Long-term efficacy of (90)Y-DOTATATE in patients with nonresectable pancreatic and small bowel neuroendocrine neoplasms.

AIM: To determine the efficacy of (90)Y [DOTA(0), D-Phe(1), Tyr(3)]-octreotate (DOTATATE) in 67 patients with pancreatic and small bowel neuroendocrine tumors (NETs). PATIENTS & METHODS: The primary efficacy end point was overall survival (OS) and secondary end points were progression-free survival (PFS) and tumor response. RESULTS: Median PFS in pancreatic and small bowel NETs was 25 and 28 months, respectively, and median OS was 42 and 38.5 months, respectively. No intergroup differences in median OS (p = 0.945) or PFS (p = 0.174) were found, also after adjustment for tumor origin, secretory status and grade, and patient's gender. CONCLUSION: (90)Y-DOTATATE may have similar efficacy in pancreatic and small bowel NETs. Better WHO performance status at baseline seems to be associated with more favorable outcomes.

Usefulness of Somatostatin Receptor Scintigraphy (Tc-[HYNIC, Tyr3]-Octreotide) and 123I-Metaiodobenzylguanidine Scintigraphy in Patients with SDHx Gene-Related Pheochromocytomas and Paragangliomas Detected by Computed Tomography.

AIMS: The aim of this study was to assess the usefulness of somatostatin receptor scintigraphy (SRS) using (99m)Tc-[HYNIC, Tyr3]-octreotide (TOC) and 123I-metaiodobenzylguanidine (mIBG) in patients with SDHx-related syndromes in which paragangliomas were detected by computed tomography and to establish an optimal imaging diagnostic algorithm in SDHx mutation carriers. METHODS: All carriers with clinical and radiological findings suggesting paragangliomas were screened by SRS and 123I-mIBG. Lesions were classified by body regions, i.e. head and neck, chest, abdomen with pelvis and adrenal gland as well as metastasis. RESULTS: We evaluated 46 SDHx gene mutation carriers (32 index cases and 14 relatives; 28 SDHD, 16 SDHB and 2 SDHC). In this group, 102 benign tumors were found in 39 studied patients, and malignant disease was diagnosed in 7 patients. In benign tumors, the sensitivity of SRS was estimated at 77% and of 123I-mIBG at 22.0%. The SRS and mIBG sensitivity was found to be clearly region dependent (p < 0.001). The highest SRS sensitivity was found in head and neck paragangliomas (HNP; 91.4%) and the lowest was found in abdominal paragangliomas and pheochromocytomas (40 and 42.9%, respectively). The highest 123I-mIBG sensitivity was found in pheochromocytomas (sensitivity of 100%) and the lowest in HNP (sensitivity of 3.7%). In metastatic disease, SRS was superior to mIBG (sensitivity of 95.2 vs. 23.8%, respectively). CONCLUSION: SRS and 123I-mIBG single photon emission computed tomography (SPECT) sensitivity in SDHx patients is highly body region dependent. In malignant tumors, SRS is superior to 123I-mIBG SPECT.

Initial study of radiological and clinical efficacy radioembolization using 188Re-human serum albumin (HSA) microspheres in patients with progressive, unresectable primary or secondary liver cancers.

BACKGROUND: The aim of this initial study was to evaluate the clinical and radiological effectiveness of radioembolization (RE) using 188Re-Human Serum Albumin (HSA) microspheres in patients with advanced, progressive, unresectable primary or secondary liver cancers, not suitable to any other form of therapy. MATERIAL/METHODS: Overall, we included 13 patients with 20 therapy sessions. Clinical and radiological responses were assessed at 6 weeks after therapy, and then every 3 months. The objective radiological response was classified according to Response Evaluation Criteria in Solid Tumors (RECIST) v.1.0 by sequential MRI. Adverse events were evaluated using NCI CTCAE v.4.03. RESULTS: There were 4 patients with hepatocellular carcinoma (HCC), 6 with metastatic colorectal cancer (mCRC), 2 with neuroendocrine carcinoma (NEC), and 1 patient with ovarian carcinoma. Mean administered activity of 188Re HSA was 7.24 GBq (range 3.8-12.4) A high microspheres labeling efficacy of over 97±2.1% and low urinary excretion of 188Re (6.5±2.3%) during first 48-h follow-up. Median overall survival (OS) for all patients was 7.1 months (CI 6.2-13.3) and progression-free survival (PFS) was 5.1 months (CI 2.4-9.9). In those patients who had a clinical partial response (PR), stable disease (SD), and disease progression (DP) as assessed 6 weeks after therapy, the median OS was 9/5/4 months, respectively, and PFS was 5/2/0 months, respectively. The treatment adverse events (toxicity) were at an acceptable level. Initially and after 6 weeks, the CTC AE was grade 2, while after 3 months it increased to grade 3 in 4 subjects. This effect was mostly related to rapid cancer progression in this patient subgroup. CONCLUSIONS: The results of this preliminary study indicate that RE using 188Re HSA is feasible and a viable option for palliative therapy in patients with extensive progressive liver cancer. It was well tolerated by most patients, with a low level of toxicity during the 3 months of follow-up.

Navigating The Prostate Cancer Frontier: A Bibliometric and Altmetric Analysis of [225Ac]Ac-PSMA Therapy.

The main aim of this study was to evaluate the current state of bibliometric and altmetric research output of [225Ac]Ac-Prostate specific membrane antigen (PSMA) and its implications for prostate cancer (PC). Both PubMed and Scopus digital libraries were systematically explored to retrieve relevant data on the topic of interest. The study of various bibliometric and altmetric indices was facilitated through the use of Microsoft Excel, Stata (Version 17.0), and VOSviewer (Version 1.6) Softwares. The parameters included in this study comprised the examination of published articles, annual trends, countries, institutions, authors, journals, and co-occurring keywords. From 2014 to 2024, our study examined a total of 100 publications within the given domain. The studies that received the highest citations primarily centered on the crucial topic of metastatic castration-resistant prostate cancer, with a particular emphasis on evaluating the safety and effectiveness of [225Ac]Ac-PSMA therapy. Moreover, much scholarly inquiry has been devoted to examining the [225Ac]Ac-PSMA adverse effects. Three high prolific countries (namely, Germany, United States, and South Africa) dominated the research render in terms of publications and citations. Finally, A strong correlation was observed between altmetric score and citation number (P < 0.001). The observed surge in scholarly research output and altmetric indicators associated with [225Ac]Ac-PSMA signifies a shift in emphasis towards embracing alpha targeted therapy in PC.

PET a tool for assessing the in vivo tumour cell and its microenvironment?

INTRODUCTION AND BACKGROUND: Positron emission tomography (PET) has started to develop beyond its roots in glucose imaging, expanding to study other parameters of the tumour and its microenvironment. SOURCES OF DATA: A review of imaging literature over the past 5 years has shown that functional imaging with PET is starting to exploit our increasing knowledge of genomics and the phenotypic expression of cells and how they interact with their microenvironment. AREAS OF AGREEMENT: For most of those working in this field, there is agreement that therapeutic outcomes for patients can only be obtained by the assessment and continued reassessment not only of the tumour microenvironment, but also how it is changed by treatment. AREAS OF CONTROVERSY: Although PET offers a tool by which the tumour and its microenvironment can be assessed in vivo without the need for multiple interventions, the cost of PET is high and there is a cumulative radiation burden with repeated studies. As the quantity and quality of PET scans increase, we are able to assess tumour cell turn over, metabolism, hypoxia, angiogenesis and a variety of other factors that might affect tumour survival and response to treatment. AREAS TIMELY FOR DEVELOPING RESEARCH: As it is impossible to do everything for every patient, we need to know what are the critical factors in the tumour cell microenvironment in each patient and need to have the tools to assess that factor.

Clinical perspectives on dosimetry in molecular radiotherapy.

Molecular radiotherapy is the use of systemically administered unsealed radioactive sources to treat cancer. Theragnostics is the term used to describe paired radiopharmaceuticals localising to a specific target, one optimised for imaging, the other for therapy. For many decades, molecular radiotherapy has developed empirically. Standard administered activity schedules have been used without the prior estimation of the resulting tumour radiation absorbed dose by theragnostic imaging, or its subsequent measurement by serial scanning. This pragmatic approach has benefited many patients, however others who should have benefited have failed to do so as the radiation absorbed dose in the tumour was suboptimal. The accurate prediction and measurement of tumour and organ at risk radiation absorbed doses allows treatment to be personalised, and offers the prospect of improved clinical outcomes. To deliver this for all molecular radiotherapy patients would require not only a significant financial investment in equipment and skilled personnel, but also a change in attitude of those who believe that simple - or simplistic - schedules are easier to deliver, and that accurate dosimetry is too much trouble. Further clinical studies are required to demonstrate beyond doubt that the advantages of individualised treatment planning outweigh the inconvenience, and that the expense is justified by enhanced results.

Clinical Utility of 18Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography (18F-FDG PET/CT) in Multivisceral Transplant Patients.

Multivisceral transplant (MVTx) refers to a composite graft from a cadaveric donor, which often includes the liver, the pancreaticoduodenal complex, and small intestine transplanted en bloc. It remains rare and is performed in specialist centres. Post-transplant complications are reported at a higher rate in multivisceral transplants because of the high levels of immunosuppression used to prevent rejection of the highly immunogenic intestine. In this study, we analyzed the clinical utility of 28 18F-FDG PET/CT scans in 20 multivisceral transplant recipients in whom previous non-functional imaging was deemed clinically inconclusive. The results were compared with histopathological and clinical follow-up data. In our study, the accuracy of 18F-FDG PET/CT was determined as 66.7%, where a final diagnosis was confirmed clinically or via pathology. Of the 28 scans, 24 scans (85.7%) directly affected patient management, of which 9 were related to starting of new treatments and 6 resulted in an ongoing treatment or planned surgery being stopped. This study demonstrates that 18F-FDG PET/CT is a promising technique in identifying life-threatening pathologies in this complex group of patients. It would appear that 18F-FDG PET/CT has a good level of accuracy, including for those MVTx patients suffering from infection, post-transplant lymphoproliferative disease, and malignancy.

Radiological and Clinical Efficacy of Intra-Arterial 90Y-DOTATATE in Patients with Unresectable, Progressive, Liver Dominant Neuroendocrine Neoplasms.

This study was performed to determine if intra-arterial (i.a.) administration of 90Y DOTATATE can provide an effective and safe alternative to the accepted standard for i.v. of peptide receptor radionuclide therapy (PRRT) in liver-dominant metastases of gastrointestinal pancreatic neuroendocrine neoplasm (GEP-NEN). A single site, prospective, preliminary case series study included 39 patients with histologically proven liver-dominant NEN. PRRT in the form of 1.15GBq 90Y DOTATATE was given selectively into the liver via radiological catheterization of the hepatic artery, up to four times. The endpoint was radiological response (RECIST). Secondary endpoints assessed clinical well-being post-treatment, progression-free survival (PFS), overall survival (OS), and toxicity. Partial response (PR) was noted in 13% of subjects six weeks post-therapy, increasing to 24% at six months and dropping to 13% at 36 months. Disease progression (DP) was not seen at six weeks, was 5% at six months, and 47% at 36 months. Clinical response based on PS seen in 74% of patients at six weeks, 69% at six months, and 39% at 36 months had PFS and OS, respectively, of 22.7 months and 38.2 months. There was no difference in OS/PFS between those with RECIST PR and SD. One patient had significant toxicity (3%). Use of i.a. PRRT appears to be safe and effective in treating patients with liver-dominant NEN. In addition, the best OS (51 vs. 22 months) was seen when i.a. was used as an upfront treatment of bulky GEP-NEN liver metastases and not after i.v. 90Y DOTATATE. The use of i.a. 90Y DOTATATE PRRT appears to be safe and effective in treating patients with liver-dominant NEN.

Efficacy of using a standard activity of (131)I-MIBG therapy in patients with disseminated neuroendocrine tumours.

PURPOSE: The aim of this analysis was to evaluate the response to standard activity of (131)I-meta-iodobenzylguanidine (MIBG) in patients with disseminated neuroendocrine tumours (NETs), comparing overall survival of patients with symptomatic response, tumour size (as assessed by CT) and relevant plasma tumour markers. METHODS: A retrospective review of patients who had undergone (131)I-MIBG treatment between March 2001 and December 2006 was carried out. The administered activity of (131)I-MIBG was 5.5 GBq (NETs) and 7 GBq (phaeochromocytoma). Three cycles of treatment were planned with an interval of 10-12 weeks. A pre-therapy scan with (123)I-MIBG was performed to ascertain appropriate biodistribution. RESULTS: Thirty-eight patients were identified. Only two patients developed significant bone marrow suppression. Symptomatic response: data were available in 37 of 38 patients: 15 patients had improved symptoms, 19 had no improvement in symptoms and 3 were asymptomatic. In those with a symptomatic response, the median overall survival was 58 months vs no response of 20.0 months (p = 0.001). CT response: in those with stable disease, the median overall survival was 58 months compared with progressive disease of 16.0 months. The difference between these groups was significant (p = 0.006). Hormonal response: this was available in only 20 of 38 patients. The median overall survival was the same for patients that had increased hormone levels and patients that had stable/decreased hormone levels (48 months). CONCLUSION: Standard activity (131)I-MIBG is well tolerated. Symptomatic response to treatment is a significant predictor of overall survival. Whilst CT response also appears to predict survival, hormonal levels do not appear to correlate with survival.

Evidence Base for the Use of PRRT.

The development of peptide receptor radionuclide therapy (PRRT) in disseminated neuroendocrine tumors (NETs) has been a long and protracted process. The idea was born within nuclear medicine academia but its translation to clinical practice has been marked by misunderstanding of the rigors of the processes used in drug registration. There were several false starts and some of the required basic science did not occur until after first in man studies. The standard process of preclinical, phase 1, 2 and 3 clinical trials were sometimes blurred and the required data including the assurances that patients were studied on protocol was missing from subsequent publications. Despite this there was a growing conviction and increasing evidence that the use of PRRT had a positive benefit in both survival and symptom relief in about 80% of treated patients. After a decade and a half of false starts and incomplete data a formal randomized controlled trial was conducted comparing PRRT with high dose somatostatin which clearly proved that PRRT was both safe, effective and the treatment of choice in hormone refractory NETs.

COVID-19: guidance for infection prevention and control in nuclear medicine.

This guidance document is a brief consensus document covering the range and breadth of nuclear medicine practice in the UK, and identifies a few steps individual nuclear medicine practitioners and departments can take in the best interests of their patients. This guidance document should be used to inform local practice and does not replace local Trust policies or any relevant legislation. At all times, the best interests of the patients should be paramount. Please read this guidance in conjunction with previous editorial (COVID-19- Nuclear Medicine Departments, be prepared! by Huang HL, Allie R, Gnanasegaran G, Bomanji. J Nucl Med Commun 2020; 41:297-299). Although some aspects of this guidance are time-sensitive due to the nature of the global emergency, we believe that there is still sufficient information to provide some key guiding principles.

ACR-ACNM-ASTRO-SNMMI Practice Parameter for the Performance of Therapy With Radium-223.

AIM/OBJECTIVES/BACKGROUND: The goal of therapy with unsealed radiopharmaceutical sources is to provide either cure or significant prolongation of disease-specific survival, and effective reduction and/or prevention of adverse disease-related symptoms or untoward events while minimizing treatment-associated side effects and complications. Radium-223 dichloride (radium-223) is an alpha particle-emitting isotope used for targeted bone therapy. This practice parameter is intended to guide appropriately trained and licensed physicians performing therapy with radium-223. Such therapy requires close cooperation and communication between the physicians who are responsible for the clinical management of the patient and those who administer radiopharmaceutical therapy and manage the attendant side effects. Adherence to this parameter should help to maximize the efficacious use of radium-223, maintain safe conditions, and ensure compliance with applicable regulations. METHODS: This practice parameter was developed according to the process described on the American College of Radiology (ACR) website ("The Process for Developing ACR Practice Parameters and Technical Standards," www.acr.org/ClinicalResources/Practice-Parameters-and-Technical-Standards) by the Committee on Practice Parameters of the ACR Commission on Radiation Oncology in collaboration with the American College of Nuclear Medicine (ACNM), the American Society for Radiation Oncology (ASTRO), and the Society of Nuclear Medicine and Molecular Imaging (SNMMI). All these societies contributed to the development of the practice parameter and approved the final document. RESULTS: This practice parameter addresses the many factors which contribute to appropriate, safe, and effective clinical use of radium-223. Topics addressed include qualifications and responsibilities of personnel, specifications of patient examination and treatment; documentation, radiation safety, quality control/improvement, infection control, and patient education. CONCLUSIONS: This practice parameter is intended as a tool to guide clinical use of radium-223 with the goal of facilitating safe and effective medical care based on current knowledge, available resources and patient needs. The sole purpose of this document is to assist practitioners in achieving this objective.

Vascular Positron Emission Tomography and Restenosis in Symptomatic Peripheral Arterial Disease: A Prospective Clinical Study.

OBJECTIVES: This study determined whether in vivo positron emission tomography (PET) of arterial inflammation (18F-fluorodeoxyglucose [18F-FDG]) or microcalcification (18F-sodium fluoride [18F-NaF]) could predict restenosis following PTA. BACKGROUND: Restenosis following lower limb percutaneous transluminal angioplasty (PTA) is common, unpredictable, and challenging to treat. Currently, it is impossible to predict which patient will suffer from restenosis following angioplasty. METHODS: In this prospective observational cohort study, 50 patients with symptomatic peripheral arterial disease underwent 18F-FDG and 18F-NaF PET/computed tomography (CT) imaging of the superficial femoral artery before and 6 weeks after angioplasty. The primary outcome was arterial restenosis at 12 months. RESULTS: Forty subjects completed the study protocol with 14 patients (35%) reaching the primary outcome of restenosis. The baseline activities of femoral arterial inflammation (18F-FDG tissue-to-background ratio [TBR] 2.43 [interquartile range (IQR): 2.29 to 2.61] vs. 1.63 [IQR: 1.52 to 1.78]; p < 0.001) and microcalcification (18F-NaF TBR 2.61 [IQR: 2.50 to 2.77] vs. 1.69 [IQR: 1.54 to 1.77]; p < 0.001) were higher in patients who developed restenosis. The predictive value of both 18F-FDG (cut-off TBRmax value of 1.98) and 18F-NaF (cut-off TBRmax value of 2.11) uptake demonstrated excellent discrimination in predicting 1-year restenosis (Kaplan Meier estimator, log-rank p < 0.001). CONCLUSIONS: Baseline and persistent femoral arterial inflammation and micro-calcification are associated with restenosis following lower limb PTA. For the first time, we describe a method of identifying complex metabolically active plaques and patients at risk of restenosis that has the potential to select patients for intervention and to serve as a biomarker to test novel interventions to prevent restenosis.

Transarterial injection of (131)I-lipiodol, compared with chemoembolization, in the treatment of unresectable hepatocellular cancer.

UNLABELLED: Transarterial chemoembolization (TACE) improves survival in patients with hepatocellular carcinoma (HCC) in whom curative therapies are not suitable. The aim of this study was to assess survival differences in patients with hepatic cirrhosis and unresectable HCC treated by (131)I-lipiodol versus TACE or transarterial embolization (TAE). METHODS: A retrospective study was performed on a cohort of 124 patients undergoing treatment for unresectable HCC between 1997 and 2006. A total of 50 patients (44 men; mean age, 59 y) received (131)I-lipiodol (mean sessions per patient, 1.7), and 74 patients (63 men; mean age, 61 y) received TACE/TAE (mean sessions per patient, 1.8). Although no significant difference between the 2 treatment groups with respect to HCC size and clinical staging was observed, a higher proportion of patients with portal vein thrombosis (PVT) was treated with (131)I-lipiodol than with TACE/TAE (28% vs. 8%, P = 0.003). RESULTS: Actuarial survival was not significantly different between patients treated with (131)I-lipiodol and patients treated with TACE/TAE. Survival at 6 mo, 1 y, 2 y, and 3 y was 86%, 69%, 54%, and 45%, respectively, after (131)I-lipiodol, compared with 77%, 62%, 47%, and 43%, respectively, after TACE/TAE. However, patients with PVT survived a mean of 454 d after (131)I-lipiodol, compared with a mean of 171 d after TACE/TAE (P = 0.025). In addition, patients with more advanced disease (Barcelona Clinic Liver Cancer stage D) lived on average 363 d after (131)I-lipiodol, compared with 36 d after TACE/TAE (P = 0.014). CONCLUSION: In patients with unresectable HCC, there was no difference in survival between (131)I-lipiodol therapy and TACE/TAE treatment. However, in the patients with advanced clinical staging or PVT, there was a significant survival advantage for those treated with (131)I-lipiodol.

The Value of Somatostatin Receptor Scintigraphy (SRS) in Patients with NETG1/G2 Pancreatic Neuroendocrine Neoplasms (p-NENs).

BACKGROUND: Neuroendocrine neoplasms of the pancreas (p-NEN) are common gastro-entero-pancreatic neuroendocrine neoplasms (GEP-NENs). The aim of this retrospective study was to review the of value of Somatostatin Receptor Scintigraphy (SRS) in initial detection of p-NEN, evaluation of tumour extent and as imaging follow-up after radical surgery in patients with confirmed well (NETG1) or moderate (NETG2) differentiated p-NEN based on pathological WHO 2017 classification. MATERIAL AND METHODS: Overall 281 patients with confirmed p-NEN were enrolled. The SRS was performed to evaluation of primary p-NEN, also to assess clinical stage of disease, based on current World Health Organization (WHO) classification and during clinical follow-up. A total of 829 examinations were performed over time in these 281 patients using 99mTc HYNICTOC. Images were acquired between 1 - 3 h after i.v. injection of radiotracer. Initially whole body WB-SPECT and then WB-SPECT/CT, with standard iterative reconstruction were used. RESULTS: There were 159 patients with NETG1 (57%) and 122 subjects with NETG2 (43%). The female to male ratio was 1.1:1. In 68 patients (22%) with NETG1/G2 eight-seven SRS (10%) were performed to confirm initial diagnosis. SRS results were as follow: true positive (TP) = 84 (97%), false negative (FN) = 3 (3%), no true negative (TN) or false positive (FP) results of SRS examination (sensitivity of SRS per patient was 96%). In 198 subjects (66%) SRS was used in evaluation and re-evaluation of the clinical stage, A total of 661 (80%) examinations were carried out in these patients. There were TP=514 (77%), TN=136 (21%), FN=7 (1%) and FP=4 (1%) results. The sensitivity and specificity per patient were: 96% and 95%. The sensitivity and specificity per study: 98% and 97%. In 35 patients (12%) SRS was used as imaging follow-up after radical surgery, there were overall 81 examination (10%) which were performed. There were 76 (91%) TN results of examinations of SRS and in 4 patients we identified recurrence (TP). In total, which consists of initial diagnosis/staging and follow-up patients, the sensitivity of SRS was 96% and specificity 97% per patient and per study sensitivity and specificity was 98%. CONCLUSIONS: SRS using 99mTc HYNICTOC acquired in WB-SPECT or WB-SPECT/CT techniques is an excellent imaging modality in detection of primary NETG1/G2 p-NEN. Our study confirms that SRS has high sensitivity and specificity, as a result has tremendous value as an examination method to assess clinical stage of disease and as an imaging follow-up after radical treatment.

Initial direct comparison of 99mTc-TOC and 99mTc-TATE in identifying sites of disease in patients with proven GEP NETs.

UNLABELLED: The imaging of neuroendocrine tumors has become one of the most significant areas in nuclear oncology. In an attempt to provide high-quality imaging and possible sensitivity at a reduced cost, time, and radiation dose, several (99m)Tc agents have been proposed. The aim of this initial study was to compare the tumor uptake and biodistribution of 2 new 6-hydrazinopyridine-3-carboxylic acid (HYNIC)-derivatized Tyr(3)-octreotide analogs, (99m)Tc-[HYNIC,Tyr(3)]octreotide ((99m)Tc-TOC) and (99m)Tc-[HYNIC,Tyr(3),Thr(8)]octreotide ((99m)Tc-TATE), in patients with somatostatin receptor-expressing tumors. METHODS: Each of 12 patients with proven gastrointestinal pancreatic neuroendocrine tumors received a mean activity of 520 MBq of (99m)Tc-TOC and (99m)Tc-TATE. Scintigraphy with both tracers was performed 3-4 h after their injection using standard whole-body and SPECT imaging. The images were reviewed subjectively by 2 readers, who reported tumor uptake lesion by lesion. RESULTS: Both radiotracers demonstrated concordance between the results in 7 patients (58%). In total, 110 sites of disease were identified with (99m)Tc-TOC, compared with 115 with (99m)Tc-TATE. There was 1 case in which (99m)Tc-TOC identified sites of disease not seen on (99m)Tc-TATE imaging but 4 cases in which some sites of disease were seen with (99m)Tc-TATE and not (99m)Tc-TOC. CONCLUSION: In this initial study, both tracers seem to show similar sites of tumor, with (99m)Tc-TATE having a slight edge in the total number of lesions seen, especially in lymph node metastases.

Neuroendocrine tumors: role of interventional radiology in therapy.

The management of neuroendocrine tumors (NETs) is complex. Although NETs can affect a variety of organ systems, hepatic metastatic disease in particular lends itself to a wide range of interventional treatment options. Prior detailed radiologic assessment and careful patient selection are required. Curative surgery should always be considered but is rarely possible. Embolization, radionuclide therapy, or ablative techniques may then be undertaken. Transcatheter arterial embolization (TAE) may be used alone or in combination with transcatheter arterial chemoembolization (TACE). NET type and extent of hepatic involvement are factors that can help predict the success of either TAE or TACE. Embolization techniques can also be useful in patients with nonhepatic NETs. Radionuclide therapy is emerging as a valuable adjunct and is dependent on positive somatostatin receptor status. Therapeutic radiopeptides may be delivered arterially. Ablative techniques have been shown to play a role in the palliation of symptoms and principally involve radiofrequency ablation. Hepatic cryotherapy and percutaneous ethanol injection have also been used. A multidisciplinary approach to treatment and follow-up is important. Imaging should involve dual-phase multidetector computed tomography and contrast material-enhanced magnetic resonance imaging. The role of the interventional radiologist will continue to expand as imaging techniques become more refined.

Technetium-99m-labelled sulesomab (LeukoScan) in the evaluation of soft tissue infections.

OBJECTIVE: To perform a retrospective review of all patients receiving technetium-99m ((99m)Tc)-labelled sulesomab over a 4-year period to determine if soft tissue infections can be accurately identified. METHODS AND MATERIALS: We reviewed the results of 124 (99m)Tc-sulesomab studies performed over a 4-year period. Of these, 34 were performed for undiagnosed fever in which soft tissue infection was suspected to be the main cause. The patients' clinical notes, microbiology reports and other imaging findings were reviewed to determine the clinical outcome following the scan. The scans were regarded as being true-positives if (i) uptake correlated with the site from which fluid or tissue was obtained and which grew bacteria, and/or (ii) the site of abnormality was reported as having an infection on other imaging or (iii) there was a clinical correlation with the referring clinician's evaluation of the patient. Planar imaging was performed using standard protocols, together with single-photon emission computed tomography (if required) at 1 and 4 h after injection of 20-30 mCi (740-1,110 MBq) (99m)Tc-sulesomab. RESULTS: Three patients were unevaluable. In the remaining 31 patients, 21 (99m)Tc-sulesomab studies were regarded as true-positives and 6 patients had true-negative scans. One patient had a false-positive scan (abnormal uptake with negative microbiology) and 3 had false-negative scans (infection confirmed but a negative scan). CONCLUSION: In suspected soft tissue infection, (99m)Tc-sulesomab imaging has a sensitivity of 88% with a specificity of 86% and overall accuracy of 87%. (99m)Tc-sulesomab provides an accurate method of imaging for suspected soft tissue infection, which is also fast and convenient, as cell labelling is not required.

Use of 18F FDG PET and the short temporal response of Hodgkin's disease to RIT.

Radioimmunotherapy (RIT) has been available for some time to treat patients with non-Hodgkin's lymphoma, but its use in Hodgkin's lymphoma has been less available, partly because of the need to find an appropriate antibody. A new radioiodinated chimeric antibody directed against the CD25 epitope (131I basiliximab) seems promising, but assessment of response has been difficult. 18F-fluorodeoxyglucose-positron emission tomography (18F-FDG-PET) has become a standard method by which the response of Hodgkin's disease to chemotherapy is both predicted and assessed with well-understood criteria of response. The aim of this study is to determine 18F-FDG-PET can be used to assess response to RIT. Pre- and post-treatment 18F-FDG-PET imaging was performed in a series of 13 patients with advanced Hodgkin's disease who had failed conventional therapy and had been enrolled on a compassionate use program for treatment with 131I basiliximab. The 131I basiliximab was given at an activity of 1200MBq/m2 with one patient receiving 2 cycles and the rest a single cycle. The 18F-FDG-PET studies were compared using the "Deauville" criteria and by comparing the maximum standardized uptake value (SUVmax) of target tumors before and 4 and 8 weeks after treatment. All patients survived long enough for their initial 18F-FDG-PET-computed tomography scan at 4 weeks after their 131I basiliximab therapy. One out of ten patients with "Deauville" Grade 4 or 5 response died during the 6-month follow-up period. Two out of three patients with a "Deauville" Grade 2 or 3 response died in the follow-up period. The mean SUVmax pretreatment was 11.9 (±4.7); at 4-week posttreatment, the mean SUVmax was significantly lower at 6.5 (±5.8) (P = 0.02). At 8 weeks, the mean SUVmax was 8.8 (±7.0), which was not significantly different from the pretreatment level. 18F-FDG-PET imaging is able to predict the short-term response to treatment of Hodgkin's disease by RIT, and an initial poor response appears to predict poor outcome. Early changes in 18F-FDG-PET uptake did not predict sustained response and by 8 weeks all but one patient had recurrent disease.