EANM procedure guideline for the treatment of liver cancer and liver metastases with intra-arterial radioactive compounds.

Primary liver tumours (i.e. hepatocellular carcinoma (HCC) or intrahepatic cholangiocarcinoma (ICC)) are among the most frequent cancers worldwide. However, only 10-20% of patients are amenable to curative treatment, such as resection or transplant. Liver metastases are most frequently caused by colorectal cancer, which accounts for the second most cancer-related deaths in Europe. In both primary and secondary tumours, radioembolization has been shown to be a safe and effective treatment option. The vast potential of personalized dosimetry has also been shown, resulting in markedly increased response rates and overall survival. In a rapidly evolving therapeutic landscape, the role of radioembolization will be subject to changes. Therefore, the decision for radioembolization should be taken by a multidisciplinary tumour board in accordance with the current clinical guidelines. The purpose of this procedure guideline is to assist the nuclear medicine physician in treating and managing patients undergoing radioembolization treatment. PREAMBLE: The European Association of Nuclear Medicine (EANM) is a professional non-profit medical association that facilitates communication worldwide among individuals pursuing clinical and research excellence in nuclear medicine. The EANM was founded in 1985. These guidelines are intended to assist practitioners in providing appropriate nuclear medicine care for patients. They are not inflexible rules or requirements of practice and are not intended, nor should they be used, to establish a legal standard of care. The ultimate judgment regarding the propriety of any specific procedure or course of action must be made by medical professionals taking into account the unique circumstances of each case. Thus, there is no implication that an approach differing from the guidelines, standing alone, is below the standard of care. To the contrary, a conscientious practitioner may responsibly adopt a course of action different from that set out in the guidelines when, in the reasonable judgment of the practitioner, such course of action is indicated by the condition of the patient, limitations of available resources or advances in knowledge or technology subsequent to publication of the guidelines. The practice of medicine involves not only the science but also the art of dealing with the prevention, diagnosis, alleviation and treatment of disease. The variety and complexity of human conditions make it impossible to always reach the most appropriate diagnosis or to predict with certainty a particular response to treatment. Therefore, it should be recognised that adherence to these guidelines will not ensure an accurate diagnosis or a successful outcome. All that should be expected is that the practitioner will follow a reasonable course of action based on current knowledge, available resources and the needs of the patient to deliver effective and safe medical care. The sole purpose of these guidelines is to assist practitioners in achieving this objective.

Estimation of French cattle herd immunity against bluetongue serotype 8 at the time of its re-emergence in 2015.

BACKGROUND: From 2006 to 2010, France experienced two bluetongue epidemics caused by serotype 1 (BTV-1) and 8 (BTV-8) which were controlled by mass vaccination campaigns. After five years without any detected cases, a sick ram was confirmed in August 2015 to be infected by a BTV-8 strain almost identical to that circulating during the previous outbreak. By then, part of the French cattle population was expected to be still protected, since bluetongue antibodies are known to last for many years after natural infection or vaccination. The objective of this study was to estimate the proportion of cattle in France still immune to BTV-8 at the time of its re-emergence in 2015. RESULTS: We used BTV group-specific cELISA results from 8525 cattle born before the vaccination ban in 2013 and 15,799 cattle born after the ban. Samples were collected from January to April 2016 to estimate seroprevalence per birth cohort. The overall seroprevalence in cattle at national and local levels was extrapolated from seroprevalence results per birth cohort and their respective proportion at each level. To indirectly assess pre-immune status of birth cohorts, we computed prevalence per birth cohort on infected farms in autumn 2015 using 1377 RT-PCR results. These revealed limited BTV circulation in 2015. Seroprevalence per birth cohort was likely to be connected to past exposure to natural infection and/or vaccination with higher seroprevalence levels in older animals. A seroprevalence of 95% was observed for animals born before 2008, of which > 90% were exposed to two compulsory vaccination campaigns in 2008-2010. None of the animals born before 2008 were found to be infected, unlike 19% of the young cattle which had never been vaccinated. This suggests that most ELISA-positive animals were pre-immune to BTV-8. We estimated that 18% (from 12% to 32% per département) of the French cattle population was probably pre-immune in 2015. CONCLUSIONS: These results strongly suggest a persistence of antibodies for at least 5-6 years after natural infection or vaccination. The herd immunity of the French cattle population probably limited BTV circulation up to 2015, by which time more than 80% of cattle were naive.

Transarterial Radioembolization (TARE) Agents beyond 90Y-Microspheres.

Liver malignancies, either primary tumours (mainly hepatocellular carcinoma and cholangiocarcinoma) or secondary hepatic metastases, are a major cause of death, with an increasing incidence. Among them, hepatocellular carcinoma (HCC) presents with a dark prognosis because of underlying liver diseases and an often late diagnosis. A curative surgical treatment can therefore only be proposed in 20 to 30% of the patients. However, new treatment options for intermediate to advanced stages, such as internal radionuclide therapy, seem particularly attractive. Transarterial radioembolization (TARE), which consists in the use of intra-arterial injection of a radiolabelled embolising agent, has led to very promising results. TARE with 90Y-loaded microspheres is now becoming an established procedure to treat liver tumours, with two commercially available products (namely, SIR-Sphere® and TheraSphere®). However, this technology remains expensive and is thus not available everywhere. The aim of this review is to describe TARE alternative technologies currently developed and investigated in clinical trials, with special emphasis on HCC.

Intra-arterial yttrium-90 radioembolization combined with systemic chemotherapy is a promising method for downstaging unresectable huge intrahepatic cholangiocarcinoma to surgical treatment.

PURPOSE: To evaluate the downstaging efficacy of yttrium-90 radioembolization (Ytt-90)-associated with chemotherapy and the results of surgery for initially unresectable huge intrahepatic cholangiocarcinoma (ICC). METHODS: Between January 2008 and October 2013, unresectable ICC were treated with chemotherapy and Ytt-90. Patients with unique tumors localized to noncirrhotic livers and without extrahepatic metastasis were considered to be potentially resectable and were evaluated every 2 months for possible secondary resection. RESULTS: Forty-five patients were treated for unresectable ICCs; ten had potentially resectable tumors, and eight underwent surgery. Initial unresectability was due to the involvement of the hepatic veins or portal vein of the future liver remnant in seven and one cases, respectively. Preoperative treatment induced significant decreases in tumor volume (295 vs. 168 ml, p = 0.02) and allowed for R0 resection in all cases. Three patients (37.5 %) had Clavien-Dindo grade three or higher complications, including two postoperative deaths. The median follow-ups were 15.6 [range 4-40.7] months after medical treatment initiation and 7.2 [0.13-36.4] months after surgery. At the end of the study period, five patients were still alive, with one patient still alive 40 months after medical treatment initiation (36.4 months after surgery); two patients experienced recurrences. CONCLUSIONS: For initially unresectable huge ICCs, chemotherapy with Ytt-90 radioembolization is an effective downstaging method that allows for secondary resectability.

Mixed-ligand complexes of yttrium-90 dialkyldithiocarbamates with 1,10-phenanthroline as a possible agent for therapy of hepatocellular carcinoma.

Yttrium-90 is a radioelement which has found wide use in targeted radionuclide therapy because of its attractive physical and chemical properties. Radioembolisation of hepatocellular carcinoma with radiolabelled Lipiodol is a method of choice. We have synthesised a series of alkyldithiocarbamate yttrium complexes, easily extracted into Lipiodol due to their high lipophilicity. Among the prepared series, a new radioconjugate, which is stable over an extended period of time, has been prepared, and could represent a potential treatment procedure for hepatocellular carcinoma.

Boosted selective internal radiation therapy with 90Y-loaded glass microspheres (B-SIRT) for hepatocellular carcinoma patients: a new personalized promising concept.

PURPOSE: To evaluate the impact of dosimetry based on MAA SPECT/CT for the prediction of response, toxicity and survival, and for treatment planning in patients with hepatocellular carcinoma (HCC) treated with (90)Y-loaded glass microspheres (TheraSphere®). METHODS: TheraSphere® was administered to 71 patients with inoperable HCC. MAA SPECT/CT quantitative analysis was used for the calculation of the tumour dose (TD), healthy injected liver dose (HILD), and total injected liver dose. Response was evaluated at 3 months using EASL criteria. Time to progression (TTP) and overall survival (OS) were evaluated using the Kaplan-Meier method. Factors potentially associated with liver toxicity were combined to construct a liver toxicity score (LTS). RESULTS: The response rate was 78.8%. Median TD were 342 Gy for responding lesions and 191 Gy for nonresponding lesions (p < 0.001). With a threshold TD of 205 Gy, MAA SPECT/CT predicted response with a sensitivity of 100% and overall accuracy of 90%. Based on TD and HILD, 17 patients underwent treatment intensification resulting in a good response rate (76.4%), without increased grade III liver toxicity. The median TTP and OS were 5.5 months (2-9.5 months) and 11.5 months (2-31 months), respectively, in patients with TD <205 Gy and 13 months (10-16 months) and 23.2 months (17.5-28.5 months), respectively, in those with TD >205 Gy (p = 0.0015 and not significant). Among patients with portal vein thrombosis (PVT) (n = 33), the median TTP and OS were 4.5 months (2-7 months) and 5 months (2-8 months), respectively, in patients with TD <205 Gy and 10 months (6-15.2 months) and 21.5 months (12-28.5 months), respectively, in those with TD >205 Gy (p = 0.039 and 0.005). The median OS was 24.5 months (18-28.5 months) in PVT patients with TD >205 Gy and good PVT targeting on MAA SPECT/CT. The LTS was able to detect severe liver toxicity (n = 6) with a sensitivity of 83% and overall accuracy of 97%. CONCLUSION: Dosimetry based on MAA SPECT/CT was able to accurately predict response and survival in patients treated with glass microspheres. This method can be used to adapt the injected activity without increasing liver toxicity, thus defining a new concept of boosted selective internal radiation therapy (B-SIRT). This new concept and LTS enable fully personalized treatment planning with glass microspheres to be achieved.

Lobar hepatocellular carcinoma with ipsilateral portal vein tumor thrombosis treated with yttrium-90 glass microsphere radioembolization: preliminary results.

Portal vein tumor thrombosis (PVTT) is a common complication of hepatocellular carcinoma (HCC) and has a negative impact on prognosis. This characteristic feature led to the rationale of the present trial designed to assess the efficacy and the safety of yttrium-90 glass-microsphere treatment for advanced-stage lobar HCC with ipsilateral PVTT. 18 patients with unresectable lobar HCC and ipsilateral PVTT were treated in our institution with (90)Y-microS radioembolization. Patients were evaluated every 3 to 6 months for response, survival, and toxicity. Mean follow-up was 13.0 months (2.2-50.6). Outcomes were: complete response (n = 2), partial response (n = 13), stable disease (n = 1), and progressive disease (n = 2) giving a disease control rate of 88.9%. Four patients were downstaged. Treating lobar hepatocellular carcinoma with ipsilateral portal vein thrombosis with yttrium-90 glass-microsphere radioembolization is safe and efficacious. Further clinical trials are warranted to confirm these results and to compare (90)Y-microS with sorafenib, taking into account not only survival but also the possibility of secondary surgery for putative curative intention after downstaging.

[((18)F)-fluorodeoxyglucose PET/CT in cervix cancer: lymph node assessment and prognostic/predictive value of primary tumour analysis]. / Tomographie par émission de positons au ((18)F)-fluorodésoxyglucose dans les cancers du col utérin : évaluation ganglionnaire et valeur pronostique/prédictive des données de la tumeur primitive.

PURPOSE: In cervix carcinoma: (a) to evaluate the ability of ((18)F)-fluorodeoxyglucose (FDG) positron emission tomography (PET) in the lymph node detection; (b) to investigate the prognostic and predictive value of the primary cervical PET parameters. PATIENTS AND METHODS: Ninety patients treated for cervix carcinoma and evaluated initially by MRI and FGD PET were included. The performances of FDG-PET for lymph node detection (relatively to the lymph node dissection) have been described (sensitivity, specificity, positive predictive value and negative predictive value). PET tumour parameters analyzed were: maximum standard uptake value (SUVmax), the volume and the maximum diameter. The prognostic and predictive values of these parameters were investigated. The tumour response was evaluated on surgical specimens. RESULTS: PET detected the cervical tumour with a sensitivity of 97% (mean values: SUVmax=15.8, volume=27 mm(3), maximum diameter=47). For the detection of the lymph nodes, the values of sensibility, specificity, positive predictive value and negative predictive value were: 86, 56, 69 and 78% in the pelvic, and 90, 67, 50 and 95% for the para-aortic area, respectively. The SUVmax was correlated with histologic response (P=0.04). The frequency of partial histological response was significantly higher for tumour SUVmax>10.9 (P=0.017). The maximum PET diameter and pathologic response had an impact on disease-free survival and overall survival in multivariate analysis (P<0.05). CONCLUSION: PET has high sensitivity in detecting pelvic and para-aortic lymph nodes. Some primary cervical tumour PET parameters are useful as prognostic and predictive factors.

[Radioembolisation for hepatocellular carcinoma]. / Traitement des carcinomes hépatocellulaires par injection intra-artérielle de radio-isotopes.

Hepatocellular carcinoma is now a major public health concern. In intermediate stages (one third of hepatocellular carcinoma patients), chemoembolization is the standard of care despite a poor tolerance and a moderate efficacy. Moreover, despite recent improvements, this technique seems in a dead end. Radioembolization could be an excellent tool for such patients. Currently (131)I-Lipiodol, (188)Re-Lipiodol, (90)Y-glass or resin microspheres are available. More recent and promising data come from microspheres, but phase II and III studies are needed before drawing any conclusion. In the future, the combination of radioembolization with systemic chemotherapy or targeted agents (particularly antiangiogenic drugs) seems very promising.

Subthalamic nucleus stimulation in Parkinson disease induces apathy: a PET study.

OBJECTIVE: Apathy may be induced by subthalamic nucleus deep brain stimulation (STN-DBS) in Parkinson disease (PD). We therefore wished to test the hypothesis that apathy induced by STN-DBS correlates with changes in glucose metabolism, using (18)FDG-PET. METHODS: Twelve patients with PD were assessed 3 months before (M-3) and 3 months after (M+3) STN-DBS with (18)FDG-PET and the Apathy Evaluation Scale. RESULTS: Apathy had significantly worsened at M+3 after STN-DBS. Positive correlations were observed between this variation in apathy scores and changes in glucose metabolism, especially in the right frontal middle gyrus (Brodmann area [BA] 10) and right inferior frontal gyrus (BA 46 and BA 47). Negative correlations between the two were observed in the right posterior cingulate gyrus (BA 31) and left medial frontal lobe (BA 9). CONCLUSION: These preliminary results confirm the role of the subthalamic nucleus in associative and limbic circuitry in humans and suggest that it is a key basal ganglia structure in motivation circuitry.

131-iodine Lipiodol therapy in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is a major health concern worldwide. Several therapeutic options are available, but transplantation is the only curative option; for the vast majority of patients, the remaining alternative is palliative care. There is some hope however with Lipiodol which, when injected into the hepatic artery remains concentrated in the liver and specifically within the malignant tumor for a long period of time. This feature has been used for internal radiation therapy using (131)Iodine-labeled Lipiodol. Phase III studies with (131)I-Lipiodol have demonstrated, in an adjuvant setting improved recurrence-free and overall survival compared with surgery alone and in a palliative setting improved survival among patients with portal thrombosis. Comparison with chemoembolization has shown similar results in terms of efficacy but with better tolerance for (131)I-lipiodol. The method would also be useful for small nodules not amendable to surgery or percutaneous treatment. The use of another radionuclide, (188)Re, could probably improve the current method by reducing the need for radioprotection. New perspectives will be forthcoming with the advent of targeted drugs using combinations in sequential or concomitant regimens.

Subthalamic nucleus stimulation affects orbitofrontal cortex in facial emotion recognition: a PET study.

Deep brain stimulation (DBS) of the bilateral subthalamic nucleus (STN) in Parkinson's disease is thought to produce adverse events such as emotional disorders, and in a recent study, we found fear recognition to be impaired as a result. These changes have been attributed to disturbance of the STN's limbic territory and would appear to confirm that the negative emotion recognition network passes through the STN. In addition, it is now widely acknowledged that damage to the orbitofrontal cortex (OFC), especially the right side, can result in impaired recognition of facial emotions (RFE). In this context, we hypothesized that this reduced recognition of fear is correlated with modifications in the cerebral glucose metabolism of the right OFC. The objective of the present study was first, to reinforce our previous results by demonstrating reduced fear recognition in our Parkinson's disease patient group following STN DBS and, second, to correlate these emotional performances with glucose metabolism using (18)FDG-PET. The (18)FDG-PET and RFE tasks were both performed by a cohort of 13 Parkinson's disease patients 3 months before and 3 months after surgery for STN DBS. As predicted, we observed a significant reduction in fear recognition following surgery and obtained a positive correlation between these neuropsychological results and changes in glucose metabolism, especially in the right OFC. These results confirm the role of the STN as a key basal ganglia structure in limbic circuits.

Malignant melanoma of soft parts. A "non plastic surgeon's land"?

Malignant melanoma of soft parts (MMSP) (or "clear cell sarcoma") is a very rare tumour that shows up without primitive skin involvement (except in subcutaneous prolongations of deep tumours), mostly predominant in the extremities of young adults. Eight files of MMSP were studied retrospectively. The mean patient is a male of 35 years old affected in an extremity (four upper, three lower and one gluteal), according to classical descriptions. The importance of radical surgery in these cases has been extensively established. Confronted with these cases, the plastic surgeon must be aware of the specifics of this rare entity to ensure its proper inclusion in his clinical suspicion. Just in case.

Description and technical pitfalls of a hepatoma model and of intra-arterial injection of radiolabelled lipiodol in the rat.

Intra-arterial metabolic radiotherapy (using lipiodol labelled with iodine-131 or rhenium-188) is a therapeutic approach that can be used for the treatment of hepatocellular carcinomas (HCC). We propose a detailed description of the tumoral model using the N1-S1 cell line as well as a technique for intra-arterial injection of radiolabelled lipiodol in order to undertake preclinical studies necessary for the evaluation of a new molecule. We also report the principal technical pitfalls that were faced. The speed of injection of the tumoral cells is a key factor in the tumoral induction since slow injections lead to a tumoral induction rate of 36.3% compared with 76.6% (P<0.01) when using very slow injections. This parameter should thus be controlled carefully during the subcapsular injection of the tumoral cells. In addition, when injecting radiolabelled lipiodol, anaesthesia should not be performed with isoflurane since this leads to a reduction in tumoral uptake. Indeed, we found a 'tumour/healthy liver' uptake ratio of only 2.1+/-0.7 with isoflurane as against 4.4+/-2.6 (P<0.05) when anaesthesia was carried out by intraperitoneal injection of ketamine. Lastly, we show that the tumour size has an influence on the tumoral uptake of radiolabelled lipiodol; therefore, this parameter must also be carefully controlled.

An in vitro study to compare 99mTc-stannous colloids and 99mTc-HMPAO for labelling human leukocytes.

AIM: Aim of the present study was to compare in vitro the labelling efficiency (LE) and cell viability (TBE) of autologous leukocytes labelled with (99m)Tc-SnF(2) and (99m)Tc-HMPAO, and to evaluate the quantity and quality of spontaneously released (99m)Tc (SR) from labelled cells at several time points after labelling. METHODS: A total of 14 patients with different diseases and 18 normal subjects were included in this study. A blood sample was collected from each patient; purified autologous leukocytes were divided into 2 samples and labelled with (99m)Tc-SnF(2) and (99m)Tc-HMPAO. LE was evaluated at the end of labelling and TBE and SR were evaluated at 10 min and 1 h, 2 h and 4 h after labelling. RESULTS: LE of (99m)Tc-SnF(2)-WBC was higher than (99m)Tc-HMPAO-WBC (61.2+/-18.7% and 43.3+/-11.3; p<0.0001) and we found an inverse correlation between blood glucose and labelling efficiency for both methods (p=0.02). Minimal differences were also observed between 2 methods after 10 min and 1 h, as far as the cell viability is concerned. The percentage of radioactivity spontaneously released from (99m)Tc-SnF(2)-WBC was significantly higher compared to (99m)Tc-HMPAO-WBC at each time point. Radioactivity released from labelled cells was predominantly (99m)Tc-SnF(2) and (99m)Tc-HMPAO with few free (99m)Tc (<20%). CONCLUSION: Both radiopharmaceuticals are not toxic for WBC. Labelling with (99m)Tc-SnF(2) give a higher LE than with (99m)Tc-HMPAO; however, radiolabelled colloids are more released from labelled cells over a period of 4 h. While (99m)Tc-HMPAO is physiological excreted into gastrointestinal tract, (99m)Tc-SnF(2) can be re-uptaken in vivo by reticulo-endothelial cells of liver and spleen. These findings suggest that (99m)Tc-SnF(2)-WBC might be better than (99m)Tc-HMPAO-WBC for studying inflammatory bowel diseases.

[Value of the association of D-dimer measurement and the evaluation of clinical probability in a non-invasive diagnostic strategy of pulmonary embolism]. / Intérêt de l'association du dosage des D-dimères et de l'évaluation de la probabilité clinique dans une stratégie diagnostique non invasive de l'embolie pulmonaire.

New diagnostic tools in suspected pulmonary embolism complete the classical diagnostic strategy of pulmonary scintigraphy and pulmonary angiography to limit the indications of these two invasive investigations. In a prospective series of 204 consecutive patients with suspected pulmonary embolism the association of D-dimer measurement and clinical probability was assessed for the exclusion of the diagnosis of pulmonary embolism. The D-DI Liatest is a new generation, unitary, rapid and quantitative latex test with a comparative diagnostic performance to that of the reference ELISA test, and well adapted to emergency situations.The clinical probability was assessed by a quantitative score based on past history, clinical symptoms and signs. The positive diagnosis of pulmonary embolism was made by spiral CT scanner and/or pulmonary angiography, associated with Duplex ultrasonography of the leg veins in nondiagnostic results. The prevalence of pulmonary embolism was 42.6% and the absence of anticoagulation in patients considered not to have pulmonary embolism was associated with a thrombo-embolic incidence of 0.9% at 3 months. Fifty-six patients had D-dimer concentrations equal or inferior to the threshold of 500 microg/L; the sensitivity was 99% and the specificity 47% with a negative predictive value of 98% to 100% in cases with a low clinical probability. D-dimer measurement is reliable and has a high cost-benefit value in ambulatory patients with suspected of pulmonary embolism and is even more valuable when the clinical probability of this diagnosis is low.

Development and biodistribution of 188Re-SSS lipiodol following injection into the hepatic artery of healthy pigs.

Although intra-arterial radiotherapy with (131)I-labelled lipiodol is a useful therapeutic approach in the treatment of hepatocellular carcinomas, various disadvantages limit its use. Here we describe the development of (188)Re-SSS lipiodol, as well as its biodistribution in the healthy pig after injection into the hepatic artery. The (188)Re-SSS lipiodol was obtained after dissolving a chelating agent, previously labelled with (188)Re, in cold lipiodol. The radiochemical purity (RCP) of the labelling was checked immediately and at 24 and 48 h. The (188)Re-SSS lipiodol was injected into the hepatic artery of six healthy pigs. They were killed 1, 24 and 48 h post injection, for ex vivo counting. An autoradiographic study was performed in three cases. (188)Re-SSS lipiodol was obtained with a yield of 87%+/-9.1%. The immediate RCP was 93%+/-3.4%. This radiolabelling was reproducible and stable at 48 h in plasma: 90.6%+/-1.5% of the activity remained in the lipiodol with an RCP of 91%+/-4%. Ex vivo counting confirmed the predominantly hepatic uptake and revealed weak lung and intestinal uptake. There was very weak urinary elimination (2.3%+/-0.5% at 48 h) and a slightly higher level of intestinal elimination (4.8%+/-1.9% at 48 h). The autoradiographic studies showed (188)Re-SSS lipiodol to be located mainly in sinusoids, like (131)I-lipiodol. By using the method described here, (188)Re-SSS lipiodol can be obtained with a very high yield and a satisfactory RCP. Its biodistribution in the healthy pig is in agreement with data published elsewhere concerning other types of radiolabelling used for lipiodol, except for the very weak urinary and intestinal elimination, which probably indicates better stability of (188)Re-SSS labelling.

Safe radiation exposure of medical personnel by using simple methods of radioprotection while administering 131I-lipiodol therapy for hepatocellular carcinoma.

The intra-arterial administration of 131I-lipiodol is a therapeutic approach increasingly used for the treatment of inoperable hepatocellular carcinomas. This technique has even become the reference treatment for hepatocellular carcinomas with portal thrombosis and is the only effective treatment to reduce the risk of recurrence among patients who could benefit from surgical operation. Currently, few data have been published concerning the levels of exposure for personnel carrying out this type of treatment. We undertook a dosimetric study targeted mainly on the exposure of the person performing the injection of 131I-lipiodol to show that this treatment can be carried out with an exposure at the extremities distinctly lower than the regulatory annual threshold by using simple means of radioprotection. The point of puncture was carried out at the level of left femoral artery, the preparation and injection of the therapeutic dose was carried out extemporaneously by the nuclear medicine specialist using a 10 ml syringe (for an injected volume of 4 ml) fitted with an adapted syringe protector. The injection was carried out as rapidly as possible under scopic control while avoiding reflux, with compression carried out by the radiologist. This study comprises 52 intra-arterial injections of 131I-lipiodol (2016+/-92 MBq). For the nuclear medicine specialists, 52 measurements were carried out at the level of the thorax and 41 on the fingers. For the radiologists, 22 measurements were carried out at the level of the thorax and six on their index fingers; nine measurements were carried out at the level of the thorax for the technologist and four at the level of the thorax for the stretcher bearer. For the nuclear medicine specialists, the average dose received at the level of the fingers varies between 140 and 443 microSv (according to the fingers) and the average dose at the thorax is 17 microSv. For the radiologists, the average dose received is 215 microSv at the level of the fingers and 15 microSv at the thorax. These results show that the administration of high therapeutic activities of 131I-lipiodol can be carried out for the exposed personnel with a dose at the level of the fingers much lower than the European regulatory limit of 500 mSv.

Diagnosis of osteomyelitis in the diabetic foot with a 99mTc-HMPAO leucocyte scintigraphy combined with a 99mTc-MDP bone scintigraphy.

BACKGROUND: The aim of this prospective study was to assess the role of 99mTc-HMPAO leucocyte scintigraphy combined with a 99mTc-MDP bone scintigraphy in the diagnosis of the diabetic foot infection (HMPAO-Leu/MDP). METHODS: 75 diabetic patients with suspected osteomyelitis were included. The HMPAO-Leu/MDP scan was considered to be consistent with osteomyelitis when the HMPAO-Leu uptake was concordant in all the incidences with an MDP bone uptake. A HMPAO-Leu uptake without concordant bone MDP activity was considered as a soft-tissue infection. The results of the HMPAO-Leu/MDP scan were compared to the following diagnostic criteria: bone infection was confirmed by radiological follow-up or bone biopsy; the absence of bone infection was confirmed by clinical (healing of the ulcer without antibiotherapy) and radiological follow up. RESULTS: According to these criteria, among the 83 ulcers, bone infection was observed in 41 (49.4%): the HMPAO-Leu/MDP scan was positive in 38 cases, including 14 ulcers with normal or doubtful radiographs at inclusion. In the group of 42 ulcers without proven bone infection, the HMPAO-Leu/MDP scan was negative in 41 cases, including 17 lesions with a soft-tissue infection. CONCLUSION: With a sensitivity of 92.6%, a specificity of 97.6%, the HMPAO-Leu/MDP scan is a reliable tool for the diagnosis of osteomyelitis in the diabetic foot. Neuroarthropathy did not affect the performances of the HMPAO-Leu/MDP scan. Owing to a high spatial resolution this test is very helpful to differentiate bone infection from soft-tissue infection especially in case of neuroarthropathy.

Scintimammography: better detection of small-sized lesions with tomoscintigraphic than planar images, a phantom study.

Planar (99)Tc(m)-methoxyisobutylisonitrile ((99)Tc(m)-MIBI) scintimammography has been used for several years to detect breast cancer tumours, but with low sensitivity for small lesions. Results of tomoscintimammography studies have not been conclusive. We conducted a phantom study to compare the detection of small-sized tumours with planar versus tomoscintigraphic images. We used a data spectrum anthropomorphic fillable breast phantom with two 9.8 mm and 12.4 mm spheres superficially or deep in the breast compartment with sphere/breast activity ratios varying from 3 to 6. We acquired planar and 180 degrees tomoscintigraphic images in each configuration using a double head standard gamma camera. In certain cases we varied different parameters (64x64 matrix or 360 degrees rotation) in a second series of tomoscintigraphic acquisitions. We simultaneously used filtered back-projection reconstruction (FBP) and iterative reconstruction (IR). Planar images were shown by the sphere in 10 out of 25 cases. Tomoscintigraphic images were shown by the sphere in nine out of 25 cases with FBP and in 18 out of 25 with IR. There was a significant difference between IR and FBP (P<0.01) and between planar and IR images (P<0.01), but no significant difference between planar and IR images. The noise/signal ratio was lower with planar images than with the two types of reconstruction (P<0.05) but was not significantly different between the two types of reconstruction. Contrast was lower on planar images than on the two types of reconstruction (P<0.05) and was also better on IR than on FBP images (P<0.05). Granularity was lower for planar images than for reconstruction images (P<0.01) and also lower for IR than for FBP (P<0.01). The tomoscintigraphic reconstructions acquired with a 64x64 matrix were only positive in four out of 10 cases, while they were positive in nine out of 10 with a 128x128 matrix. We concluded that, in this phantom study, tomoscintimammography with IR provides a significant improvement in the detection of small-sized breast tumours compared with planar images. In addition, for tomoscintigraphic images, a 128x128 matrix is preferable to a 64x64 matrix. Those results have, of course, to be confirmed in vivo in a large population of patients with small-sized breast lesions.