(18)F-deoxyglucose PET: useful in the management of patients with stem cell transplantation for lymphoma?

(18)F-deoxyglucose (FDG) positron emission tomography (PET) and more recently FDG PET/computed tomography (CT) has become an important tool in the management of patients with Hodgkin and non-Hodgkin lymphoma. It adds metabolic and functional information to conventional anatomical imaging, mainly assessed by CT. Especially for the detection of early response to treatment and prognostic considerations, this type of information seems better suited than anatomical information. Consequently, the ability of FDG PET to predict the outcome in patients with stem cell transplantation (SCT) for lymphoma has been tested in several studies. Results in patients with autologous SCT have been promising, and pretransplant FDG PET is likely to become routine in this group of patients. The evaluated study investigates, for the first time, the predictive value of pretransplant FDG PET in allogeneic SCT, as well as the utility of FDG PET for the follow-up of these patients. All 80 patients included in the prospective study had reduced-intensity conditioning. In contrast to FDG PET before autologous SCT, there was no correlation at all between pretransplant FDG PET results and the outcome after allogeneic SCT. This reflects the fact that other or additional reasons, especially the graft-versus-leukemia effect, are substantial for the outcome of allogeneic SCT in comparison with autologous SCT. Follow-up with FDG PET after reduced-intensity allogeneic SCT was significantly more sensitive than CT to detect disease progression or relapse, and was useful in guiding treatment in the situation of disease relapse.     

Controversies on the prognostic value of interim FDG‐PET in advanced‐stage Hodgkin lymphoma

Hodgkin lymphoma, even in advanced‐stage, is a highly curable malignancy, but treatment is associated with short‐term toxicity and long‐term side effects. Early predictive markers are required to identify those patients who do not require the full‐length standard therapy (and thus qualify for therapy de‐escalation) and those patients who will not be cured by standard therapy (and thus qualify for therapy escalation). Multiple trials have assessed the value of ¹⁸F‐fluoro‐2‐deoxy‐d ‐glucose positron emission tomography (FDG‐PET) after a few cycles of chemotherapy (also known as ‘interim FDG‐PET’) in predicting outcome in advanced‐stage Hodgkin lymphoma. Furthermore, multiple interim FDG‐PET‐adapted trials, in which patients with positive interim FDG‐PET scans are assigned to escalated therapies, and patients with negative interim FDG‐PET scans are assigned to de‐escalated therapies, have recently been published or are currently ongoing, with generally heterogeneous results. The present article reports the currently available evidence (and controversies) on the prognostic value of interim FDG‐PET in advanced‐stage Hodgkin lymphoma in patients with positive and negative interim FDG‐PET findings following continuation of standard chemotherapy or escalated/de‐escalated therapy.     

Pretransplant FDG‐PET in aggressive non‐Hodgkin lymphoma: systematic review and meta‐analysis

This study aimed to systematically review and meta‐analyze the value of pretransplant FDG‐PET in predicting outcome after autologous stem cell transplantation in aggressive non‐Hodgkin lymphoma. MEDLINE was systematically searched; included studies were methodologically assessed and meta‐analyzed, when possible. Overall methodological quality of included studies (n = 11) was poor, with moderate risk of bias in the domains of study participation (n = 7) and prognostic factor measurement (n = 7), and high risk of bias in the domains of outcome measurement (n = 10), and study confounding (n = 11). In all aggressive non‐Hodgkin lymphomas, pooled sensitivity and specificity were 54.0% and 73.1% in predicting treatment failure, and 54.5% and 68.7% in predicting death. Because of interstudy heterogeneity, additional subgroup analyses were performed. In newly diagnosed aggressive non‐Hodgkin lymphoma, pooled sensitivity and specificity were 20.0% and 70.0% in predicting treatment failure, and 8.3% % and 30.5% in predicting death. In refractory/relapsed aggressive non‐Hodgkin lymphoma, pooled sensitivity and specificity were 68.1% and 72.1% in predicting treatment failure, and 77.3% and 69.6% in predicting death. At present, pretransplant FDG‐PET cannot be recommended in aggressive non‐Hodgkin lymphoma, because available studies suffer from major methodological flaws, and reported prognostic estimates are low (i.e., poor in newly diagnosed and moderate in refractory/relapsed aggressive non‐Hodgkin lymphoma).     

Value of F-18 fluorodeoxyglucose positron emission tomography for predicting the clinical outcome of patients with aggressive lymphoma prior to and after autologous stem-cell transplantation

STUDY OBJECTIVES: To determine and compare the values of positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) and CT for predicting clinical outcome of patients with aggressive lymphoma undergoing salvage cytoreductive chemotherapy followed by high-dose chemotherapy and autologous stem-cell transplantation (ASCT). PATIENTS AND METHODS: Forty-three patients with lymphoma who underwent ASCT with FDG-PET evaluation were studied. Group 1 (n = 20) patients (6 patients with Hodgkin disease [HD], and 14 patients with non-Hodgkin lymphoma [NHL]) underwent PET 2 to 5 weeks after initiation of salvage chemotherapy, prior to ASCT. Group 2 (n = 23) patients (6 patients with HD, and 17 patients with NHL) underwent PET within a median interval of 2.4 months (range, 2 to 6 months) after ASCT. MEASUREMENTS AND RESULTS: Study end points were complete remission, relapse, or death. In group 1, 8 of 20 patients (40%) were disease free after a median follow-up of 13.3 months; 12 patients relapsed or died. PET findings were true-negative in 7 of 8 patients and true-positive in 11 of 12 patients who relapsed after ASCT. In group 2, 9 of 23 patients (39%) were disease free after a median follow-up of 16.5-months; 14 patients relapsed. PET findings were true-negative in 8 of 9 patients and true-positive in 13 of 14 patients who relapsed. Positive and negative predictive values of PET were 92% and 88% (group 1) and 93% and 89% (group 2), respectively. Predictive accuracy values of PET were 90% and 91% for group 1 and group 2, respectively, vs 58% and 67% for CT (p < 0.05). CONCLUSIONS: PET findings but not CT results were strongly correlated with disease-free survival (p < 0.01). Our results show that FDG-PET can be used to predict the post-ASCT outcome of lymphoma patients with high accuracy.     

The role of FDG‐PET/CT in the evaluation of residual disease in paediatric non‐Hodgkin lymphoma

¹⁸F‐labelled–fluorodeoxyglucose positron emission tomography (FDG‐PET) findings are challenging to interpret for residual disease versus complete response in paediatric patients with non‐Hodgkin lymphoma (NHL). A biopsy is often warranted to confirm the presence or absence of viable tumour if there is clinical or radiographic evidence of residual disease. In this study, we compared conventional imaging and FDG‐PET/computerized tomography (CT) findings with biopsy results in 18 children with NHL. Our goal was to provide additional data to establish more reliable criteria for response evaluation. Residual disease was suspected after conventional imaging alone in eight patients, after FDG‐PET/CT alone in three and after both modalities in seven patients. Biopsy confirmed the presence of viable tumour in two patients. Two additional patients experienced progressive disease or relapse. The sensitivity and negative predictive value of FDG‐PET/CT using the London criteria to indicate residual tumour detectable by biopsy were 100%, but specificity was low (60%), as was the positive predictive value (25%). Thus, in this study, a negative FDG‐PET/CT finding was a good indicator of complete remission. However, because false‐positive FDG‐PET/CT findings are common, biopsy and close monitoring are required for accurate determination of residual disease in individual patients.     

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.     

Predictive value of early 18F-fluoro-deoxyglucose positron emission tomography in chemosensitive relapsed lymphoma

18F-fluoro-deoxyglucose (FDG) positron emission tomography (PET) might be a better tool than computerized tomography (CT) in predicting long-term treatment outcome in patients with relapsed chemosensitive lymphoma who are candidates for autologous stem cell transplantation (ASCT). We studied patients with recurrent or persistent aggressive non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD), who were treated with three courses of second-line induction chemotherapy [DHAP-VIM (dexamethasone, cytarabine, cisplatin followed by etoposide, iphosphamide and methotrexate)-DHAP], followed by myeloablative therapy and ASCT if chemosensitive. FDG-PET was performed in parallel to conventional diagnostic methods before starting, and after two courses of, second-line therapy. Of 68 relapsed lymphoma patients, 46 chemosensitive patients (33 NHL and 13 HD) were included, of whom 39 were transplanted. After DHAP-VIM, the second PET scan was normalized in 15/46 patients; progression-free survival at 2 years was 62% for PET-negative patients versus 32% for PET-positive patients (P = 0.048). The relative risk for progressive disease in patients with < 90% intensity reduction was 2.85 (95% confidence interval 1.15-7.05, P = 0.018). Early FDG-PET may help to predict the long-term treatment outcome of ASCT in chemosensitive patients with relapsed lymphoma and identify those patients who need extra or alternative treatment. Disappearance or > 90% reduction of intensity of abnormal FDG uptake after two courses of reinduction therapy was correlated with a favourable outcome.     

Managing relapsed and refractory Hodgkin lymphoma

Despite a high curability rate, some patients with Hodgkin lymphoma (HL) fail to respond to, or relapse after, primary conventional treatment. This review aims to identify prognostic factors at relapse and guidelines for treatment in relapsed HL. Patients with relapsed HL should be identified according to their prognostic factors at relapse (duration of remission and extranodal disease or stage). This enables relapsing patients to be separated in to three different prognostic groups; primary refractory patients should be included in the unfavourable group because of their poor prognosis. All relapsed HL should receive second-line chemotherapy and the response to this chemotherapy is crucial for the outcome. Benefit of autologous stem-cell transplantation (ASCT) has been shown in a large randomized study and, although is often proposed in relapsed HL, it may be not necessary in the rare group of patients with stage I/II and late relapse who can receive additional radiotherapy after response to chemotherapy. Patients with intermediate and unfavourable relapse should receive high-dose chemotherapy and ASCT when chemosensitive; the first goal is to achieve this chemosensitivity. For patients in the unfavourable group, including refractory patients, the role of tandem HDT or allogeneic SCT will be discussed and should be proposed for patients not in complete remission at the time of HDT.     

F‐18 FDG‐PET predicts outcomes for patients receiving total lymphoid irradiation and autologous blood stem‐cell transplantation for relapsed and refractory Hodgkin lymphoma

Total lymphoid irradiation (TLI) followed by high‐dose chemotherapy and autologous haematopoietic stem cell transplant (aHSCT) is an effective strategy for patients with relapsed/refractory classical Hodgkin lymphoma (HL). We report outcomes for patients with relapsed/refractory HL who received TLI followed by high‐dose chemotherapy and aHSCT. Pre‐transplant fludeoxyglucose positron emission tomography (FDG‐PET) studies were scored on the 5‐point Deauville scale. Of 51 patients treated with TLI and aHSCT, 59% had primary refractory disease and 63% had active disease at aHSCT. The 10‐year progression‐free survival (PFS) and overall survival (OS) for all patients was 56% and 54%, respectively. Patients with complete response (CR) by PET prior to aHSCT had a 5‐year PFS and OS of 85% and 100% compared to 52% and 48% for those without CR (P = 0·09 and P = 0·007, respectively). TLI and aHSCT yields excellent disease control and long‐term survival rates for patients with relapsed/refractory HL, including those with high‐risk disease features. Achievement of CR with salvage therapy is a powerful predictor of outcome.     

Relapsed or poorly responsive nodular lymphocyte predominant Hodgkin lymphoma in children and adolescents – a report from the United Kingdom's Children's Cancer and Leukaemia Study Group

There is a paucity of data on the treatment outcome in children with relapsed or poorly responsive nodular lymphocyte predominant Hodgkin lymphoma (nLPHL). This retrospective report evaluates the treatment outcome in a national cohort of children with relapsed or poorly responsive nLPHL. A total of 37 patients, 22 with relapsed and 15 with poorly responding disease, are the subjects of this report. Of the 22 patients with relapsed nLPHL, 11 had relapsed after primary excision biopsy, 10 after chemotherapy and 1 after chemotherapy and involved field radiotherapy. The majority had localized disease at relapse. The median time to relapse was 8 months after chemotherapy and 11 months after excision biopsy. Seven of the 15 patients with poorly responding nLPHL had variant histology. Three patients with initial poor response did not receive any further treatment and have had no disease progression. Transformation to diffuse large B cell lymphoma, in addition to evolution from typical to variant nLPHL occurred in one patient each. Thirty‐four patients have been successfully re‐treated with second chemotherapy or radiotherapy. Multiple relapses were uncommon but treatable. Relapse or poorly responsive nLPHL is fully salvageable with either additional chemotherapy and or radiotherapy.     

Optimal treatment for relapsing patients with Hodgkin lymphoma

Relapsed or refractory classical Hodgkin lymphoma (HL) remains a therapeutic challenge. Patients with relapsed HL should be identified according to their prognostic factors at relapse (duration of remission and extranodal disease or stage). Patients with refractory disease, defined as progression during induction treatment or within 90 days after the end of treatment, have the worst prognosis. Following non-crossresistant salvage chemotherapy to achieve cytoreduction, high-dose therapy (HDT) and autologous stem cell transplantation has been shown to be better than conventional-dose chemotherapy for first-relapse/refractory HL. For patients with very unfavorable relapse or primary refractory HL, outcome remains poor with HDT. For these patients, the role of tandem HDT or allogeneic stem cell transplantation will be discussed. In this setting, novel investigational treatments will be presented.     

FDG-PET in the clinical management of Hodgkin lymphoma

Positron emission tomography (PET) is a molecular functional imaging technique that provides qualitative and quantitative information about the localization and activity of pathophysiological processes. The most commonly used tracer for oncological purposes is 2-[18F]fluoro-2-deoxy-d-glucose (FDG). FDG-PET has within recent years become the most important nuclear medicine imaging modality in the management of lymphoma. This review summarizes the data published so far concerning the value of FDG-PET in staging, treatment monitoring, therapy planning, and follow-up of Hodgkin lymphoma (HL). FDG-PET detects more disease sites and involved organs than conventional staging procedures including computerized tomography (CT) and has a large influence on staging. FDG-PET during and after therapy appears to provide considerable prognostic information. However, the impact on patient outcome is not clear since no controlled trials are conducted and follow-up periods are generally short. The value of dual-modality PET/CT and its potential role in the radiotherapy planning is discussed.     

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. Am. J. Hematol. 90:975–980, 2015. © 2015 Wiley Periodicals, Inc.     

Thoracic positron emission tomography using 18F-fluorodeoxyglucose for the evaluation of residual mediastinal Hodgkin disease.

Residual mediastinal masses are frequently observed in patients with Hodgkin disease (HD) after completed therapy, and the discrimination between active tumor tissue and fibrotic residues remains a clinical challenge. We studied the diagnostic value of metabolic imaging by 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in detecting active mediastinal disease and predicting relapse. Twenty-eight HD patients with a residual mediastinal mass of at least 2 cm after initial therapy or after salvage chemotherapy were prospectively assigned to 29 examinations with FDG PET and were evaluated as 29 "subjects." Patients were monitored for at least 1 year after examination and observed for signs of relapse. Median follow-up was 28 months (range, 16 to 68 months). A PET-negative mediastinal tumor was observed in 19 subjects, of whom 16 stayed in remission and 3 relapsed. Progression or relapse occurred in 6 of 10 subjects with a positive PET, whereas 4 subjects remained in remission. The negative predictive value (negative PET result and remission) at 1 year was 95%, and the positive predictive value (positive PET result and relapse) was 60%. The disease-free survival for PET-negative and PET-positive patients at 1 year was 95% and 40%, respectively. The difference was statistically significant. A negative FDG PET indicates that an HD patient with a residual mediastinal mass is unlikely to relapse before 1 year, if ever. On the other hand, a positive PET result indicates a significantly higher risk of relapse and demands further diagnostic procedures and a closer follow-up.     

Hodgkin lymphoma: 2016 update on diagnosis,risk‐stratification,and management

Disease overview : Hodgkin lymphoma (HL) is an uncommon B‐cell lymphoid malignancy affecting 9,050 new patients annually and representing approximately 11.2% of all lymphomas in the United States. Diagnosis: HL is composed of two distinct disease entities; the more commonly diagnosed classical HL and the rare nodular lymphocyte predominant HL. Nodular sclerosis, mixed cellularity, lymphocyte depletion, and lymphocyte‐rich HL are subgroups under the designation of classical HL. Risk stratification: An accurate assessment of the stage of disease in patients with HL is critical for the selection of the appropriate therapy. Prognostic models that identify patients at low or high risk for recurrence, as well as the response to therapy as determined by positron emission tomography (PET) scan, are used to optimize therapy. Risk‐Adapted Therapy: Initial therapy for HL patients is based on the histology of the disease, the anatomical stage and the presence of poor prognostic features. Patients with early stage disease are typically treated with combined modality strategies utilizing abbreviated courses of combination chemotherapy followed by involved‐field radiation therapy, while those with advanced stage disease receive a longer course of chemotherapy often without radiation therapy. Management of relapsed/refractory disease: High‐dose chemotherapy (HDCT) followed by an autologous stem cell transplant (ASCT) is the standard of care for most patients who relapse following initial therapy. For patients who fail HDCT with ASCT, brentuximab vedotin, PD‐1 blockade, nonmyeloablative allogeneic transplant or participation in a clinical trial should be considered. Am. J. Hematol. 91:435–442, 2016. © 2016 Wiley Periodicals, Inc.     

Early post-transplantation positron emission tomography in patients with Hodgkin lymphoma is an independent prognostic factor with an impact on overall survival

The aim of the present study was to investigate the prognostic role of pre- and/or early post-autologous stem cell transplantation (ASCT) ¹⁸F-flourodeoxyglucose (FDG) positron emission tomography (PET) in patients with relapsed/refractory Hodgkin lymphoma. Forty-three consecutive patients were enrolled in this study. FDG-PET/CT was performed following salvage chemotherapy within 6 weeks of undergoing ASCT and at the first month after ASCT. FDG-PET positivity was found in 26 patients before ASCT and in 13 patients after ASCT. The patients who had negative PET scan before or after ASCT had significantly better outcomes in terms of overall survival (OS) and progression-free survival (PFS). Pre- and post-ASCT FDG-PET positivity was found to be independently associated with PFS while post-ASCT FDG-PET was an independent factor with an impact on OS in multivariate analysis. ¹⁸F-flourodeoxyglucose positron emission tomography imaging may be useful in predicting prognosis after ASCT. Furthermore, effective treatment options including allogeneic stem cell transplantation might be considered in patients with positive FDG-PET scan after salvage chemotherapy and ASCT.     

Role of 18FDG-PET/CT in detecting relapse during follow-up of patients with Hodgkin’s lymphoma

The role of ¹⁸FDG-PET/CT during follow-up of patients affected by Hodgkin’s lymphoma (HL) in complete remission after treatment is not fully elucidated, since a wide use of ¹⁸F fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸FDG-PET/CT) in this setting could be limited by a relative high rate of false-positive results. Herein, we summarize a retrospective analysis of 27 patients with Hodgkin’s lymphoma in complete remission after the first-line (n?=?20) or salvage (n?=?7) therapy receiving serial ¹⁸FDG-PET/CT scans during follow-up. Out of 165 scans, 13 were suspected for relapse, which was confirmed in seven patients. All relapses were correctly identified by ¹⁸FDG-PET/CT positivity, with a 100% sensitivity; false-positive rate was 46% and negative predictive value was 100%. True-positive findings were mostly associated with multiple sites, subdiaphragmatic involvement, and/or previous sites of disease. According to our results, we conclude that performing routine PET/CT scan during follow-up of those patients who are at high risk of relapse would be advisable, although caution must be adopted when interpreting PET/CT results due to the relatively high rate of false-positive findings. If FDG abnormal uptake is present at multiple nodal sites, subdiaphragmatic lymph nodes, or previous sites of disease, histological verification of PET abnormal findings is warranted.     

Outcome after autologous stem cell transplantation in primary refractory or relapsed Hodgkin lymphoma—a long-term follow-up single center experience

Autologous stem cell transplantation (autoSCT) can achieve long-term remission in primary refractory or relapsed Hodgkin lymphoma (r/r HL); however, still up to 50% of patients relapse after autoSCT. In this retrospective analysis, we investigated the impact of autologous stem cell transplantation in a consecutive, unselected cohort of primary refractory and relapsed Hodgkin lymphoma patients (n = 66) with the majority of patients treated in the pre-brentuximab vedotin and immune checkpoint inhibitor era. In our cohort, a 5-year overall survival (OS) from autoSCT of 59.5% and a 5-year progression-free survival (PFS) after autoSCT of 46.1% was achieved. Multivariate analysis revealed primary refractory disease and early relapse (< 12 months) after initial therapy as well as the presence of B symptoms at relapse as independent risk factors associated with a higher risk for relapse and an inferior PFS and OS. Several other clinical factors, including the presence of extranodal disease at relapse and failure to achieve a complete response to salvage chemotherapy, were associated with a trend towards an inferior survival. Patients relapsing after autoSCT had a particularly poor outcome, regardless of eligibility to undergo allogeneic stem cell transplantation (alloSCT). We further evaluated recently published prognostic models for r/r HL patients undergoing autoSCT and could validate several risk scores in our independent “real world” cohort.     

Therapeutic evaluation and prognostic value of interim hybrid PET/CT with 18F-FDG after three to four cycles of chemotherapy in non-Hodgkin's lymphoma

Abstract

Purpose: Modern risk-adapted treatment requires accurate assessment of the patient's prognosis. This study assessed the value of hybrid PET/CT with 2-[18F]fluoro-2-deoxy-D-glucose (¹⁸F-FDG) after 3–4 cycles of chemotherapy for early evaluation of response to therapy and prediction of progression-free survival (PFS) in non-Hodgkin's lymphoma (NHL).

Methods: Sixty-one consecutive NHL patients (37 male and 24 female) were included. The ¹⁸F-FDG hybrid PET/CT scans were performed prior to chemotherapy (initial scan) and after 3–4 cycles of chemotherapy (interim scan). Interim FDG findings were correlated to the PFS using Kaplan–Meier analysis. Regression analyses were employed to test for independence of established pretreatment prognostic factors.

Results: After 3–4 cycles of chemotherapy, positive ¹⁸F-FDG lesions were found in 28 patients, minimal residual uptake (MRU) in 8 and negative scans in 25 patients. In FDG-positive group, 22 patients showed progress and three died. Nine ¹⁸F-FDG-negative patients and 4 patients from the MRU group relapsed. Survival analyses showed highly significant associations between early interim FDG imaging and PFS (P < 0.0005). The 2-year PFS rate for FDG-negative patients was 72.2 and 23.0% for FDG-positive patients. The regression model showed that the predictive value of FDG imaging owed its significance to the very high hazard ratio between patients with positive FDG imaging and patients with negative FDG imaging (P < 0.001).

Conclusions: Early interim FDG imaging is an excellent and independent predictor of PFS in NHL. An early assessment of chemotherapy response with FDG scans may provide useful information for selection of patients for alternative therapeutic strategies.     

Treatment outcome in children and adolescents with relapsed Hodgkin lymphoma – results of the UK HD3 relapse treatment strategy

The purpose of this national retrospective study was to evaluate the outcome in children with relapsed or primary refractory Hodgkin lymphoma [HL] after a primary chemotherapy alone treatment strategy. Between 2000 and 2005 , 80 children with relapsed [n = 69] or primary refractory [n = 11] HL were treated on a standardized treatment protocol of 4–6 cycles of EPIC [etoposide, prednisolone, ifosfa3mide and cisplatin] chemotherapy. Radiotherapy was recommended to all relapsed sites. High dose therapy with stem cell rescue [SCT] was recommended for patients with poor response. The 5‐year overall survival [OS] and progression‐free survival from relapse was 75·8% [64·8–83·9] and 59·9% [48·3–69·7] respectively. Duration of first remission was strongly associated with OS; risk of death was decreased by 53% [Hazard ratio (HR): 0·47, 95% confidence interval (CI): 0·19–1·18] for those with a time from end of treatment to relapse of 3–12 months (compared to <3 months) and reduced by 80% (HR 0·20, 95% CI: 0·04–0·90) for those >12 months after end of treatment. Other poor prognostic factors included advanced stage disease at relapse and B symptoms at first diagnosis. The most important factor associated with salvage failure was time to relapse . Survival outcome in children with primary refractory HL is poor.