Fixation extraosseuse du radiotraceur lors de la réalisation d’une scintigraphie du squelette chez un patient atteint de bêta-thalassémie : à propos d’un cas

Red blood cell transfusion, main therapeutic modality of beta-thalassemia, leads to iron overload which may perturb several metabolic ways. The aim of this paper is to illustrate the uptake abnormalities observed on bone scan of thalassemic patients and to discuss mechanisms of extraosseous accumulation of the radiopharmaceutical in this pathology. We report a 16-year-old child suffering from beta-thalassemia major undergoing transfusion therapy. A bone scan was indicated to look for osseous infection. This study revealed a little skeletal uptake and abnormal liver, splenic and renal accumulation. A repeat bone scan, performed three weeks later showed a better skeletal uptake which enabled the discovery of focal abnormalities and made the diagnostic easier. The effect of iron overload on radiopharmaceuticals's uptake in bone scan is known since 1975. Dissociation of ^99mTc from the carrier ligand due to the presence of iron excess seems the most plausible hypothesis. Free ^99mTc can be bound to other tissular substrates which can explain extraosseous uptake. The normally available pool for bone is reduced and then the skeletal uptake decreased. This report limits considerably the sensitivity of the bone scan. A well-led iron chelation and eventually the use of diuretic drug may guarantee a better quality of bone scan images.     

Skeletal Scintigraphy

Skeletal scintigraphy, using phosphates or diphosphonates labeled with technetium 99m, is a sensitive method of detecting bone abnormalities. The most important and most frequent role of bone scanning is evaluating the skeletal areas in patients who have a primary cancer, especially a malignant condition that has a tendency to spread to bone areas. The bone scan is superior to bone radiographs in diagnosing these abnormalities; 15 percent to 25 percent of patients with breast, prostate or lung cancer, who have normal roentgenograms, also have abnormal scintigrams due to metastases. The majority of bone metastases appear as hot spots on the scan and are easily recognized. The incidence of abnormal bone scans in patients with early stages (I and II) of breast cancer varies from 6 percent to 26 percent, but almost invariably those patients with scan abnormalities have a poor prognosis and should be considered for additional therapies. Progression or regression of bony lesions can be defined through scanning, and abnormal areas can be identified for biopsy. The incidence of metastases in solitary scan lesions in patients with known primary tumors varies from 20 percent to 64 percent. Bone scintigraphy shows positive uptake in 95 percent of cases with acute osteomyelitis. Stress fractures and trauma suspected in battered babies can be diagnosed by scanning before there is radiological evidence. The procedure is free from acute or long-term side effects and, except in cases of very young patients, sedation is seldom necessary.Although the test is sensitive, it is not specific and therefore it is difficult to overemphasize the importance of clinical, radiographic, biochemical and scanning correlation in each patient.     

Intérêt de l’imagerie scintigraphique, à Madagascar,dans le diagnostic de l’adénome parathyroïdien ectopique – à propos d’un cas

This study reports the first case of ectopic parathyroid adenoma, diagnosed in the Department of Nuclear Medicine in Antananarivo. This clinical vignette illustrates the interest of the MIBI-Tc-99 m scan in locating this adenoma and its diagnostic confirmation after six years of erratic diagnosis. A whole body bone scintigraphy has also allowed to assess the state of bone metabolism and study outbreaks of fracture. The parathyroid scintigraphy was carried out after intra-venous administration of 666 MBq of MIBI-Tc99m. Dynamic images, static early and late static were acquired with a gamma camera E-Cam Siemens. The whole body bone scan was carried out after administration of 555 MBq of MDP-Tc-99 m. The results evidenced the presence of an para-aortic increased uptake area pointing to a left parathyroid adenoma. The persistence of a late left submaxillary increased uptake area raises, however, a reservation about the existence of a second adenoma. The bone scan displayed global skeletal remodeling, non suggestive of metastases, as it was mentioned with the CT-scan. In a diagnostic tools limited environment, skeletal pain refractory to painkillers, a chronic hypercalcemia associated with an increased parathyroid hormone level, should trigger the scintigarphic exploration in order to avoid bone and renal complications.     

Comparison of 99mTc-3PRGD2 Integrin Receptor Imaging with 99mTc-MDP Bone Scan in Diagnosis of Bone Metastasis in Patients with Lung Cancer: A Multicenter Study

Purpose

^99mTc-3PRGD2, a promising tracer targeting integrin receptor, may serve as a novel tumor-specific agent for single photon emission computed tomography (SPECT). A multi-center study was prospectively designed to evaluate the diagnostic accuracy of ^99mTc-3PRGD2 imaging for bone metastasis in patients with lung cancer in comparison with the conventional ^99mTc-MDP bone scan.

Methods

The patients underwent whole-body scan and chest tomography successively at both 1 h and 4 h after intravenous injection of 11.1 MBq/Kg ^99mTc-3PRGD2. ^99mTc-MDP whole-body bone scan was routinely performed within 1 week for comparison. Three experienced nuclear medicine physicians blindly read the ^99mTc-3PRGD2 and ^99mTc-MDP images. The final diagnosis was established based on the comprehensive assessment of all available data.

Results

A total of 44 patients (29 male, 59±10 years old) with suspected lung cancer were recruited from 4 centers. Eighty-nine bone lesions in 18 patients were diagnosed as metastases and 23 bone lesions in 9 patients were benign. In a lesion-based analysis, ^99mTc-3PRGD2 imaging demonstrated a sensitivity, specificity, and accuracy of 92.1%, 91.3%, and 92.0%, respectively. The corresponding diagnostic values for ^99mTc-MDP bone scan were 87.6%, 60.9%, and 82.1%, respectively in the same patients. ^99mTc-MDP bone scan had better contrast in most lesions, whereas the ^99mTc-3PRGD2 imaging seemed to be more effective to exclude pseudo-positive lesions and detect bone metastases without osteogenesis.

Conclusion

^99mTc-3PRGD2 is a novel tumor-specific agent based on SPECT technology with a promising value in diagnosis of bone metastasis in patients with lung cancer.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01737112","term_id":"NCT01737112"}}NCT01737112     

Technetium-99m monoclonal antibody fragment (FAb) scintigraphy in the evaluation of small cell lung cancer: a preliminary report

Small cell lung cancer (SCC) has the most rapid growth rate of the four cell types and metastasizes early. Present imaging modalities for staging include chest x-ray, CT, MRI and bone scans. In this preliminary study, we assessed the clinical role of ^99mTc-monoclonal antibody (MOAB) scintigraphy in five patients with histologically proven SCC. Each patient was infused with 20–30 mCi of ^99mTc labeled Fab fragment of MOAB (NR-LU-10, NeoRx, Seattle, Wash.). Total body simultaneous anterior and posterior images were obtained 14–16 h post injection. SPECT images of the chest were obtained through a 360 ° rotation of the gamma camera and recorded on a 62 × 64 × 16 matrix. Images (1.2cm thick) were generated in transaxial, sagittal and coronal views.Fourteen of fifteen chest lesions detected by CT were confirmed by ^99mTc MOAB scintigraphy. Scintigraphy detected one additional chest lesion not seen by CT. Scintigraphy failed to detect a brain lesion (2 cm), a chest lesion, and two adrenal lesions, all of which were seen by CT. In one patient with multiple (more than 10) lesions in the liver, both scintigraphy and CT detected all lesions. Three spine lesions seen on ^99mTc MDP scan and positive for metastasis on MRI concentrated ^99mTc MOAB, but two rib lesions seen on ^99mTc MDP bone scan did not concentrate ^99mTc MOAB. It is concluded from these preliminary results that the potential usefulness of ^99mTc MOAB scintigraphy as a complementary imaging modality in the staging of small cell lung cancer should be investigated further.     

Radiologic follow-up and prognosis of efficiency of systemic Sr-89 Cl-2 therapy of bone metastases in prostate cancer

We evaluated possibilities of bone scintigraphy with 99mTc-methylendiphosphonate (99mTc-MDP) and magnetic resonance imaging (MRI) in follow-up and prediction of effect in patients with extensive bone metastatic disease treated with betha-emitter 89SrCl2. 24 patients with prostate cancer and extensive metastatic involvement of skeleton were referred for the study. 89SrCl2 was injected as single injection of 150 MBq (4 mCi), in eighteen from Amersham plc., England, as Metastron, in six--from Medradiopreparat, Russia). In all patients bone scintigraphy with 99mTc-MDP and MRI study of metastatic regions were performed before and in 3 months after 89SrCl2 injection. Patients treated with Metsatron were also studied in 6 months after injection. Quantitative analysis of data comprised count and anatomic dimensions of metastatic areas and calculation of indices [metastasis/intact bone] both for scintillation count of 99mTc-MDP bone scans and signal intensity of T1-weighted MRI scan. Henceforth, we conclude the data of bone scanning with 99mTc-MDP and of MRI give evidencies for significant regress of bone metastases in patients treated with 89SrCl2 besides symptomatic suppression of pain syndrome. 99mTc-MDP bone scanning is also of predictive value for the prognosis of therapeutic effect of systemic radiotherapy with 89SrCl2 in prostate cancer.     

The role of PET-CT scan with somatostatin analogue labelled with gallium-68 (⁶⁸Ga-DOTA-TATE PET-CT) in diagnosing patients with disseminated medullary thyroid carcinoma (MTC)

INTRODUCTION: Calcitonin is a very sensitive marker of medullary thyroid carcinoma (MTC). High concentrations of basal or pentagastrin stimulated calcitonin in patients with MTC is a signal of recurrence or metastatic disease. Detection of metastatic foci remains a diagnostic and therapeutic challenge. The aim of the study was to present examples of the use of ??Ga-DOTA-TATE PET-CT examinations in the diagnosis of patients with MTC and concomitant elevated serum calcitonin concentrations. Initially the study involved eight patients with MTC and elevated basal or stimulated calcitonin, in which earlier diagnostic imaging was negative for metastasis: neck ultrasound, chest and mediastinal CT scan, liver MRI, bone scintigraphy, and 1?F-FDG-PET. A total body scan was performed using ??Ga-DOTA-TATE PET-CT. Two patients with positive diagnostic imaging tests were referred for surgery including resection of cervical lymph nodes with histopathological examination for assessment of metastases. CONCLUSIONS: On the basis of the presented cases we conclude that PET-CT scan with somatostatin analogue labelled with gallium (??Ga-DOTA-TATE PET-CT) may be useful in the diagnostic imaging of patients with disseminated MTC.     

Diagnosis of bone and liver metastases in breast cancer comparing tumor markers and imaging techniques

One hundred and forty-seven patients were examined by bone scintigraphy, ultrasonography and scintigraphic scan of the liver, at different times after surgical removal of a breast cancer, to rule out skeletal and hepatic metastases. At the same time as imaging procedures, serum levels of tumor markers (CEA, TPA and CA 15-3) were determined using radioimmunometric methods. One or more markers were elevated in all 13 patients with hepatic metastases; 9 out of 46 patients with bone metastases had all serum markers normal, with a sensitivity of 80%. Combined assay of the markers proved useful, TPA and CA 15-3 showing the best sensitivity in bone metastases, and all three markers in liver metastases.     

Unusual spread of the follicular thyroid carcinoma,metastases to liver and pancreas

We report a multimetastatic follicular thyroid carcinoma(FTC) with match lesions between ¹⁸F-FDG PET/CT and post-treatment ¹³¹I imaging. The patient had a history of thoracic vertebra corpectomy surgery and liver tru-cut biopsy; both resulted in metastases of FTC. After total thyroidectomy surgery, the patient was referred to the ¹⁸F-FDG PET/CT to investigate other possible metastatic foci. ¹⁸F-FDG PET/CT showed increased FDG uptakes on a cervical lymph node, bones, lung, liver, and pancreas. After treatment of ¹³¹I, post-treatment iodine scintigraphy demonstrated iodine uptakes in the same areas as the ¹⁸F-FDG PET/CT scan and at the thyroid bed. All the matched lesions were concluded as a spread of the FTC. Here we describe an infrequent differentiated thyroid carcinoma case with metastases to the liver and pancreas. This case report also highlights the importance of ¹⁸F-FDG PET/CT in determining the extent of thyroid cancer.     

Mécanisme de fixation du 99mTc-HMDP sur les carcinomes urothéliaux calcifiés de vessie

We report a case of transitional cell carcinoma of the bladder visualized on a ^99mTc-HMDP bone scintigraphy. CT demonstrated irregular tumor of the bladder with curvilinear calcifications on the surface areas and multiple bilateral pulmonary metastases. Bone scintigraphy showed intense uptake corresponding to the bladder tumor and two bone metastases on the left femur. A few days later, the patient underwent retrograde injection of ^99mTc-HMDP into the bladder. Imaging made after voiding showed a tumour uptake of the skeletal labelled agent. Through this case report, we debate ^99mTc-biphosphonate uptake mechanisms in transitional cell carcinoma.     

Potential for improvement in clinical decision-making: tumor imaging with in-111 labeled liposomes results of a phase ii-iii study

Abstract

Liposome scanning using In- 111 labeled VS102 liposomes (VesCan^R) has previously been shown to image a wide variety of common human tumors, probably related to tumor neovascular capIIIary fenestrations and binding of liposomes to tumor cells. We further tested In-III VS102 liposomes in a Phase II trial (27 patients) and a Phase III trial (38 patients). The sensitivity for detecting tumors in primary sites was 82% and in metastatic sites was 65% at the recommended lipid dose of 100 mg. There was 1 false positive scan (specificity 98%). Tumors which have been imaged include carcinomas of the breast, lung, head-neck, prostate, colon, ovary, cervix, thyroid, kidney, testes, melanoma, sarcoma and lymphoma. Sites imaged have included soft tissue, breast, mediastinum, bone, lung, lymph node, liver and pelvis. We also describe five patients in whom a In-111 liposome scan was performed in addition to standard tests, and in whom therapy plans were changed by use of liposome scan results. In two instances, no therapy would have been given without In-III liposome scan, but chemotherapy or radiotherapy were used based on liposome scan results and confirmatory tests. In one patient, surgery would have been used in the absence of In-III liposome scans, versus radiotherapy with In-III liposome scan results. In two other patients, palliative radiotherapy or chemotherapy would have been given without In-111 liposome scan. One of the patients would have required further therapy and the other needed curative surgery after liposome scan evaluation. These results suggest In-111 liposome scans may be useful to complement standard diagnostic tests in cancer patient management.     

Clinical examination or whole-body magnetic resonance imaging: the Holy Grail of spondyloarthritis imaging

Whole-body magnetic resonance imaging allows acquisition of diagnostic images in the shortest scan time, leading to better patient compliance and artifact-free images. Methods of clinical examination of the anterior chest wall joints vary between physician groups and consideration of the rules of rib motion is suggested. The type of joint and its synovial lining may also aid imaging/clinical correlation. This well-written study by experts in the field with a standardized design and methodology allows good scientific analysis and suggests the advantages of whole-body magnetic resonance imaging in anterior chest wall imaging. Selection of clinical examination criteria and specific joints may have had an influence on the study results and the lack of association reported.     

Radiologic diagnosis of bone metastases recurrence in patients with prostate cancer treated strontium-89

Aiming to evaluate efficiency of 89SrCl (Metastron) in patients with metastatic lesion of the skeleton in prostate cancer we have performed a follow-up scintigraphy of the skeleton with 99mTc-methylendiphosphonate (MDP) and MRI with quantitative study of metastatic foci. 12 patients with prostate cancer (on the average 11 +/- 6 bone metastases were examined using scintigraphy of the skeleton with 99mTc-MDP and MRI study in T1, T2 and proton density modes. Investigations were performed before injected as a single dose of 150 MBq (4 mCi). At all the stages there was made a quantitative study of foci of pathological uptake of 99mTc-MDP compromising numbers of foci, focus parameters, intensity of 99mTc-MDP accumulation in the pathological part relatively the contralateral region as well as quantification of MRI signals from metastatic areas in signal intensity units. In 3 month 4 patients with extensive metastatic skeletal lesion (> 12) showed a considerable decrease of number of foci of pathological 99mTc-MDP uptake (on average to 6 +/- 3). In the remained metastatic foci there was noted a decrease of dimensions and 99mTc-MDP uptake intensity at an average by 29.8 +/- 15%, improvement in T1 intensity by 113 +/- 55.6 units. In 2 patients who initially presented a "superscan" pattern on 99mTc-MDP bone scintigraphy the 89SrCl treatment converted this of low intensity had demonstrated their complete regression. Results of radiologic follow-up of bone metastases in prostate cancer using MRI and bone scintigraphy with 99mTc-MDP argue that systemic radiotherapy with 89SrCl induces significant regress of metastatic process that involves all volume of the metastases.     

Zero echo time MRI-only treatment planning for radiation therapy of brain tumors after resection

Using magnetic resonance imaging (MRI) as the sole imaging modality for patient modeling in radiation therapy (RT) is a challenging task due to the need to derive electron density information from MRI and construct a so-called pseudo-computed tomography (pCT) image. We have previously published a new method to derive pCT images from head T1-weighted (T1-w) MR images using a single-atlas propagation scheme followed by a post hoc correction of the mapped CT numbers using local intensity information. The purpose of this study was to investigate the performance of our method with head zero echo time (ZTE) MR images. To evaluate results, the mean absolute error in bins of 20 HU was calculated with respect to the true planning CT scan of the patient. We demonstrated that applying our method using ZTE MR images instead of T1-w improved the correctness of the pCT in case of bone resection surgery prior to RT (that is, an example of large anatomical difference between the atlas and the patient).     

Apport de la scintigraphie au 99mTc-dépréotide pour le diagnostic de lésions osseuses secondaires dans le cancer bronchopulmonaire non à petites cellules stade III–IV

ObjectiveIn non-small cell lung cancer (NSCLC), metastatic bone involvement is usually assessed using conventional ^99mTc-HMDP bone scintigraphy, which has a high sensitivity but a poor specificity. The purpose of this study was to assess the usefulness of the ^99mTc-D scintigraphy for the detection of malignant bone metastases in patients with NSCLC stage III or IV and to compare these results with ^99mTc-HMDP bone scan findings.MethodsNineteen patients (13 M and 6 F, mean age 59 years) with proven NSCLC, suspected to have stage III or IV were enrolled prospectively. All patients underwent whole body ^99mTc-HMDP and ^99mTc-D scintigraphy to detect bone metastases within a mean interval of 14 days. Each focal uptake of ^99mTc-D or ^99mTc-HMDP was considered benign or malignant, leading to positive or negative diagnosis for bone involvement. The final diagnosis of bone metastases was established by a lung specialist, on the basis of additional imaging modalities and of 12 months follow-up.ResultsTwelve bone lesions were identified by ^99mTc-D scintigraphy, 10 were classified as bone metastases and two were classified as inflammatory bone lesions. Four patients were metastatic. Fifty eight bone lesions were detected by ^99mTc-HMDP scintigraphy, 26 of whom were considered malignant, eight patients were thus considered metastatic. Thereby, the two nuclear medicine modalities were concordant for 13 patients, that is 68% of cases and were discordant for six patients, representing 32% of cases. Diagnostic sensitivity, specificity and accuracy of depreotide scintigraphy and ^99mTc-HMDP bone scintigraphy were 75% for both, 93.3 and 73.3%, and 89.5 and 73.3% respectively.ConclusionOur data suggest that depreotide scintigraphy with the same sensitivity, a better accuracy and specificity than those of ^99mTc-HMDP bone scan can detect metastatic bone lesions in patients with NSCLC suspected to have stage III or IV disease.     

Iron accumulation in deep cortical layers accounts for MRI signal abnormalities in ALS: correlating 7 Tesla MRI and pathology

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder characterized by cortical and spinal motor neuron dysfunction. Routine magnetic resonance imaging (MRI) studies have previously shown hypointense signal in the motor cortex on T(2)-weighted images in some ALS patients, however, the cause of this finding is unknown. To investigate the utility of this MR signal change as a marker of cortical motor neuron degeneration, signal abnormalities on 3T and 7T MR images of the brain were compared, and pathology was obtained in two ALS patients to determine the origin of the motor cortex hypointensity. Nineteen patients with clinically probable or definite ALS by El Escorial criteria and 19 healthy controls underwent 3T MRI. A 7T MRI scan was carried out on five ALS patients who had motor cortex hypointensity on the 3T FLAIR sequence and on three healthy controls. Postmortem 7T MRI of the brain was performed in one ALS patient and histological studies of the brains and spinal cords were obtained post-mortem in two patients. The motor cortex hypointensity on 3T FLAIR images was present in greater frequency in ALS patients. Increased hypointensity correlated with greater severity of upper motor neuron impairment. Analysis of 7T T(2)(*)-weighted gradient echo imaging localized the signal alteration to the deeper layers of the motor cortex in both ALS patients. Pathological studies showed increased iron accumulation in microglial cells in areas corresponding to the location of the signal changes on the 3T and 7T MRI of the motor cortex. These findings indicate that the motor cortex hypointensity on 3T MRI FLAIR images in ALS is due to increased iron accumulation by microglia.     

In vivo transchelation of copper-64 from TETA-octreotide to superoxide dismutase in rat liver

An understanding of the metabolic fate of radiometal-labeled peptides is important due to their application in the areas of diagnostic imaging and targeted radiotherapy. Radioisotopes of copper ((64)Cu, T(1/2) = 12.7 h; (67)Cu, T(1/2) = 62 h) have been labeled to monoclonal antibodies (mAbs) and peptides and have applications in the areas of PET imaging and targeted radiotherapy of cancer. Copper-64-TETA-D-Phe(1)-octreotide ([(64)Cu]TETA-OC) has been shown to bind to the somatostatin receptor, both in vitro and in vivo, and this agent inhibited the growth of somatostatin-receptor positive tumors in rats. Copper-64-TETA-OC, however, showed a retention of activity in the blood, liver, and bone marrow, suggesting possible dissociation of (64)Cu from TETA-OC in vivo. The purpose of this study was to determine if (64)Cu dissociates from [(64)Cu]TETA-OC and binds to the protein, superoxide dismutase (SOD) in rat liver. The liver metabolism of [(64)Cu]TETA-OC was examined in normal rats using a gel-electrophoresis assay specific for SOD and size-exclusion chromatography. The major metabolite in rat liver at 20 h postinjection had a molecular weight of 32 kDa as shown by size-exclusion chromatography. A gel electrophoresis assay specific for the detection of SOD [nitro-blue tetrazolium (NBT)] showed that a (64)Cu-labeled protein isolated from rat liver homogenates comigrated with SOD. Evaluating the metabolic fate of copper radiopharmaceuticals demonstrated that Cu(II) dissociates from macrocyclic chelators such as TETA and binds to proteins in high concentrations, namely SOD in rat liver.     

Disseminated malignant phaeochromocytoma: localisation with iodine-131-labelled meta-iodobenzylguanidine.

Meta-iodobenzylguanidine, a guanethidine analogue, is a newly synthesised substance capable of imaging the adrenal medulla. In a woman in whom phaeochromocytoma has been diagnosed iodine-131-labelled metaiodobenzylguanidine was given intravenously; gamma-camera images showed bilateral adrenal tumours and uptake corresponding to bone and liver metastases. 131I-meta-iodobenzylguanidine is effective in localising phaeochromocytomas, and the technique is safe, specific, and non-invasive.     

Ectopie de la parathyroïde objectivée par la scintigraphie au MIBI-Tc 99m. À propos de deux cas. Expérience du service de médecine nucléaire – CHU Ibn Sina-Rabat

The presence of a parathyroid gland in ectopic position is the most common cause of persistent hyperparathyroidism. Detection is a source of topographic diagnostic difficulties especially for purely morphological examinations. To this end, the MIBI-Tc 99m scintigraphy acts as a means of functional imaging to determine the topography of the ectopic parathyroid gland at a favorable dosimetry cost. In our work, undertaken in the nuclear medicine department of Ibn-Sina hospital center university hospital of Rabat-Salé, the MIBI-Tc 99m scan double-phase is of great interest to the extent that it could assert the existence of an ectopic mediastinal parathyroid gland in a patient with persistent hyperparathyroidism after a subtotal parathyroidectomy with recurrent primary hyperparathyroidism with low phosphorus and a cervical ectopic but supraclavicular focus in another patient of 43 years with persistent hyperparathyroidism due to secondary hyperparathyroidism in chronic renal failure. This allowed the orientation of the surgical resection of the ectopic gland. Follow-up was marked by a clear clinical and biological improvement. The MIBI-99m Tc scan seems to offer the highest diagnostic efficacy for the assessment of persistent hyperparathyroidism, a fortiori, when it comes to localize multiple and/or ectopic parathyroid glands.