-related adverse events. OBJECTIVE. The purpose of our study was to evaluate chest CT findings in patients receiving ICI therapy presenting to the ED and to explore these findings' associations with clinical parameters. METHODS. This retrospective study included 136 patients (75 men, 61 women; mean age, 65 ± 12 [SD] years) receiving ICI therapy who underwent chest CT at 163 ED visits between 2011 and 2018. Two radiologists independently reviewed chest CT examinations for various findings and resolved discrepancies by consensus. Clinical parameters, including survival at last available follow-up, were recorded. Chest CT findings were summarized, and interreader agreement was evaluated using kappa coefficients. Associations between CT findings and clinical parameters were explored using Fisher exact, chi-square, Wilcoxon, and Kruskal-Wallis tests. RESULTS. A total of 62.5% of patients had primary lung cancer; 52.9% received nivolumab monotherapy, and 30.1% received pembrolizumab monotherapy. A total of 55.8% of ED visits occurred within 60 days after ICI initiation. The most common CT findings were worsening lung tumor burden (60.1%), new consolidation unrelated to tumor (30.1%), new or worsening pleural effusion (23.9%), and ICI-associated pneumonitis (12.9%). The most common CT pneumonitis pattern was radiation recall pneumonitis (6/21, 28.6%). A total of 78.5% of ED visits with chest CT resulted in hospitalization; 66.9% of patients subsequently died. Survival was worse for patients with, versus without, worsening tumor (72.2% vs 49.1% of patients deceased vs alive at follow-up, p = .006) and for patients with, versus without, pleural effusion (39.2% vs 17.5% of patients deceased vs alive at follow-up, p = .04). Kappa values for interreader agreement of evaluated chest CT findings ranged from 0.66 (worsening tumor burden) to 1.00 (numerous findings). CONCLUSION. Most ED chest CT examinations in patients receiving ICI therapy exhibited worsening lung tumor burden, which was associated with worse survival. New consolidation and ICI-associated pneumonitis (most commonly radiation recall pneumonitis) were also commonly detected in the ED setting. CLINICAL IMPACT. Understanding pathologies detected on chest CT in patients undergoing ICI therapy who present to the ED may guide radiologists in interpreting such imaging.

Past, Present, and Future of Serum Tumor Markers in Management of Ovarian Cancer: A Guide for the Radiologist.

The ability to accurately detect early ovarian cancer and subsequently monitor treatment response is essential to improving survival for patients with ovarian malignancies. Several serum tumor markers (STMs)-including cancer antigen 125 (CA-125), human epididymis protein 4 (HE4), cancer antigen 19-9 (CA 19-9), and carcinoembryonic antigen (CEA)-have been used as a noninvasive method of identifying ovarian cancer in conjunction with imaging. Although current guidelines do not recommend use of STMs as screening tools for ovarian cancer, these markers have clinical utility in both diagnosis and surveillance for women with ovarian cancer. CA-125 is the most commonly used STM; its level may be elevated in several types of ovarian cancer, including epithelial cell tumors, carcinosarcoma, teratomas, and secondary ovarian malignancies. An elevated level of CA 19-9 is associated with clear cell tumors, teratomas, and secondary malignancies. CEA is most commonly associated with mucinous ovarian cancers. Finally, HE4 is being increasingly used to identify certain subtypes of epithelial ovarian cancers, particularly serous and endometrioid tumors. Diagnosis of ovarian cancers relies on a combination of CA-125 levels and US findings, which include a large adnexal mass or high-risk features, including septa and increased vascularity. CT is preferred for staging and is used along with PET and STM monitoring for surveillance. Increasingly, MRI is being used to characterize ovarian lesions that are indeterminate at US or CT. The future of STM testing involves development of "liquid biopsies," in which plasma samples are analyzed for evidence of tumors, including circulating tumor DNA or tumor cells and tumor micro-RNA. When combined with traditional imaging techniques, liquid biopsies may lead to earlier diagnosis and improved survival. An invited commentary by Shinagare is available online. ©RSNA, 2021.

Utility and Clinical Implications of Appendicular Skeleton Magnetic Resonance Imaging in Multiple Myeloma: A Single-Institutional 15-Year Experience.

OBJECTIVE: The aim of this study was to evaluate the utility of appendicular skeleton magnetic resonance imaging (MRI) in the management of multiple myeloma over 15 years. METHODS: A total of 107 appendicular MRIs were obtained from 67 patients. Variables including age, sex, diagnosis, stage, indication, transplant status, MRI result, and treatment course were analyzed. RESULTS: The most common indication was pain (76.6%). The most commonly affected bone groups were the proximal lower (54.3%) and upper extremity (47.6%). Most (83%) positive examinations demonstrated focal disease. Advanced Durie-Salmon stage was associated with increase in appendicular disease (P = 0.0056). Increasing age and prior negative positron emission tomography/computed tomography were associated with a decrease in appendicular disease (P = 0.0036 and 0.0011). When neoplasm was seen, 58.5% underwent management alteration. Advanced stage and history of relapse were associated with treatment alterations (P = 0.0096 and 0.0031). CONCLUSION: Appendicular MRIs comprised 9.6% of MRIs ordered. Appendicular MRI elucidates both neoplastic and nonneoplastic causes of pain. Most examinations with MRI positive for myeloma had subsequent skeletal disease and resulted in altered management.

Posttransplant Lymphoproliferative Disorder Status Post-Solid Organ Transplant Presenting to the Emergency Department: Single Institute Experience.

OBJECTIVE: The objective of this study was to evaluate the clinical, laboratory, imaging, and pathology findings associated with emergency department presentations of posttransplant lymphoproliferative disorder (PTLD) after solid organ transplant (SOT). METHODS: Fifteen patients presenting to a single tertiary care center between 2004 and 2019 with PTLD after SOT were identified from a pathology database. Twelve patients presenting through the emergency department were included in the study. Demographic, clinical, imaging, pathology, treatment, and outcome data were reviewed. RESULTS: Among this 12 patient cohort (7 men; mean age, 44.2 years), transplant history included 4 combined kidney/pancreas, 4 kidney, 2 liver, 1 cardiac, and 1 lung. Mean time from transplant to diagnosis was 7.6 years. Posttransplant lymphoproliferative disorder was identified on initial computed tomography scans in 10 of 12 patients. The most common sites for PTLD development were the gastrointestinal tract (4/12) and liver (3/12). Outcomes included resolution of PTLD in 9 of 12 patients, with 3 patients dying within 6 months of diagnosis. CONCLUSIONS: Posttransplant lymphoproliferative disorder is a serious consequence of solid organ transplantation that can present in various locations and with varied symptomatology in the emergency setting. Other posttransplant complications may present similarly including chronic rejection and infection. Posttransplant lymphoproliferative disorder should be considered in SOT patients presenting with worsening abdominal pain or constitutional symptoms, even with normal laboratory workup.

The Past, Present, and Future (Liquid Biopsy) of Serum Tumor Markers in Lung Cancer: A Primer for the Radiologist.

ABSTRACT: Lung cancer continues to be a major cause of death throughout the world. The ability to both accurately diagnose lung cancer in its early stages and monitor response to treatment is essential to reducing the morbidity and mortality associated with the disease. Serum tumor markers have been identified as potential biomarkers that may aid in lung cancer diagnosis and surveillance. These markers, when combined with cross-sectional imaging, may result in more robust screening and surveillance protocols. The future role of serum tumor markers in lung cancer includes the advancement of "liquid biopsies," in which peripheral blood samples are analyzed for tumor components without the need for a tissue biopsy.

Diagnostic utility of computed tomography in patients presenting to the emergency department with unintended weight loss.

PURPOSE: Unintended weight loss (UWL) is a common presenting symptom in the emergency department (ED) with several etiologies. Our study looks to evaluate the diagnostic utility of computed tomography (CT) in the evaluation of UWL in the ED. METHODS: We identified all patients who underwent CT of the chest, abdomen, or pelvis in the ED at our institution for the diagnosis of UWL from 2004 to 2020 and retrospectively reviewed their clinical history and imaging. CT findings were organized into 4 types: (1) definite cause for UWL identified, (2) possible findings for UWL, (3) incidental findings unrelated to UWL, and (4) normal scan. Associations between clinical and laboratory findings with positive CT scans were also examined. RESULTS: One hundred seventy-three eligible patients were identified; 40 patients were excluded due to history of malignancy or inadequate follow-up. One hundred thirty-three patients were included in the final cohort. Overall, the most common causes of UWL were non-malignant gastrointestinal (GI) conditions (n = 41, 30%) and cancer (n = 30, 23%). True-positive CT findings were identified in 48.8% of patients (65/133). Elevated white blood cell counts (p = <0.0001) and physical exam abnormalities (p = 0.02) were both significantly associated with CT abnormalities. CONCLUSION: The use of CT scanning in the evaluation of UWL in the ED yielded a diagnosis in approximately half of all cases, indicating good diagnostic value. The most common causes of UWL were non-malignant GI conditions and cancer in this cohort.

COVID-19 infection in the cancer population: a study of emergency department imaging utilization and findings.

PURPOSE: To analyze emergency department (ED) computerized tomography (CT) utilization in cancer patients with coronavirus disease 2019 (COVID-19). METHODS: A retrospective chart review was performed to identify cancer patients who received COVID-19 diagnosis within the single healthcare system and presented to the ED within 30 days of COVID-19 positive date between May 1 and December 31, 2020. RESULTS: In our 61 patients, the mean age was 72.5 years old, with 34% of patients (n = 21) on active cancer therapy and 66% (n = 40) on surveillance only. Most patients (n = 53) received their COVID-19 diagnosis within the ED, with 8 patients diagnosed prior to initial ED visit. The most common CT studies ordered within the ED were CT chest (n = 25), CT abdomen/pelvis (A/P) (n = 20), CT head (n = 8), and CT chest/abdomen/pelvis (C/A/P) (n = 7). COVID-19 findings were present on 33 scans, findings of worsening malignancy on 12 scans, and non-COVID non-cancer findings on 9 scans. Significant differences in CT severity score (p = 0.0001), indication for hospitalization (p = 0.026), length of hospitalization (p = 0.004), interventions (remdesivir, mechanical ventilation, and vasopressor support) while hospitalized (p < 0.05), and mortality (p = 0.042) were found between the prior diagnosis and ED diagnosis groups. No such differences were found between the active treatment and surveillance groups. CONCLUSION: ED CT imaging findings in patients with cancer and COVID-19 are predominantly related to COVID-19 infection, rather than cancer history or anti-cancer therapy status.

Decoding the Genomic Report for Radiologists.

OBJECTIVE. The purpose of this review is to provide a guide for radiologists that explains the language and format of modern genomic reports and summarizes the relevance of this information for modern oncologic imaging. CONCLUSION. Genomic testing plays a critical role in guiding oncologic therapies in the age of targeted treatments. Understanding and interpreting genomic reports is a valuable skill for radiologists involved with oncologic imaging interpretation.

The Role of Imaging and Systemic Treatments in Myeloma: A Primer for Radiologists.

OBJECTIVE. The purpose of this article is to provide an up-to-date guide for radiologists on imaging and systemic therapies in myeloma and related conditions, with a focus on radiologic findings for diagnosis and treatment response assessment. CONCLUSION. Knowledge of the unique imaging presentations of myeloma is highly useful for radiologists. An understanding of the utility of different imaging modalities and the systemic therapies used in multiple myeloma is also critical in the realm of oncologic imaging.

Hemophagocytic Lymphohistiocytosis: A Primer for Radiologists.

OBJECTIVE. The purpose of this article is to provide for radiologists an overview of the radiologic, clinical, and pathologic features of hemophagocytic lymphohistiocytosis. CONCLUSION. Hemophagocytic lymphohistiocytosis is a rare, life-threatening syndrome characterized by abnormal, excessive activation of the immune system. Imaging plays an important role in determining the extent of involvement of hemophagocytic lymphohistiocytosis. Knowledge of this entity, including its imaging, clinical, and pathologic findings, is critical to facilitate timely diagnosis.

Systemic Therapies for Melanoma Brain Metastases: A Primer for Radiologists.

OBJECTIVE: The purpose of this article is to provide a primer for radiologists outlining the modern systemic therapies used in melanoma brain metastases, including tyrosine kinase inhibitors and immune checkpoint inhibitors. The role of radiologic treatment response evaluation will be discussed from the standpoint of both modern systemic therapies and more traditional treatments. CONCLUSION: Understanding the role of systemic treatments in melanoma brain metastases is critical for oncologic imaging interpretation in this unique patient population.

Clinical, Imaging Findings, Responses, and Outcomes of Patients With Classical Hodgkin Lymphoma and Non-Hodgkin Lymphoma Undergoing Immune Checkpoint Inhibitor Therapy: A Single-Institution Experience.

OBJECTIVE: The aim of the study was to study clinical, imaging findings, response patterns, and immune-related adverse events in classical Hodgkin lymphoma (cHL) and non-Hodgkin lymphoma (NHL) patients treated with immune checkpoint inhibitors (ICIs). METHODS: A retrospective search was performed to identify patients with relapsed/refractory cHL and NHL treated with ICIs from 2015 to 2019. Clinical and laboratory data were collected. Imaging studies were reviewed for treatment response and immune-related adverse events. RESULTS: Ten patients with relapsed/refractory cHL (median age, 41 years) and 14 patients with relapsed/refractory NHL (median age, 61 years) were identified. Overall response rate was 70% for cHL patients. None of the NHL patients demonstrated complete or partial response. One case of hyperprogression and one case with atypical response were radiologically detected in cHL patients. Hypothyroidism requiring treatment occurred in 2 (20%) of 10 cHL patients, one of which had imaging correlate. Of 14 NHL patients, 1 (7%) had radiologic evidence of pneumonitis and 1 (7%) had colitis. CONCLUSIONS: This single-institution observational study demonstrated that overall response rate was higher in patients with cHL undergoing ICI. Immune checkpoint inhibitor therapy has unique response patterns and toxicities in both cHL and NHL patients that radiologists should keep in mind.