PET Scans for Staging and Restaging in Diffuse Large B-Cell and Follicular Lymphomas

Real-World Challenges of Managing Diffuse Large B-Cell Lymphoma in a Developing Country

PURPOSE

To highlight challenges and cancer care disparities in patients of diffuse large B-cell lymphoma management in resource-constrained settings.

MATERIALS AND METHODS

This multicenter retrospective study included 738 patients from 12 public and private sector hematology-oncology centers across Pakistan. Patients were divided into limited-resource and enhanced-resource settings as per national diffuse large B-cell lymphoma (DLBCL) guidelines.

RESULTS

The median age at diagnosis was 47 years (range, 14-89). Male:female ratio was 2.5:1. Majority of the patients (69.3%) were treated in limited-resource settings. Computed tomography was used as a staging modality in 442 (60%) patients. Limited-stage DLBCL was present in 13.5% of patients, while 86.3% had advanced-stage disease at diagnosis. First-line regimens included rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone in 56% and cyclophosphamide, doxorubicin, vincristine, prednisone in 34% of patients, while 10% of patients received palliative regimens upfront. Of evaluable data, complete remission was documented in 299 (74.4%) patients, 39 (9.8%) had partial response and 63 (13.5%) had progressive disease. Disease-free survival (DFS) and overall survival (OS) status were not available for 345 (46.8%) patients at the time of data collection. Overall study cohort had a median follow-up of 2.2 years with a median OS of 3.6 years (95% CI, 3.1 to 4.1), median DFS of 3.1 years (95% CI, 2.6 to 3.6), and a 5-year OS of 40% and DFS of 36%.

CONCLUSION

Patients from low- and middle-income countries present at an earlier age and have more advanced disease. Patients were frequently lost to follow-up, and record keeping was inadequate more so in patients treated in limited-resource settings. There is a need to establish a national lymphoma registry, improve record keeping, and standardize treatments to ensure improvement in treatment outcomes.

FDG-PET/CT Provides Clues on Bone Marrow Involvement in Follicular Lymphoma and Carries Important Prognostic Information

Objectives: To compare the diagnostic efficacy of PET-CT and bone marrow biopsy (BMB) in the detection of bone marrow involvement (BMI) in newly diagnosed patients with follicular lymphoma (FL), as well as their prognostic implications in such patients. Methods: Retrospective analysis was conducted on clinical data from 165 newly diagnosed FL patients. The benefits and drawbacks of PET-CT and BMB in assessing BMI in FL patients were compared and evaluated. Moreover, the prognostic outcomes and factors affecting the survival of FL patients were examined. Results: Among 165 patients, bone marrow involvement (BMI) was diagnosed by PET-CT (PET+) in 54 cases (32.7%), by bone marrow biopsy (BMB+) in 50 cases (30.3%), and by either PET+ or BMB+ in 80 cases (48.5%). PET-CT scans upgraded 32 patients (19.4%) to stage IV, including 1 stage I and 4 stage II cases. Four patients were elevated to stage IV by BMB, all of whom had a previous stage III diagnosis. No patients with previous stages I or II were elevated to stage IV by BMB. The median follow-up time was 6.6 years (range,0-11.0 years). The 5-year OS was 86.7%, and the 5-year PFS was 44.8%. Multivariate analysis revealed that BMI by PET-CT was the only independent predictor of PFS reduction. Regarding OS, grade 3a and BMI by PET-CT were independent predictors of decreased survival. Conclusion: PET-CT enables a thorough evaluation of bone marrow involvement in patients with FL, and BMI identified by PET-CT can have substantially implications for patient prognosis. PET-CT obtains vital data for the diagnosis, treatment, and prognosis of FL patients. By contrast, BMB seldom augments crucial data.

Accuracy and prognostic impact of FDG PET / CT and biopsy in bone marrow assessment of follicular lymphoma at diagnosis: A Nation‐Wide cohort study

BACKGOUND

In the workup of follicular lymphoma (FL), bone marrow biopsy (BMB) assessment is a key component of FLIPI and FLIPI2, the most widely used outcome scores. During the previous decade, several studies explored the role of FDG-PET/CT for detecting nodal and extranodal disease, with only one large study comparing both techniques.

METHODS

The aim of our study was to evaluate the diagnostic accuracy and the prognostic impact of both procedures in a retrospective cohort of 299 FL patients with both tests performed at diagnosis. In order to avoid a collinearity bias, FLIPI2 was deconstructed in its founding parameters, and the bone marrow involvement (BMI) parameter separately included as: a positive BMB, a positive PET/CT, the combined "PET/CT and BMB positive" or "PET/CT or BMB positive". These variables were also confronted independently with the POD24 in 233 patients treated with intensive regimens.

RESULTS

In the total cohort, bone marrow was involved in 124 and 60 patients by BMB and PET/CT, respectively. In terms of overall survival, age > 60 y.o. and the combined "PET/CT or BMB positive" achieved statistical independence as a prognostic factor. In patients treated with an intensive regimen, only the combined "PET/CT or BMB positive" added prognostic value for a shorter overall survival, when confronted with the POD24.

CONCLUSION

Our results show that in FL both BMB and PET/CT should be considered at diagnosis, as their combined assessment provides independent prognostic value in the context of the most widely use clinical scores.

Imaging Features and Prognostic Value of FDG PET/CT in Patients with Intravascular Large B-Cell Lymphoma

Purpose

The clinical value of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in intravascular large B-cell lymphoma (IVLBCL) is unknown. This study investigated the association between PET/CT features and prognosis in IVLBCL patients.

Patients and Methods

Subjects were 30 newly diagnosed Asian variant IVLBCL patients at a single institution. Baseline PET/CT was analyzed for the distribution and intensity of FDG lesions, and PET/CT pattern groups were compared for the outcome.

Results

Eight patients had hypermetabolic lymph node (LN) lesions (Nodal group). The remaining 22 patients with extranodal (EN) involvement were categorized into Deauville score 3–4 (EN/DS3-4; n = 14) and DS5 groups (EN/DS5; n = 8). First-line therapy resulted in a complete or partial response in 75.0%, 64.3%, and 100% of the respective groups. Treatment-related deaths occurred in one nodal group and three EN/DS3-4 group cases, but none among the EN/DS5 group. During 56 months of follow-up, disease progression or relapse occurred in five, four, and one case of respective groups. Cancer-related death occurred more frequently in the Nodal (n = 6) and EN/DS3-4 groups (n = 7) than the EN/DS5 group (n = 1; P = 0.041). Nodal and EN/DS3-4 groups had worse 5-year event-free survival (EFS; 25.0% and 49.0%, respectively, P = 0.010 and 0.076) and overall survival (OS; 33.3% and 48.2%, P = 0.010 and 0.068) compared to the EN/DS5 group (87.5% EFS and 87.5% OS).

Conclusion

In patients with Asian variant IVLBCL, the distribution and intensity of FDG uptake lesions on PET/CT can be useful for predicting treatment outcomes and survival.

Long-term results of PET-guided radiation in patients with advanced-stage diffuse large B-cell lymphoma treated with R-CHOP

Consolidative radiation therapy (RT) for advanced-stage diffuse large B-cell lymphoma (DLBCL) remains controversial, with routine practice continuing to include RT in patients with initial bulky disease or residual masses. Positron emission tomography (PET)-computed tomography is a sensitive modality for detecting the presence of residual disease at the end of treatment (EOT). A PET-guided approach to selectively administering RT has been the policy in British Columbia since 2005. Patients with advanced-stage DLBCL diagnosed from 1 January 2005 to 1 March 2017 and treated with at least 6 cycles of R-CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone plus rituximab), who underwent EOT PET, were included in this analysis. Those with complete metabolic response (PET-negative [PET-NEG]) were observed; those with PET-positive (PET-POS) scans were offered consolidative RT, when feasible. Of the patient records reviewed, 723 were identified, with median follow-up of 4.3 years: 517 (72%) were PET-NEG; 206 (28%) were PET-POS. Time to progression (TTP) and overall survival (OS) at 3 years were 83% vs 56% and 87% vs 64%, in patients with PET-NEG and PET-POS scans, respectively. PET-POS patients with nonprogressing disease treated with consolidative RT (109 and 206; 53%) had outcomes approaching those of PET-NEG patients, with 3-year estimates of 76% and 80% for TTP and OS. PET-NEG patients who had bulky disease (≥10 cm) at diagnosis had outcomes indistinguishable from those without bulk, despite the omission of RT. These data suggest that patients with advanced-stage DLBCL who are PET-NEG at EOT and receive no RT have excellent outcomes. 18F-fluorodeoxyglucose-PET can reliably guide selective administration of consolidative RT, even in patients with initially bulky disease.

Overview and recent advances in PET/CT imaging in lymphoma and multiple myeloma

Imaging in hematological diseases has evolved extensively over the past several decades. Positron emission tomography/computed tomography (PET/CT) with of 2-[18 F]-fluoro-2-deoxy-d-glucose ([18 F] FDG) is currently essential for accurate staging and for early and late therapy response assessment for all FDG-avid lymphoproliferative histologies. The widely adopted visual Deauville 5-point scale and Lugano Classification recommendations have recently standardized PET scans interpretation and improved lymphoma patient management. In addition [18 F] FDG-PET is routinely recommended for initial evaluation and treatment response assessment of Multiple Myeloma (MM) with significant contribution in risk-stratification and prognostication, although magnetic resonance imaging remains the Gold Standard for the assessment of bone marrow involvement. In this review, an overview of the role of [18 F] FDG-PET, in hematological malignancies is provided, particularly focusing on Hodgkin lymphoma (HL) and Diffuse Large B Cell Lymphoma (DLBCL), both in adult and pediatric populations, and MM, at each point of patient management. Potential alternative molecular imaging applications in this field, such as non-[18 F] FDG-tracers, whole body magnetic resonance imaging (WB-MRI), hybrid PET/MRI and emerging radiomics research are briefly presented.

Baseline FDG-PET/CT detects bone marrow involvement in follicular lymphoma and provides relevant prognostic information

In follicular lymphoma (FL), detection of bone marrow (BM) involvement (BMI) by 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) improves the accuracy of staging vs BM biopsy (BMB) alone. Our objective was to determine the diagnostic utility of PET for BMI FL and the prognostic value of BMI by PET (positive PET result [PET+]). Records of patients (2002-2016) with PET and BMB at the time of initial treatment were reviewed. BMI was identified by positive BMB result (BMB+) and/or unifocal or multifocal BM FDG uptake on blindly reviewed PET scans with no corresponding CT abnormality (PET+). Among 261 patients, BMI was diagnosed in 78 patients (29.9%) by PET+, in 81 patients (31.0%) by BMB+, and in 113 patients (43.3%) by either PET+ or BMB+. PET+ upstaged 24 patients to stage IV, including 10 from stages I or II to stage IV. Median duration of follow-up was 6.0 years (range, 0-16.6 years). In univariate analysis, a high Follicular Lymphoma International Prognosis Index (FLIPI) score, PET+, and BMB+ correlated with shorter progression-free survival (PFS; all P ≤ .03), and high FLIPI, PET+, and combined PET+ and BMB+ with shorter overall survival (OS; all P ≤ .01). In multivariate analysis, PET+ was the only independent predictor of PFS, whereas high FLIPI score and PET+ predicted OS (P ≤ .03). Combined PET and BMB identify BMI more accurately than either BMB or PET alone, but BMB rarely adds critical information. For patients initiating treatment of FL, identification of BMI by PET is predictive of PFS and OS.

Interim and end-of-treatment PET-CT suffers from high false-positive rates in DLBCL: Biopsy is needed prior to treatment decisions

The application of positron emission tomography (PET)-computed tomography (CT) in treatment response evaluation has increased in diffuse large B-cell lymphoma (DLBCL), although its predictive value is controversial. We retrospectively analyzed the rate of false-positive PET-CTs performed as interim (n = 94) and end-of-treatment (n = 8) assessments among 102 DLBCL patients treated during 2010-2017 at Oulu University Hospital. In PET-CT Deauville score ≥4 was regarded as positive. A biopsy was performed on 35 patients, and vital lymphoma tissue was detected from nine patients. Positive biopsy findings were associated with poor disease outcomes in this study. This difference was statistically significant: 2-year failure-free survival (FFS) was 44% in patients with a positive biopsy versus 83% for those with a negative biopsy (p = 0.003). The corresponding overall survival (OS) rates were 53% versus 95% (p = 0.010). In the multivariate analyses, a negative biopsy was an independent protective factor in FFS (Hazard Ratio (HR) 0.093 (95% confidence interval [CI] 0.017-0.511); p = 0.006) unrelated to the International Prognostic Index (IPI) (HR 1.139 [95% CI 0.237-5.474] p = 0.871) or stage (HR 1.365 [95% CI 0.138-13.470]; p = 0.790). There was no statistically significant difference in OS according to the PET results, but the FFS rate was significantly higher in patients with a negative PET. The value of PET-CT as an evaluation method suffers from a high false-positive rate, and it is inadequate alone for the justification of treatment decisions. Biopsy results provide more reliable prognostic information for the evaluation of treatment response and outcome and should be used to assess patients with positive PET-CT scans.

5-Hydroxymethylcytosine profiles of cfDNA are highly predictive of R-CHOP treatment response in diffuse large B cell lymphoma patients

Background

Although R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) remains the standard chemotherapy regimen for diffuse large B cell lymphoma (DLBCL) patients, not all patients are responsive to the scheme, and there is no effective method to predict treatment response.

Methods

We utilized 5hmC-Seal to generate genome-wide 5hmC profiles in plasma cell-free DNA (cfDNA) from 86 DLBCL patients before they received R-CHOP chemotherapy. To investigate the correlation between 5hmC modifications and curative effectiveness, we separated patients into training (n = 56) and validation (n = 30) cohorts and developed a 5hmC-based logistic regression model from the training cohort to predict the treatment response in the validation cohort.

Results

In this study, we identified thirteen 5hmC markers associated with treatment response. The prediction performance of the logistic regression model, achieving 0.82 sensitivity and 0.75 specificity (AUC = 0.78), was superior to existing clinical indicators, such as LDH and stage.

Conclusions

Our findings suggest that the 5hmC modifications in cfDNA at the time before R-CHOP treatment are associated with treatment response and that 5hmC-Seal may potentially serve as a clinical-applicable, minimally invasive approach to predict R-CHOP treatment response for DLBCL patients.

Available prognostic models for risk stratification of diffuse large B cell lymphoma patients: a systematic review

The International Prognostic Index (IPI) has been used for risk stratification for a long time in diffuse large B cell lymphoma (DLBCL). Based on new clinical and biological prognostic markers, many new prognostic models have been described. This review aims to present the progress in development and validation of these prognostic models. A comprehensive literature review was performed to identify studies that proposed a new prognostic model in DLBCL. A total of 38 studies met the inclusion criteria. The IPI, revised IPI (R-IPI), and National Comprehensive Cancer Network (NCCN)-IPI were the most studied prognostic indexes, externally validated and commonly used to compare to other models. Despite an increasing number of prognostic models have been proposed lately, most of them lack external validation. Further studies, that combine biological and clinical markers with prognostic significance, are needed to determine the optimal prognostic tool for more personalized treatment approach to DLBCL patients.

Non-traumatic splenic rupture - a rare first presentation of diffuse large B-cell lymphoma and a review of the literature

Background

Cases of non-traumatic splenic rupture are rare and entails a potentially grave medical outcome. Hence, it is important to consider the differential diagnosis of a non-traumatic splenic rupture in patients with acute or insidious abdominal pain. The incidence of rupture in Diffuse B-cell non-Hodgkin Lymphoma is highly infrequent (Paulvannan and Pye, Int J Clin Pract 57:245–6, 2003; Gedik et el., World J Gastroenterol 14:6711–6716, 2008), despite reports of various non-traumatic splenic rupture in the literature (Orloff and Peksin, Int Abstr Surg 106:1-11, 1958; Paulvannan and Pye, Int J Clin Pract 57:245–6, 2003). In this article, we attempt to highlight the features of a rare cause of splenic rupture that might serve as a future reference point for the detection of similar cases during routine clinical practice.

Case presentation

A 40-year-old man presented with 1 week history of left hypochondriac pain associated with abdominal distention. There was no history of preceding trauma or fever. Clinical examination revealed signs of tachycardia, pallor and splenomegaly. He had no evidence of peripheral stigmata of chronic liver disease. In addition, haematological investigation showed anemia with leucocytosis and raised levels of lactate dehydrogenase enzyme. However, peripheral blood film revealed no evidence of any blast or atypical cells. In view of these findings, imaging via ultrasound and computed tomography of the abdomen was performed. The results of these imaging tests showed splenic collections that was suggestive of splenic rupture and hematoma. Patient underwent emergency splenectomy and the histopathological report confirmed the diagnosis as DLBCL.

Conclusions

The occurrence of true spontaneous splenic rupture is uncommon. In a recent systematic review of 613 cases of splenic rupture, only 84 cases were secondary to hematological malignancy. Acute leukemia and non-Hodgkin lymphoma were the most frequent causes of splenic rupture, followed by chronic and acute myelogeneous leukemias. At present, only a few cases of diffuse large B-cell lymphoma (DLBCL) have been reported. The morbidity and mortality rate is greatly increased when there is a delay in the diagnosis and intervention of splenic rupture cases. Hence, there should be an increased awareness amongst both physicians and surgeons that a non-traumatic splenic rupture could be the first clinical presentation of a DLBCL.

Comparison Between Different PET and CT-Based Imaging Interpretation Criteria at Interim Imaging in Patients With Diffuse Large B-Cell Lymphoma

OBJECTIVE

To evaluate the predictive value of interim PET (iPET) in diffuse large B-cell lymphoma (DLBCL) using 5 different imaging interpretation criteria: Deauville 5-point scale criteria, International Harmonization Project (IHP) criteria, Response Evaluation Criteria In Solid Tumors (RECIST) 1.1, European Organization for Research and Treatment of Cancer, and PET Response Criteria in Solid Tumors (PERCIST) 1.0.

METHODS

We retrospectively reviewed records from 38 patients with DLBCL who underwent baseline and iPET at our institution. Imaging was interpreted according to the previously mentioned criteria. Results were correlated with end-of-treatment response, based on reports at the end of treatment radiological examinations, overall survival (OS), and progression-free survival (PFS) to assess and compare the predictive value of iPET according to each criterion. We also evaluated the concordance between different criteria.

RESULTS

The Deauville and PERCIST criteria were the most reliable for predicting end-of-treatment response, reporting an accuracy of 81.6%. They also correlated with OS and PFS (P = 0.0004 and P = 0.0001, and P = 0.0007 and P = 0.0002, for Deauville and PERCIST, respectively). Interim PET according to European Organization for Research and Treatment of Cancer also predicted the end-of-treatment response with an accuracy of 73.7% and had a significant correlation with OS (P = 0.007) and PFS (P = 0.007). In contrast, the IHP criteria and RECIST did not predict outcomes: the accuracy for end-of-treatment response was 34.2% and 36.8%, respectively, with no significant correlation with OS or PFS (P = 0.182 and P = 0.357, and P = 0.341 and P = 0.215, for OS and PFS, respectively).

CONCLUSIONS

The predictive value of iPET in DLBCL patients is most reliable using the Deauville and PERCIST criteria. Criteria that rely on anatomical characteristics, namely, RECIST and IHP criteria, are less accurate in predicting patient outcomes in DLBCL.

Lugano 2014 criteria for assessing FDG-PET/CT in lymphoma: an operational approach for clinical trials

An operationalized workflow paradigm is presented and validated with pilot subject data. This approach is reproducible with a high concordance rate between individual readers (kappa 0.73 [confidence interval 0.59-0.87; P=<0.0001]) using a 5-point scale to assess [18F] labeled fluorodeoxyglucose metabolic activity in lymphomatous lesions. These results suggest an operationally practical 5-point scale workflow paradigm for potential use in larger clinical trials evaluating lymphoma therapeutics.

18F-FDG PET/CT in the clinical management of patients with lymphoma

The aim of this work was to review the current recommendations for staging and response assessment of patients with Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) in routine clinical practice after chemotherapy and/or stem cell transplantation. A five-point scale (5-PS) from the First International Workshop on PET in Lymphoma in Deauville, France, in 2009, was recommended as the standard tool to score imaging to assess treatment response in patients with lymphoma using ¹⁸F-Fluorodeoxyglucose (FDG) PET/CT. Following the recommendations of the 11th and 12th International Conferences on Malignant Lymphoma held in Lugano (Switzerland), in 2011 and 2013, respectively, a consensus (the so-called Lugano Classification) was reached regarding the use of PET/CT for staging and response assessment in FDG-avid lymphomas. As a result, ¹⁸F-FDG PET/CT was formally incorporated into standard staging for FDG-avid lymphomas. A bone marrow biopsy is no longer indicated for the routine staging of HL and most diffuse large B-cell lymphomas. PET/CT will be used to assess response in FDG-avid histologies using the 5-point scale. The recent introduction of biological agents with immune mechanisms requires flexibility in interpretations of the Lugano criteria due to tumour flare or a pseudo-progression effect produced by these agents. Provisional criteria have been proposed (Lymphoma Response to Immunomodulatory Therapy Criteria) with the introduction of the term 'Indeterminate Response' in order to identify this phenomenon until confirmed as flare/pseudoprogression or true progression. All these recommendations will improve evaluations of patients with lymphoma, and allow comparison of results from clinical practice and trials.