18F-fluorodeoxyglucose-positron emission tomography before, during and after treatment in mature T/NK lymphomas: a study from the GOELAMS group

PET/CT in Non-Hodgkin Lymphoma: An Update

Non-Hodgkin lymphomas represents a heterogeneous group of lymphoproliferative disorders characterized by different clinical courses, varying from indolent to highly aggressive. ¹⁸F-FDG-PET/CT is the current state-of-the-art diagnostic imaging, for the staging, restaging and evaluation of response to treatment in lymphomas with avidity for ¹⁸F-FDG, despite it is not routinely recommended for surveillance. PET-based response criteria (using five-point Deauville Score) are nowadays uniformly applied in FDG-avid lymphomas. In this review, a comprehensive overview of the role of ¹⁸F-FDG-PET in Non-Hodgkin lymphomas is provided, at each relevant point of patient management, particularly focusing on recent advances on diffuse large B-cell lymphoma and follicular lymphoma, with brief updates also on other histotypes (such as marginal zone, mantle cell, primary mediastinal- B cell lymphoma and T cell lymphoma). PET-derived semiquantitative factors useful for patient stratification and prognostication and emerging radiomics research are also presented.

Interim FDG-PET/CT for Response Assessment of Lymphoma

The clinical use and prognostic value of interim FDG-PET/CT (iPET/CT), which is performed after treatment initiation but prior to its completion, varies by lymphoma subtype. Evidence supporting the prognostic value of iPET/CT is more robust for classical Hodgkin lymphoma (cHL), and in this lymphoma subtype, response-adapted treatment approaches guided by iPET/CT are a widely used standard of care for first-line therapy. The data supporting use of iPET/CT among patients with non-Hodgkin lymphoma (NHL) is less well-established, but failure to achieve complete metabolic response on iPET/CT is generally considered a poor prognostic factor with likely consequences for progression free survival. This review will present the available evidence supporting use of iPET/CT in lymphoma patients, particularly as it relates to prognostication and the ability to inform response-adapted treatment strategies. The latter will be addressed through a discussion on the major iPET-response adapted clinical trials with mention of ongoing trials. Special attention will be given to cHL and a few subtypes of NHL, including diffuse large B cell lymphoma (DLBCL), follicular lymphoma (FL), and peripheral T cell lymphoma (PTCL).

Breast Implant-Associated Anaplastic Large Cell Lymphoma Following Gender Reassignment Surgery: A Review of Presentation, Management, and Outcomes in the Transgender Patient Population

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is a rare peripheral T-cell lymphoma with approximately 650-700 reported cases worldwide. The incidence, however, is increasing as more practitioners become aware of the diagnosis, and recent studies show that early diagnosis and treatment is critical to improve prognosis. There have been four cases of BIA-ALCL in total reported in the transgender population in the literature. These reported cases were reviewed in detail to determine presentation and management of BIA-ALCL in transgender patients compared to the larger population of BIA-ALCL patients. This review highlights BIA-ALCL in transgender women, a population that is often excluded from breast screening and follow-up. Transgender women may not routinely go through the same post-operative follow-up protocols as patients with breast implants for breast cancer reconstruction and can thus be at risk for delayed recognition and diagnosis. BIA-ALCL is a rare complication of breast implantation, and it is important to counsel all patients undergoing implant placement, including transgender women, on its risk.

Baseline and interim PET-based outcome prediction in peripheral T-cell lymphoma: A subgroup analysis of the PETAL trial

The prospective randomized Positron Emission Tomography (PET)-Guided Therapy of Aggressive Non-Hodgkin Lymphomas (PETAL) trial was designed to test the ability of interim PET (iPET) to direct therapy. As reported previously, outcome remained unaffected by iPET-based treatment changes. In this subgroup analysis, we studied the prognostic value of baseline total metabolic tumor volume (TMTV) and iPET response in 76 patients with T-cell lymphoma. TMTV was measured using the 41% maximum standardized uptake value (SUV_41max ) and SUV₄ thresholding methods. Interim PET was performed after two treatment cycles and evaluated using the ΔSUV_max approach and the Deauville scale. Because of significant differences in outcome, patients with anaplastic lymphoma kinase (ALK)-positive lymphoma were analyzed separately from patients with ALK-negative lymphoma. In the latter, TMTV was statistically significantly correlated with progression-free survival, with thresholds best dichotomizing the population, of 232 cm³ using SUV_41max and 460 cm³ using SUV₄ . For iPET response, the respective thresholds were 46.9% SUV_max reduction and Deauville score 1-4 vs 5. The proportion of poor prognosis patients was 46% and 29% for TMTV by SUV_41max and SUV₄ , and 29% and 25% for iPET response by ΔSUV_max and Deauville, respectively. At diagnosis, the hazard ratio (95% confidence interval) for poor prognosis vs good prognosis patients according to TMTV was 2.291 (1.135-4.624) for SUV_41max and 3.206 (1.524-6.743) for SUV₄ . At iPET, it was 3.910 (1.891-8.087) for ΔSUV_max and 4.371 (2.079-9.187) for Deauville. On multivariable analysis, only TMTV and iPET response independently predicted survival. Patients with high baseline TMTV and poor iPET response (22% of the population) invariably progressed or died within the first year (hazard ratio, 9.031 [3.651-22.336]). Due to small numbers and events, PET did not predict survival in ALK-positive lymphoma. Baseline TMTV and iPET response are promising tools to select patients with ALK-negative T-cell lymphoma for early allogeneic transplantation or innovative therapies.

18F-FDG PET/CT imaging findings in anaplastic large cell lymphoma, a rare subtype of lymphoma

OBJECTIVE

To investigate the 18F-FDG PET/CT imaging manifestations for anaplastic large cell lymphoma (ALCL), a rare subtype of T/NK cell lymphoma.

METHODS

Fifty patients with ALCL, including 32 anaplastic lymphoma kinase (ALK)-positive patients and 18 ALK-negative patients, were enrolled. The positive detection, maximal standardized uptake value (SUVmax), and distribution of nodal and extranodal involvement were recorded and analysed. Fifty patients with diffuse large B cell lymphoma (DLBCL) were collected as a control group.

RESULTS

ALCL lesions were demonstrated to be 18F-FDG-avid tumours with a mean SUVmax of 19.4 ± 12.6. Most (76%) ALCL patients presented with stage III-IV disease, and nodal and extranodal involvement occurred in 74.0 and 72.0% of the patients, respectively. ALCL and DLBCL showed many similarities in tumour stage, 18F-FDG uptake and tumour involvement (P > 0.05), although the preferred extranodal organs of involvement (bone and the gastrointestinal tract, respectively) were different (P < 0.05). Compared to ALK-negative lesions, a higher uptake of 18F-FDG was found in the ALK-positive lesions (SUVmax: 22.1 ± 14.3 vs. 15.1 ± 6.6, t = 2.354, P = 0.023). ALK-positive ALCL was more likely to involve the lymph nodes than ALK-negative ALCL (84.3% vs. 55.5%, χ2 = 4.973, P = 0.043), while ALK-negative ALCL was more prone to involve the extranodal organs compared to ALK-positive ALCL (88.9% vs. 62.5%, χ2 = 3.979, P = 0.046).

CONCLUSION

The present study demonstrated that ALCL is a systemic 18F-FDG-avid lymphoma with many imaging manifestations similar to DLBCL on PET/CT. The present study also showed that ALK expression actually influenced tumour 18F-FDG uptake and lesion distribution. These findings may be useful to improve the understanding of the biological characteristics of ALCL.

Prognostic value of pre- and post-transplantation 18F-fluorodeoxyglucose positron emission tomography results in non-Hodgkin lymphoma patients receiving autologous stem cell transplantation

Objective

High-dose chemotherapy (HDC) followed by autologous stem cell transplantation (ASCT) is the standard of care in the upfront or relapsed/refractory setting in some patients with non-Hodgkin lymphoma (NHL). However, a proportion of patients do not respond to ASCT. ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) has been widely used for staging, response evaluation, and prognosis prediction. Here, we investigated the prognostic role of PET/CT in NHL patients before and after ASCT.

Methods

A retrospective study was conducted at Peking University Cancer Hospital. All NHL patients who underwent ASCT between March 2010 and July 2016 were identified. Patients who had PET/CT scan before and after ASCT were included. Deauville criteria (5-point scale) were used to interpret PET scans. Univariate and multivariate survival analyses were performed using Cox regression. The predictive value of PET scanning was estimated by comparing the area under the receiver operating characteristic (ROC) curve.

Results

In total, 79 patients were enrolled in this study. In univariate analysis, pre- and post-ASCT PET result was identified as prognostic factors for 3-year progression-free survival (PFS) and overall survival (OS). Patients with negative pre-ASCT PET result demonstrated significantly better PFS (84.2% vs. 54.2%) and OS (89.2% vs. 63.6%) than patients with positive pre-ASCT PET result. PFS (91.6% vs. 25.3%) and OS (96.5% vs. 36.8%) were also significantly different between patients with negative and positive post-ASCT PET result. Multivariate analysis also showed a significant association between survival and post-ASCT PET result. ROC analysis revealed that the predictive value of post-ASCT PET result was superior to that of pre-ASCT PET result alone. Combined pre- and post-ASCT PET result is better for predicting outcomes in patients with NHL receiving transplantation. Deauville criteria score >3 was identified as the best cutoff value for post-ASCT PET.

Conclusions

Post-ASCT PET result was more important than pre-ASCT PET result in predicting outcomes for NHL patients who underwent ASCT. The prognostic significance can be improved when combining pre-ASCT PET result with post-ASCT PET result. Deauville criteria can be used for interpreting PET scans in this scenario.

Predictive Value of PET Response Combined with Baseline Metabolic Tumor Volume in Peripheral T-Cell Lymphoma Patients

Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of aggressive non-Hodgkin lymphomas with poor outcomes on current therapy. We investigated whether response assessed with PET/CT combined with baseline total metabolic tumor volume (TMTV) could detect early relapse or refractory disease. Methods: From 7 European centers, 140 patients with nodal PTCL who underwent baseline PET/CT were selected. Forty-three had interim PET (iPET) performed after 2 cycles (iPET2), 95 had iPET performed after 3 or 4 cycles (iPET3/4), and 96 had end-of-treatment PET (eotPET). Baseline TMTV was computed with a 41% SUV_max threshold, and PET response was reported using the Deauville 5-point scale. Results: With a median of 43 mo of follow-up, the 2-y progression-free survival (PFS) and overall survival (OS) were 51% and 67%, respectively. iPET2-positive patients (Deauville score ≥ 4) had a significantly worse outcome than iPET2-negative patients (P < 0.0001, hazard ratio of 6.8 for PFS; P < 0.0001, hazard ratio of 6.6 for OS). The value of iPET3/4 was also confirmed for PFS (P < 0.0001) and OS (P < 0.0001). The 2-y PFS and OS for iPET3/4-positive (n = 28) and iPET3/4-negative (n = 67) patients were 16% and 32% versus 75% and 85%, respectively. The eotPET results also reflected patient outcome. A model combining TMTV and iPET3/4 stratified the population into distinct risk groups (TMTV ≤ 230 cm³ and iPET3/4-negative [2-y PFS/OS, 79%/85%]; TMTV > 230 cm³ and iPET3/4-negative [59%/84%]; TMTV ≤ 230 cm³ and iPET3/4-positive [42%/50%]; TMTV > 230 cm³ and iPET3/4-positive [0%/18%]). Conclusion: iPET response is predictive of outcome and allows early detection of high-risk PTCL patients. Combining iPET with TMTV improves risk stratification in individual patients.

The aggressive peripheral T-cell lymphomas: 2017

BACKGROUND

T-cell lymphomas make up approximately 10%-15% of lymphoid malignancies. The frequency of these lymphomas varies geographically, with the highest incidence in parts of Asia.

DIAGNOSIS

The diagnosis of aggressive peripheral T-cell lymphoma (PTCL) is usually made using the World Health Organization classification. The ability of hematopathologists to reproducibly diagnose aggressive PTCL is lower than that for aggressive B-cell lymphomas, with a range of 72%-97% for the aggressive PTCLs. Risk Stratification: Patients with aggressive PTCL are staged using the Ann Arbor Classification. Although somewhat controversial, positron emission tomography scans seem to be useful as they are in aggressive B-cell lymphomas. The specific subtype of aggressive PTCL is an important risk factor with the best survival seen in anaplastic large-cell lymphoma-particularly young patients with the anaplastic lymphoma kinase positive subtype.

RISK-ADAPTED THERAPY

Anaplastic large-cell lymphoma is the only subgroup to have a good response to a CHOP-like regimen. Angioimmunoblastic T-cell lymphoma has a prolonged disease-free survival in only ∼20% of patients, but younger patients who have an autotransplant in remission seem to do better. PTCL-not otherwise specified is not one disease. Anthracycline-containing regimens have disappointing results, and a new approach is needed. Natural killer/T-cell lymphoma localized to the nose and nasal sinuses seems to be best treated with radiotherapy-containing regimens and the majority of patients are cured. Enteropathy-associated PTCL and hepatosplenic PTCL are rare disorders with a generally poor response to therapy although selected patients with enteropathy- associated PTCL seem to benefit from intensive therapy.

Accuracy of 18-F FDG PET/CT to detect bone marrow clearance in patients with peripheral T-cell lymphoma - tissue remains the issue

Staging of peripheral T-cell non-Hodgkin lymphoma (PTCL) is determined by 18-F FDG PET scan and bone marrow biopsy. This study addressed the accuracy of PET at detecting bone marrow (BM) involvement at restaging in patients with known involvement pretreatment. We identified patients with biopsy proven BM PTCL at diagnosis and concomitant BM and PET at the end of therapy. Pre-treatment PET demonstrated 50% (8/16) had a false-negative PET scan of the BM. After induction, repeat biopsy revealed 62.5% (10/16) with BM involvement. Of these 10, two had a positive PET; eight were false negative by PET. Of the six patients with a negative posttherapy BM biopsy, four were PET negative and two false positive. The sensitivity of PET at end of treatment was 20% (2/10) with a specificity of 66.7% (4/6). PET/CT is not an accurate predictor of BM involvement in patients with known PTCL in the marrow.

Value of interim FDG PET/CT for predicting outcome of patients with angioimmunoblastic T-cell lymphoma

Subjects were 45 patients with angioimmunoblastic T-cell lymphoma (AITL) who underwent 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography/computed tomography (PET/CT) at baseline and interim after 2-4 cycles. Predictors of progression-free survival (PFS) and overall survival (OS) were assessed. Positive interim PET/CT (Deauville score ≥3) was a significant independent predictor of poor PFS (Hazard ratio, 4.42; p=.028), and showed marginal significance to predict OS (p=.065). Less than 60% decrease in the average change of maximum standardized uptake value normalized by lean body mass (SUL_max) also was a significant independent predictor of poor PFS (Hazard ratio, 12.96; p=.001) and poor OS (Hazard ratio, 24.11; p=.006). Interim PET/CT has a significant prognostic value for predicting PFS and OS in patients with AITL. Deauville score and percent decrease of SUL_max have the potential to be useful parameter in classifying patients into good and poor responders.

Advancing Precision Nuclear Medicine and Molecular Imaging for Lymphoma

PET with fluorodeoxyglucose F 18 (¹⁸F FDG-PET) is a meaningful biomarker for the detection, targeted biopsy, and treatment of lymphoma. This article reviews the evolution of ¹⁸F FDG-PET as a putative biomarker for lymphoma and addresses the current capabilities, challenges, and opportunities to enable precision medicine practices for lymphoma. Precision nuclear medicine is driven by new imaging technologies and methodologies to more accurately detect malignant disease. Although quantitative assessment of response is limited, such technologies will enable a more precise metabolic mapping with much higher definition image detail and thus may make it a robust and valid quantitative response assessment methodology.

Use of 18F-fludeoxyglucose positron emission tomography-CT in the management of breast implant-associated anaplastic large cell lymphoma

The prognosis and preferred management of breast implant-associated anaplastic large cell lymphoma is dependent on whether lymphoproliferative cells are confined to within the fibrous capsule, in an effusion or lining the fibrous capsule, or if there is spread beyond the capsule in the form of a mass lesion. We describe a case where ¹⁸F-fludeoxyglucose positron emission tomography-CT was used to confirm localized disease and guide management decisions.

The utility of positron emission tomography with and without computed tomography in patients with nonmelanoma skin cancer

Combined positron emission tomography (PET) and computed tomography (CT) scans are widely used in the staging and monitoring of most malignancies. The differential for PET-positive cutaneous lesions includes primary skin cancers, infections, cutaneous metastases from distant malignancies, and benign neoplasms. In dermatology, PET/CT scans have been most widely studied in patients with melanoma and Merkel cell carcinoma. The role of PET/CT scans in the management of other cutaneous malignancies is less clear, but it has shown great promise in the management of patients with squamous cell carcinoma and cutaneous lymphoma. This review seeks to address the usefulness of PET/CT scans in nonmelanoma skin cancer and to provide guidance regarding the management of patients with incidental PET-positive nodules. Currently, there is limited experience with PET/CT scans for staging and monitoring of non-head and neck metastatic basal cell and squamous cell carcinomas, and results show limited sensitivity and specificity. We also address the evidence for management of an incidental PET-positive cutaneous nodule and recommend obtaining a biopsy specimen in patients with a known noncutaneous malignancy, a history of primary skin cancer, or a high risk of either cutaneous or noncutaneous malignancy.

Utility of interim and end-of-treatment PET/CT in peripheral T-cell lymphomas: A review of 124 patients

According to the updated guidelines for imaging in lymphoma, 18F-FDG positron emission tomography/computed tomography (PET/CT) is recommended for staging and evaluation of treatment response in FDG-avid lymphomas. The purpose of the study was to evaluate the utility of PET/CT in nodal peripheral T-cell lymphomas (PTCL). Patients with newly diagnosed nodal PTCL (peripheral T-cell lymphoma NOS, anaplastic large-cell lymphoma, or angioimmunoblastic T-cell lymphoma) seen at five Danish hematology centers during the period 2006 to 2012 were included, if they had been pretherapeutically staged with PET/CT. Medical records were reviewed for baseline clinical and follow-up information. Staging, interim (I-PET), and end-of-treatment PET/CT (E-PET) studies were centrally reviewed, and reported using the Deauville 5-point score (DS). A total of 124 patients fulfilled the inclusion criteria. The median age was 58 years, and 88% received CHOP/CHOP-like therapy. Five years PFS and OS of the study population was 36.8% (95% CI 27.3-46.4) and 49.7% (95% CI 38.9-59.6), respectively. The presence of PET/CT-ascertained lung and/or liver involvement was associated with a worse outcome. The sensitivity of PET/CT for detecting biopsy-defined bone marrow involvement was only 18% (95% CI 4-43). An interim DS >3 was not prognostic for worse OS and PFS among CHOP/CHOP-like treated patients in uni- or multivariate analyses. A DS >3 after treatment predicted a worse prognosis. In conclusion, I-PET was not predictive of outcome in CHOP/CHOP-like treated PTCL patients when using the DS. Prospective studies are needed to determine the optimal use of PET/CT in PTCL including the role of quantitative PET/CT analysis.

The aggressive peripheral T-cell lymphomas: 2015

BACKGROUND

T-cell lymphomas make up approximately 10%-15% of lymphoid malignancies. The frequency of these lymphomas varies geographically, with the highest incidence in parts of Asia.

DIAGNOSIS

The diagnosis of aggressive peripheral T-cell lymphoma (PTCL) is usually made using the World Health Organization classification. The ability of hematopathologists to reproducibly diagnosis aggressive PTCL is lower than that for aggressive B-cell lymphomas, with a range of 72%-97% for the aggressive PTCLs.

RISK STRATIFICATION

Patients with aggressive PTCL are staged using the Ann Arbor Classification. Although somewhat controversial, positron emission tomography scans seem to be useful as they are in aggressive B-cell lymphomas. The most commonly used prognostic index is the International Prognostic Index. The specific subtype of aggressive PTCL is an important risk factor, with the best survival seen in anaplastic large-cell lymphoma-particularly young patients with the anaplastic lymphoma kinase positive subtype.

RISK-ADAPTED THERAPY

Anaplastic large-cell lymphoma is the only subgroup to have a good response to a CHOP-like regimen. Angioimmunoblastic T-cell lymphoma has a prolonged disease-free survival in only ~20% of patients, but younger patients who have an autotransplant in remission seem to do better. PTCL-not otherwise specified is not one disease. Anthracycline-containing regimens have disappointing results, and a new approach is needed. Natural killer/T-cell lymphoma localized to the nose and nasal sinuses seems to be best treated with radiotherapy-containing regimens. Enteropathy-associated PTCL and hepatosplenic PTCL are rare disorders with a generally poor response to therapy, although selected patients with enteropathy-associated PTCL seem to benefit from intensive therapy.

Management of advanced NK/T-cell lymphoma

NK/T-cell lymphomas are aggressive malignancies, and the outlook is poor when conventional anthracycline-containing regimens designed for B-cell lymphomas are used. With the advent of L-asparaginase-containing regimens, treatment outcome has significantly improved. L-asparaginase-containing regimens are now considered the standard in the management of NK/T-cell lymphomas. In advanced diseases, however, outcome remains unsatisfactory, with durable remission achieved in only about 50% of cases. Stratification of patients with advanced NK/T-cell lymphomas is needed, so that poor-risk patients can be given additional therapy to improve outcome. Conventional presentation parameters are untested and appear inadequate for prognostication when L-asparaginase-containing regimens are used. Recent evidence suggests that dynamic factors during treatment and interim assessment, including Epstein-Barr virus (EBV) DNA quantification and positron emission tomography computed tomography findings, are more useful in patient stratification. The role of high-dose chemotherapy and haematopoietic stem cell transplantation requires evaluation in an overall risk-adapted treatment algorithm.

International Pediatric Non-Hodgkin Lymphoma Response Criteria

PURPOSE

Response criteria are well established for adult patients with non-Hodgkin lymphoma (NHL). A revised set of response criteria in adults with NHL was recently published. However, NHL in children and adolescents involves different histologies, primary sites of disease, patterns of metastatic spread, approaches to therapy, and responses to treatment compared with adult NHL. However, there are no standardized response criteria specific to pediatric NHL. Therefore, we developed international standardized methods for assessing response to therapy in children and adolescents with NHL.

METHODS

An international multidisciplinary group of pediatric oncologists, pathologists, biologists, and radiologists convened during and after the Third and Fourth International Childhood, Adolescent and Young Adult NHL Symposia to review existing response and outcome data, develop methods for response evaluation that reflect incorporation of more sensitive technologies currently in use, and incorporate primary and metastatic sites of disease for the evaluation of therapeutic response in children and adolescents with NHL.

RESULTS

Using the current adult NHL response criteria as a starting point, international pediatric NHL response criteria were developed incorporating both contemporary diagnostic imaging and pathology techniques, including novel molecular and flow cytometric technologies used for the determination of minimal residual disease.

CONCLUSION

Use of the international pediatric NHL response criteria in children and adolescents receiving therapy for NHL incorporates data obtained from new and more sensitive technologies that are now being widely used for disease evaluation, providing a standardized means for reporting treatment response.

Utility of ¹⁸fluoro-deoxyglucose positron emission tomography for prognosis and response assessments in a phase 2 study of romidepsin in patients with relapsed or refractory peripheral T-cell lymphoma

BACKGROUND

For patients with peripheral T-cell lymphoma (PTCL), the value of (18)fluoro-deoxyglucose positron emission tomography (FDG-PET) scans for assessing prognosis and response to treatment remains unclear. The utility of FDG-PET, in addition to conventional radiology, was examined as a planned exploratory end point in the pivotal phase 2 trial of romidepsin for the treatment of relapsed/refractory PTCL.

PATIENTS AND METHODS

Patients received romidepsin at a dose of 14 mg/m(2) on days 1, 8, and 15 of 28-day cycles. The primary end point was the rate of confirmed/unconfirmed complete response (CR/CRu) as assessed by International Workshop Criteria (IWC) using conventional radiology. For the exploratory PET end point, patients with at least baseline FDG-PET scans were assessed by IWC + PET criteria.

RESULTS

Of 130 patients, 110 had baseline FDG-PET scans, and 105 were PET positive at baseline. The use of IWC + PET criteria increased the objective response rate to 30% compared with 26% by conventional radiology. Durations of response were well differentiated by both conventional radiology response criteria [CR/CRu versus partial response (PR), P = 0.0001] and PET status (negative versus positive, P < 0.0001). Patients who achieved CR/CRu had prolonged progression-free survival (PFS, median 25.9 months) compared with other response groups (P = 0.0007). Patients who achieved PR or stable disease (SD) had similar PFS (median 7.2 and 6.3 months, respectively, P = 0.6427). When grouping PR and SD patients by PET status, patients with PET-negative versus PET-positive disease had a median PFS of 18.2 versus 7.1 months (P = 0.0923).

CONCLUSIONS

Routine use of FDG-PET does not obviate conventional staging, but may aid in determining prognosis and refine response assessments for patients with PTCL, particularly for those who do not achieve CR/CRu by conventional staging. The optimal way to incorporate FDG-PET scans for patients with PTCL remains to be determined.

TRIAL REGISTRATION

NCT00426764.

Prognostic significance of interim PET/CT based on visual, SUV-based, and MTV-based assessment in the treatment of peripheral T-cell lymphoma

Backgrounds

The role of interim PET/CT in peripheral T-cell lymphoma (PTCL) is less identified compared to other subtype of lymphoma. This study prospectively investigated the prognostic accuracy of sequential interim PET/CT using visual and quantitative assessment to determine whether it provided prognostic information for the treatment of PTCL.

Methods

Sixty-three patients with newly diagnosed PTCL were enrolled, and 59 patients underwent interim PET/CT after three or four courses of induction treatment. The response of interim PET/CT was assessed by three parameters: the Deauville five-point scale (5-PS), ΔSUVmax, and ΔMTV2.5.

Results

Over a median follow up of 40.3 months, each assessment of interim PET/CT using the 5-PS, ΔSUVmax, and ΔMTV2.5 had predictive value for progression-free survival. To increase the predictive accuracy of interim PET/CT, we divided patients into three groups according to the sum of scores for three adverse responses based on the visual, SUV-based and MTV-based assessment: favorable, intermediate, and poor responder. The clinical outcome of patients in the favorable group was significantly superior to patients in the poor or intermediate group.

Conclusion

Visual, quantitative SUV-based, and MTV-based assessment in interim PET/CT are valuable for early treatment response assessment in patients with PTCL, and the combined approach using the three parameters was more efficient in discriminating between patients with different survival outcomes compared with single-parameter assessment.

Trial registration

NCT01470066.

Primary treatment response rather than front line stem cell transplantation is crucial for long term outcome of peripheral T-cell lymphomas

Outcome of systemic peripheral T-cell lymphomas (PTCL) is unsatisfactory and no controlled clinical study guides the therapy. Phase II studies suggest to consolidate response achieved after front-line treatment with stem cell transplant (SCT). We retrospectively evaluate the impact of front-line SCT consolidation in a single Center cohort of 209 patients treated during the last two decades. Median age was 49 years (range 15-85) with a prevalence of male sex (61%), advanced stage (68%) while IPI was >2 in 44%. Primary treatment was MACOP-B (39%) CHO(E)P (39%), intensive regimens (18%) or others (4%). Complete response to primary treatment (i.e. before SCT) was 60% (5% partial remission). Forty-four patients further proceeded to SCT while 92 did not receive consolidation. Outcome of primary responders was good, with a 3-year overall survival of 74% (82% in ALCL ALK+ and 69% for the other histologies). By multivariate analysis a better overall survival was significantly associated with IPI<2 (P=0.001), primary response (P=0.000), and ALCL ALK+ (P=0.012). The multivariate analysis performed on responders, showed that only IPI was predictive of a better survival while ALCL ALK+ and undergoing SCT were not. Response to primary treatment rather than post-remission programs is the crucial determinant of PTCL outcome.

Assessment of the prognostic capacity of pretreatment, interim, and post-therapy (18)F-FDG PET/CT in extranodal natural killer/T-cell lymphoma, nasal type

OBJECTIVE

Although the prognostic value of positron emission tomography/computed tomography (PET/CT) using [(18)F]-fluorodeoxyglucose ((18)F-FDG) has been widely confirmed for diffuse large B cell lymphoma, its value for extranodal natural killer/T-cell lymphoma, nasal type (ENKTL), is still controversial. Therefore, we designed a prospective study to investigate the prognostic value of (18)F-FDG PET/CT in patients with ENKTL.

MATERIALS AND METHODS

Thirty-three patients with newly diagnosed, untreated ENKTL, were enrolled in this study. Interim and post-therapy PET/CT scans were analyzed by visual evaluation, in accordance with the criteria set forth by the International Harmonization Project. Patients were classified as either positive or negative. Pretreatment maximum standardized uptake values (SUVmax) of (18)F-FDG were recorded in the most (18)F-FDG-intense lesions. The pretreatment (18)F-FDG SUV as well as the interim and post-therapy PET/CT results were assessed for the ability to predict progression-free survival (PFS) and overall survival (OS).

RESULTS

On the pretreatment scan, the SUVmax of the indicator lesion was >10.00 in 81.8% of patients who were treatment-resistant and ≤10.00 in 86.4% of patients who were treatment non-resistant (mean SUVmax, 12.93 and 8.10, respectively). Univariate analyses revealed that pretreatment SUVmax is a significant predictor (P < 0.01, P < 0.01) of PFS and OS, respectively. Multivariate analyses revealed that pretreatment SUVmax (P < 0.01, P = 0.01) and post-therapy PET/CT result (P < 0.01, P = 0.04) are independent predictors of PFS and OS, respectively.

CONCLUSIONS

(18)F-FDG uptakes prior to treatment and post-therapy PET/CT results can predict unfavorable outcomes following treatment in patients with ENKTL, but interim PET/CT results have little value in predicting survival.

Role of imaging in the staging and response assessment of lymphoma: consensus of the International Conference on Malignant Lymphomas Imaging Working Group

PURPOSE

Recent advances in imaging, use of prognostic indices, and molecular profiling techniques have the potential to improve disease characterization and outcomes in lymphoma. International trials are under way to test image-based response–adapted treatment guided by early interim positron emission tomography (PET)–computed tomography (CT). Progress in imaging is influencing trial design and affecting clinical practice. In particular, a five-point scale to grade response using PET-CT, which can be adapted to suit requirements for early- and late-response assessment with good interobserver agreement, is becoming widely used both in practice- and response-adapted trials. A workshop held at the 11th International Conference on Malignant Lymphomas (ICML) in 2011 concluded that revision to current staging and response criteria was timely.

METHODS

An imaging working group composed of representatives from major international cooperative groups was asked to review the literature, share knowledge about research in progress, and identify key areas for research pertaining to imaging and lymphoma.

RESULTS

A working paper was circulated for comment and presented at the Fourth International Workshop on PET in Lymphoma in Menton, France, and the 12th ICML in Lugano, Switzerland, to update the International Harmonisation Project guidance regarding PET. Recommendations were made to optimize the use of PET-CT in staging and response assessment of lymphoma, including qualitative and quantitative methods.

CONCLUSION

This article comprises the consensus reached to update guidance on the use of PET-CT for staging and response assessment for [18F]fluorodeoxyglucose-avid lymphomas in clinical practice and late-phase trials.

Gamma-delta t-cell lymphomas

Gamma-delta T-cell lymphomas are aggressive and rare diseases originating from gamma-delta lymphocytes. These cells, which naturally play a role in the innate, non-specific immune response, develop from thymic precursor in the bone marrow, lack the major histocompatibility complex restrictions and can be divided into two subpopulations: Vdelta1, mostly represented in the intestine, and Vdelta2, prevalently located in the skin, tonsils and lymph nodes. Chronic immunosuppression such as in solid organ transplanted subjects and prolonged antigenic exposure are probably the strongest risk factors for the triggering of lymphomagenesis. Two entities are recognised by the 2008 WHO Classification: hepatosplenic gamma-delta T-cell lymphoma (HSGDTL) and primary cutaneous gamma-delta T-cell lymphoma (PCGDTL). The former is more common among young males, presenting with B symptoms, splenomegaly and thrombocytopenia, usually with the absence of nodal involvement. Natural behaviour of HSGDTL is characterised by low response rates, poor treatment tolerability, common early progression of disease and disappointing survival figures. PCGDTL accounts for <1% of all primary cutaneous lymphomas, occurring in adults with relevant comorbidities. Cutaneous lesions may vary, but its clinical behaviour is usually aggressive and long-term survival is anecdotal. Available literature on gamma-delta T-cell lymphomas is fractioned, mostly consisting of case reports or small cumulative series. Therefore, clinical suspicion and diagnosis are usually delayed, and therapeutic management remains to be established. This review critically analyses available evidence on diagnosis, staging and behaviour of gamma-delta T-cell lymphomas, provides recommendations for therapeutic management in routine practice and discusses relevant unmet clinical needs for future studies.

Prognostic value of interim positron emission tomography in patients with peripheral T-cell lymphoma

The definition of the role of positron emission tomography (PET) in peripheral T-cell lymphomas (PTCLs) is still under investigation. The purpose of the present observational retrospective study was to assess the early prognostic value of PET after the first three cycles of therapy (PET+3), evaluating visual data in de novo PTCL patients treated in first line with standard chemotherapy and followed by both PET and computed tomography scan. Of 27 PET+3-negative patients, 19 also had a negative PET at the end of treatment (PET+6), whereas 8 of 27 had a positive final one; 6 of 7 PET+3-positive patients had a positive PET+6, whereas only 1 patient had a negative PET+6. Estimated overall survival plotted according to PET+3 results showed 78.6% for negative patients and 21.4% for positive patients at 88.7 months with a significant difference. Patients with negative PET+3 had superior progression-free survival of 72.6% compared with 16.7% of PET+3-positive patients. At the time of this analysis, 17 of 19 (89.5%) patients with negative PET+3 are in continuous complete response (CCR) and only 1 of 7 (14.2%) patients with positive PET+3 is still in CCR. In conclusion, our results indicate that positive PET+3 is predictive of a worse outcome in PTCL, and this significant statistical difference between the two curves could be clinically informative. Larger and prospective studies and harmonization of PET reading criteria are needed.

When should FDG-PET be used in the modern management of lymphoma?

Positron Emission Tomography (PET) is a functional imaging technique that, combined with computerized tomography (PET-CT), is increasingly used in lymphoma. Most subtypes accumulate fluorodeoxyglucose (FDG) and the increased sensitivity of PET-CT, especially for extranodal disease, compared to CT, makes PET-CT an attractive staging tool. The availability of a staging PET-CT scan also improves the accuracy of subsequent response assessment. 'Interim' PET-CT can be used to assess early response and end-of-treatment PET-CT assesses remission. Clinical trials are currently seeking to establish whether the predictive value of PET-CT can be successfully used to guide individual treatment to reduce toxicity and/or to improve outcomes. Standardized methods for performing and reporting PET have been developed in the context of trials. The role of PET in transplantation selection is currently evolving, as it appears to be more accurate and prognostic than CT. The role of FDG PET-CT throughout the management course in patients with lymphoma is explored in this review, with areas discussed that may limit the use of PET-CT imaging which clinicians should be familiar with to inform practice.

The aggressive peripheral T-cell lymphomas: 2013

BACKGROUND

T-cell lymphomas make up approximately 10-15% of lymphoid malignancies. The frequency of these lymphomas varies geographically, with the highest incidence in parts of Asia.

DIAGNOSIS

The diagnosis of aggressive peripheral T-cell lymphoma (PTCL) is usually made using the WHO classification. The ability of hematopathologists to reproducibly diagnosis aggressive PTCL is lower than for aggressive B-cell lymphomas, with a range of 72-97% for the aggressive PTCLs.

RISK STRATIFICATION

Patients with aggressive PTCL are staged using the Ann Arbor Classification. Although somewhat controversial, PET scans appear to be useful as they are in aggressive B-cell lymphomas. The most commonly used prognostic index is the International Prognostic Index. The specific subtype of aggressive PTCL is an important risk factor, with the best survival seen in anaplastic large cell lymphoma-particularly young patients with the anaplastic lymphoma kinase positive subtype.

RISK ADAPTED THERAPY

Anaplastic large cell lymphoma is the only subgroup to have a good response to a CHOP-like regimen. Angioimmunoblastic T-cell lymphoma has a prolonged disease-free survival in only ~20% of patients, but younger patients who have an autotransplant in remission seem to do better. PTCL-NOS (not otherwise specified) is not one disease. Anthracycline containing regimens have disappointing results and a new approach is needed. NK/T-cell lymphoma localized to the nose and nasal sinuses seems to be best treated with radiotherapy containing regimens. Enteropathy associated PTCL and hepatosplenic PTCL are rare disorders with a generally poor response to therapy, although selected patients with enteropathy associated PTCL seem to benefit from intensive therapy.

(18)F-FDG PET in Patients with Primary Systemic Anaplastic Large Cell Lymphoma: Differential Features According to Expression of Anaplastic Lymphoma Kinase

PURPOSE

Primary systemic anaplastic large cell lymphoma (ALCL) is divided into two entities according to the expression of anaplastic lymphoma kinase (ALK). We investigated (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) findings in primary systemic ALCL according to ALK expression.

METHODS

Thirty-seven patients who had baseline PET before CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone)-based chemotherapy were enrolled. Among them, patients who underwent interim and/or post-therapy PET were further investigated for the treatment response and survival analysis. Baseline PET was analyzed visually and semi-quantitatively using peakSUV, and interim and post-therapy PETs were visually analyzed.

RESULTS

All cases were (18)F-FDG-avid on baseline PET. The peakSUV of ALK-positive ALCL (n = 16, 18.7 ± 10.5) was higher than that of ALK-negative ALCL (n = 21, 10.0 ± 4.9) (P = 0.006). In ALK-negative ALCL, complete response (CR) rate in negative-interim PET was higher than positive-interim PET (100 % vs 37.5 %, P = 0.02); however, there was no such difference in ALK-positive ALCL (100 % vs 75 %, P = 0.19). The 3-year progression-free survival (PFS) was not significantly different between ALK-positive and ALK-negative ALCL (72.7 % vs 47.6 %, P = 0.34). In ALK-negative ALCL, negative interim and post-therapy PET patients had better 3-year PFS than positive interim (83.3 % vs 25.0 %, P = 0.06) and post-therapy PET patients (70.0 % vs 20.0 %, P = 0.04). In contrast, ALK-positive ALCL had no such differences between PFS and PET results.

CONCLUSIONS

On baseline PET, all cases showed (18)F-FDG-avidity, and ALK expression was related to higher (18)F-FDG uptake. ALK-positive patients tend to have better PFS than ALK-negative patients. Negative-interim PET was a good indicator of CR, and interim or post-therapy PET was helpful for predicting the prognosis only in the ALK-negative group.

FDG PET/CT in children and adolescents with lymphoma

The aim of this review is to give an overview of FDG PET/CT applications in children and adolescents with lymphoma. Today, FDG PET is used for tailoring treatment intensity in children with Hodgkin lymphoma within the framework of international treatment optimisation protocols. In contrast, the role of this method in children with Non-Hodgkin lymphoma is not well defined. This paper overviews clinical appearance and metabolic behaviour of the most frequent lymphoma subtypes in childhood. The main focus of the review is to summarise knowledge about the role of FDG PET/CT for initial staging and early response assessment.

PET scan integration in lymphoma management

SUMMARY Despite a marked improvement in lymphoma treatment outcome, current prognostic models, relying on a pretreatment set of static clinical variables, appear unable to support a risk-adapted therapeutic strategy. On the other hand, functional imaging with 18F-fluoro-2-deoxy-D-glucose (FDG)-PET proved to be a reliable tool to dynamically assess tumor FDG uptake changes during and after treatment. In this article we aim to review the prognostic value of FDG-PET in all the stages of Hodgkin’s and non-Hodgkin’s lymphoma management, without the intent to address the diagnostic value of PET or to replace available consensus guidelines. In particular we focused on two critical issues: the cost–effectiveness of PET in the overall strategy of lymphoma diagnosis and treatment; and ongoing clinical trials adopting an interim PET-based strategy to modulate treatment intensity based on PET results. Finally, new trends in multimodality imaging, as well as in new radiopharmaceutical tracers, are briefly reviewed.

18F-fluorodeoxyglucose positron emission tomography in the staging and prognosis of T cell lymphoma

We previously reported that (18)F-fluorodeoxyglucose positron emission tomography scan (FDG-PET) is almost universally positive in patients with T cell lymphoma. In the present analysis we examined the impact of FDG-PET on the initial staging of peripheral T cell lymphomas (PTCLs), and the prognostic value of interim FDG-PET. This retrospective analysis identified patients with mature T or natural killer (NK) lymphomas who had PET scans as part of initial staging or staging at relapse [(n = 95) (staging cohort)] in the PTCL database at Memorial Sloan-Kettering Cancer Center. A subset of these patients had repeat PET for interim restaging during initial therapy with curative intent [(n = 50) (interim restaging cohort)]. The frequency of specific T cell histologies included in this analysis were: PTCL not otherwise specified (NOS) (n = 35); angioimmunoblastic T cell lymphoma (AITL) (n = 17); anaplastic large cell lymphoma (ALCL), ALK-1+ (n = 11) and ALK-1- (n = 12); adult T cell lymphoma/leukemia (ATLL) (n = 7); NK/T cell lymphoma (NKTCL) (n = 10); and enteropathy-associated T cell lymphoma (EATL) (n = 3). In the staging cohort, 77 patients were newly diagnosed, and 18 had relapsed disease. Pretreatment FDG-PET was positive in 96% of patients. PET identified additional disease sites in 47/95 patients (50%) when added to conventional staging. Most frequently identified additional sites were: other nodal (n = 24); bone (n = 10); skin (n = 8); nasopharynx (n = 4); spleen (n = 3); and lung (n = 2). However, FDG-PET modified computed tomography (CT)-based staging in only 5/95 patients (5.2%): two patients were upstaged and three patients were downstaged. FDG-PET-based staging did not alter planned treatment for any patient. Interim restaging with PET was performed after a median of 4 cycles of chemotherapy. In this cohort, treatment regimens included cyclophosphamide, doxorubicin, vincristine and prednisone CHOP (n = 19); CHOP/ifosfamide, carboplatin and etoposide (ICE) (n = 26); and other (n = 7). Subsequently, 29 patients were consolidated with either autologous (n = 22) or allogeneic (n = 7) stem cell transplant. After a median follow-up of 3.4 years for surviving patients, those with negative interim PET had superior progression-free survival (PFS) compared to patients with positive interim PET (p = 0.03). There were no differences in overall survival (OS). In PTCL, FDG-PET commonly identifies additional sites of disease but infrequently impacts CT-based staging and does not influence therapy. Interim FDG-PET may predict for PFS. FDG-PET should be integrated into prospective trials to confirm these findings.

Positron emission tomographic scans in lymphoma: convention and controversy

The use of sensitive and specific imaging techniques for accurate initial staging and evaluation of response to therapy in patients with lymphoma is essential for their optimal management. Fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET) integrated with computed tomography (CT) has emerged as a powerful imaging tool and is being routinely used in staging, response evaluation, and posttreatment surveillance in patients with non-Hodgkin lymphoma and Hodgkin lymphoma. PET/CT is currently widely used in clinical practice, but the established clinical benefit is currently restricted to the posttreatment evaluation of Hodgkin lymphoma, diffuse large B-cell lymphoma, and follicular lymphoma. Although used in other histologic subtypes and in other clinical situations including response assessment, its impact on patient outcome remains to be demonstrated. We performed a literature search of PubMed from 1999 to 2011 using the following keywords: PET scan, FDG-PET, PET/CT, lymphoma. This review addresses the challenges and controversies in the use of PET/CT scans in the management of patients with lymphoma.

The aggressive peripheral T-cell lymphomas: 2012 update on diagnosis, risk stratification, and management

BACKGROUND

T-cell lymphomas make up approximately 10-15% of lymphoid malignancies. The frequency of these lymphomas varies geographically, with the highest incidence in parts of Asia.

DIAGNOSIS

The diagnosis of aggressive peripheral T-cell lymphoma (PTCL) is usually made using the WHO classification. The ability of hematopathologists to reproducibly diagnose aggressive PTCL is lower than for aggressive B-cell lymphomas, with a range of 72-97% for the aggressive PTCLs.

RISK STRATIFICATION

Patients with aggressive PTCL are staged using the Ann Arbor Classification. Although somewhat controversial, positron emission tomography (PET) scans appear to be useful as they are in aggressive B-cell lymphomas. The most commonly used prognostic index is the International Prognostic Index. The specific subtype of aggressive PTCL is an important risk factor, with the best survival seen in anaplastic large-cell lymphoma-particularly young patients with the anaplastic lymphoma kinase positive subtype.

RISK ADAPTED THERAPY

Anaplastic large-cell lymphoma is the only subgroup to have a good response to a cyclophosphamide, doxorubicin, vincristine, prednisone (CHOP)-like regimen. Angioimmunoblastic T-cell lymphoma has a prolonged disease-free survival in only ∼20% of patients, but younger patients who have an autotransplant in remission seem to do better. PTCL-not otherwise specified (NOS) is not one disease. Anthracycline containing regimens have disappointing results and a new approach is needed. NK/T-cell lymphoma localized to the nose and nasal sinuses seems to be best treated with radiotherapy containing regimens. Enteropathy associated PTCL and hepatosplenic PTCL are rare disorders with a generally poor response to therapy, although selected patients with enteropathy associated PTCL seem to benefit from intensive therapy.

Burkitt lymphoma: staging and response evaluation

The refinements in both the staging and response evaluation of children with Burkitt lymphoma (BL) have contributed to the improvements in treatment outcome observed over the past 40 years. Ziegler and Magrath designed a staging system in the 1970s for children with BL in equatorial Africa. Currently, the most widely used staging system around the world is that described by Murphy in 1980, which was developed for children with non-Hodgkin lymphoma (NHL) of any histology. There are opportunities for refinement in this system, particularly with respect to certain extra-nodal sites, such as skin and bone. The findings obtained at diagnosis with novel technologies (functional imaging [e.g., positron emission tomography [PET]] and minimal residual disease [MRD] technology), which are more sensitive with respect to disease detection than historic modalities, also need to be considered. Technological advances have also had impact on the assessment of response evaluation. Standard x-rays were routinely used in the 1960s; nuclear imaging became widely used in the 1970s; computerized axial tomography was incorporated in the 1980s; PET imaging was incorporated and, in many cases, has replaced gallium/bone scans since 2000; and MRD technology has been explored in some of the most recent clinical trials. There is clearly a need for more clinical data on the use of PET and MRD technology in the determination of response evaluation of children with BL as well as other histological subtypes of NHL. An international working group is currently addressing the refinement of both disease staging and response evaluation in children with NHL.

The extent of cutaneous lesions predicts outcome in extranodal nasal-type natural killer/T-cell lymphoma of the upper aerodigestive tract with secondary cutaneous involvement

This study determined the clinical characteristics and prognosis for patients with extranodal nasal-type natural killer/T-cell lymphoma (NKTCL) with secondary cutaneous involvement. Twenty-eight patients with NKTCL of the upper aerodigestive tract with secondary cutaneous involvement were reviewed. The median overall survival (OS) was 21.5 months from the first diagnosis, and 12.3 months from the presentation of a cutaneous lesion. The 5-year OS rate was 43.1% (median, 28 months) for patients with localized cutaneous disease compared with 0% (median, 3.6 months) for generalized cutaneous disease (p = 0.017). The 2-year OS rates were 67.5% for patients who achieved a complete response (CR) compared with 19.4% (median, 5.2 months) for patients who did not (p = 0.003). Patients with NKTCL with secondary cutaneous dissemination overall have a poor prognosis, but a relatively favorable prognosis was identified for the small subgroup of patients who had localized cutaneous lesions and achieved a CR.