Sonia L. Betancourt Cuellar

Primary Pericardial Tumors

Primary pericardial tumors are rare and may be classified as benign or malignant. The most common benign lesions are pericardial cysts and lipomas. Mesothelioma is the most common primary malignant pericardial neoplasm. Other malignant tumors include a wide variety of sarcomas, lymphoma, and primitive neuroectodermal tumor. When present, signs and symptoms are generally nonspecific. Patients often present with dyspnea, chest pain, palpitations, fever, or weight loss. Although the imaging approach usually begins with plain radiography of the chest or transthoracic echocardiography, the value of these imaging modalities is limited. Cross-sectional imaging, on the other hand, plays a key role in the evaluation of these lesions. Computed tomography and magnetic resonance imaging allow further characterization and may, in some cases, provide diagnostic findings. Furthermore, the importance of cross-sectional imaging lies in assessing the exact location of the tumor in relation to neighboring structures. Both benign and malignant tumors may result in compression of vital mediastinal structures. Malignant lesions may also directly invade structures, such as the myocardium and great vessels, and result in metastatic disease. Imaging plays an important role in the detection, characterization, and staging of pericardial tumors; in their treatment planning; and in the posttreatment follow-up of affected patients. The prognosis of patients with benign tumors is good, even in the few cases in which surgical intervention is required. On the other hand, the length of survival for patients with malignant pericardial tumors is, in the majority of cases, dismal.

Clinical Staging of Patients with Early Esophageal Adenocarcinoma: Does FDG-PET/CT Have a Role?

Background: Esophageal carcinoma is a significant worldwide health problem and the incidence is increasing faster than that of any other malignancy. 18F-2-deoxy-D-glucose (FDG)-positron emission tomography/computed tomography (PET/CT) is important in the management of patients with potentially resectable esophageal cancer and is useful in initial staging of locally advanced cancer and after neoadjuvant therapy. The purpose of this study is to determine the utility of FDG-PET/CT in the clinical staging of early-stage esophageal cancer. Methods: Subjects in this retrospective study were 79 consecutive patients with cTisN0 (high-grade dysplasia) and cT1N0 primary esophageal adenocarcinoma diagnosed by endoscopy and endoscopic ultrasound biopsy that were evaluated with preoperative FDG-PET/CT and had not received neoadjuvant therapy. Seventh edition American Joint Committee on Cancer cTNM and FDG-PET/CT were compared with postoperative pTNM staging. pT1 was subdivided into intramucosal cancers with lamina propria or muscularis mucosa invasion (pT1a) and submucosal cancers (pT1b). Results: In pT staging, the frequency of FDG uptake increased with increasing pT, from pT1a 21 of 39 (53.8%) to pT1b 19 of 22 (55.8%). pTis was three of five (60.0%). Similarly, the maximum standardized uptake value of FDG-avid lesions increased with increasing pT, with median values of 3.7 for pTis, 3.8 for pT1a and 4.2 for T1b. In cN staging, FDG-PET/CT was negative in 76 patients and positive in three patients. All three patients with FDG-avid nodes on FDG-PET/CT were negative for metastatic disease on biopsy. In 12 patients with pN1 and in one patient with N2, FDG-PET/CT was falsely negative. Sensitivity and positive predictive value for pN disease were 0% and accuracy was 82%. There were no distant metastases. In cM staging, FDG-PET/CT was falsely positive in five patients (FDG avid nodules n = 3, distant nodal metastasis n = 2) and resulted in unwarranted biopsy in four patients. Conclusion: FDG-PET/CT is not useful in the TNM staging of primary adenocarcinoma of the esophagus when endoscopy and biopsy indicate cTis and cT1. In fact, FDGPET/CT can be detrimental to patient management. Because regional nodal metastases are uncommon and distant metastases rare, and as FDG-PET/CT can result in inappropriate clinical care, FDG-PET/CT should not be performed in the evaluation of early-stage esophageal cancer.

Staging of Lung Cancer

Primary lung cancer is the leading cause of cancer mortality in the world. Thorough clinical staging of patients with lung cancer is important, because therapeutic options and management are to a considerable degree dependent on stage at presentation. Radiologic imaging is an essential component of clinical staging, including chest radiography in some cases, computed tomography, MRI, and PET. Multiplanar imaging modalities allow assessment of features that are important for surgical, oncologic, and radiation therapy planning, including size of the primary tumor, location and relationship to normal anatomic structures in the thorax, and existence of nodal and/or metastatic disease.

Radiologists remember mountains better than radiographs, or do they?

Abstract. Expertise with encoding material has been shown to aid long-term memory for that material. It is not clear how relevant this expertise is for image memorability (e.g., radiologists’ memory for radiographs), and how robust over time. In two studies, we tested scene memory using a standard long-term memory paradigm. One compared the performance of radiologists to naïve observers on two image sets, chest radiographs and everyday scenes, and the other radiologists’ memory with immediate as opposed to delayed recognition tests using musculoskeletal radiographs and forest scenes. Radiologists’ memory was better than novices for images of expertise but no different for everyday scenes. With the heterogeneity of image sets equated, radiologists’ expertise with radiographs afforded them better memory for the musculoskeletal radiographs than forest scenes. Enhanced memory for images of expertise disappeared over time, resulting in chance level performance for both image sets after weeks of delay. Expertise with the material is important for visual memorability but not to the same extent as idiosyncratic detail and variability of the image set. Similar memory decline with time for images of expertise as for everyday scenes further suggests that extended familiarity with an image is not a robust factor for visual memorability.

Phase I Dose-Escalation Study of Anti–CTLA-4 Antibody Ipilimumab and Lenalidomide in Patients with Advanced Cancers

Preclinical data suggest that combining a checkpoint inhibition with immunomodulatory derivative can increase anticancer response. We designed a dose-escalation study using a 3 + 3 design to determine the safety, maximum tolerated dose (MTD) or recommended phase II dose (R2PD) and dose-limiting toxicities (DLT) of the anti–CTLA-4 antibody ipilimumab (1.5–3 mg/kg intravenously every 28 days × 4) and lenalidomide (10–25 mg orally daily for 21 of 28 days until disease progression or unacceptable toxicity) in advanced cancers. Total of 36 patients (Hodgkin lymphoma, 7; melanoma, 5; leiomyosarcoma, 4; renal cancer, 3; thyroid cancer, 3; other cancers, 14; median of 3 prior therapies) were enrolled. The MTD has not been reached and ipilimumab 3 mg/kg and lenalidomide 25 mg have been declared as R2PD. DLT were grade (G) 3 rash (3 patients) and G3 pancreatitis (1 patient). G3/4 drug-related toxicities other than DLT were G3 anemia (5 patients), G3 thromboembolism (2 patients), G3 thrombocytopenia, G3 rash, G3 hypopituitarism, G3 pneumonitis, G3 transaminitis, and G4 hypopituitarism (all in 1 patient). Eight patients had tumor shrinkage per immune-related response criteria (−79% to −2%) including a PR (−79% for 7.2+ months) in a refractory Hodgkin lymphoma. Using comprehensive genomic profiling, a total mutation burden (mutations/Mb) was evaluated in 17 patients, with one of the patients achieving a PR demonstrated intermediate mutation burden. In conclusion, combination of ipilimumab and lenalidomide is well tolerated and demonstrated preliminary signals of activity in patients with refractory Hodgkin lymphoma and other advanced cancers. Mol Cancer Ther; 17(3); 671–6. ©2017 AACR.

Early clinical esophageal adenocarcinoma (cT1): Utility of CT in regional nodal metastasis detection and can the clinical accuracy be improved?

INTRODUCTION Treatment of early esophageal cancer depends on the extent of the primary tumor and presence of regional lymph node metastasis.(RNM). Short axis diameter>10mm is typically used to detect RNM. However, clinical determination of RNM is inaccurate and can result in inappropriate treatment. Purpose of this study is to evaluate the accuracy of a single linear measurement (short axis>10mm) of regional nodes on CT in predicting nodal metastasis, in patients with early esophageal cancer and whether using a mean diameter value (short axis+long axis/2) as well as nodal shape improves cN designation. METHODS CTs of 49 patients with cT1 adenocarcinoma treated with surgical resection alone were reviewed retrospectively. Regional nodes were considered positive for malignancy when round or ovoid and mean size>5mm adjacent to the primary tumor and>7mm when not adjacent. Results were compared with pN status after esophagectomy. RESULTS 18/49 patients had pN+ at resection. Using a single short axis diameter>10mm on CT, nodal metastasis (cN) was positive in 7/49. Only 1 of these patients was pN+ at resection (sensitivity 5%, specificity 80%, accuracy 53%). Using mean size and morphologic criteria, cN was positive in 28/49. 11 of these patients were pN+ at resection (sensitivity 61%, specificity 45%, accuracy 51%). EUS with limited FNA of regional nodes resulted in 16/49 patients with pN+ being inappropriately designated as cN0. CONCLUSIONS Evaluation of size, shape and location of regional lymph nodes on CT improves the sensitivity of cN determination compared with a short axis measurement alone in patients with cT1 esophageal cancer, although clinical utility is limited.

Radiation Effects in the Mediastinum and Surroundings: Imaging Findings and Complications ☆

Radiotherapy is one of the cornerstones for treatment of patients with cancer. Although advances in radiotherapy technology have considerably improved radiation delivery, potential adverse effects are still common. Postradiation changes to the mediastinum can include different structures such as the heart, great vessels, and esophagus. The purpose of the article was to illustrate the expected variety of changes to the mediastinum and adjacent lung resulting from external beam radiotherapy and radiotherapy-induced complications to the mediastinum and to discuss different radiotherapy delivery techniques.

Evaluation of a novel elastic respiratory motion correction algorithm on quantification and image quality in abdomino-thoracic PET/CT

Our aim was to evaluate in phantom and patient studies a recently developed elastic motion deblurring (EMDB) technique that makes use of all the acquired PET data and compare its performance with other conventional techniques such as phase-based gating (PBG) and HD⋅Chest (HDC), both of which use fractions of the acquired data. Comparisons were made with respect to static whole-body (SWB) images with no motion correction. Methods: A phantom simulating respiratory motion of the thorax with lung lesions (5 spheres with internal diameters of 10–28 mm) was scanned with 0, 1, 2, and 3 cm of motion. Four reconstructions were performed: SWB, PBG, HDC, and EMDB. For PBG, the average (PBGave) and maximum bin (PBGmax) were used. To compare the reconstructions, the ratios of SUVmax, SUVpeak, and contrast-to-noise ratio (CNR) were calculated with respect to SWB. Additionally, 46 patients with lung or liver tumors less than 3 cm in diameter were studied. Measurements of SUVmax, SUVpeak, and CNR were made for 46 lung and 19 liver lesions. To evaluate image noise, the SUV SD was measured in healthy lung and liver tissue and in the phantom background. Finally, the subjective image quality of patient examinations was scored on a 5-point scale by 4 radiologists. Results: In the phantom, EMDB increased SUVmax and SUVpeak over SWB but to a lesser extent than the other reconstruction methodologies. The ratio of CNR with respect to SWB for EMDB, however, was higher than all other reconstructions (0.68 with EMDB > 0.54 with HDC > 0.41 with PBGmax > 0.31 with PBGave). Similar results were seen in patient studies. SUVmax and SUVpeak were higher by, respectively, 19.3% and 11.1% with EMDB, 21.6% and 13.9% with HDC, 22.8% and 12.8% with PBGave, and 45.6% and 26.8% with PBGmax, compared with SWB. Lung and liver noise increased with EMDB by, respectively, 3% and 15%, with HDC by 35% and 56%, with PBGave by 100% and 170%, and with PBGmax by 146% and 219%. CNR increased in lung and liver tumors only with EMDB (18% and 13%, respectively) and decreased with HDC (−14% and −23%), PBGave (−39% and −63%), and PBGmax (−18% and −46%). The average radiologist scores of image quality were 4.0 ± 0.8 with SWB, 3.7 ± 1.0 with EMDB, 3.1 ± 1.0 with HDC, and 1.5 ± 0.7 with PBG. Conclusion: The EMDB algorithm had the least increase in image noise, improved lesion CNR, and had the highest overall image quality score.

Imaging of Radiation Treatment of Lung Cancer

Radiation therapy is an important modality in the treatment of patients with lung cancer. Recent advances in delivering radiotherapy were designed to improve loco-regional tumor control by focusing higher doses on the tumor. More sophisticated techniques in treatment planning include 3-dimensional conformal radiation therapy, intensity-modulated radiotherapy, stereotactic body radiotherapy, and proton therapy. These methods may result in nontraditional patterns of radiation injury and various radiologic appearances that can be mistaken for recurrence, infection and other lung diseases. Knowledge of radiological manifestations, awareness of new radiation delivery techniques and correlation with radiation treatment plans are essential in order to correctly interpret imaging in these patients.

Pitfalls and Misinterpretations of Cardiac Findings on PET/CT Imaging: A Careful Look at the Heart in Oncology Patients

Positron emission tomography (PET) computed tomography (CT) with 2-[fluorine-18] fluoro-2-deoxy-d-glucose (FDG) has been established as an effective modality for evaluation of cancer. Interpretations of patterns of physiologic 18F-FDG uptake by the heart is particularly difficult given the wide normal variations of 18F-FDG metabolic activity observed. Atypical patterns of focal or diffuse physiologic cardiac 18F-FDG uptake and post-therapeutic effects after radiation therapy, systemic diseases, or cardiomyopathy may also be confused with malignant disease on 18F-FDG PET/CT. In this article, we review the variations of normal cardiac 18F-FDG uptake observed in oncology patients and the appearances of other patterns of pathologic metabolic activity, related or not related to the malignancy being investigated, that may lead to false-negative and false-positive results.