Highlights from 2017: impactful topics published in the Annals of Nuclear Medicine.

The aim of the review is to highlight articles published in 2017 in the Annals of Nuclear Medicine, an official peer-reviewed journal of the Japanese Society of Nuclear Medicine. Among all published manuscripts during the past year, we conducted a subjective selection of the most relevant topics. Fourteen fascinating articles are included in this review, ranging in topic from preclinical to clinical arenas.

Correction to: Highlights from 2017: impactful topics published in the Annals of Nuclear Medicine.

The author names in the original version of this article were inversed. Correct author names were reflected here.

European Association of Nuclear Medicine Practice Guideline/Society of Nuclear Medicine and Molecular Imaging Procedure Standard 2019 for radionuclide imaging of phaeochromocytoma and paraganglioma.

PURPOSE: Diverse radionuclide imaging techniques are available for the diagnosis, staging, and follow-up of phaeochromocytoma and paraganglioma (PPGL). Beyond their ability to detect and localise the disease, these imaging approaches variably characterise these tumours at the cellular and molecular levels and can guide therapy. Here we present updated guidelines jointly approved by the EANM and SNMMI for assisting nuclear medicine practitioners in not only the selection and performance of currently available single-photon emission computed tomography and positron emission tomography procedures, but also the interpretation and reporting of the results. METHODS: Guidelines from related fields and relevant literature have been considered in consultation with leading experts involved in the management of PPGL. The provided information should be applied according to local laws and regulations as well as the availability of various radiopharmaceuticals. CONCLUSION: Since the European Association of Nuclear Medicine 2012 guidelines, the excellent results obtained with gallium-68 (68Ga)-labelled somatostatin analogues (SSAs) in recent years have simplified the imaging approach for PPGL patients that can also be used for selecting patients for peptide receptor radionuclide therapy as a potential alternative or complement to the traditional theranostic approach with iodine-123 (123I)/iodine-131 (131I)-labelled meta-iodobenzylguanidine. Genomic characterisation of subgroups with differing risk of lesion development and subsequent metastatic spread is refining the use of molecular imaging in the personalised approach to hereditary PPGL patients for detection, staging, and follow-up surveillance.

Interpretation criteria for FDG PET/CT in multiple myeloma (IMPeTUs): final results. IMPeTUs (Italian myeloma criteria for PET USe).

ᅟ: FDG PET/CT (18F-fluoro-deoxy-glucose positron emission tomography/computed tomography) is a useful tool to image multiple myeloma (MM). However, simple and reproducible reporting criteria are still lacking and there is the need for harmonization. Recently, a group of Italian nuclear medicine experts defined new visual descriptive criteria (Italian Myeloma criteria for Pet Use: IMPeTUs) to standardize FDG PET/CT evaluation in MM patients. The aim of this study was to assess IMPeTUs reproducibility on a large prospective cohort of MM patients. MATERIALS AND METHODS: Patients affected by symptomatic MM who had performed an FDG PET/CT at baseline (PET0), after induction (PET-AI), and the end of treatment (PET-EoT) were prospectively enrolled in a multicenter trial (EMN02)(NCT01910987; MMY3033). After anonymization, PET images were uploaded in the web platform WIDEN® and hence distributed to five expert nuclear medicine reviewers for a blinded independent central review according to the IMPeTUs criteria. Consensus among reviewers was measured by the percentage of agreement and the Krippendorff's alpha. Furthermore, on a patient-based analysis, the concordance among all the reviewers in terms of positivity or negativity of the FDG PET/CT scan was tested for different thresholds of positivity (Deauville score (DS 2, 3, 4, 5) for the main parameters (bone marrow, focal score, extra-medullary disease). RESULTS: Eighty-six patients (211 FDG PET/CT scans) were included in this analysis. Median patient age was 58 years (range, 35-66 years), 45% were male, 15% of them were in stage ISS (International Staging System) III, and 42% had high-risk cytogenetics. The percentage agreement was superior to 75% for all the time points, reaching 100% of agreement in assessing the presence skull lesions after therapy. Comparable results were obtained when the agreement analysis was performed using the Krippendorff's alpha coefficient, either in every single time point of scanning (PET0, PET-AI or PET-EoT) or overall for all the scans together. DS proved highly reproducible with the highest reproducibility for score 4. CONCLUSIONS: IMPeTUs criteria proved highly reproducible and could therefore be considered as a base for harmonizing PET interpretation in multiple myeloma. A prospective clinical validation of IMPeTUs criteria is underway.

Liver metastases from prostate cancer at 11C-Choline PET/CT: a multicenter, retrospective analysis.

AIM: During our daily clinical practice using 11C-Choline PET/CT for restaging patients affected by relapsing prostate cancer (rPCa) we noticed an unusual but significant occurrence of hypodense hepatic lesions with a different tracer uptake. Thus, we decided to evaluate the possible correlation between rPCa and these lesions as possible hepatic metastases. MATERIALS AND METHODS: We retrospectively enrolled 542 patients diagnosed with rPCa in biochemical relapse after a radical treatment (surgery and/or radiotherapy). Among these, patients with a second tumor or other benign hepatic diseases were excluded. All patients underwent 11C-Choline PET/CT during the standard restaging workup of their disease. We analyzed CT images to evaluate the presence of hypodense lesions and PET images to identify the relative tracer uptake. In accordance to the subsequent oncological history, five clinical scenarios were recognized [Table 1]: normal low dose CT (ldCT) and normal tracer distribution (Group A); evidence of previously unknown hepatic round hypodense areas at ldCT with normal rim uptake (Group B); evidence of previously known hepatic round hypodense areas at ldCT stable over time and with normal rim uptake (Group C); evidence of previously known hepatic round hypodense areas at ldCT, in a previous PET/CT scan, with or without rim uptake and significantly changing over time in terms of size and/or uptake (Group D); evidence of hepatic round hypodense areas at ldCT with or without rim uptake confirmed as prostate liver metastases by histopathology, triple phase ceCT, ce-ultra sound (CEUS) and clinical/biochemical evaluation (Group E). We evaluated the correlation with PSA level at time of scan, rim SUVmax and association with local relapse or non-hepatic metastases (lymph nodes, bone, other parenchyma). RESULTS: Five hundred and forty-two consecutive patients were retrospectively enrolled. In 140 of the 542 patients more than one 11C-choline PET/CT had been performed. A total of 742 11C-Choline PET/CT scans were analyzed. Of the 542 patients enrolled, 456 (84.1%) had a normal appearance of the liver both at ldCT and PET (Group A). 19/542 (3,5%) belonged to Group B, 13/542 (2.4%) to Group C, 37/542 (6.8%) to Group D and 18/542 (3.3%) to Group E. Mean SUVmax of the rim was: 4.5 for Group B; 4.2 for Group C; 4.8 for Group D; 5.9 for Group E. Mean PSA level was 5.27 for Group A, 7.9 for Group B, 10.04 for Group C, 10.01 for Group D, 9.36 for Group E. Presence of positive findings at 11C-Choline PET/CT in any further anatomical area (local relapse, lymph node, bone, other extra hepatic sites) correlated with an higher PSA (p = 0.0285). In both the univariate and multivariate binary logistic regression analyses. PSA, SUVmax of the rim, local relapse, positive nodes were not associated to liver mets (Groups D-E) (p > 0.05). On the contrary, a significant correlation was found between the presence of liver metG (group D-E) and bone lesions (p= 0.00193). CONCLUSION: Our results indicate that liver metastases in relapsing prostate cancer may occur frequently. The real incidence evaluation needs more investigations. In this case and despite technical limitations, Choline PET/CT shows alterations of tracer distribution within the liver that could eventually be mistaken for simple cysts but can be suspected when associated to high trigger PSA, concomitant bone lesions or modification over time. In this clinical setting an accurate analysis of liver tracer distribution (increased or decreased uptake) by the nuclear medicine physician is, therefore, mandatory.

Diverse Imaging Methods May Influence Long-Term Oncologic Outcomes in Oligorecurrent Prostate Cancer Patients Treated with Metastasis-Directed Therapy (the PRECISE-MDT Study).

Metastasis-directed therapy (MDT) has been tested in clinical trials as a treatment option for oligorecurrent prostate cancer (PCa). However, there is an ongoing debate regarding the impact of using different imaging techniques interchangeably for defining lesions and guiding MDT within clinical trials. Methods: We retrospectively identified oligorecurrent PCa patients who had 5 or fewer nodal, bone, or visceral metastases detected by choline or prostate-specific membrane antigen (PSMA) PET/CT and who underwent MDT stereotactic body radiotherapy with or without systemic therapy in 8 tertiary-level cancer centers. Imaging-guided MDT was assessed as progression-free survival (PFS), time to systemic treatment change due to polymetastatic conversion (PFS2), and overall survival predictor. Propensity score matching was performed to account for clinical differences between groups. Results: Of 402 patients, 232 (57.7%) and 170 (42.3%) underwent MDT guided by [18F]fluorocholine and PSMA PET/CT, respectively. After propensity score matching, patients treated with PSMA PET/CT-guided MDT demonstrated longer PFS (hazard ratio [HR], 0.49 [95% CI, 0.36-0.67]; P < 0.0001), PFS2 (HR, 0.42 [95% CI, 0.28-0.63]; P < 0.0001), and overall survival (HR, 0.39 [95% CI, 0.15-0.99]; P < 0.05) than those treated with choline PET/CT-guided MDT. Additionally, we matched patients who underwent [68Ga]Ga-PSMA-11 versus [18F]F-PSMA-1007 PET/CT, observing longer PFS and PFS2 in the former subgroup (PFS: HR, 0.51 [95% CI, 0.26-1.00]; P < 0.05; PFS2: HR, 0.24 [95% CI, 0.09-0.60]; P < 0.05). Conclusion: Diverse imaging methods may influence outcomes in oligorecurrent PCa patients undergoing MDT. However, prospective, head-to-head studies, ideally incorporating a randomized design, are necessary to provide definitive evidence and facilitate the practical application of these findings.

Optimization of Precursor Preparation in PSMA-11 Radiolabeling to Obtain a Highly Reproducible Radiochemical Yield.

[68Ga]Ga-PSMA-11 PET/CT plays a pivotal role in the diagnosis and staging of prostate cancer because of its higher sensitivity and detection rate compared with traditional choline PET/CT. A highly reproducible radiochemical yield of the radiopharmaceutical to be used in the clinical routine is an important parameter for planning and optimization of clinical activity. During radiometallation of PSMA-11, the presence of metal ion contaminants in the peptide precursor may cause a decrease in the [68Ga]Ga-PSMA-11 radiochemical yield because of metal ion contaminants competition with gallium-68. To optimize the radiochemical yield of [68Ga]Ga-PSMA-11 radiosynthesis, data obtained by preparing the solution of the PSMA-11 precursor with three different methods (A, B, and C) were compared. Methods A and B consisted of the reconstitution of different quantities of precursor (1000 µg and 30 µg, respectively) to obtain a 1 µg/mL solution. In Method A, the precursor solution was aliquoted and stored frozen, while the precursor solution obtained with Method B was entirely used. Method C consisted of the reconstitution of 1000 µg of precursor taking into account net peptide content as described in European Pharmacopoeia. Radiosynthesis data demonstrated that reconstitution methods B and C gave a consistently higher and reproducible radiochemical yield, highlighting the role of metals and precursor storage conditions on the synthesis performance.

Clinical aspects of mCRPC management in patients treated with radium-223.

Bone is the most common site of metastasis in metastatic castration-resistant prostate cancer (mCRPC), which is associated with pain and skeletal events. Radium-223 dichloride (Xofigo) is an alpha-emitting radioactive isotope that can specifically target bone lesions. Herein, we report the results of a retrospective analysis that documents our experience in the use of radium-223. Data from 63 patients (pts) with mCRPC who underwent radium-223 treatment from December 2015 to September 2017 were collected. Radium-223 (55 kBq/kg) was administered every 4 weeks for up to 6 cycles. The primary endpoint was OS. Radium-223 was administered as first line therapy in 11 pts, as second line in 19 pts, as third line in 16 pts and in successive lines in 17 pts; 42 pts out of 63 (67%) completed all six cycles. Within one month after the end of 6 cycles of radium-223, 15 pts out of 42 (35.7%) had achieved PR, 11 pts out of 42 (26.2%) had SD and 14 pts out of 42 (33.3%) had PD. Levels of pain decreased with progressive cycles of radium-223. After a minimum follow-up of 2 months and a maximum of 43 months, median OS was 15 months and median PFS was 8 months. The most frequent radium-223 related toxicity was low grade haematologic toxicity, predominantly G1-G2, that occurred halfway through treatment in about 75% of pts. The favourable results reported herein confirm that radium-223 can be considered well tolerated and effective in mCRPC, and is associated with significant decreases in pain.

Importance of the correct assessment of bone fractures in the clinical management of metastatic castration-resistant prostate cancer treated with radium-223: A case report.

Patients who undergo radium-223 treatment for metastatic castration-resistant prostate cancer (mCRPC) generally have a long history of androgen deprivation therapy and/or steroid therapy, which leads to bone loss and causes osteoporosis. Notably, Osteoporosis in combination with metastatic bone disease increases the risk of bone fracture. An 84-year-old man with multi-metastatic bone CRPC underwent six administrations of intravenous radium-223, which induced a good biochemical and clinical response. However, two months following the treatment, the patient reported acute pain localized to the lumbar spine mimicking bone progression disease and presented with stable prostate-specific antigen levels. A prostate-specific membrane antigen-positron emission tomography scan showed no tracer uptake in that site, whereas a magnetic resonance imaging scan and subsequent vertebral biopsy confirmed the absence of cancer progression and showed the presence of vertebral crushing of L4-L5, which was probably due to an osteoporotic process. The patient had never received bisphosphonate therapy and refused it during α-emitting therapy with radium-223. The osteoporotic process, in association with metastatic bone disease, more easily leads to bone fractures that have an important impact on performance status, quality of life and prognosis quoad vitam in patients with advanced prostate cancer. Use of bisphosphonates or anti-RANKL antibody appears to be effective in improving bone mineral density. Notably, patients with multi-metastatic bone disease who undergo radium-223 therapy should be treated in conjunction with anti-osteoporotic therapy (bisphosphonates or anti-RANKL antibody) and adequate calcium and vitamin D supplementation. Early recognition and differentiation of osteoporotic processes when determining the progression of cancer-associated bone disease is crucial in evaluating the response to radium-223 therapy and, consequently, for further therapeutic decision making.

223Ra-chloride therapy in men with hormone-refractory prostate cancer and skeletal metastases: Real-world experience.

BACKGROUND: Radium-223 (223Ra) chloride, an alpha emitter, has been shown to improve overall survival (OS) and pain control, and to delay skeletal-related events, in patients with castration-resistant prostate cancer (CRPC) and bone metastases. Our retrospective observational study presents the first Italian experience on the efficacy and safety of 223Ra therapy in routine clinical practice. METHODS: A total of 83 patients with metastatic CRPC were treated with 223Ra at 3 Italian centers between August 2013 and August 2016. 223Ra-chloride (55 kBq/kg) was administered every 4 weeks for a total of 6 cycles. Primary endpoints were OS and progression-free survival (PFS). Secondary endpoints included toxicity, pain evaluation using numeric rating scale (NRS), symptomatic skeletal-related events and biomarkers response. RESULTS: Patients had a median age of 75 (range 53-89) years. The majority of men showed a Gleason score of 7, 8, or 9. Forty-one patients completed 6 treatment cycles; 33 stopped treatment before completing 6 cycles. Nine were still receiving therapy at the time of data collection. At the end of therapy, NRS pain scores significantly improved ( p < .000001). OS was a mean of 10.1 months, while median OS had not been attained. According to Kaplan-Meier estimation, OS and PFS were 17.5 and 7.7 months, respectively. There was a significant correlation between OS and PFS with the number of 223Ra cycles; patients receiving all 6 cycles experienced the major benefit from the therapy. 223Ra was well-tolerated. CONCLUSIONS: 223Ra alpha therapy is an important therapeutic option for men with CRPC and symptomatic skeletal metastases.

Incidentally detected increased FDG uptake in bowel and its correlation with hystopathological data: our experience in a case series study.

When an intense intestinal FDG accumulation occurs, especially if focal, it can be referred to either physiological intestinal activity or bowel disease, thus leading to a radical change in patient's prognosis. Within a year, we recommended a colonoscopy to 103 of 7365 patients who were subjected to a total body FDG PET/CT. In a case-series study, we re-evaluated the patients and their lesions if already investigated with colonoscopy and biopsy. Only 18 patients were included in our study, but in none of them biopsy was negative and 3 adenocarcinomas, 8 adenomas, 5 inflammatory patterns, 1 hyperplastic polyp and 1 eosinophilic infiltrate were diagnosed. In 16 patients, no suspicion was present and diagnosis was absolutely incidental. Besides, among the three major groups (adenocarcinomas, adenomas and phlogosis), SUVmax values were significantly different. Adenocarcinomas are linked with high SUVmax values (ranging from 8.3 to 20.2) and large size (ranging from 26 to 43 mm). PET/CT sensitivity is low in detecting adenomas, being 71.4% if they are larger than 6 mm and 50% if SUVmax is lower than 4.9. SUVmax values in inflammatory lesions can range from 5.7 to 12. Colorectal cancer is still the second leading cause of cancer death, for this reason in many countries screening programs have been approved and colonoscopy is considered the golden standard. PET/CT cannot be considered as a screening test, but if it incidentally reveals intestinal abnormalities, this data cannot be underestimated and colonoscopy is highly recommended.