[Role of FDG-PET in Staging and Therapy of Children with Hodgkin Lymphoma]

The paediatric Hodgkin lymphoma treatment optimisation concepts aim at reduction of treatment intensity with preservation of the high cure rates. A negative interim FDG-PET result after 2 cycles of chemotherapy is associated with a good prognosis. In the current EuroNet-PHL-C1 study radiotherapy is being omitted, if interim PET becomes negative. In addition to the early interim PET after 2 cycles of chemotherapy, all patients undergo an initial PET investigation which is part of the staging processs and plays an essential role for the interpretation of the interim PET. Skeletal involvement can be detected by a typical FDG-PET uptake pattern with high sensitivity and specifity. Therefore, in the forthcoming EuroNet-PHL-C2 study bone marrow biopsy and bone scintigraphy will no longer be part of the staging algorithm.

A patient with a large recurrent pheochromocytoma demonstrating the pitfalls of diagnosis

BACKGROUND

A 59-year-old man presented for a follow-up, 6 years after surgery for a large pheochromocytoma. He had suffered from diabetes mellitus, hypertension and abdominal pain in the right flank region. Previous postoperative follow-up did not reveal tumor recurrence.

INVESTIGATION

Measurement of plasma free metanephrine and normetanephrine by high-performance liquid chromatography and radioimmunoassay; 123I-metaiodobenzylguanidine (MIBG) scintigraphy; hybrid 123I-MIBG single-photon emission CT (SPECT)-CT; MRI; testing for plasma norepinephrine and epinephrine; intraoperative ultrasonography; histological staining for chromogranin A and synaptophysin; and postoperative 18F-dihydroxyphenylalanine (DOPA) PET scan.

DIAGNOSIS

Recurrent pheochromocytoma.

MANAGEMENT

Laparotomy with tumor resection. Reduction of antihypertensive medications. Further follow-up by MRI, hybrid 123I-MIBG SPECT-CT and testing for plasma catecholamines and free metanephrines.

[18F]Fluorodeoxyglucose positron emission tomography for detection of bone marrow involvement in children and adolescents with Hodgkin's lymphoma

PURPOSE

Currently, a routine bone marrow biopsy (BMB) is performed to detect bone marrow (BM) involvement in pediatric Hodgkin's lymphoma (HL) stage greater than IIA. [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) is increasingly used for the initial staging of HL. The value of using FDG-PET to detect BM involvement has not been sufficiently defined. We compared the results of BMBs and FDG-PET for the diagnosis of BM involvement in a large pediatric group with HL.

PATIENTS AND METHODS

The initial staging of 175 pediatric patients with newly diagnosed classical HL stage greater than IIA was determined by using BMB, FDG-PET, chest computed tomography (CT), and magnetic resonance imaging (MRI) or CT of the neck, abdomen, and pelvis. Staging images were prospectively evaluated by a central review board. Skeletal regions that were suggestive of BM involvement by either method were re-evaluated by using different imaging modalities. In suspicious cases, bone scintigraphy was performed. If follow-up FDG-PET scans were available, the remission of skeletal lesions during treatment was evaluated.

RESULTS

BMB results were positive in seven of 175 patients and were identified by FDG-PET. FDG-PET scans showed BM involvement in 45 patients. In addition, the lesions of 32 of these 45 patients had a typical multifocal pattern. In 38 of 39 follow-up positron emission tomography scans, most of the skeletal lesions disappeared after chemotherapy. There was no patient with skeletal findings suggestive of BM involvement by MRI or CT with a negative FDG-PET.

CONCLUSION

FDG-PET is a sensitive and specific method for the detection of BM involvement in pediatric HL. The sensitivity of a BMB appears compromised by the focal pattern of BM involvement. Thus, FDG-PET may safely be substituted for a BMB in routine staging procedures.

[Imaging diagnostics of osteitis, osteomyelitis and joint infections]

Imaging diagnostics and surgical treatment of bone and joint infections are of paramount interest. The main purpose of our survey is to give a detailed overview about methods, indications, image criteria and efficiency of imaging diagnostics as a state of the art presentation. In conclusion we attempt to give some recommendations for clinical scenarios and diagnostic procedures concerning bone and joint infections. This paper has been prepared under the patronage of the AG Septische Chirurgie of the Deutsche Gesellschaft für Unfallchirurgie in Germany. It is our aim to update the paper with respect to the technical and clinical improvements and to publish it again after a number of years.

Dissociation of lipotoxicity and glucotoxicity in a mouse model of obesity associated diabetes: role of forkhead box O1 (FOXO1) in glucose-induced beta cell failure

AIMS/HYPOTHESIS

Carbohydrate-free diet prevents hyperglycaemia and beta cell destruction in the New Zealand Obese (NZO) mouse model. Here we have used a sequential dietary regimen to dissociate the effects of obesity and hyperglycaemia on beta cell function and integrity, and to study glucose-induced alterations of key transcription factors over 16 days.

METHODS

Mice were rendered obese by feeding a carbohydrate-free diet for 18 weeks. Thereafter, a carbohydrate-containing diet was given. Plasma glucose, plasma insulin and total pancreatic insulin were determined, and forkhead box O1 protein (FOXO1) phosphorylation and the transcription factors pancreatic and duodenal homeobox 1 (PDX1), NK6 homeobox 1 protein (NKX6.1) and v-maf musculoaponeurotic fibrosarcoma oncogene family, protein A (avian) (MAFA) were monitored by immunohistochemistry for 16 days.

RESULTS

Dietary carbohydrates produced a rapid and continuous increase in plasma glucose in NZO mice between day 2 and 16 after the dietary challenge. Hyperglycaemia caused a dramatic dephosphorylation of FOXO1 at day 2, followed by a progressive depletion of insulin stores. The loss of beta cells was triggered by apoptosis (detectable at day 8), associated with reduction of crucial transcription factors (PDX1, NKX6.1 and MAFA). Incubation of isolated islets from carbohydrate-restricted NZO mice or MIN6 cells with palmitate and glucose for 48 h resulted in a dephosphorylation of FOXO1 and thymoma viral proto-oncogene 1 (AKT) without changing the protein levels of both proteins.

CONCLUSIONS/INTERPRETATION

The dietary regimen dissociates the effects of obesity (lipotoxicity) from those of hyperglycaemia (glucotoxicity) in NZO mice. Obese NZO mice are unable to compensate for the carbohydrate challenge by increasing insulin secretion or synthesising adequate amounts of insulin. In response to the hyperglycaemia, FOXO1 is dephosphorylated, leading to reduced levels of beta cell-specific transcription factors and to apoptosis of the cells.

Diet dependence of diabetes in the New Zealand Obese (NZO) mouse: total fat, but not fat quality or sucrose accelerates and aggravates diabetes

BACKGROUND

Obesity and diabetes in mice can be modified by dietary variables. Here we systematically analysed the effect of the sucrose and fat content and of the fat quality in New Zealand Obese mice, a mouse model of the metabolic syndrome.

RESULTS

Male NZO mice fed a semi-purified diet with sucrose exhibited an identical weight gain and diabetes incidence as controls without sucrose. In contrast, mice on a chow diet gained weight more slowly and developed diabetes approximately 10 weeks later than those on the semi-purified diet (energy density 3.05 vs. 3.85 kcal/g; fibre content 12.9 vs. 4.7%). In a second experimental series, neither the fat content (10 vs. 40% of the total energy) nor the quality of the fat (lard, safflower oil, or fish oil) of semi-purified diets modified weight gain. However, diabetes started approximately 2 weeks earlier and appeared more severe (blood glucose 30 vs. 20 mmol/l at week 13) in the high-fat diet group (energy density 4.58 kcal/g; fibre content 5.7%).

CONCLUSIONS

Obesity in NZO mice develops independent of the dietary sucrose or fat content, and of the fat quality. However, the dietary fat content accelerates the onset of diabetes without enhancing adiposity. In contrast, chow diet exerts an anti-adipogenic/anti-diabetogenic effect that appears to be due to its lower caloric density and/or its higher fibre content.

Residual lymph node metastasis in stage 4 neuroblastoma--advantage of radio-guided surgery?

Log-term prognosis of children suffering from high-risk neuroblastomas is characterized by a shortened event-free survival, especially if metastases remain after chemotherapy. We report the case of a 3-year-old boy afflicted with a stage 4 neuroblastoma and persistent residual lymph node metastases despite the administration of a various number of treatment modalities. The insertion of a MIBG (metaiodobenzylguanidine) single-photon emission computed tomography (SPECT)-CT and radio-guided surgery implementing a hand held gamma probe finally allowed the exact localization and resection of the suspected lymphatic tissue. As a consequence, the child has been under event-free remission for 20 months. Because study-based knowledge is missing due to the small number of affected patients, individual case reports are helpful to improve future treatment strategies.

Procarbazine-free OEPA-COPDAC chemotherapy in boys and standard OPPA-COPP in girls have comparable effectiveness in pediatric Hodgkin's lymphoma: the GPOH-HD-2002 study

PURPOSE

Vincristine, etoposide, prednisone, and doxorubicin (OEPA)-cyclophosphamide, vincristine, prednisone, and dacarbazine (COPDAC) is derived from standard vincristine, procarbazine, prednisone, and doxorubicin (OPPA)-cyclophosphamide, vincristine, procarbazine, and prednisone (COPP) chemotherapy by replacing procarbazine with etoposide and dacarbazine for a potentially less gonadotoxic regimen for boys with Hodgkin's lymphoma (HL).

PATIENTS AND METHODS

Five hundred seventy-three pediatric patients with classical HL were enrolled onto the German Society of Pediatric Oncology and Hematology-Hodgkin's Disease (GPOH-HD) -2002 study between November 2002 and December 2005. Boys received two courses of OEPA and girls received two courses of OPPA for induction. Treatment group (TG) -2 (intermediate stages) and TG-3 (advanced stages) patients received further two or four cycles COPP (girls) or COPDAC (boys), respectively. After chemotherapy all patients received involved-field irradiation with 19.8 Gy, except for patients with early-stage disease (TG-1) in complete remission.

RESULTS

Five hundred seventy-three patients (287 males and 286 females) were less than 18 years old and fulfilled all inclusion criteria; 195 patients (34.0%) were allocated to TG-1, 139 (24.3%) were allocated to TG-2, and 239 (41.7%) were allocated to TG-3. Toxicity of OEPA-COPDAC was tolerable overall. Hematotoxicity was more pronounced with OEPA than OPPA, whereas it was less pronounced with COPDAC compared with COPP. The median observation time was 58.6 months. Overall survival and event-free survival (EFS) rates (+/- SE) at 5 years were 97.4% +/- 0.7% and 89.0% +/- 1.4%, respectively. In TG-1, overall EFS was 92.0% +/- 2.0%. EFS of patients without irradiation (93.2% +/- 3.3%) was similar to that of irradiated patients (91.7% +/- 2.5%), confirming results of the previous GPOH-HD-95 study. In TG-2+3, EFS did not significantly differ between boys and girls (90.2% +/- 2.3 v 84.7% +/- 2.7, respectively; P = .12).

CONCLUSION

In TG-2+3, results in boys and girls are superimposable. OPPA-COPP and OEPA-COPDAC seem to be exchangeable regimens in intermediate- and advanced-stage classical HL in pediatric patients.

[Procedure guidelines for whole-body 18F-FDG PET and PET/CT in children with malignant diseases]

The purpose of these guidelines is to offer the nuclear medicine and the appropriate interdisciplinary team a framework for performing and reporting positron emission tomography (PET) and the combination with computed tomography (PET/CT) in children with malignant diseases mainly using the radiopharmaceutical 18F-fluorodeoxy-glucose (FDG). These guidelines are based on the recent guidelines of the Paediatric Committee of the European Association of Nuclear Medicine (EANM) (57) and have been translated and adapted to the current conditions in Germany. The adaptation of CT-parameters using PET/CT in children is covered in a more detailed way than in the EANM guideline taking into account that in Germany already a good portion of PET examinations is performed using an integrated PET/CT-scanner. Furthermore, a CT-scan without adoption of the CT acquisition parameters would result in a not tolerably high radiation exposition of the child. There are excellent guidelines for FDG PET and PET/CT in oncology published by the German Society of Nuclear Medicine (Deutsche Gesellschaft für Nuklearmedizin, DGN) (42) and EANM (4). These guidelines aim at providing additional information on issues particularly relevant to PET and PET/CT imaging in children. These guidelines should be taken in the context of local and national current standards of quality and rules.

Diet-induced gene expression of isolated pancreatic islets from a polygenic mouse model of the metabolic syndrome

AIMS/HYPOTHESIS

Numerous new genes have recently been identified in genome-wide association studies for type 2 diabetes. Most are highly expressed in beta cells and presumably play important roles in their function. However, these genes account for only a small proportion of total risk and there are likely to be additional candidate genes not detected by current methodology. We therefore investigated islets from the polygenic New Zealand mouse (NZL) model of diet-induced beta cell dysfunction to identify novel genes and pathways that may play a role in the pathogenesis of diabetes.

METHODS

NZL mice were fed a diabetogenic high-fat diet (HF) or a diabetes-protective carbohydrate-free HF diet (CHF). Pancreatic islets were isolated by laser capture microdissection (LCM) and subjected to genome-wide transcriptome analyses.

RESULTS

In the prediabetic state, 2,109 islet transcripts were differentially regulated (>1.5-fold) between HF and CHF diets. Of the genes identified, 39 (e.g. Cacna1d, Chd2, Clip2, Igf2bp2, Dach1, Tspan8) correlated with data from the Diabetes Genetics Initiative and Wellcome Trust Case Control Consortium genome-wide scans for type 2 diabetes, thus validating our approach. HF diet induced early changes in gene expression associated with increased cell-cycle progression, proliferation and differentiation of islet cells, and oxidative stress (e.g. Cdkn1b, Tmem27, Pax6, Cat, Prdx4 and Txnip). In addition, pathway analysis identified oxidative phosphorylation as the predominant gene-set that was significantly upregulated in response to the diabetogenic HF diet.

CONCLUSIONS/INTERPRETATION

We demonstrated that LCM of pancreatic islet cells in combination with transcriptional profiling can be successfully used to identify novel candidate genes for diabetes. Our data strongly implicate glucose-induced oxidative stress in disease progression.