Interim FDG-PET improves treatment failure prediction in primary central nervous system Lymphoma: a LOC network prospective multicentric study

PURPOSE

The purpose of our study was to assess the predictive and prognostic role of 2-18F-fluoro-2-deoxy-D-glucose (FDG) PET/MRI during high-dose methotrexate-based chemotherapy (HD-MBC) in de novo primary central nervous system lymphoma (PCNSL) patients aged 60 and above.

METHODS

This prospective multicentric ancillary study included 65 immunocompetents patients who received induction HD-MBC as part of the BLOCAGE01 phase III trial. FDG-PET/MRI were acquired at baseline, post two cycles (PET/MRI2), and post-treatment (PET/MRI3). FDG-PET response was dichotomized, with "positive" indicating persistent tumor uptake higher than the contralateral mirroring brain region. Performances of FDG-PET and International PCNSL Collaborative Group criteria in predicting induction response, progression-free survival (PFS), and overall survival (OS) were compared.

RESULTS

Of 48 PET2 scans performed, nine were positive and aligned with a partial response (PR) on MRI2. Among these, eight (89%) progressed by the end of the induction phase. In contrast, 35/39 (90%) of PET2-negative patients achieved complete response (CR). Among the 18 discordant responses at interim (PETCR/MRIPR), 83% ultimately achieved CR. 87% of the PET2-negative patients were disease-free at 6 months versus 11% of the PET2-positive patients (p<0.001). The MRI2 response did not significantly differentiate patients based on their PFS, regardless of whether they were in CR or PR. Both PET2 and MRI2 independently predicted OS in multivariate analysis, with PET2 showing stronger association.

CONCLUSION

Our study highlights the potential of interim FDG-PET for early management of PCNSL patients. Response-driven treatment based on PET2 may guide future clinical trials.

Long-Term Follow-Up of the Response-Adapted Intergroup EORTC/LYSA/FIL H10 Trial for Localized Hodgkin Lymphoma

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned co-primary or secondary analyses are not yet available. Clinical Trial Updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.The primary analysis of the Early positron emission tomography (ePET) Response-Adapted Treatment in localized Hodgkin Lymphoma H10 Trial demonstrated that in ePET-negative patients, the risk of relapse increased when involved-node radiotherapy (INRT) was omitted and that in ePET-positive patients, switching from doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) to bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPPesc) significantly improved 5-year progression-free survival (PFS). Here, we report the final results of a preplanned analysis at a 10-year follow-up. In the favorable (F) ePET-negative group, the 10-year PFS rates were 98.8% versus 85.4% (hazard ratio [HR], 13.2; 95% CI, 3.1 to 55.8; P value for noninferiority = .9735; difference test P < .0001) in favor of ABVD + INRT; in the unfavorable (U) ePET-negative group, the 10-year PFS rates were 91.4% and 86.5% (HR, 1.52; 95% CI, 0.84 to 2.75; P value for noninferiority = .8577; difference test P = .1628). In ePET-positive patients, the difference in terms of PFS between standard ABVD and intensified BEACOPPesc was no longer statistically significant (HR, 0.67; 95% CI, 0.37 to 1.20; P = .1777). In conclusion, the present long-term analysis confirms that in ePET-negative patients, the omission of INRT is associated with lower 10-year PFS. Instead, in ePET-positive patients, no significant difference between standard and experimental arms emerged although intensification with BEACOPPesc was safe, with no increase in late adverse events, namely, second malignancies.

[18F]FDG PET-MRI provides survival biomarkers in primary central nervous system lymphoma in the elderly: an ancillary study from the BLOCAGE trial of the LOC network

PURPOSE

Primary central nervous system lymphoma (PCNSL) incidence is rising among elderly patients, presenting challenges due to poor prognosis and treatment-related toxicity risks. This study explores the potential of combining [18F]fluorodeoxyglucose ([18F]FDG) PET scans and multimodal MRI for improving management in elderly patients with de novo PCNSL.

METHODS

Immunocompetent patients over 60 years with de novo PCNSL were prospectively enrolled in a multicentric study between January 2016 and April 2021. Patients underwent brain [18F]FDG PET-MRI before receiving high-dose methotrexate-based chemotherapy. Relationships between extracted PET (metabolic tumor volume (MTV), sum of MTV for up to five lesions (sumMTV), metabolic imaging lymphoma aggressiveness score (MILAS)) and MRI parameters (tumor contrast-enhancement size, cerebral blood volume (CBV), cerebral blood flow (CBF), apparent diffusion coefficient (ADC)) and treatment response and outcomes were analyzed.

RESULTS

Of 54 newly diagnosed diffuse large B-cell PCNSL patients, 52 had positive PET and MRI with highly [18F]FDG-avid and contrast-enhanced disease (SUVmax: 27.7 [22.8-36]). High [18F]FDG uptake and metabolic volume were significantly associated with low ADCmean values and high CBF at baseline. Among patients, 69% achieved an objective response at the end of induction therapy, while 17 were progressive. Higher cerebellar SUVmean and lower sumMTV at diagnosis were significant predictors of complete response: 6.4 [5.7-7.7] vs 5.4 [4.5-6.6] (p = 0.04) and 5.5 [2.1-13.3] vs 15.9 [4.2-19.5] (p = 0.01), respectively. Two-year overall survival (OS) was 71%, with a median progression-free survival (PFS) of 29.6 months and a median follow-up of 37 months. Larger tumor volumes on PET or enhanced T1-weighted MRI were significant predictors of poorer OS, while a high MILAS score at diagnosis was associated with early death (< 1 year).

CONCLUSION

Baseline cerebellar metabolism and sumMTV may predict response to end of chemotherapy in PCNSL. Tumor volume and MILAS at baseline are strong prognostic factors.

Final results of brentuximab vedotin combined with ifosfamide-carboplatin-etoposide in first refractory/relapsed Hodgkin lymphoma: a lymphoma study association phase I/II study

This phase I/II study assessed the combination of brentuximab vedotin (BV) with ifosfamide-carboplatin-etoposide (ICE) as a second-line therapy in refractory/relapsed (R/R) classical Hodgkin lymphoma (cHL) patients. Phase I study was designed to determine the maximum tolerated dose (MTD) of BV (10 patients) and phase II evaluated the rate of complete metabolic response (CMR) after 2 cycles of BV-ICE (42 patients). There were no dose-limiting toxicities (DLT) during phase I recommending BV 1.8 mg/kg for phase II. Twenty-six patients (61.9%) achieved CMR after 2 cycles of BV-ICE and 37 patients (88%) were transplanted. With a median follow-up of 38 months, the 3-year progression free survival (PFS) and overall survival (OS) rate were 64.3% and 100%, respectively. Hematological toxicities (81%) and infections (21%) were the most frequent adverse event encountered BV-ICE regimen is feasible with manageable toxicities and could be an alternative to other salvage treatments. Trial Registration: ClinicalTrials.gov identifier: NCT02686346.

Positron Emission Tomography-Driven Strategy in Advanced Hodgkin Lymphoma: Prolonged Follow-Up of the AHL2011 Phase III Lymphoma Study Association Study

PURPOSE

The AHL2011 study (ClinicalTrials.gov identifier: NCT01358747) demonstrated that a positron emission tomography (PET)-driven de-escalation strategy after two cycles of bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPP) provides similar progression-free survival (PFS) and overall survival (OS) and reduces early toxicity compared with a nonmonitored standard treatment. Here, we report, with a prolonged follow-up, the final study results.

METHODS

Patients with advanced Hodgkin lymphoma (stage III, IV, or IIB with mediastinum/thorax ratio > 0.33 or extranodal involvement) age 16-60 years were prospectively randomly assigned between 6 × BEACOPP and a PET-driven arm after 2 × BEACOPP delivering 4 × ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) in PET2- and 4 × BEACOPP in PET2+ patients. PET performed after four cycles of chemotherapy had to be negative to complete the planned treatment.

RESULTS

In total, 823 patients were enrolled including 413 in the standard arm and 410 in the PET-driven arm. With a 67.2-month median follow-up, 5-year PFS (87.5% v 86.7%; hazard ratio [HR] = 1.07; 95% CI, 0.74 to 1.57; P = .67) and OS (97.7% in both arms; HR = 1.012; 95% CI, 0.50 to 2.10; P = .53) were similar in both randomization arms. In the whole cohort, full interim PET assessment predicted patients' 5-year PFS (92.3% in PET2-/PET4-, 75.4% [HR = 3.26; 95% CI, 18.3 to 5.77] in PET2+/PET4- and 46.5% [HR = 12.4; 95% CI, 7.31 to 19.51] in PET4+ patients, respectively; P < .0001) independent of international prognosis score. Five-year OS was also affected by interim PET results, and PET2+/PET4- patients (93.5%; HR = 3.3; 95% CI, 1.07 to 10.1; P = .036) and PET4+ patients (91.9%; HR = 3.756; 95% CI, 1.07 to 13.18; P = .038) had a significant lower OS than PET2-/PET4- patients (98.2%). Twenty-two patients (2.7%) developed a second primary malignancy, 13 (3.2%) and 9 (2.2%) in the standard and experimental arms, respectively.

CONCLUSION

The extended follow-up confirms the continued efficacy and favorable safety of AHL2011 PET-driven strategy, which is noninferior to standard six cycles of BEACOPP. PET4 provides additional prognostic information to PET2 and allows identifying patients with particularly poor prognosis.

Use of FDG-PET/CT for systemic assessment of suspected primary central nervous system lymphoma: a LOC study

INTRODUCTION

Primary Central Nervous System Lymphoma (PCNSL) is a rare disease with different therapeutic implications than systemic lymphoma. In this study, we evaluated whole-body ¹⁸FDG-PET/CT for pre-chemotherapy imaging of suspected PCNSL.

METHODS

One hundred and thirty consecutive immunocompetent patients were retrospectively included. The results of initial ¹⁸FDG-PET/CT, contrast-enhanced CT (CeCT) and bone marrow biopsy (BMB) when available were compared to a gold standard based on pathological diagnosis or follow-up.

RESULTS

CNS lesion pathology showed large B-cell lymphoma in 95% of patients, including 11 patients with primary vitro-retinal lymphoma. Ten patients (8%) where ultimately diagnosed with systemic lymphoma involvement, including five pathologically confirmed cases, all of which were detected by ¹⁸FDG-PET/CT. ¹⁸FDG-PET/CT showed incidental systemic findings unrelated to lymphoma in 14% of patients. An SUVmax threshold of nine enabled good discrimination between systemic lymphoma and other lesions (sensitivity 92% and specificity 89%). CeCT and BMB performed in 108 and 77 patients respectively revealed systemic lesions in only three patients.

CONCLUSION

¹⁸FDG-PET/CT detected concomitant occult systemic involvement in a non-negligible proportion of suspected PCNSL cases (8%). In this setting its sensitivity is higher than that of CeCT. All of our patients ultimately diagnosed with concomitant systemic involvement had positive ¹⁸FDG-PET/CT. We believe it constitutes a safe one-stop shop evaluation for the systemic pre-treatment imaging of suspected PCNSL.

18F-FDG PET and CT Scans Detect New Imaging Patterns of Response and Progression in Patients with Hodgkin Lymphoma Treated by Anti-Programmed Death 1 Immune Checkpoint Inhibitor

The response evaluation criteria in patients with Hodgkin lymphoma (HL) were designed for the assessment of chemotherapy and targeted molecular agents. We investigated the accuracy of 3-mo ¹⁸F-FDG PET/CT for the identification of HL patients responding to immune-checkpoint blockade by anti-programmed death 1 antibodies (anti-PD1). We also reported the frequency of new immune patterns of response and progression. Methods: Retrospectively, we recruited consecutive HL patients treated by anti-PD1 (pembrolizumab or nivolumab) at Gustave Roussy from 2013 to 2015. ¹⁸F-FDG PET/CT and contrast-enhanced CT scans were acquired every 3 mo. We recorded the best overall response according to the International Harmonization Project Cheson 2014 criteria and LYmphoma Response to Immunomodulatory therapy Criteria (LYRIC) (2016 revised criteria). Patients achieving an objective response at any time during the anti-PD1 treatment were classified as responders. Results: Sixteen relapsed or refractory classic HL patients were included. The median age was 39 y (age range, 19-69 y). The median previous lines of therapy was 6 (range, 3-13). The mean follow-up was 22.6 mo. Nine of 16 patients (56%) achieved an objective response. Two deaths occurred due to progressive disease at 7 mo. ¹⁸F-FDG PET/CT detected all responders at 3 mo and reclassified best overall response in 5 patients compared with CT alone. A decrease in tumor metabolism and volume (SUV_mean, metabolic tumor volume) and increase in healthy splenic metabolism at 3 mo were observed in responders (area under the curve > 0.85, P < 0.04). Five of 16 patients (31%) displayed new imaging patterns related to anti-PD1; we observed 2 transient progressions consistent with indeterminate response according to the LYRIC (2016) (IR2b at 14 mo and IR3 at 18 mo) and 3 patients with new lesions associated with immune-related adverse events. Conclusion: Three-month ¹⁸F-FDG PET/CT scans detected HL patients responding to anti-PD1. New patterns were encountered in 31% of patients, emphasizing the need for further evaluation in larger series and close collaboration between imaging and oncology specialists on a per-patient basis.

Early Positron Emission Tomography Response–Adapted Treatment in Stage I and II Hodgkin Lymphoma: Final Results of the Randomized EORTC/LYSA/FIL H10 Trial

Purpose

Patients who receive combined modality treatment for stage I and II Hodgkin lymphoma (HL) have an excellent outcome. Early response evaluation with positron emission tomography (PET) scan may improve selection of patients who need reduced or more intensive treatments.

Methods

We performed a randomized trial to evaluate treatment adaptation on the basis of early PET (ePET) after two cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) in previously untreated—according to European Organisation for Research and Treatment of Cancer criteria favorable (F) and unfavorable (U)—stage I and II HL. The standard arm consisted of ABVD followed by involved-node radiotherapy (INRT), regardless of ePET result. In the experimental arm, ePET-negative patients received ABVD only (noninferiority design), whereas ePET-positive patients switched to two cycles of bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPPesc) and INRT (superiority design). Primary end point was progression-free survival (PFS).

Results

Of 1,950 randomly assigned patients, 1,925 received an ePET—361 patients (18.8%) were positive. In ePET-positive patients, 5-year PFS improved from 77.4% for standard ABVD + INRT to 90.6% for intensification to BEACOPPesc + INRT (hazard ratio [HR], 0.42; 95% CI, 0.23 to 0.74; P = .002). In ePET-negative patients, 5-year PFS rates in the F group were 99.0% versus 87.1% (HR, 15.8; 95% CI, 3.8 to 66.1) in favor of ABVD + INRT; the U group, 92.1% versus 89.6% (HR, 1.45; 95% CI, 0.8 to 2.5) in favor of ABVD + INRT. For both F and U groups, noninferiority of ABVD only compared with combined modality treatment could not be demonstrated.

Conclusion

In stage I and II HL, PET response after two cycles of ABVD allows for early treatment adaptation. When ePET is positive after two cycles of ABVD, switching to BEACOPPesc + INRT significantly improved 5-year PFS. In ePET-negative patients, noninferiority of ABVD only could not be demonstrated: risk of relapse is increased when INRT is omitted, especially in patients in the F group.

Abstract P4-01-03: Predictive value of FDG-PET/CT after neoadjuvant endocrine treatment in breast cancer

Background: Neaodjuvant endocrine therapy (NET) has demonstrated efficacy in terms of clinical response and outcome in hormone-receptor positive (HR+) post-menopausal patients (pts) with breast cancer (BC) not eligible for primary breast conservative surgery (BCS). However, the monitoring of tumor response to NET is challenging and clinical response is the current gold standard. The aim of the present study was to investigate the contribution of the early metabolic response (eMR) at one month in FDG-PET/CT in a NET setting for post-menopausal pts with HR+, HER2- BC compared to morphological and pathological responses. We also aimed to evaluate the prognostic value of eMR.

Methods: This was a prospective and ancillary study of CARMINA 02, UCBG0609 (Cancer in press), a phase II clinical trial evaluating the efficacy of 4 to 6 months neoadjuvant anastrozole or fulvestrant. FDG-PET/CT exams were performed at baseline (M0), after 1 month of treatment (M1: eMR) and pre-Op (late metabolic response: lMR) in 11 pts (74.2 years ± 3.6) from 2007 to 2010. Pts were classified “metabolic responders” (mR) if SUVmax values decrease was ≥ 40% at M1 and “non-metabolic responders” (mNR) if otherwise; lMR was also assessed in mR and mNR groups defined at M1. We compared eMR to morphological response (clinical, breast US and MRI) at M1 and pre-op, to the pathological response according to Sataloff classification and to Ki67 score variation during treatment. Early metabolic response was also correlated with the PEPI (Preoperative Endocrine Prognostic Index) score and survival (overall survival, OS and relapse free survival, RFS).

Results: Main results are summarized in Table I. There was a significant difference between mR and mNR pts at M1 (eMR) and pre-op (lMR). One patient with a complete metabolic response at pre-op had the best pathological response (Sataloff TB). Also, mR pts had a better clinical response: 2 partial response (PR) in mR vs 1 in mNR group and 2 mNR patients were classified PD (progressive disease). There was a trend toward better survival for mR pts in OS and RFS (Kaplan-Meier p=0.18 and 0.06, respectively) and all the pejorative events occurred in the mNR group: 3 deaths and 3 metastatic progressions. Besides, no difference in eMR was observed regarding the histological subtype (ductal or lobular; p&gt;0.05) nor the treatment group (p&gt;0.05).

Table I: Metabolic, morphological and pathological response at M1, Pre-Op and on the surgical specimen.  MR : 5ptsmNR : 6ptsP valueM1SUVmax2.6±1.13.9±1.40.00017 Clinical size42.5mm±11.951.7mm±7.50.19 US size22.6mm±6.334.2mm±2.40.02 MRI size21.2mm±4.239.7mm±4.79.16 E-5 Ki 673.6%±1.98.2%±80.19Pre-OpSUVmax2±1.33.3±1.40.018 Clinical size31mm±12.448.3mm±10.80.035 US size18.5mm±7.331.3mm±9.50.07 MRI size17.9mm±7.134.8mm±7.70.003Surgical SpecimenSataloff (TA+TB vs TC+TD)20% vs 80%0 vs 100%1 PEPI score (I+II vs III)80% vs 20%33 vs 67%0.048 Ki 678.6%±9.812.3%±7.90.41

Conclusions: These preliminary results showed the value of the early metabolic response in FDG- PET/CT in a NET setting compared to the morphological or the pathological responses alone. Early metabolic responders patients had better OS, RFS and PEPI scores.

Citation Format: Boughdad S, Champion L, Becette V, Cherel P, Fourme E, Edeline V, Lemonnier J, Lerebours F, Alberini JL. Predictive value of FDG-PET/CT after neoadjuvant endocrine treatment in breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-01-03.

Classical Hodgkin's lymphoma: the Lymphoma Study Association guidelines for relapsed and refractory adult patients eligible for transplant

The Hodgkin's Lymphoma Committee of the Lymphoma Study Association (LYSA) gathered in 2012 to prepare guidelines on the management of transplant-eligible patients with relapsing or refractory Hodgkin's lymphoma. The working group is made up of a multidisciplinary panel of experts with a significant background in Hodgkin's lymphoma. Each member of the panel of experts provided an interpretation of the evidence and a systematic approach to obtain consensus was used. Grades of recommendation were not required since levels of evidence are mainly based on phase II trials or standard practice. Data arising from randomized trials are emphasized. The final version was endorsed by the scientific council of the LYSA. The expert panel recommends a risk-adapted strategy (conventional treatment, or single/double transplantation and/or radiotherapy) based on three risk factors at progression (primary refractory disease, remission duration < 1 year, stage III/IV), and an early evaluation of salvage chemosensitivity, including (18)fluorodeoxy glucose-positron emission tomography interpreted according to the Deauville scoring system. Most relapsed or refractory Hodgkin's lymphoma patients chemosensitive to salvage should receive high-dose therapy and autologous stem-cell transplantation as standard. Efforts should be made to increase the proportion of chemosensitive patients by alternating non-cross-resistant chemotherapy lines or exploring the role of novel drugs.

Relationship between lymphoscintigraphy and clinical findings in lower limb lymphedema (LO): toward a comprehensive staging

Although radionuclide lymphoscintigraphy (RNL) is widely used diagnostically for patients with lymphedema (LE), it has not been utilized for LE staging, which is still based upon clinical findings. The aim of this work is to establish whether the results of both conventional RNL and fusion imaging obtained from hybrid detectors may be used for a comprehensive clinicoimaging staging in LE. Radiolabeled nanocolloids (0.2 ml) were subcutaneously injected in 4,328 patients (23-78 years) with clinical lower limb LE and without venous disease. Patients were classified according to the ISL classification and had a minimal follow-up of 2 years. Images were taken 60 minutes after the injection as a whole body scanning and fusion images of functional SPET and anatomical CT. Clinical and RNL results were not in accordance, and a specific RNL staging was established. The association of clinical and functional staging yields a new method to grade LE patients, and this staging correlated with treatment efficacy. RNL is an important tool in lymphology, and its association with the clinical evaluation offers a new grading system which may be able to delineate patients with good prognosis, patients at risk for a complex decongestive physiotherapy (CDP) failure, and patients who may benefit from other therapeutic protocols.

Prospective study of bone marrow infiltration in aggressive lymphoma by three independent methods: whole-body MRI, PET/CT and bone marrow biopsy

PURPOSE

Initial lymphoma staging requires bone marrow assessment in aggressive lymphomas. Bone marrow lymphoma infiltration is routinely assessed by bone marrow biopsy (BMB), considered as the "gold standard". The aim of this study was to compare the performance of BMB, whole-body MRI and PET/CT for evaluation of BM infiltration.

METHODS

Patients with newly diagnosed aggressive lymphoma were evaluated by BMB, MRI and PET/CT. Two radiologists, two nuclear medicine physicians and one pathologist independently assessed the results of the three modalities. Bone was considered as involved if BM was positive or if PET/CT or MRI was positive and if there was a resolution of the abnormal image shown on PET/CT or MRI halfway or at the end of therapy.

RESULTS

Both MRI and PET/CT detected bone marrow lesions in the 9/43 patients, but two patients with multiple lesions had more lesions detected by PET/CT compared to MRI. Among these nine patients, two with an iliac crest lesion detected by both MRI and PET/CT had bone marrow involvement with large-cell lymphoma on histological examination. The other seven patients had focal MRI and PET/CT lesions in areas other than the iliac crest, where the blind BMB was done. The other patients had bone marrow without large-cell lymphoma involvement. In all cases, after lymphoma therapy bone marrow involvement regressed on histological examination, PET and MRI.

CONCLUSION

These preliminary results suggest that non-invasive morphological procedures could be superior to BMB for bone marrow assessment in aggressive lymphomas. Ongoing study is underway to validate these results.

Imaging of malignant tumours of the long bones in children: monitoring response to neoadjuvant chemotherapy and preoperative assessment

This review focuses on imaging of osteosarcoma and Ewing's sarcoma of the long bones in children during preoperative neoadjuvant chemotherapy. Morphological criteria on plain films and conventional static MRI are insufficiently correlated with histological response. We review the contribution of dynamic MRI, diffusion-weighted MR and nuclear medicine (18FDG-PET) to monitor tumoural necrosis. MRI is currently the best method to evaluate local extension prior to tumour resection, especially to assess the feasibility of conservative surgery. Quantitative models in dynamic MRI and 18FDG-PET are currently being developed in order to find new early prognostic criteria, but for the time being, treatment protocols are still based on the gold standard of histological response.

Nouvelle technique d'imagerie scintigraphique. Tomographie par émission de positons au 18F-fluorodéoxyglucose : technique et indications en oncologie pédiatrique

Positron emission tomography is the last non invasive imaging technique introduced in clinical practice. Its remarkable efficiency for cancer diagnosis and for the optimization of the therapeutical management of adult patients in oncology is now well known. Pathophysiology of tumors being comparable, the same results are expected for children. Highly interesting reports have already established such good performances about lymphoma or bone sarcomas. Complementary data are necessary to define the optimal place of PET in the care of children cancer because PET can be regarded as only at the eve of its development with the upraising of new technical possibilities and new radiopharmaceuticals providing various and complementary informations about tumors.

Central nervous system metastases in neuroblastoma: radiologic, clinical, and biologic features in 23 patients

BACKGROUND

Central nervous system (CNS) metastases rarely occur in patients with neuroblastoma, although recent reports suggest an increase in the rate. CNS recurrence may represent a different mechanism of spread than bone and bone marrow metastases and may be associated with unique genetic determinants. Further definition of the radiologic, clinical, and biologic features may provide clues to the predisposing factors and mechanisms of CNS dissemination.

METHODS

A retrospective analysis of all children ages 0-21 years with Stage IV neuroblastoma who were diagnosed at the Institut Curie and the Institut Gustave-Roussy between 1985 and 2000 was performed with direct review of medical records and magnetic resonance images, computed tomography scans, and iodine-123 or iodine-131 metaiodobenzylguanidine scintiscans (MIBG scans). When tumor tissue was available, genetic analysis was performed using comparative genomic hybridization (CGH).

RESULTS

Of 434 patients with Stage 4 disease, 23 children had the CNS as their site of first recurrence. The estimated risk of CNS recurrence was 8.0% at 3 years, with no significant change in risk over the 15-year period. Eleven patients had isolated CNS recurrences, and the remaining patients developed recurrences concomitantly in other sites. The sites of recurrences were parenchymal (n = 8 patients), parenchymal with meningeal (n = 7 patients), and meningeal alone (n = 8 patients). MIBG scans detected CNS lesions in only 43% of patients. Significant risk factors for CNS recurrence included lumbar puncture at diagnosis, ages 2-3 years, and MYCN gene amplification. Abnormalities that were identified using CGH, in addition to 2p24 amplification in 5/7, included gains of 17q and 18q and losses of 1p, 3p, 10q25-26, and 11q.

CONCLUSIONS

The risk of CNS recurrence in patients with neuroblastoma is 8% at 3 years after diagnosis and has not increased in the last 15 years. Because the CNS often is the sole site of recurrence, either it may be a sanctuary site, or the biologic determinants of CNS metastasis may be unique. Elucidation of risk factors and pathogenesis may allow prevention of this fatal event. Cancer 2003;98:155-65.

[Current strategy for the imaging of neuroblastoma]

Advances in the management of neuroblastoma lead radiologists and nuclear medicine specialists to optimize their procedures in order to propose a rational use of their techniques, adjusted to the various clinical presentations and to therapeutic management. The aim of this paper is to assess the imaging procedures for the diagnosis and follow-up of neuroblastoma in children according to current therapeutic European protocols. An imaging strategy at diagnosis is first proposed: optimal assessment of local extension of the primary tumour is made with MRI, or spiral-CT when MRI is not available, for all locations except for abdominal tumours for which CT remains the best imaging modality. Metastatic extension is assessed with mIBG scan and liver sonography. Indications for bone metastasis evaluation with either radiological or radionuclide techniques are detailed. Imaging follow-up during treatment for metastatic or unresectable tumours is described. A check-list of radiological main points to be evaluated before surgery is proposed for localized neuroblastoma. The imaging strategy for the diagnosis of "occult" neuroblastoma is considered. Finally, we explain the management of neuroblastoma detected during the prenatal or neonatal period.

Metaiodobenzylguanidine assessment of metastatic neuroblastoma: observer dependency and chemosensitivity evaluation. The SFOP Group

BACKGROUND

In children over 1 year of age with metastatic neuroblastoma, clearance of metaiodobenzylguanidine (MIBG) skeletal uptake after four courses of induction chemotherapy is one of the most powerful prognostic factors. How subjective is quantification of MIBG uptake, and can earlier MIBG scintigraphy separate good and bad responders?

PROCEDURE

The data from 47 patients who received uniform induction therapy were reviewed. A novel scoring system of MIBG update intensity was proposed. Initial, intermediate (after two courses), and final (after four courses) intensities were scored (0 to 21 points) independently by six different observers. The initial global score and the relative score (calculated by dividing the global score after two courses by the initial score) were compared to the final score. Good responders were those who scored 0 at final MIBG.

RESULTS

Between two observers, the correlation coefficient for the global score was superior to 0.80, in nine of ten comparisons established between observers 1-5. The initial score did not predict the final score insofar as only nine of fourteen patients with low initial scores were good responders. The relative score also failed to predict outcome; only six of ten patients with favorable relative score (i.e., <20%), were good responders.

CONCLUSIONS

This scoring system is reliable and may be used in multicentric trials. However, both initial and relative scores failed to predict final outcome. Thus, intermediate MIBG may be omitted during induction therapy assessment.

Could somatostatin scintigraphy be superior to MIBG scan in the staging of stage IVs neuroblastoma (Pepper's syndrome)?

A 4-month-old infant suffering from Stage IVs neuroblastoma (NB IVs; Pepper's syndrome) was repeatedly examined by I-123 MIBG and somatostatin analog in-111 pentetreotide (SMS) scintigraphy, during a 2-year period. Treatment was restricted to surgery of the primary tumor. I-123 MIBG and SMS scan results were positive in the primary tumor and liver, but I-123 MIBG yielded very poor images and failed to reliably detect bone marrow metastases in the lower limbs and skull, whereas SMS precisely visualized these lesions. Six months after diagnosis, the infant was in complete clinical remission. I-123 MIBG and SMS images had returned to normal at 1 year. The prognostic implication of positive SMS imaging, in combination with positive or negative I-123 MIBG scan results, is not known in NB IVs and requires further investigation.

Indium-111-pentetreotide scintigraphy in children with neuroblast-derived tumors

The somatostatin analog 111In-pentetreotide was evaluated in 11 children with sympathetic embryonic cell-derived tumors.

METHODS

Six neuroblastomas, four ganglioneuroblastomas and one ganglioneuroma (benign) were imaged 4 and 24 hr after injection of 111In-pentetreotide (5 MBq/kg) and 24 hr after administration of 123I-metaiodobenzylguanidine (MIBG) (3.7 MBq/kg).

RESULTS

Primary tumor was detected with both tracers in four of the five patients studied before surgery (one Stage III neuroblastoma, one Stage IV neuroblastoma, one Stage IVs neuroblastoma, one ganglioneuroblastoma), but the ganglioneuroma was not localized. Detection of bone marrow metastases was clearly better with 111In-pentetreotide in two patients, similar or slightly better with MIBG in six and (true) negative with both procedures in three. The positivity rate of 111In-pentetreotide for imaging of metastases was higher in undifferentiated malignant tumors (six neuroblastomas: two very positive, three positive, one true-negative) than in histologically well-differentiated tumors (four ganglioneuroblastomas: three weakly positive, one true-negative). All patients with positive 111In-pentetreotide imaging results had elevated urinary catecholamine levels, and the two most 111In-pentetreotide-positive metastases were found in neuroblastomas from children with an aneuploid primary tumor. The 111In-pentetreotide and MIBG results were only partly correlated with bone marrow status, as assessed by immunocytological and histological studies at the time of scanning.

CONCLUSION

Abnormalities detected in 111In-pentetreotide uptake were slightly different from those seen with MIBG as a first-line routine method in neuroblast-derived tumors. However, some MIBG as a first-line routine method in neuroblast-derived tumors. However, some MIBG-negative tumor sites were detected by 111In-pentetreotide in patients with neuroblastomas. Thus, 111In-pentetreotide could provide novel information on the biology and prognosis of tumors whose clinical significance remains to be defined.

A new 123I-MIBG whole body scan scoring method--application to the prediction of the response of metastases to induction chemotherapy in stage IV neuroblastoma

A new semi-quantitative scoring system is proposed, especially designed for the comparative interpretation of sequential whole-body meta-iodo-benzyl-guanidine (MIBG) scans in stage IV neuroblastoma children. This method was applied to assess whether MIBG scan at mid-course of induction chemotherapy could predict the final response. 27 newly diagnosed children were investigated by three sequential 123I-MIBG scans performed at the beginning, at mid-course (6 weeks) and at the end of neoadjuvant chemotherapy (12 weeks). Whole body scans were divided into nine regions in which the extension of bone metastases was separately quoted (score range: 0-3). The overall absolute scores were obtained by adding the scores of the nine regions. Relative scores were calculated by dividing the absolute score at each time by the corresponding pretreatment score. The score at mid-induction correctly predicted the overall response of metastases at the end of induction (P < 0.0001) in most cases. This method is easy to use, reproducible, subject to little inter-investigator variation, and thus well adapted to multicentric trials.

Factor analysis as a means of determining response to chemotherapy in patients with osteogenic sarcoma

The prognosis of localized osteogenic sarcoma (OS) has improved considerably since the introduction of neoadjuvant chemotherapy. However, there is a subset of patients who do not show full benefit from neoadjuvant chemotherapy because of chemoresistance. The early identification of poor responders to chemotherapy during neoadjuvant therapy remains difficult. In order to evaluate the role of bone scintigraphy we report our experience of dynamic technetium-99m hydroxymethylene diphosphonate bone scintigraphy in 19 cases of paediatric osteogenic sarcomas. Before the beginning of chemotherapy, a dynamic scan was recorded during 30 min followed by static images at 3 h. The procedure was repeated halfway through the course of chemotherapy (6th week). Histological grading of the response to chemotherapy was carried out in the 12th week, showing nine good responses and ten poor responses. Factor analysis of dynamic structures (FADS) applied to dynamic scans allowed us to identify three factors termed vascular, "soft tissue" and osseous factors. The effect of chemotherapy on each factor was evaluated. Using FADS we were able to detect all the poor histological responders with the combination of vascular and osseous factors. Six out of nine good histological responders were also classified as scintigraphic responders. FADS applied to dynamic bone scans allowed us to identify at an early stage all the poor histological responders to neoadjuvant chemotherapy. This method may have clinical relevance for the therapeutic strategy in patients with OS.

[Control of perfusion by angioscintigraphy during hepatic intra-arterial chemotherapy]

Intra-arterial hepatic chemotherapy is effective in the treatment of liver metastases, and it has been used at the Gustave Roussy Institute since 1983. During laparotomy, arterial catheters are introduced usually into the gastroduodenal artery, and they are connected either to a subcutaneous access or to an implantable pump. Seventy-one patients with liver metastases from colorectal adenocarcinoma were examined by angioscintigraphy to evaluate the quality of liver perfusion. Our technique uses three radioactive compounds and makes it possible to obtain a standard liver scintigram with technetium 99-colloidal rhenium sulphur, a dynamic view of liver arterial perfusion by injection of pure technetium 99 pernechtate, and a static mapping of well-perfused territories after injection of technetium 99-labelled macroaggregated albumin. This technique is reliable to explain most of the problems encountered during intra-arterial hepatic chemotherapy. In our experience, the quality of perfusion was highly variable and had a prognostic value. Objective responses were more frequent in well-vascularized metastases (64 percent) than in metastases with hypoperfusion (36 percent). Survival was also better in the former case, with a median survival of 18 months as against 12 months (p = 0.028).