Role of FDG PET-CT in the treatment management of Hodgkin lymphoma.

Fluorodeoxyglucose (FDG) positons emission tomography (PET)-computed tomography (CT) is used in many ways at baseline and during the treatment of patients with Hodgkin lymphoma. Many properties of the technique are used in the different steps of patient's management. Initial staging with PET-CT is more accurate than conventional imaging and PET-CT also became the gold standard imaging at the end of treatment with a negative PET-CT mandatory for reaching a complete remission. Early assessment of response by PET-CT is one of the most powerful prognostic factors for progression-free survival of patients with localized and advanced stages and allows guiding treatment. Conversely, previous studies showed that there is no role of FDG PET-CT for the patient's follow-up.

Multimodality imaging using PET/CT (18F)-fluorodeoxyglucose for radiotherapy field delineation of localized Hodgkin lymphoma.

It is now well demonstrated that (18F)-fluorodeoxyglucose PET/CT is the most accurate imaging method for determining disease extent in Hodgkin lymphoma. Thus, up-front PET/CT is mandatory for involved node radiation therapy design. For a proper use of this new imaging modality for radiotherapy, some adaptations should be made to the PET/CT acquisition as well as to the report. Initial PET/CT should be performed in the radiotherapy treatment position. Nuclear medicine physicians should report to the radiation oncologist the precise location of each involved lymph node, for which the use of a common atlas of upper diaphragmatic nodal stations could be useful. All these new procedures have to be implemented in close collaboration among the different medical specialists providing care to Hodgkin lymphoma patients. We report here the usual procedures of PET/CT acquisition in the radiotherapy environment and propose a more sophisticated description of the different lymph nodes for a more efficient nuclear medicine report to the radiation oncologist.

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.

[Technique and indications in pediatric oncology. Positron emission tomography with 18F-fluorodeoxyglucose]. / Nouvelle technique d'imagerie scintigraphique. Tomographie par émission de positions 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.

[Current strategy for the imaging of neuroblastoma]. / Stratégie actuelle d'imagerie des neuroblastomes.

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.

UNLABELLED: 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]. / Contrôles de perfusion par angioscintigraphie lors des chimiothérapies intra-artérielles hépatiques.

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).