Multiple thrombi mimicking metastases in the right atrium of patients with non-Hodgkin's lymphoma diagnosed by multimodal cardiac imaging: one case report

BACKGROUND

Right-side heart mass can be found incidentally on routine transthoracic echocardiography (TTE). Accurate diagnosis of cardiac mass often requires more than one imaging method. We present a mid-age woman with non-Hodgkin lymphoma who was found to have multiple right atrial masses mimicking metastases on routine TTE, which were finally diagnosed as thrombi by multimodal cardiac imaging.

CASE PRESENTATION

A 52-year-old woman was diagnosed with primary mediastinal diffuse large B cell lymphoma (DLBCL) almost six months prior. The TTE revealed multiple masses in the right atrium with normal cardiac function when she was being evaluated for the next chemotherapy. On arrival, she was hemodynamically stable and asymptomatic. Physical examination was no remarkable. Laboratory findings showed leukocytosis of 17,900 cells/mm3, hemoglobin of 7.5 mg/dL, and a normal D-dimer level. The suspicious diagnosis of right atrial metastasis was made by TEE. However, the diagnosis of right atrial thrombi was made by contrast CMR. Finally, the 18 F-FDG PET-CT demonstrated no metabolic activity in the right atrium, which further supported the diagnosis of thrombi. Eventually, the masses were removed by cardiopulmonary bypass thoracotomy because of a high risk of pulmonary embolism. Histopathology confirmed the diagnosis of thrombi.

CONCLUSIONS

This case highlights the importance of multimodality cardiac imaging in the appropriate diagnosis of a RA masses in patient of lymphoma. Diagnosis of RA masses can be made using multimodal cardiac imaging like TTE, TEE and CMR, even PET. Echocardiography is the most commonly used on multimodal imaging in cardiac thrombus. CMR has high specificity in differentiating a tumor from thrombus, while 18 F-FDG PET has good sensitivity to determine the nature of the masses.

Update on FDG-PET in pediatric lymphoma

Lymphoma represent the third most common malignant disease in childhood and adolescence. They are divided into pediatric Hodgkin lymphoma (P-HL) and pediatric non-Hodgkin lymphoma (P-NHL). In P-HL, excellent cure rates are achieved through combined modality treatment using chemotherapy and radiotherapy. For more than 20 years, FDG-PET has been an integral part of the treatment and guides its intensity through improved staging and precise assessment of chemotherapy response. In P-NHL, good cure rates are achieved with chemotherapy alone. At present FDG-PET plays only a subordinate role in the treatment setting. Its potential to contribute to treatment management is far from being fully utilised. In this article, the current status of FDG-PET in pediatric lymphoma is presented in detail. The core elements are the sections on staging and response assessment. In addition, challenges and pitfalls are discussed and future developments are outlined.

Prediction model of radiotherapy outcome for Ocular Adnexal Lymphoma using informative features selected by chemometric algorithms

BACKGROUND

Ocular Adnexal Lymphoma (OAL) is a non-Hodgkin's lymphoma that most often appears in the tissues near the eye, and radiotherapy is the currently preferred treatment. There has been a controversy regarding the prognostic factors for systemic failure of OAL radiotherapy, the thorough evaluation prior to receiving radiotherapy is highly recommended to better the patient's prognosis and minimize the likelihood of any adverse effects.

PURPOSE

To investigate the risk factors that contribute to incomplete remission in OAL radiotherapy and to establish a hybrid model for predicting the radiotherapy outcomes in OAL patients.

METHODS

A retrospective chart review was performed for 87 consecutive patients with OAL who received radiotherapy between Feb 2011 and August 2022 in our center. Seven image features, derived from MRI sequences, were integrated with 122 clinical features to form comprehensive patient feature sets. Chemometric algorithms were then employed to distill highly informative features from these sets. Based on these refined features, SVM and XGBoost classifiers were performed to classify the effect of radiotherapy.

RESULTS

The clinical records of from 87 OAL patients (median age: 60 months, IQR: 52-68 months; 62.1% male) treated with radiotherapy were reviewed. Analysis of Lasso (AUC = 0.75, 95% CI: 0.72-0.77) and Random Forest (AUC = 0.67, 95% CI: 0.62-0.70) algorithms revealed four potential features, resulting in an intersection AUC of 0.80 (95% CI: 0.75-0.82). Logistic Regression (AUC = 0.75, 95% CI: 0.72-0.77) identified two features. Furthermore, the integration of chemometric methods such as CARS (AUC = 0.66, 95% CI: 0.62-0.72), UVE (AUC = 0.71, 95% CI: 0.66-0.75), and GA (AUC = 0.65, 95% CI: 0.60-0.69) highlighted six features in total, with an intersection AUC of 0.82 (95% CI: 0.78-0.83). These features included enophthalmos, diplopia, tenderness, elevated ALT count, HBsAg positivity, and CD43 positivity in immunohistochemical tests.

CONCLUSION

The findings suggest the effectiveness of chemometric algorithms in pinpointing OAL risk factors, and the prediction model we proposed shows promise in helping clinicians identify OAL patients likely to achieve complete remission via radiotherapy. Notably, patients with a history of exophthalmos, diplopia, tenderness, elevated ALT levels, HBsAg positivity, and CD43 positivity are less likely to attain complete remission after radiotherapy. These insights offer more targeted management strategies for OAL patients. The developed model is accessible online at: https://lzz.testop.top/.

Utility of FDG-PET in predicting the histology of relapsed or refractory lymphoma

ABSTRACT

18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) is a valuable prognostic tool in modern lymphoma care. In this study, we explored the use of quantitative FDG-PET parameters in predicting the histology of suspected relapsed or refractory (R/R) lymphoma. We retrospectively analyzed 290 FDG-PET scans performed for suspected R/R lymphoma. FDG-PET parameters measured were maximum and mean standardized uptake value (SUVMax and SUVMean), total metabolic tumor volume, and total lesion glycolysis (TLG). Receiver operating characteristic curve analysis was used to obtain the optimal thresholds that best discriminate (1) benign vs R/R lymphoma, (2) indolent vs aggressive non-Hodgkin lymphoma (NHL), and (3) aggressive transformation of indolent NHL. We found that although all 4 FDG-PET parameters discriminated R/R lymphoma from benign histology, TLG was the best performing parameter (optimal cut-off ≥245, sensitivity 63%, specificity 86%, positive predictive value [PPV] 97%, negative predictive value [NPV] 30%, area under the curve [AUC] 0.798, and P < .001). SUVMax discriminated aggressive from indolent NHL with modest accuracy (optimal threshold ≥15, sensitivity 46%, specificity 79%, PPV 82%, NPV 38%, AUC 0.638, and P < .001). In patients with a prior diagnosis of indolent NHL, SUVMax was a modest predictor of transformation (optimal cut-off ≥12, sensitivity 71%, specificity 61%, PPV 50%, NPV 78%, AUC 0.676, and P .006). Additionally, SUVMax ≥25 and an increase in SUVMax (ΔSUVMax) from baseline ≥150% were highly specific (96% and 94%, respectively). These FDG-PET thresholds can aid in identification of suspected R/R lymphoma cases with higher likelihood of R/R disease and aggressive transformation of indolent NHL, guiding the necessity and urgency of biopsy.

Spontaneous Remission of High-Grade Non-Hodgkin Lymphoma After SARS-CoV-2 Infection: A Case Report

ABSTRACT

Despite extensive research into COVID-19 since its emergence in late 2019, there is still much not fully understood about its long-term effects. When infected with SARS-CoV-2, cancer patients have been reported to be at higher risk for unfavorable outcomes. Nevertheless, evidence suggests that viruses may exhibit an antitumor effect in some cases, which has recently been anecdotally reported with SARS-CoV-2. We present the case of a patient with a recent high-grade non-Hodgkin lymphoma diagnosis and without any cancer-specific therapy, in whom a complete metabolic response on 2-[ 18 F]FDG PET/CT was observed after COVID-19.

Development and validation of CT‑based radiomics model of PET-negative residual CT masses: a potential biomarker for predicting relapse‑free survival in non-Hodgkin lymphoma patients showing complete metabolic response

PURPOSE

PET-negative residual CT masses (PnRCMs) are usually dismissed as nonviable post-treatment lesions in non-Hodgkin lymphoma (NHL) patients showing complete metabolic response (CMR). We aimed to develop and validate computed tomography (CT)-based radiomics model of PET-negative residual CT mass (PnRCM) for predicting relapse-free survival (RFS) in NHL patients showing CMR.

METHODS

A total of 224 patients who showed CMR after completing first-line chemotherapy for PET-avid NHL were recruited for model development. Patients with PnRCM were selected in accordance with the Lugano classification. Three-dimensional segmentation was done by two readers. Radiomic scores (RS) were constructed using features extracted using the Least-absolute shrinkage and selection operator analysis among radiomics features of PnRCMs showing more than substantial interobserver agreement (> 0.6). Cox regression analysis was performed with clinical and radiologic features. The performance of the model was evaluated using area under the curve (AUC). For validation, 153 patients from an outside hospital were recruited and analyzed in the same way.

RESULTS

In the model development cohort, 68 (30.4%) patients had PnRCM. Kaplan-Meier analysis showed that patients with PnRCM had significantly (p = 0.005) shorter RFS than those without PnRCM. In Kaplan-Meier analysis, the high RS group showed significantly (p = 0.038) shorter RFS than the low-scoring group. Multivariate Cox regression analysis showed that high IPI score [hazard ratio (HR) 2.46; p = 0.02], treatment without rituximab (HR 3.821; p = 0.019) were factors associated with shorter RFS. In estimating RFS, combined model in both development and validation cohort showed AUC values of 0.81.

CONCLUSION

The combined model that incorporated both clinical parameters and CT-based RS showed good performance in predicting relapse in NHL patients with PnRCM.

Comparison of diffusion-weighted MRI and [18F]FDG PET/MRI for treatment monitoring in pediatric Hodgkin and non-Hodgkin lymphoma

OBJECTIVE

To compare tumor therapy response assessments with whole-body diffusion-weighted imaging (WB-DWI) and 18F-fluorodeoxyglucose ([18F]FDG) PET/MRI in pediatric patients with Hodgkin lymphoma and non-Hodgkin lymphoma.

MATERIALS AND METHODS

In a retrospective, non-randomized single-center study, we reviewed serial simultaneous WB-DWI and [18F]FDG PET/MRI scans of 45 children and young adults (27 males; mean age, 13 years ± 5 [standard deviation]; age range, 1-21 years) with Hodgkin lymphoma (n = 20) and non-Hodgkin lymphoma (n = 25) between February 2018 and October 2022. We measured minimum tumor apparent diffusion coefficient (ADCmin) and maximum standardized uptake value (SUVmax) of up to six target lesions and assessed therapy response according to Lugano criteria and modified criteria for WB-DWI. We evaluated the agreement between WB-DWI- and [18F]FDG PET/MRI-based response classifications with Gwet's agreement coefficient (AC).

RESULTS

After induction chemotherapy, 95% (19 of 20) of patients with Hodgkin lymphoma and 72% (18 of 25) of patients with non-Hodgkin lymphoma showed concordant response in tumor metabolism and proton diffusion. We found a high agreement between treatment response assessments on WB-DWI and [18F]FDG PET/MRI (Gwet's AC = 0.94; 95% confidence interval [CI]: 0.82, 1.00) in patients with Hodgkin lymphoma, and a lower agreement for patients with non-Hodgkin lymphoma (Gwet's AC = 0.66; 95% CI: 0.43, 0.90). After completion of therapy, there was an excellent agreement between WB-DWI and [18F]FDG PET/MRI response assessments (Gwet's AC = 0.97; 95% CI: 0.91, 1).

CONCLUSION

Therapy response of Hodgkin lymphoma can be evaluated with either [18F]FDG PET or WB-DWI, whereas patients with non-Hodgkin lymphoma may benefit from a combined approach.

CLINICAL RELEVANCE STATEMENT

Hodgkin lymphoma and non-Hodgkin lymphoma exhibit different patterns of tumor response to induction chemotherapy on diffusion-weighted MRI and PET/MRI.

KEY POINTS

• Diffusion-weighted imaging has been proposed as an alternative imaging to assess tumor response without ionizing radiation. • After induction therapy, whole-body diffusion-weighted imaging and PET/MRI revealed a higher agreement in patients with Hodgkin lymphoma than in those with non-Hodgkin lymphoma. • At the end of therapy, whole-body diffusion-weighted imaging and PET/MRI revealed an excellent agreement for overall tumor therapy responses for all lymphoma types.

A hybrid few-shot multiple-instance learning model predicting the aggressiveness of lymphoma in PET/CT images

BACKGROUND AND OBJECTIVE

Patients with aggressive non-Hodgkin lymphoma (NHL) undergo distinct therapy strategies compared with indolent NHL patients. However, it is challenging to estimate NHL aggressiveness based on visual inspection of positron emission tomography (PET) or computed tomography (CT) images. Since diffuse large B-cell lymphoma (DLBCL) and Follicular lymphoma (FL) are the most typical and dominant aggressive and indolent NHL, respectively, this study aims to develop an artificial-intelligence-enabled model to distinguish DLBCL from FL in PET/CT images as the first step to tackle this challenge.

METHODS

We propose a hybrid few-shot multiple-instance learning model to predict the aggressiveness of the NHL. First, rotation-based self-supervision learning (SSL) has been employed to train the encoder on a large-scale, publicly available CT image dataset. Second, hybrid instance-level features are obtained for each NHL lesion by combining deep features with the radiomics features from both PET and CT modalities. Third, instance-level features are transformed into bag-level (or patient-level) representations. Finally, bag-level representations are fed into a distance-based classifier through few-shot learning to predict NHL aggressiveness.

RESULTS

Our model achieves an accuracy of 0.751 ± 0.008, a sensitivity of 0.787 ± 0.012, a specificity of 0.715 ± 0.013, an F1-score of 0.753 ± 0.009, and an area under the curve (AUC) of 0.795 ± 0.009 at the bag level. It outperforms the typical counterparts that use the radiomic features, random forest for feature selection, and support vector machines (SVMs) as classifiers. The three counterparts yield accuracies of 0.714 ± 0.023, 0.705 ± 0.008, and 0.698 ± 0.008, respectively. Moreover, settings of the SSL training dataset (Deep lesion) and task (rotation), hybrid CT and radiomic PET features, the pool-layer strategy of maximum, and distance-based classifier generate the best model.

CONCLUSIONS

A hybrid few-shot multiple-instance learning model can predict lymphoma aggressiveness in PET/CT images and could be a potential tool for determining therapy strategies. Hybrid features and the combination of SSL, few-shot learning, and weakly supervised learning are the two powerful pillars of the model, and these can be expanded to other medical applications with limited samples and incomplete annotations.

Diagnosis of non-Hodgkin's lymphoma due to a tiny polyp in the cecum

Endoscopic findings in primary or secondary intestinal lymphoma are non-specific, which can lead to finding a polyp, an ulcer or a completely normal mucosa. As a matter of fact, this makes having a high clinical suspicion with only the endoscopic technique, quite difficult. Due to this reason, we believe that either taking random biopsies or biopsies from visible lesions of affected sections in another imaging tests, should be indicated in order to increase the diagnostic capacity of the endoscopic technique.

Imaging of ovarian lymphoma

OBJECTIVE

The aim of the study is to describe the radiological spectrum of appearances of ovarian lymphoma (OL). The manuscript describes the radiological aspects of OL to assist the radiologist in achieving correct orientation of the diagnosis.

METHODS

We conducted a retrospective evaluation of imaging studies of 98 cases of non-Hodgkin's lymphoma, with extra-nodal localisation (ovaries) in three cases (1 primary, 2 secondary). A literature review was also performed.

RESULTS

Of the three evaluated women, one had a primary ovarian involvement and two had a secondary ovarian involvement. The most common lesion characteristics were a well-defined, solid homogeneous and hypoechoic mass at US. CT depicts OL as a well-defined, non-infiltrating, homogeneous hypodense solid mass, with mild contrast enhancement. On T1-weight MRI, OL appears as a homogeneous mass of low signal intensity, which enhances avidly following intravenous gadolinium.

CONCLUSION

Clinical and serological presentation of OL can be similar to that of primary ovarian cancer. As imaging plays a central role in the diagnosis of OL, the radiologist should be familiar with US, CT and MRI appearances of this condition to correctly orient the diagnosis and so avoid unnecessary adnexectomy.

Non-Hodgkin's Lymphoma with Intraspinal Involvement Mimics Bilateral Thoracolumbar Plexopath

PURPOSE

Non-Hodgkin lymphoma (NHL) is the most common type of lymphoma, and its extranodal manifestation is rare. Skeletal muscle involvement is noted in only 1.1% of patients with NHL. Here, we present a case of high-grade B-cell lymphoma (HGBL); it infiltrated the left neural foramina from the left psoas muscle before encroaching on the whole spinal canal and subsequently invading the contralateral neural foramina from T12 to L3.

CASE REPORT

A 43-year-old man with HGBL who could function independently presented with numbness and weakness of the left thigh 2 months after a diagnosis of infiltrative lymphoma in the left psoas muscle. His symptoms were urine incontinence and unsteady gait. A neurological examination revealed weakness in the left psoas and quadriceps with hyporeflexia and hypesthesia. Lumbar spine magnetic resonance imaging (MRI) revealed intraspinal extradural invasion from T12 to L3 with multiple left-sided root compression despite the resolution of primary psoas lymphoma. At 6 weeks after symptom onset, his symptoms progressed to weakness, numbness, and hyporeflexia of the bilateral lower extremities with preserved anal sensation. Follow- up MRI revealed the progression of intraspinal invasion, which spread through the spinal canal and invaded the contralateral neural foramina from T12 to L3. The patient was finally bound to a wheelchair.

CONCLUSION

Clinicians must check for possible intraspinal involvement in patients with HGBL, particularly patients with known paraspinal soft-tissue involvement. The resolved infiltration of the soft tissue does not preclude the possibility of further neurological involvement. Additionally, MRI may provide higher resolution findings for clarifying the structure of the neural foramina and thecal sac. Keyword: Non-Hodgkin's Lymphoma, high-grade B-cell lymphoma, plexopathy.

Endoscopic ultrasound-guided fine needle aspiration in the diagnosis of non-Hodgkin's diffuse large B-cell lymphoma with pancreatic metastasis

Non-Hodgkin lymphoma with pancreatic metastasis is extremely rare, it's easy to be misdiagnose as pancreatic solid tumor and delay treatment. We report a case of Endoscopic ultrasound-guided fine-needle aspiration in the diagnosis of non-Hodgkin's diffuse large B-cell lymphoma with pancreatic metastasis.

Clinical, Radiological and Histopathological Evaluation of Primary Colon Lymphoma

BACKGROUND

In this study, we aimed to examine the clinical, radiological, histopathological, immunohistochemical, and prognostic features of a case series undergoing surgery for non-Hodgkin's primary colon lymphoma (NHL).

METHODS

The data of six patients diagnosed with NHL who were operated on in our clinic between January 2010 and January 2020 were retrospectively analyzed. NHL was detected in six of the patients operated on for colon tumors. B (n=5) and T (n=1) cell lymphomas were detected based on their cellular subtypes.

RESULTS

The median age at diagnosis was 66 (52-70). The most common complaints were abdominal pain, weight loss, nausea, and vomiting. One patient underwent emergency surgery, and five underwent elective surgery due to obstruction. While CT was used in all patients, Positron emission tomography-computed tomography (PET/CT) was taken only in patients who underwent elective surgery. The masses were localized in the cecum in two patients, in the right colon in two patients, and in the transverse colon and sigmoid colon in one patient each. All patients underwent mesocolic resection. The mean tumor size was 7.51±2.20 (4.5-11) cm. The median number of total lymph nodes was 33 (18-44), and the median number of metastatic lymph nodes was 15 (4-39).

CONCLUSION

The overall and disease-free survival of the patient with T-cell lymphoma was shorter than that of patients with B-cell colon lymphoma. NHL is a rare disease. The cellular subtype effectively determines the survival time and prognosis of NHL.

Imaging recommendations in pediatric lymphoma: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) are both malignancies originating in the lymphatic system and both affect children, but many features differ considerably, impacting workup and management. This paper provides consensus-based imaging recommendations for evaluation of patients with HL and NHL at diagnosis and response assessment for both interim and end of therapy (follow-up).

Treatment Resulting Changes in Volumes of High-18F-FDG-Uptake Adipose Tissues over Orbit and Epicardium Correlate with Treatment Response for Non-Hodgkin's Lymphoma

BACKGROUND

A regimen of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) is the standard treatment for non-Hodgkin's lymphoma. Brown adipose tissue possesses anti-cancer potential. This study aimed to explore practical biomarkers for non-Hodgkin's lymphoma by analyzing the metabolic activity of adipose tissue.

METHODS

Twenty patients who received R-CHOP for non-Hodgkin's lymphoma were reviewed. Positron emission tomography/computed tomography (PET/CT) images, lactate dehydrogenase (LDH) levels, and body mass index (BMI) before and after treatment were collected. Regions with a high standardized uptake value (SUV) in epicardial and orbital adipose tissue were selected and analyzed by a PET/CT viewer. The initial measurements and changes in the high SUV of epicardial and orbital adipose tissues, LDH levels, and BMI of treatment responders and non-responders, and complete and partial responders, were compared.

RESULTS

The volumes of high-SUV epicardial and orbital adipose tissues significantly increased in responders after R-CHOP (p = 0.03 and 0.002, respectively). There were significant differences between changes in the high-SUV volumes of epicardial and orbital adipose tissues (p = 0.03 and 0.001, respectively) and LDH levels (p = 0.03) between responders and non-responders. The changes in high-SUV epicardial adipose tissue volumes were greater among complete responders than partial responders (p = 0.04). Poorer treatment responses were observed in patients with lower high-SUV epicardial adipose tissue volumes and higher LDH levels after R-CHOP (p = 0.03 and 0.03, respectively).

CONCLUSIONS

The preliminary results of greater changes in high-SUV epicardial and orbital adipose tissue volumes among responders indicate that brown adipose tissue could be considered a favorable prognostic biomarker.

Application of the Lugano Classification for Initial Evaluation, Staging, and Response Assessment of Hodgkin and Non-Hodgkin Lymphoma: The PRoLoG Consensus Initiative (Part 1-Clinical)

Our objective was to provide consensus recommendations from a consortium of academic and industry experts in the field of lymphoma and imaging for consistent application of the Lugano classification. Methods: Consensus was obtained through a series of meetings from July 2019 until September 2021 sponsored by the Pharma Imaging Network for Therapeutics and Diagnostics (PINTaD) as part of the PINTaD Response Criteria in Lymphoma Working Group (PRoLoG) consensus initiative. Results: Consensus recommendations clarified technical considerations for PET/CT and diagnostic CT from the Lugano classification, including updating the FDG avidity of different lymphoma entities, clarifying the response nomenclature, and refining lesion classification and scoring, especially with regard to scores 4 and 5 and the X category of the 5-point scale. Combination of metabolic and anatomic responses is clarified, as well as response assessment in cases of discordant or missing evaluations. Use of clinical data in the classification, especially the requirement for bone marrow assessment, is further updated on the basis of lymphoma entities. Clarification is provided with regard to spleen and liver measurements and evaluation, as well as nodal response. Conclusion: Consensus recommendations are made to comprehensively address areas of inconsistency and ambiguity in the classification encountered during response evaluation by end users, and such guidance should be used as a companion to the 2014 Lugano classification.

Interim FDG-PET analysis to identify patients with aggressive non-Hodgkin lymphoma who benefit from treatment intensification: a post-hoc analysis of the PETAL trial

The randomized PETAL trial failed to demonstrate a benefit of interim FDG-PET (iPET)-based treatment intensification over continued standard therapy with CHOP (plus rituximab (R) in CD20-positive lymphomas). We hypothesized that PET analysis of all lymphoma manifestations may identify patients who benefitted from treatment intensification. A previously developed neural network was employed for iPET analysis to identify the highest pathological FDG uptake (max-SUVAI) and the mean FDG uptake of all lymphoma manifestations (mean-SUVAI). High mean-SUVAI uptake was determined separately for iPET-positive and iPET-negative patients. The endpoint was time-to-progression (TTP). There was a significant interaction of additional rituximab and mean-SUVAI in the iPET-negative group (HR = 0.6, p < 0.05). Patients with high mean-SUVAI had significantly prolonged TTP when treated with 6xR-CHOP + 2 R (not reached versus 52 months, p < 0.05), whereas max-SUVmanual failed to show an impact of additional rituximab. In the iPET-positive group, patients with high mean-SUVAI had a significantly longer TTP with (R-)CHOP than with the Burkitt protocol (14 versus 4 months, p < 0.01). Comprehensive iPET evaluation may provide new prognosticators in aggressive lymphoma. Additional application of rituximab was associated with prolonged TTP in iPET-negative patients with high mean-SUVAI. Comprehensive iPET interpretation could identify high-risk patients who benefit from study-specific interventions.

Quantification of chemotherapy-induced changes in body composition in pediatric, adolescent, and young adult lymphoma using standard of care CT imaging

OBJECTIVES

The objective of this study was to use computed tomography (CT) imaging to quantify chemotherapy-induced changes in body composition (BC) in pediatric, adolescent, and young adult (AYA) patients with lymphoma and to compare image-derived changes in BC measures to changes in traditional body mass index (BMI) measures.

METHODS

Skeletal muscle (SkM), subcutaneous adipose tissue (SAT), and visceral adipose tissue (VAT) volumes were manually segmented using low-dose CT images acquired from a 10-year retrospective, single-site cohort of 110 patients with lymphoma. CT images and BMI percentiles (BMI%) were acquired from baseline and first therapeutic follow-up. CT image segmentation was performed at vertebral level L3 using 5 consecutive axial CT images.

RESULTS

CT imaging detected significant treatment-induced changes in BC measures from baseline to first follow-up time points, with SAT and VAT significantly increasing and SkM significantly decreasing. BMI% measures did not change from baseline to first follow-up and were not significantly correlated with changes in image-derived BC measures. Patients who were male, younger than 12 years old, diagnosed with non-Hodgkin's lymphoma, and presented with stage 3 or 4 disease gained more adipose tissue and lost more SkM in response to the first cycle of treatment compared to their clinical counterparts.

CONCLUSIONS

Standard of care CT imaging can quantify treatment-induced changes in BC that are not reflected by traditional BMI assessment. Image-based monitoring of BC parameters may offer personalized approaches to lymphoma treatment for pediatric and AYA patients by guiding cancer treatment recommendations and subsequently enhance clinical outcomes.

KEY POINTS

• Standard of care low-dose CT imaging quantifies chemotherapy-induced changes in body composition in pediatric, adolescent, and young adults with lymphoma. • Body mass index could not detect changes in body composition during treatment that were quantified by CT imaging. • Pediatric and AYA patients who were male, younger than 12 years old, and diagnosed with non-Hodgkin's lymphoma, and presented with stage 3 or 4 disease gained more adipose tissue and lost more skeletal muscle tissue in response to the first cycle of treatment compared to their clinical counterparts.

Radiotheranostic Agents in Hematological Malignancies

Radioimmunotherapy (RIT) is a cancer treatment that combines radiation therapy with tumor-directed monoclonal antibodies (Abs). Although RIT had been introduced for the treatment of CD20 positive non-Hodgkin lymphoma decades ago, it never found a broad clinical application. In recent years, researchers have developed theranostic agents based on Ab fragments or small Ab mimetics such as peptides, affibodies or single-chain Abs with improved tumor-targeting capacities. Theranostics combine diagnostic and therapeutic capabilities into a single pharmaceutical agent; this dual application can be easily achieved after conjugation to radionuclides. The past decade has seen a trend to increased specificity, fastened pharmacokinetics, and personalized medicine. In this review, we discuss the different strategies introduced for the noninvasive detection and treatment of hematological malignancies by radiopharmaceuticals. We also discuss the future applications of these radiotheranostic agents.

Patients undergoing multiple 18F-FDG PET/CT exams: Assessment of frequency, dose and disease classification

OBJECTIVE

To analyse the frequency, demographics, primary disease and cumulative effective dose of patients undergoing two or more 18F-FDG PET/CT examinations in a year.

METHODS

In a retrospective study performed at a tertiary-care hospital, patients who underwent ≥2 18F-FDG PET/CT scans in a calendar year were identified for two consecutive years. The CT radiation dose was calculated using dose-length-product and sex-specific conversion factors. The primary malignancy of patients was retrieved from electronic medical records.

RESULTS

10,714 18F-FDG PET/CT exams were performed for 6,831 unique patients in 2 years, yielding an average of 1.6 exams per patient. The maximum number of 18F-FDG PET/CT examinations any patient underwent in a single year was seven. 20.9% patients had ≥2 18F-FDG PET/CT exams in any single year. Thirty nine percent patients in the cohort were below 60 years age. The median dose for 18F-FDG PET/CT examination was 25.1 mSv and maximum value reaching 1.7 to 2.9 times the median value. Cumulative effective dose (CED) was≥100 mSv in 12-13% of the patients. The cumulative dose for both years combined demonstrated the 25th percentile, 50th percentile and 75th percentile as well as the mean to be over 100 mSv, with the 25th percentile being 109 mSv. The dominant primary malignancies contributing to serial 18F-FDG PET/CTs in decreasing frequency were melanoma, non-Hodgkin's lymphoma (NHL), gastrointestinal cancer, breast cancer and Hodgkin's lymphoma.

CONCLUSIONS

A sizeable number of patients undergo≥2 18F-FDG PET/CT exams with one out of every eight patients receiving cumulative dose≥100 mSv and that includes patients with long-life expectancy.

ADVANCES IN KNOWLEDGE

The study found that one of five patients had≥2 18F-FDG PET/CT exams in a calendar year, one of four patients in two years and one of eight patients received cumulative dose≥100 mSv. Top malignancies associated with serial imaging in decreasing order of frequency included melanoma, non-Hodgkin's lymphoma (NHL), gastrointestinal cancer, breast cancer and Hodgkin's lymphoma.

Jaundice and a testicular lump: a rare cause of malignant biliary obstruction

Biliary obstruction from metastatic deposits in the pancreas is rare. We present a case of primary testicular lymphoma (PTL) with pancreatic metastasis. A 56-year-old man presented to the general surgical department with signs and symptoms of obstructive jaundice. A computed tomography scan revealed multiple pancreatic metastases and a right primary testicular malignancy. Histology and positron emission tomography scanning subsequently confirmed PTL with pancreatic metastases. Metastasis to the pancreas from primary testicular malignancy is extremely rare. There is variation in prognosis between primary and secondary pancreatic malignancies and therefore in atypical cases of malignant biliary obstruction consideration must be given to the rarer secondary malignancies.

A CT-based radiomics nomogram for differentiation of squamous cell carcinoma and non-Hodgkin's lymphoma of the palatine tonsil

OBJECTIVES

Accurate preoperative differentiation between squamous cell carcinoma (SCC) and non-Hodgkin's lymphoma (NHL) in the palatine tonsil is crucial because of their different treatment. This study aimed to construct and validate a contrast-enhanced CT (CECT)-based radiomics nomogram for preoperative differentiation of SCC and NHL in the palatine tonsil.

METHODS

This study enrolled 135 patients with a pathological diagnosis of SCC or NHL from two clinical centers, who were divided into training (n = 94; SCC = 50, NHL = 44) and external validation sets (n = 41; SCC = 22, NHL = 19). A radiomics signature was constructed from radiomics features extracted from routine CECT images and a radiomics score (Rad-score) was calculated. A clinical model was established using demographic features and CT findings. The independent clinical factors and Rad-score were combined to construct a radiomics nomogram. Performance of the clinical model, radiomics signature, and nomogram was assessed using receiver operating characteristics analysis and decision curve analysis.

RESULTS

Eleven features were finally selected to construct the radiomics signature. The radiomics nomogram incorporating gender, mean CECT value, and radiomics signature showed better predictive value for differentiating SCC from NHL than the clinical model for training (AUC, 0.919 vs. 0.801, p = 0.004) and validation (AUC, 0.876 vs. 0.703, p = 0.029) sets. Decision curve analysis demonstrated that the radiomics nomogram was more clinically useful than the clinical model.

CONCLUSIONS

A CECT-based radiomics nomogram was constructed incorporating gender, mean CECT value, and radiomics signature. This nomogram showed favorable predictive efficacy for differentiating SCC from NHL in the palatine tonsil, and might be useful for clinical decision-making.

KEY POINTS

• Differential diagnosis between SCC and NHL in the palatine tonsil is difficult by conventional imaging modalities. • A radiomics nomogram integrated with the radiomics signature, gender, and mean contrast-enhanced CT value facilitates differentiation of SCC from NHL with improved diagnostic efficacy.

FDG PET/CT to detect bone marrow involvement in the initial staging of patients with aggressive non-Hodgkin lymphoma: results from the prospective, multicenter PETAL and OPTIMAL>60 trials

PURPOSE

Fluorine-18 fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG PET/CT) is the standard for staging aggressive non-Hodgkin lymphoma (NHL). Limited data from prospective studies is available to determine whether initial staging by FDG PET/CT provides treatment-relevant information of bone marrow (BM) involvement (BMI) and thus could spare BM biopsy (BMB).

METHODS

Patients from PETAL (NCT00554164) and OPTIMAL>60 (NCT01478542) with aggressive B-cell NHL initially staged by FDG PET/CT and BMB were included in this pooled analysis. The reference standard to confirm BMI included a positive BMB and/or FDG PET/CT confirmed by targeted biopsy, complementary imaging (CT or magnetic resonance imaging), or concurrent disappearance of focal FDG-avid BM lesions with other lymphoma manifestations during immunochemotherapy.

RESULTS

Among 930 patients, BMI was detected by BMB in 85 (prevalence 9%) and by FDG PET/CT in 185 (20%) cases, for a total of 221 cases (24%). All 185 PET-positive cases were true positive, and 709 of 745 PET-negative cases were true negative. For BMB and FDG PET/CT, sensitivity was 38% (95% confidence interval [CI]: 32-45%) and 84% (CI: 78-88%), specificity 100% (CI: 99-100%) and 100% (CI: 99-100%), positive predictive value 100% (CI: 96-100%) and 100% (CI: 98-100%), and negative predictive value 84% (CI: 81-86%) and 95% (CI: 93-97%), respectively. In all of the 36 PET-negative cases with confirmed BMI patients had other adverse factors according to IPI that precluded a change of standard treatment. Thus, the BMB would not have influenced the patient management.

CONCLUSION

In patients with aggressive B-cell NHL, routine BMB provides no critical staging information compared to FDG PET/CT and could therefore be omitted.

TRIAL REGISTRATION

NCT00554164 and NCT01478542.

Fried egg sign: A typical ultrasonography feature of neurolymphomatosis

Neurolymphomatosis (NL) is a rare condition caused by non-Hodgkin's lymphoma or leukemia. We present a case of NL and describe ultrasound features, including the "fried egg sign" in which there is a clear demarcation between an avascular echogenic core and a hypoechoic vascularized peripheral zone that may help to distinguish NL from primary nerve sheath tumors.

A Case of Solitary Laryngotracheal Lymphoma Evaluated by 18F-FDG PET/CT

ABSTRACT

Solitary non-Hodgkin lymphoma of the trachea is extremely rare. Herein, we reported a case of solitary laryngotracheal lymphoma in a 55-year-old man. He complained of cough, tachypnea, and dyspnea. 18F-FDG PET/CT showed a hypermetabolic lesion in the subglottic larynx and upper cervical trachea. The subsequent histology and immunohistochemistry of the laryngotracheal lesion tissue confirmed the diagnosis of non-Hodgkin lymphoma (mucosa-associated lymphatic tissue lymphoma).

Different roles of surveillance positron emission tomography according to the histologic subtype of non-Hodgkin's lymphoma

BACKGROUND/AIMS

Although the use of surveillance 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is discouraged in patients with diffuse large B-cell lymphoma, its usefulness in different subtypes has not been thoroughly investigated.

METHODS

We retrospectively evaluated 157 patients who showed positive results on surveillance FDG-PET/CT every 6 months following complete response for up to 5 years. All of the patients also underwent biopsies.

RESULTS

Seventy-eight (49.6%) of 157 patients had true positive results; the remaining 79 (50.3%), including eight (5.1%) with secondary malignancies, were confirmed to yield false positive results. Among the 78 patients with true positive results, the disease in seven (8.9%) had transformed to a different subtype. The positive predictive value (PPV) of FDG-PET/CT for aggressive B-cell non-Hodgkin's lymphoma (NHL) was lower than that for indolent B-cell or aggressive T-cell NHL (p = 0.003 and p = 0.018, respectively), especially in patients with a low/low-intermediate international prognostic index (IPI) upon a positive PET/CT finding. On the other hand, indolent B-cell and aggressive T-cell NHL patients showed PPVs of > 60%, including those with low/low-intermediate secondary IPIs.

CONCLUSION

The role of FDG-PET/CT surveillance is limited, and differs according to the lymphoma subtype. FDG-PET/CT may be useful in detecting early relapse in patients with aggressive T-cell NHL, including those with low/low-intermediate risk secondary IPI; as already known, FDG-PET/CT has no role in aggressive B-cell NHL. Repeat biopsy should be performed to discriminate relapse or transformation from false positive findings in patients with positive surveillance FDG-PET/CT results.

Solitary Vulvar Involvement of Ovarian Non-Hodgkin Lymphoma Mimicking Bartholin's Abscess on 18F-FDG PET/CT

ABSTRACT

A 49-year-old woman was diagnosed with diffuse large B-cell lymphoma of the left ovary. Two months after the hysterectomy and bilateral salpingo-oophorectomy operation, the patient was referred to 18F-FDG PET/CT for staging. A mass lesion measuring 2.8 × 3 cm with intense 18F-FDG uptake was observed at right labium majus, which could be considered as a Bartholin's cyst or abscess. The lesion was excised, and non-Hodgkin lymphoma involvement of vulva was revealed by histopathology.

Difficulty in distinguishing malignant gastric lymphoma from advanced gastric cancer: Focusing on endoscopic findings of the Borrmann type

Malignant gastric lymphoma (MGL) accounts for a small proportion (upto 5%) of gastric malignancies. However, unlike for advanced gastric cancer (AGC) that requires surgical treatment, the standard treatments for MGL are chemotherapy and radiotherapy. Hence, the initial impression of the endoscopist is critical for the differential diagnosis and for planning future treatment. The purpose of this study was to assess the endoscopic diagnostic accuracy and the possibility of distinguishing between AGC and MGL depending on the endoscopist's experience.A total of 48 patients who had MGL, and 48 age and sex-matched patients who had AGC were assessed by endoscopic review at a tertiary referral hospital between June 2008 and February 2017. Two endoscopic specialists reviewed the endoscopic findings and divided these diagnoses into 5 groups: Borrmann type (1, 2, 3, and 4) and early gastric cancer-like type. After this, 7 experts and 8 trainees were asked to complete a quiz that was comprised of 6 images for each of the 96 cases and to provide an endoscopic diagnosis for each case. The test results were analyzed to assess the diagnostic accuracy according to the pathologic results, endoscopic subgroups, and endoscopists' experience. For inter-observer agreement was calculated with Fleiss kappa values.The overall diagnostic accuracy of endoscopic findings by the experts was 0.604 and that by the trainees was 0.493 (P = .050). There was no significant difference in the diagnosis according to the final pathology (lymphoma cases, 0.518 vs 0.440, P = .378; AGC cases, 0.690 vs 0.547, P = .089, respectively). In the subgroup analysis, the experts showed significantly higher diagnostic accuracy for the endoscopic Borrmann type 4 subgroup, including lymphoma or AGC cases, than the trainees (P = .001). Inter-observer agreement of final diagnosis (Fleiss kappa, 0.174) and endoscopic classification groups (Fleiss kappa, 0.123-0.271) was slightly and fair agreement.The experts tended to have a higher endoscopic diagnostic accuracy. Distinguishing MGL from AGC based on endoscopic findings is difficult, especially for the beginners. Even if the endoscopic impression is AGC, it is important to consider MGL in the differential diagnosis.

High 18F-FDOPA PET Uptake in Primary Central Nervous System Lymphoma

We present a 42-year-old woman with primary central nervous system lymphoma (PCNSL) and strong F-FDOPA PET uptake. F-FDOPA PET has high diagnostic accuracy in gliomas and brain metastases. The L-type amino acid transporter 1, targeted by F-FDOPA and C-MET PET, is a cell-type transporter usually upregulated in malignant tumors, including PCNSL. In this line, strong uptake was already shown with C-MET in PCNSL. We report the same findings with F-FDOPA. Consequently, PCNSL is a possible differential neoplastic diagnosis of F-FDOPA uptake among neoplastic lesions.

FDG PET/CT parameters and correlations with tumor-absorbed doses in a phase 1 trial of 177Lu-lilotomab satetraxetan for treatment of relapsed non-Hodgkin lymphoma

Purpose

¹⁷⁷Lu-lilotomab satetraxetan targets the CD37 antigen and has been investigated in a first-in-human phase 1/2a study for relapsed non-Hodgkin lymphoma (NHL). Tumor dosimetry and response evaluation can be challenging after radioimmunotherapy (RIT). Changes in FDG PET/CT parameters after RIT and correlations with tumor-absorbed doses has not been examined previously in patients with lymphoma. Treatment-induced changes were measured at FDG PET/CT and ceCT to evaluate response at the lesion level after treatment, and correlations with tumor-absorbed doses were investigated.

Methods

Forty-five tumors in 16 patients, with different pre-treatment and pre-dosing regimens, were included. Dosimetry was performed based on multiple SPECT/CT images. FDG PET/CT was performed at baseline and at 3 and 6 months. SUV_max, MTV, TLG, and changes in these parameters were calculated for each tumor. Lesion response was evaluated at 3 and 6 months (PET_3months and PET_6months) based on Deauville criteria. Anatomical changes based on ceCT at baseline and at 6 and 12 months were investigated by the sum of perpendiculars (SPD).

Results

Tumor-absorbed doses ranged from 35 to 859 cGy. Intra- and interpatient variations were observed. Mean decreases in PET parameters from baseline to 3 months were ΔSUV_max-3months 61%, ΔMTV_3months 80%, and ΔTLG_3months 77%. There was no overall correlation between tumor-absorbed dose and change in FDG PET or ceCT parameters at the lesion level or significant difference in tumor-absorbed doses between metabolic responders and non-responders after treatment.

Conclusion

Our analysis does not show any correlation between tumor-absorbed doses and changes in FDG PET or ceCT parameters for the included lesions. The combination regimen, including cold antibodies, may be one of the factors precluding such a correlation. Increased intra-patient response with increased tumor-absorbed doses was observed for most patients, implying individual variations in radiation sensitivity or biology.

Trial registration

ClinicalTrials.gov Identifier (NCT01796171). Registered December 2012

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-020-05098-x.

Secondary gastric lymphoma - Do we know its endoscopic findings?

The proportion of Non-Hodgkin's Lymphoma (NHL) is higher in patients with human immunodeficiency virus (HIV) infection and the gastrointestinal (GI) tract is the most common primary site of extra-nodal lymphomas. Endoscopically, the diagnosis of gastric lymphoma is challenging and there are a wide range of endoscopic findings. We report a case of a secondary gastrointestinal lymphoma in an HIV-patient.

Primary lymphoma of the tibia in children: Two case reports

RATIONALE

Primary lymphoma of the bones (PLB) is a rare extranodal non-Hodgkin lymphoma (NHL) that is particularly rare in children. The clinical presentation and radiological features of PLB are often nonspecific, making clinical diagnosis challenging and misdiagnosis frequent. Here, we report 2 children with PLB focusing on clinical presentation, differential diagnosis, and treatment outcomes.

PATIENTS CONCERNS

A 9-year-old boy presented with left knee swelling and pain for 4 months after a fall. He was previously misdiagnosed with traumatic soft tissue injury. The second patient was an 11-year-old boy with a 6-month history of intermittent left knee pain. He was previously misdiagnosed with bone tuberculosis and chronic osteomyelitis.

DIAGNOSES

A 9-year-old boy showed an abnormal signal of the left tibia metaphysis, diaphysis, and epiphysis, and tibia with periosteal reactions and surrounding soft tissue swelling. Tumor biopsy and immunohistochemistry confirmed a diagnosis of B-cell lymphoblastic lymphoma.An 11-year-old boy showed a permeative lesion in the metaphysis and diaphysis of the left proximal tibia. Tumor biopsy and immunohistochemistry confirmed the diagnosis of diffuse large B-cell lymphoma.

INTERVENTIONS

Both patients were treated with 6 courses of NHL-Berlin-Frankfurt-Münster-95.

OUTCOMES

Both patients are in complete clinical remission with a follow-up of 27 and 18months after treatment, respectively.

LESSONS

PLB is a rare malignancy that is difficult to diagnose, particularly in children. Clinicians should increase the awareness of the disease and consider a differential diagnosis of bone lesions. Chemotherapy combined with radiotherapy is a favorable treatment for children with PLB. Early diagnosis and active treatment can improve patient prognosis.

[Computer tomography and magnetic resonance imaging of perirenal non-hodgkins lymphoma]

A description of specific features of CT-MRI in rare patient with perirenal non-Hodgkins lymphoma is presented in the article. CT scan was used to determine the accumulation of contrast medium and pathological vessels along the right kidneys border. Diffusion weighted MRI revealed the low values of the measured diffusion coefficient (MDC) and high accumulation index of the paramagnetic in the tumor tissue (0.59-0.62). The specific features of perirenal non-Hodgkins lymphoma on CT/MRI, an evaluation of the tumors volume and stage, and signs of malignancy are described.

Multiple primary central nervous system lymphoma in the elderly: A case report

RATIONALE

Multiple primary central nervous system lymphoma (MPCNSL) is a rare disease with differential diagnosis and treatment. As the underlying pathogenesis is not yet clarified, the early-stage clinical manifestations are occult and atypical. Also, the imaging manifestations are not specific, which is challenging for the clinical diagnosis and treatment. Therefore, additional clinical research is essential to understand the etiology of the disease.

PATIENT CONCERNS

A 63-year-old male patient suffered from MPCNSLs but without typical clinical manifestations. The findings of the imaging examination were as follows. Magnetic resonance imaging (MRI) showed long T1 and T2 signal shadows in the right frontal lobe, right hippocampus, right cerebellar hemisphere, and the left occipital lobe. In addition, patchy T1-enhanced signal shadows were observed in the right frontal lobe and around the midline. Frontal lesions were detected in the magnetic resonance spectroscopy (MRS), Cho peak increased, and N-acetylaspartate (NAA) peak decreased. On the other hand, in the diffusion weighted imaging (DWI), apparent dispersion coefficient (ADC) showed low-value changes and high signal changes. The positron emission tomography-computed tomography (PET-CT) displayed radioactive accumulation in the right frontal lobe.

DIAGNOSIS

Multiple primary central nervous system lymphoma.

INTERVENTIONS

The patient received some conservative medical treatment, but his condition continued to worsen. Finally, he received a pathological biopsy, and refused further treatment after the result was reported.

OUTCOMES

The patient died 1 week after biopsy, and the course of disease was about 100 days.

LESSONS

PCNSL is a primary intracranial malignancy with low incidence and a high degree of malignancy and specificity in clinical manifestations. To facilitate early clinical treatment and improve the long-term survival of patients, it is necessary to master the imaging diagnostic methods and its features. The comprehensive application of multiple imaging examinations, such as CT, MRI, PET/CT, and PET/MRI, as well as, cerebrospinal fluid cytology can greatly improve the diagnosis of PCNSL.

Pre-dosing with lilotomab prior to therapy with 177Lu-lilotomab satetraxetan significantly increases the ratio of tumor to red marrow absorbed dose in non-Hodgkin lymphoma patients

PURPOSE

177Lu-lilotomab satetraxetan is a novel anti-CD37 antibody radionuclide conjugate for the treatment of non-Hodgkin lymphoma (NHL). Four arms with different combinations of pre-dosing and pre-treatment have been investigated in a first-in-human phase 1/2a study for relapsed CD37+ indolent NHL. The aim of this work was to determine the tumor and normal tissue absorbed doses for all four arms, and investigate possible variations in the ratios of tumor to organs-at-risk absorbed doses.

METHODS

Two of the phase 1 arms included cold lilotomab pre-dosing (arm 1 and 4; 40 mg fixed and 100 mg/m2 BSA dosage, respectively) and two did not (arms 2 and 3). All patients were pre-treated with different regimens of rituximab. The patients received either 10, 15, or 20 MBq 177Lu-lilotomab satetraxetan per kg body weight. Nineteen patients were included for dosimetry, and a total of 47 lesions were included. The absorbed doses were calculated from multiple SPECT/CT-images and normalized by administered activity for each patient. Two-sided Student's t tests were used for all statistical analyses.

RESULTS

Organs with distinct uptake of 177Lu-lilotomab satetraxetan, in addition to tumors, were red marrow (RM), liver, spleen, and kidneys. The mean RM absorbed doses were 0.94, 1.55, 1.44, and 0.89 mGy/MBq for arms 1-4, respectively. For the patients not pre-dosed with lilotomab (arms 2 and 3 combined) the mean RM absorbed dose was 1.48 mGy/MBq, which was significantly higher than for both arm 1 (p = 0.04) and arm 4 (p = 0.02). Of the other organs, the highest uptake was found in the spleen, and there was a significantly lower spleen absorbed dose for arm-4 patients than for the patient group without lilotomab pre-dosing (1.13 vs. 3.20 mGy/MBq; p < 0.01). Mean tumor absorbed doses were 2.15, 2.31, 1.33, and 2.67 mGy/MBq for arms 1-4, respectively. After averaging the tumor absorbed dose for each patient, the patient mean tumor absorbed dose to RM absorbed dose ratios were obtained, given mean values of 1.07 for the patient group not pre-dosed with lilotomab, of 2.16 for arm 1, and of 4.62 for arm 4. The ratios were significantly higher in both arms 1 and 4 compared to the group without pre-dosing (p = 0.05 and p = 0.02). No statistically significant difference between arms 1 and 4 was found.

CONCLUSIONS

RM is the primary dose-limiting organ for 177Lu-lilotomab satetraxetan treatment, and pre-dosing with lilotomab has a mitigating effect on RM absorbed dose. Increasing the amount of lilotomab from 40 mg to 100 mg/m2 was found to slightly decrease the RM absorbed dose and increase the ratio of tumor to RM absorbed dose. Still, both pre-dosing amounts resulted in significantly higher tumor to RM absorbed dose ratios. The findings encourage continued use of pre-dosing with lilotomab.

Ultra-early response assessment in lymphoma treatment: [18F]FDG PET/MR captures changes in glucose metabolism and cell density within the first 72 hours of treatment

PURPOSE

To determine whether, in patients with Hodgkin lymphoma (HL) or non-Hodgkin lymphoma (NHL), [18F]FDG PET/MR can capture treatment effects within the first week after treatment initiation, and whether changes in glucose metabolism and cell density occur simultaneously.

METHODS

Patients with histologically proven HL or NHL were included in this prospective IRB-approved study. Patients underwent [18F]FDG PET/MR before, and then 48-72 h after (follow-up 1, FU-1) and 1 week after (FU-2) initiation of the first cycle of their respective standard chemotherapy (for HL) or immunochemotherapy (for NHL). Standardized [18F]FDG uptake values (SUVmax, SUVmean) and apparent diffusion coefficients (ADCmin, ADCmean) based on diffusion-weighted MRI, and metabolic and morphological tumour volumes (MTV, VOL) were assessed at each time-point. Multilevel analyses with an unstructured covariance matrix, and pair-wise post-hoc tests were used to test for significant changes in SUVs, ADCs, MTVs and VOLs between the three time-points.

RESULTS

A total of 58 patients (11 with HL and 47 with NHL) with 166 lesions were analysed. Lesion-based mean rates of change in SUVmax, SUVmean, ADCmin, ADCmean, MTV and VOL between baseline and FU-1 were -46.8%, -33.3%, +20.3%, +14%, -46% and -12.8%, respectively, and between baseline and FU-2 were -65.1%, -49%, +50.7%, +32.4%, -61.1% and -24.2%, respectively. These changes were statistically significant (P < 0.01) except for the change in VOL between baseline and FU-1 (P = 0.079).

CONCLUSION

In lymphoma patients, [18F]FDG PET/MR can capture treatment-induced changes in glucose metabolism and cell density as early as 48-72 h after treatment initiation.

Clinical Utility of Radioimmunoscintigraphy of Non-Hodgkin's Lymphoma with Radiolabelled LL2 Monoclonal Antibody., Lymphoscan™: Preliminary Results

Aims and Background

Adequate clinical staging of non-Hodgkin's lymphoma patients is essential because only localized disease can be treated satisfactorily. Many imaging procedures are necessary to stage the disease accurately. The objective of this study was to evaluate the efficacy of an anti-lymphoma antibody in the Fab’ fragment form, labelled with 99mTc, to detect malignant lesions.

Methods

Radioimmunodetection (RAID) with 99mTc-labelled B-cell lymphoma monoclonal antibody IMMU-LL2-Fab’ (LymphoSCAN™; Immunomedics, Morris Plain, NJ, USA) was investigated in 10 patients (5 females and 5 males; age range, 20-72 years) with histologically proved non-Hodgkin's lymphoma. Of the 10 lymphomas, 7 were intermediate grade and 3 were low grade. Whole body images with multiple planar views were obtained at 30 min, 4-6 and 24 h after i.v. injection of 1 mg LL2-Fab’ labelled with 740-925 MBq of 99mTc. SPET of the chest or abdomen was performed in all patients 5-8 h after the immunoreagent injection.

Results

No adverse reactions were observed in any patient after Mab infusion, and no appreciable changes were seen in the blood counts, renal or liver function tests. A total of 18 of 21 (85.7%) lymphoma lesions were detected by RAID. All the tumor localizations were confirmed by clinical examination and with other imaging techniques, such as CT scan, MRI or gallium scan. In this series of patients no false-positive results were noted. As regards the biodistribution of the immunoreagent, no appreciable bone marrow activity was seen; splenic targeting was demonstrated in all patients; the tumor-to-non-tumor ratios ranged from 1.2 to 2.8 ad measured by the ROI technique; no difference in uptake was noted for different tumor grades. The images obtained 24 h after injection did not reveal new lesions, but areas of doubtful uptake were seen as positive focal areas in the delayed scan.

Conclusions

LymphoSCAN™ seems to be useful for detection, staging and follow-up of non-Hodgkin's lymphoma patients.

Primary Cerebral Lymphoma: A Retrospective Study in 22 Immunocompetent Patients

Aims and background

Primary CNS lymphomas are uncommon tumors in immunocompetent patients. We describe the radiological features that should orient towards performing a biopsy and analyze the results in our series of patients.

Methods

We reviewed 22 immunocompetent patients with primary central nervous system lymphoma admitted in our Institute between 1977 and 1997. The follow-up period ranged from 2 months (patient deceased) to 69 months. Fourteen patients underwent surgical removal of the tumor and the remainder a biopsy. All patients received radiotherapy and 8 patients radiotherapy plus chemotherapy.

Results

Two of the 14 patients treated by surgical removal of the tumor died. There was no mortality related to biopsy procedures. Patients treated with radiotherapy had 1-year, 2-year and 5-year survival rates of 66%, 41.6% and 16.6%, compared to 87.5%, 62.5% and 50%, respectively, for patients who received radiotherapy and chemotherapy.

Conclusions

At present, there is no definite treatment for these highly malignant brain tumors. The most favorable results seem related to biopsy followed by radiotherapy plus chemotherapy versus surgical removal, which is related to a high risk of severe postoperative deficit for both the deep location and infiltrating nature of these lesions.

Differential Diagnosis of Sinonasal Lymphoma and Squamous Cell Carcinoma on CT, MRI, and PET/CT

Objective The purpose of this study was to analyze computed tomography (CT) and magnetic resonance (MR) images and to evaluate the maximum standardized uptake value (SUV max) of positron emission tomography (PET)/CT parameters between sinonasal non-Hodgkin's lymphoma (NHL) and squamous cell carcinoma (SCC), knowing the imaging features that distinguish sinonasal NHL from SCC. Study Design Case series with chart review. Setting University tertiary care facility. Subjects and Methods We analyzed the features on CT, MR imaging, and PET/CT of 78 patients diagnosed with sinonasal NHL or SCC histopathologically. The CT (n = 34), MRI (n = 25), and PET/CT (n = 33) images of 39 patients with sinonasal NHL and the CT (n = 38), MR (n = 28), and PET/CT (n = 31) images of 39 patients with SCC were evaluated. The sinonasal NHL was diagnosed as natural killer/T-cell lymphoma (n = 28) and diffuse large B-cell lymphoma (n = 11). Results Patients with sinonasal NHL had a larger tumor volume and higher tumor homogeneity than patients with SCC on T2-weighted and postcontrast MR images. Most of the sinonasal NHL and SCC showed a high degree of enhancement. The apparent diffusion coefficient (ADC) values and adjacent bone destruction were significantly lower in sinonasal NHL than in SCC. However, cervical lymphadenopathy, Waldeyer's ring involvement, and PET/CT SUV max showed no significant differences between sinonasal NHL and SCC. Conclusion CT and MR images of sinonasal masses showing a bulky lesion, marked homogeneity, and low ADC values without adjacent bone destruction are more suggestive of sinonasal NHL than SCC.

Usefulness of 18F-FDG PET/CT for evaluating response of ocular adnexal lymphoma to treatment

The purpose of this study was to investigate the efficacy of F-fluoro-deoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for evaluating the ocular adnexal lymphoma treatment responses.We retrospectively reviewed data for 9 histologically confirmed cases of malignant lymphoma. All patients had at least one ocular adnexal tumor site and underwent FDG PET/CT before and after treatment. Patients' histological disease subtypes included diffuse large B-cell lymphoma (n = 3), mucosa-associated lymphoid tissue lymphoma (n = 2), follicular lymphoma (n = 1), NK/T-cell lymphoma (n = 1), lymphoplasmacytic lymphoma (n = 1), and Hodgkin lymphoma (n = 1). The highest FDG uptake by the ocular adnexal lesions was calculated as the maximum standardized uptake value (SUVmax). FDG uptake at ocular adnexal sites and sites of systemic disease after treatment were also assessed using the 5-point Deauville scale.In 1 of the 9 patients, a conjunctival lesion could not be detected by either pre- or posttreatment PET/CT. For 8 of the 9 patients, the SUVmax value at the ocular adnexal site significantly decreased after treatment (7.1 ± 5.1 vs 1.6 ± 0.58; P = .0196). For 7 of the 9 patients, the first posttreatment FDG uptake at the ocular adnexal site was considered a complete metabolic response, and these patients showed an improved clinical ophthalmic presentation with no relapse at ocular adnexal sites during follow-up.FDG PET/CT is useful for evaluation of the response of ocular adnexal lymphoma to treatment, although its usefulness may depend on the histological subtype and site of the lesion.

Magnetic Resonance Imaging in Evaluation of Sinonasal Masses with Histopathological Correlation

Sinonasal mass is the abnormal growth of tissue from nasal cavity and mucosa of the paranasal sinuses. The growth may be benign or malignant. The benign lesion grows slowly and does not metastasize. The malignant lesion grows rapidly and metastasizes early. The aim of this study is to evaluate and diagnose the various types of sinonasal masses with MRI and its correlation with histopathological findings. This cross sectional descriptive study was carried out for a period of 02 years, from July 2015 to June 2017. The patients were selected from the ENT outpatient department and from the department Radiology & Imaging of Mymensingh Medical College Hospital, Mymensingh, Bangladesh who were reported as case of sinonasal masses. Thirty three (33) patients (17 males and 16 females) with sinonasal masses were included after fulfilling exclusion & inclusion criteria which was confirmed by proper clinical examination & were subjected to MRI and histopathological examination. The age range was 11 to 85 years. The nasal cavity was the most commonly involved site with sinonasal malignancies (were 4 cases, 12.12%) followed by the maxillary sinuses (were 2 cases, 6.06%). The least commonly affected site was the frontal sinuses (was 1 case, 3.03%). Histopathological findings shows benign sinonasal tumors were present in 25 cases. The most common benign lesion was sinonasal polyposis 10 cases (30.30%), followed by inverted papilloma 6 cases (18.18%) & juvenile nasopharyngeal angiofibroma 6 cases (18.18%), adenoma 02 cases (6.06%), and one case was rhinosporidiosis (3.03%). Malignant sinonasal tumors were present in 8 cases. Most common malignant tumors were nasopharyngeal carcinoma in 4 cases (12.12%), adenoid cystic carcinoma in 3 cases (9.09%) and non-Hodgkin lymphoma was present in 01 case (3.03%). MRI report shows benign masses in 23 cases of which nasopharyngeal polyposis was 10(30.30%), inverted papilloma 6(18.18%), juvenile angiofibroma 4(12.12%), adenoma 02(6.06%) & rhinosporidiosis 1(3.03%). Among 10 malignant tumors nasopharyngeal carcinoma were 6(18.18%), adenoid cystic carcinoma 3(9.09%) & non-Hodgkin lymphoma 1(3.03%). MRI findings of malignant sinonasal masses revealed that sensitivity 87.5%, specificity 40.0%, positive predictive value (PPV) 70% & negative predictive value 66%. Statistically significant association was observed between histopathology & MRI findings, p value was 0.305. Statistically significant association was found between histopathology & MRI findings.

Daily CT guidance improves target coverage during definitive radiation therapy for gastric MALT lymphoma

PURPOSE

Radiation therapy (RT) for gastric mucosa-associated lymphoid tissue (MALT) lymphoma is challenging because of variation in the stomach's position, size, and shape. We investigated the interfractional changes in stomach location, consequent dosimetric effects, and impact of daily computed tomography image guidance RT (CT-IGRT).

METHODS AND MATERIALS

Twelve patients treated for gastric MALT lymphoma with intensity modulated radiation therapy, using a breath-hold technique and restriction of oral intake, were studied retrospectively. The planning target volume (PTV) comprised a 0.5 to 1.0 cm expansion of the stomach. The prescription dose was 30 Gy in 15 to 20 fractions. CT-IGRT was performed daily using CT-on-Rails. Dosimetry was calculated on 229 daily CT images after bony versus CT-based soft tissue alignment, and doses delivered to the target and adjacent structures were compared with the treatment plan. Target coverage was expressed as the percent of the clinical target volume (CTV) and PTV receiving ≥95% of the prescribed dose (V95%).

RESULTS

The average change in stomach volume was -12.4% (range, -47.6% to 38.6%). The average shift required for target coverage was 1.0 cm (maximum, 2.2 cm). With CT-based alignment to the stomach, the average V95% was 98.5% for CTV and 94.9% for PTV; with bony alignment, these values were 94.5% and 90.4%, respectively (P < .01 for CTV and PTV). With bony alignment, the PTV V95% was ≤90% in 4 patients (33%) over the course of treatment and was as low as 72.5% for 1 fraction. The kidney position varied with respect to the stomach and bony anatomy. Consequently, the dose to the left kidney was higher based on daily CT scans than on planning scans. Dose to other organs at risk did not vary significantly.

CONCLUSIONS

Substantial interfractional variation in stomach volume was observed, despite treatment with breath-hold and restriction of oral intake. Daily CT-IGRT improved target coverage, enabling excellent coverage despite the use of small PTV margins.

Four-dimensional cone-beam computed tomography-guided radiotherapy for gastric lymphoma

PURPOSE

We describe a treatment method with four-dimensional cone-beam computed tomography (4D-CBCT)-guided radiotherapy for gastric lymphoma.

MATERIALS AND METHODS

We performed image-guided radiotherapy (IGRT) with 15 fractions for a gastric mucosa-associated lymphoid tissue lymphoma patient, using 4D-CBCT. The stomach was delineated based on 4D-CT images. For image guidance, an automatic registration between planning CT and 4D-CBCT images was performed based on the bony anatomy (bone matching), followed by manual registration based on the stomach in 4D-CBCT images of all 10 phases (4D matching). We calculated the covering ratio (CR) with variable stomach-to-planning target volume (PTV) margins, based on the images of all phases [CR (%) = the number of covering phases/all 150 phases × 100].

RESULTS

The patient underwent radiotherapy (RT) as scheduled, without any significant adverse effects. The appropriate PTV margins (CR ≥ 95%) were 25 mm (CR 99.3%) and 15 mm (CR 98.7%) for bone and 4D matching, respectively.

CONCLUSION

4D matching using 4D-CBCT is appropriate for IGRT of gastric lymphomas.

Spinal cord involvement in primary CNS lymphoma

LETM is a common syndrome and the diagnosis of CNS lymphoma is not usually considered in the list of differentials. Primary CNS lymphoma can present as longitudinally extensive transverse myelopathy. Failure to suspect and evaluate leads to delay in diagnosis and treatment. PCNSL may be non contrast enhancing on gadolinium enhanced MRI. CSF analysis should be done preferably before starting corticosteroids as it is usual practice in treatment of transverse myelitis, as steroids may lead to transient improvement and mask the correct diagnosis. Repeated CSF examinations may be needed to clinch the diagnosis.

[Diagnostic value of diffusion-weighted magnetic resonance imaging for solid tumors affecting the base of tongue and glossopharynx]

PURPOSE

The objective of the present study was to evaluate the potential application value of diffusion-weighted magnetic resonance imaging (DW-MRI) to differentiate solid benign from malignant tumors affecting the base of tongue and glossopharynx.

METHODS

Sixty-one patients who presented with solid tumors affecting the base of tongue and glossopharynx underwent conventional MRI and DW-MRI before pathologic verification. Based on pathologic findings, the tumors were classified into 4 groups: Group 1, solid benign tumor (n=10); Group 2, epithelial carcinoma (n=35); Group 3: non- epithelial malignant tumor (n=16); and Group 4: malignant tumor (n=51, a combination of Group 2 and 3). The mean apparent diffusion coefficients (ADCs) were computed from DW-MRI scans obtained with b factors of 0 and 1000 s/mm2. SAS 9.1 software package was used for Wilcoxon test.

RESULTS

The mean ADCs were significantly different (P<0.05) between group 1 and the other 3 groups, and between group 2 and group 3, respectively. Among all kinds of pathological types of lesions, non-Hodgkin lymphoma had a lowest mean ADC value, and schwannoma had a highest mean ADC value. In addition, the mean ADCs among epithelial carcinoma subtypes were not significantly different(P>0.05).

CONCLUSIONS

DW-MRI has differential diagnostic value of solid tumors affecting the base of tongue and glossopharynx, especially in distinguishing between benign solid tumors and malignant tumors, and between epithelial carcinomas and non-epithelial malignant tumors.