Amyloid myopathy: expanding the clinical spectrum of transthyretin amyloidosis-case report and literature review.

We identified two patients with transthyretin (ATTR) amyloid myopathy (one ATTR variant amyloidosis, ATTRv; one wild-type ATTR amyloidosis, ATTRwt). Myopathy was the initial manifestation in ATTRwt, whereas it followed neuropathy and cardiomyopathy in ATTRv. The ATTRwt patient showed muscular tracer uptake on 99mTc-DPD planar scintigraphy at the time of initial diagnosis, consistent with ATTR amyloid myopathy. The ATTRv patient underwent heart transplantation because of progressive heart failure. Within the next two years, progressive myopathic symptoms and extracardiac tracer uptake on 99mTc-DPD planar scintigraphy were documented, attributable to ATTR amyloid myopathy. Interstitial amyloid deposits were confirmed by muscle biopsy in both patients, with a particularly high amyloid burden in the adipose tissue. This case report highlights the frequent concomitant presence of cardiac ATTR amyloidosis and ATTR amyloid myopathy. ATTR amyloid myopathy may precede cardiac manifestation in ATTRwt or occur after heart transplantation in ATTRv. Due to the high diagnostic accuracy of 99mTc-DPD scintigraphy for detecting ATTR amyloid myopathy and the emergence of novel therapeutics, it is important to increase the awareness of its presence.

Impact of forced diuresis with furosemide and hydration on the halo artefact and intensity of tracer accumulation in the urinary bladder and kidneys on [68Ga]Ga-PSMA-11-PET/CT in the evaluation of prostate cancer patients.

PURPOSE: to assess the influence of intravenous hydration and forced diuresis with furosemide in two different dosages (20 vs 40 mg) on the intensity of tracer accumulation in the urinary collection system and on the occurrence of halo artefact surrounding the urinary bladder and kidneys in [68Ga]Ga-PSMA-11-PET/CT scans. MATERIALS AND METHODS: Comparison of four groups with 50 patients each, receiving different preparation prior to [68Ga]Ga-PSMA-11-PET/CT. Group one, no preparation. Group two, 500 ml sodium chloride administered immediately after tracer injection. Group three, 500 ml sodium chloride and injection of 20 mg furosemide immediately after tracer administration. Group four, 500 ml sodium chloride and injection of 40 mg furosemide immediately after tracer injection. Images were judged visually whether halo artefact was present; semiquantitative measurements were performed with standardised uptake value (SUV). RESULTS: Halo artefact of the urinary bladder was present in twelve patients without preparation, in eight patients receiving only sodium chloride, in one patient injected with 20 mg furosemide/sodium chloride and in two patients receiving 40 mg furosemide/sodium chloride, showing a median SUVmean in the bladder of 45.8, 14.4, 4.6 and 5.8, respectively. Differences between patient group without preparation and the two groups with furosemide/sodium chloride were statistically significant. Patient groups receiving 20 mg furosemide and 40 mg furosemide did not differ significantly. Renal halo artefacts were observed in 15 patients of group one, in ten patients of group two, in 14 patients of group three and in 14 patients of group four, with corresponding median SUVmean values of 33.9, 32.0, 37.8 and 30.4 (no statistically significant differences). CONCLUSION: Performing [68Ga]Ga-PSMA-11-PET/CT, intravenous injection of 20-mg furosemide and 500-ml sodium chloride significantly reduces the number of bladder halo artefacts and intensity of tracer accumulation in the urinary bladder. A total of 40 mg furosemide does not further improve results.

Organ-sparing surgery of penile cancer: higher rate of local recurrence yet no impact on overall survival.

PURPOSE: To report on the oncological outcome of organ-sparing surgery (OSS) compared to (total or partial) penectomy regarding recurrence patterns and survival in squamous cell carcinoma (SCC) of the penis. METHODS: This was a retrospective study of all patients with penile SCC and eligible follow-up data of at least 2 years at our institution. Patients with tumors staged ≥ pT1G2 underwent invasive lymph node (LN) staging by dynamic sentinel-node biopsy or modified inguinal lymphadenectomy. Radical inguinal lymphadenectomy was performed when LNs were palpable at diagnosis and in those with a positive LN status after invasive nodal staging. Follow-up visits were assessed, and local, regional and distant recurrences were defined and analyzed. RESULTS: 55 patients were identified with a mean follow-up of 63.7 months. Surgical management was OSS in 26 patients (47.2%) and partial or total penectomy in 29 cases (52.8%). Histopathological staging was: pTis (12.7%), pTa (16.3%), pT1a (18.2%), pT1b (5.5%), pT2 (29.1%) and pT3 (18.2%), respectively. Patients in the penectomy group were significantly older (mean 68 vs. 62 years; p = 0.026) with a higher rate of advanced tumor stage (≥ pT2: 44.8% vs. 11.5%; p = 0.002). The local recurrence rate was 42.3% (n = 11) following OSS compared to 10.3% (n = 3) after penectomy (p = 0.007). Kaplan-Meier curves showed no significant differences between the two groups regarding metastasis-free and overall survival. CONCLUSIONS: OSS is associated with a higher local recurrence rate compared to penectomy, yet it has no negative impact on overall and metastasis-free survival.

Current status of functional imaging in neuroblastoma, pheochromocytoma, and paraganglioma disease.

Diagnostic imaging plays an important role in the detection of paraganglioma (PGL), pheochromocytoma (PCC), and neuroblastoma (NB). Anatomic imaging, for example CT or MRI, offers high sensitivity in these neuroendocrine tumors (NET) but only moderate specificity, often associated with difficulties in clearly distinguishing between NET and non-NET. Functional imaging, as in the use of different radioisotopes, is indispensable in oncological imaging. The introduction of PET and PET/CT, respectively, led to a dramatic improvement in both malignant and non-malignant PGL, PCC, and NB, assessing the exact tumor extent. This review gives an overview of functional and anatomical imaging in PGL, PCC, and NB.

Comparison of [68Ga]Ga-PSMA-11 PET/CT with [18F]NaF PET/CT in the evaluation of bone metastases in metastatic prostate cancer patients prior to radionuclide therapy.

AIM: The purpose of this study was to investigate the diagnostic performance of 68Ga-PSMA-11 PET/CT in the evaluation of bone metastases in metastatic prostate cancer (PC) patients scheduled for radionuclide therapy in comparison to [18F]sodium fluoride (18F-NaF) PET/CT. METHODS: Sixteen metastatic PC patients with known skeletal metastases, who underwent both 68Ga-PSMA-11 PET/CT and 18F-NaF PET/CT for assessment of metastatic burden prior to radionuclide therapy, were analysed retrospectively. The performance of both tracers was calculated on a lesion-based comparison. Intensity of tracer accumulation of pathologic bone lesions on 18F-NaF PET and 68Ga-PSMA-11 PET was measured with maximum standardized uptake values (SUVmax) and compared to background activity of normal bone. In addition, SUVmax values of PET-positive bone lesions were analysed with respect to morphologic characteristics on CT. Bone metastases were either confirmed by CT or follow-up PET scan. RESULTS: In contrast to 468 PET-positive lesions suggestive of bone metastases on 18F-NaF PET, only 351 of the lesions were also judged positive on 68Ga-PSMA-11 PET (75.0%). Intensity of tracer accumulation of pathologic skeletal lesions was significantly higher on 18F-NaF PET compared to 68Ga-PSMA-11 PET, showing a median SUVmax of 27.0 and 6.0, respectively (p < 0.001). Background activity of normal bone was lower on 68Ga-PSMA-11 PET, with a median SUVmax of 1.0 in comparison to 2.7 on 18F-NaF PET; however, tumour to background ratio was significantly higher on 18F-NaF PET (9.8 versus 5.9 on 68Ga-PSMA-11 PET; p = 0.042). Based on morphologic lesion characterisation on CT, 18F-NaF PET revealed median SUVmax values of 23.6 for osteosclerotic, 35.0 for osteolytic, and 19.0 for lesions not visible on CT, whereas on 68Ga-PSMA-11 PET median SUVmax values of 5.0 in osteosclerotic, 29.5 in osteolytic, and 7.5 in lesions not seen on CT were measured. Intensity of tracer accumulation between18F-NaF PET and 68Ga-PSMA-11 PET was significantly higher in osteosclerotic (p < 0.001) and lesions not visible on CT (p = 0.012). CONCLUSION: In comparison to 68Ga-PSMA-11 PET/CT, 18F-NaF PET/CT detects a higher number of pathologic bone lesions in advanced stage PC patients scheduled for radionuclide therapy. Our data suggest that 68Ga-PSMA-11 PET should be combined with 18F-NaF PET in PC patients with skeletal metastases for restaging prior to initiation or modification of therapy.

Early dynamic imaging in 68Ga- PSMA-11 PET/CT allows discrimination of urinary bladder activity and prostate cancer lesions.

PURPOSE: PET/CT with 68Ga-labelled prostate-specific membrane antigen (PSMA)-ligands has been proven to establish a promising imaging modality in the work-up of prostate cancer (PC) patients with biochemical relapse. Despite a high overall detection rate, the visualisation of local recurrence may be hampered by high physiologic tracer accumulation in the urinary bladder on whole body imaging, usually starting 60 min after injection. This study sought to verify whether early dynamic 68Ga-PSMA-11 (HBED-CC)PET/CT can differentiate pathologic PC-related tracer uptake from physiologic tracer accumulation in the urinary bladder. METHODS: Eighty consecutive PC patients referred to 68Ga -PSMA-11 PET/CT were included in this retrospective analysis (biochemical relapse: n = 64; primary staging: n = 8; evaluation of therapy response/restaging: n = 8). In addition to whole-body PET/CT acquisition 60 min post injection early dynamic imaging of the pelvis in the first 8 min after tracer injection was performed. SUVmax of pathologic lesions was calculated and time-activity curves were generated and compared to those of urinary bladder and areas of physiologic tracer uptake. RESULTS: A total of 55 lesions consistent with malignancy on 60 min whole body imaging exhibited also pathologic 68Ga-PSMA-11 uptake during early dynamic imaging (prostatic bed/prostate gland: n = 27; lymph nodes: n = 12; bone: n = 16). All pathologic lesions showed tracer uptake within the first 3 min, whereas urinary bladder activity was absent within the first 3 min of dynamic imaging in all patients. Suvmax was significantly higher in PC lesions in the first 6 min compared to urinary bladder accumulation (p < 0.001). In the subgroup of PC patients with biochemical relapse the detection rate of local recurrence could be increased from 20.3 to 29.7%. CONCLUSIONS: Early dynamic imaging in 68Ga-PSMA-11 PET/CT reliably enables the differentiation of pathologic tracer uptake in PC lesions from physiologic bladder accumulation. Performance of early dynamic imaging in addition to whole body imaging 60 min after tracer injection might improve the detection rate of local recurrence in PC patients with biochemical relapse referred for 68Ga-PSMA-11 PET/CT.

68Ga-PSMA-11 PET/CT in primary staging of prostate cancer: PSA and Gleason score predict the intensity of tracer accumulation in the primary tumour.

PURPOSE: Prostate cancer (PC) cells typically show increased expression of prostate-specific membrane antigen (PSMA), which can be visualized by 68Ga-PSMA-11 PET/CT. The aim of this study was to assess the intensity of 68Ga-PSMA-11 uptake in the primary tumour and metastases in patients with biopsy-proven PC prior to therapy, and to determine whether a correlation exists between the primary tumour-related 68Ga-PSMA-11 accumulation and the Gleason score (GS) or prostate-specific antigen (PSA) level. METHODS: Ninety patients with transrectal ultrasound biopsy-proven PC (GS 6-10; median PSA: 9.7 ng/ml) referred for 68Ga-PSMA-11 PET/CT were retrospectively analysed. PET images were analysed visually and semiquantitatively by measuring the maximum standardized uptake value (SUVmax). The SUVmax of the primary tumour and pathologic lesions suspicious for lymphatic or distant metastases were then compared to the physiologic background activity of normal prostate tissue and gluteal muscle. The SUVmax of the primary tumour was assessed in relation to both PSA level and GS. RESULTS: Eighty-two patients (91.1%) demonstrated pathologic tracer accumulation in the primary tumour that exceeded physiologic tracer uptake in normal prostate tissue (median SUVmax: 12.5 vs. 3.9). Tumours with GS of 6, 7a (3+4) and 7b (4+3) showed significantly lower 68Ga-PSMA-11 uptake, with median SUVmax of 5.9, 8.3 and 8.2, respectively, compared to patients with GS >7 (median SUVmax: 21.2; p < 0.001). PC patients with PSA ≥10.0 ng/ml exhibited significantly higher uptake than those with PSA levels <10.0 ng/ml (median SUVmax: 17.6 versus 7.7; p < 0.001). In 24 patients (26.7%), 82 lymph nodes with pathologic tracer accumulation consistent with metastases were detected (median SUVmax: 10.6). Eleven patients (12.2%) revealed 55 pathologic osseous lesions suspicious for bone metastases (median SUVmax: 11.6). CONCLUSIONS: The GS and PSA level correlated with the intensity of tracer accumulation in the primary tumours of PC patients on 68Ga-PSMA-11 PET/CT. As PC tumours with GS 6+7 and patients with PSA values ≤10 ng/ml showed significantly lower 68Ga-PSMA-11 uptake, 68Ga-PSMA-11 PET/CT should be preferentially applied for primary staging of PC in patients with GS >7 or PSA levels ≥10 ng/ml.

Early PET imaging with [68]Ga-PSMA-11 increases the detection rate of local recurrence in prostate cancer patients with biochemical recurrence.

PURPOSE: PET/CT using 68Ga-labelled prostate-specific membrane antigen PSMA-11 (HBEDD-CC) has emerged as a promising imaging method in the diagnostic evaluation of prostate cancer (PC) patients with biochemical recurrence. However, assessment of local recurrence (LR) may be limited by intense physiologic tracer accumulation in the urinary bladder on whole-body scans, normally conducted 60 min post-tracer injection (p.i.). It could be shown on early dynamic imaging studies that 68Ga-PSMA-11 uptake in PC lesions occurs earlier than tracer accumulation in the urinary bladder. This study aims to investigate whether early static PET acquisition increases detection rate of local recurrence on 68Ga-PSMA-11 PET/CT in comparison to PET imaging 60 min p.i.. METHODS: 203 consecutive PC patients with biochemical failure referred to 68Ga-PSMA-11 PET/CT were analysed retrospectively (median prostate specific antigen (PSA) value: 1.44 ng/ml). In addition to whole-body PET/CT scans 60 min p.i., early static imaging of the pelvis was performed, starting at a median time of 283 s p.i. (range: 243-491 s). Assessment was based on visual analysis and calculation of maximum standardized uptake value (SUVmax) of pathologic lesions present in the pelvic area found on early PET imaging and on 60 min-PET scans. RESULTS: 26 patients (12.8%) were judged positive for LR on PET scans 60 min p.i. (median SUVmax: 10.8; range: 4.7-40.9), whereas 50 patients (24.6%) revealed a lesion suggestive of LR on early PET imaging (median SUVmax: 5.9; range: 2.9-17.6), resulting in a significant rise in detection rate (p < 0.001). Equivocal findings on PET scans 60 min p.i. decreased significantly with the help of early imaging (15.8% vs. 4.5% of patients; p < 0.001). Tracer activity in the urinary bladder with a median SUVmax of 8.2 was present in 63 patients on early PET scans (31.0%). However, acquisition starting time of early PET scans differed significantly in the patient groups with and without urinary bladder activity (median starting time of 321 vs. 275 s p.i.; range: 281-491 vs. 243-311 s p.i.; p < 0.001). Median SUVmax value of lesions suggestive of LR on early images was significantly higher in comparison to gluteal muscle, inguinal vessels and seminal vesicle/anastomosis (median SUVmax: 5.9 vs. 1.9, 4.0 and 2.4, respectively). CONCLUSIONS: Performance of early imaging in 68Ga-PSMA-11 PET/CT in addition to whole-body scans 60 min p.i. increases the detection rate of local recurrence in PC patients with biochemical recurrence. Acquisition of early PET images should be started as early as 5 min p.i. in order to avoid disturbing tracer activity in the urinary bladder occuring at a later time point.

Current knowledge on the sensitivity of the (68)Ga-somatostatin receptor positron emission tomography and the SUVmax reference range for management of pancreatic neuroendocrine tumours.

Physiologically increased pancreatic uptake at the head/uncinate process is observed in more than one-third of patients after injection of one of the three (68)Ga-labelled octreotide-based peptides used for somatostatin (sst) receptor (r) imaging. There are minor differences between these (68)Ga-sstr-binding peptides in the imaging setting. On (68)Ga-sstr-imaging the physiological uptake can be diffuse or focal and usually remains stable over time. Differences in the maximal standardised uptake values (SUVmax) reported for the normal pancreas as well as for pancreatic neuroendocrine tumour (PNET) lesions may be related to several factors, including (a) differences in the peptide binding affinities as well as differences in sstr subtype expression of pancreatic α- and ß-cells, and heterogeneity / density of tumour cells, (b) differences in scanner resolution, image reconstruction techniques and acquisition protocols, (c) mostly retrospective study designs, (d) mixed patient populations, or (e) interference with medications such as treatment with long-acting sst analogues. The major limitation in most of the studies lies in the lack of histopathological confirmation of abnormal findings. There is a significant overlap between the calculated SUVmax-values for physiological pancreas and PNET-lesions of the head/uncinate process that do not favour the use of quantitative parameters in the clinical setting. Anecdotal long-term follow-up studies have even indicated that increased uptake in the head/uncinate process still can turn out to be malignant over years of follow up. SUVmax-data for the pancreatic body and tail are limited. Therefore, any visible focal tracer uptake in the pancreas must be considered as suspicious for malignancy irrespective of quantitative parameters. In general, sstr-PET/CT has significant implications for the management of NET patients leading to a change in treatment decision in about one-third of patients. Therefore, follow-up with (68)Ga-sstr-PET/CT is mandatory in the clinical setting if uptake in the head/uncinate process is observed.

(68)Ga-DOTA (0)-Tyr (3)-octreotide positron emission tomography in nasopharyngeal carcinoma.

PURPOSE: PET/CT with (68)Ga-labelled [DOTA(0),Tyr(3)]-octreotide ((68)Ga-DOTA-TOC PET/CT) is a routinely used imaging modality for neuroendocrine tumours expressing somatostatin receptors (SSTR). Recent studies have shown SSTR expression in head and neck squamous cell carcinoma, albeit lower than in highly differentiated neuroendocrine tumours. We sought to determine whether nasopharyngeal carcinoma (NPC) positive for Epstein-Barr virus (EBV), a rare subtype of head and neck cancer, shows increased (68)Ga-DOTA-TOC uptake indicating expression of SSTR. METHODS: Five patients with untreated, histologically proven EBV-positive NPC were referred for (68)Ga-DOTA-TOC PET/CT. Tracer uptake in tumour lesions was assessed visually and semiquantitatively measuring maximum standardized uptake values (SUVmax) and tumour to background ratios. RESULTS: Increased tumour-specific uptake was detected in all five patients with a median SUVmax of 10.6 (range 3.6 - 17.1) in the primary tumour and 13.2 (range 6.1 - 14.5) in cervical lymph node metastases. CONCLUSION: (68)Ga-DOTA-TOC PET/CT demonstrated tracer uptake in EBV-positive NPC comparable to that in highly differentiated neuroendocrine tumours. This observation is consistent with increased SSTR expression in EBV-positive NPC and may open new diagnostic and therapeutic windows in NPC.

Nuclear imaging of neuroendocrine tumors with unknown primary: why, when and how?

Neuroendocrine tumors (NETs) with unknown primary (CUP-NET) are associated with a poor prognosis (10-year survival 22%), grade 1 and 2 NETs having a more favorable outcome than grade 3 (also called carcinoma). There is evidence that an effort should be made to localize the primary tumor even in the presence of metastasis because resection of the primary tumor(s) may improve disease-free and overall survival, and because the choice of chemotherapeutic agent depends on the location of the primary tumor. Localization of the tumors remains challenging and often relies on a combination of radiological, endoscopic and functional imaging. The functional imaging protocol for evaluation of these patients has historically relied on somatostatin receptor scintigraphy (SRS). However, the sensitivity and specificity of SRS may be unsatisfactory, especially for NETs of midgut origin. Newer PET radiotracers such as (68)Ga-labeled somatostatin analogs ((68)Ga-DOTA-SSTa) and (18)F-DOPA have shown promise. In direct comparisons between (68)Ga-DOTA-SSTa PET/CT and (99m)Tc-HYNIC-octreotide/(111)In-pentetreotide SPECT(/CT), (68)Ga-DOTA-SSTa performed better than other techniques, giving a compelling reason for switching from SPECT/CT to PET/CT imaging. (18)F-DOPA performs better than SRS and CT in well-differentiated NETs of the small intestine. For detecting pancreatic NETs, the high background uptake of (18)F-DOPA by the normal exocrine pancreas can be somewhat overcome by pretreatment with carbidopa. We have suggested a protocol in which SRS is replaced by one of the two agents (preferably with (68)Ga-DOTA-SSTa, alternatively (18)F-DOPA) as first-line nuclear tracer for detection of CUP-NET in patients with well-differentiated NETs and (18)F-FDG PET/CT may be an additional diagnostic test for poorly differentiated tumors and for prognostication. In the near future, it is expected that patients with CUP-NET will benefit from newly developed PET approaches (radiopharmaceuticals) and intraoperative PET imaging.

(68)Ga-DOTATOC PET/CT provides accurate tumour extent in patients with extraadrenal paraganglioma compared to (123)I-MIBG SPECT/CT.

PURPOSE: The aim of this study was to compare the accuracy of (123)I-MIBG SPECT/CT with that of (68)Ga-DOTATOC PET/CT for staging extraadrenal paragangliomas (PGL) using both functional and anatomical images (i.e. combined cross-sectional imaging) as the reference standards. METHODS: The study included three men and seven women (age range 26 to 73 years) with anatomical and/or histologically proven disease. Three patients had either metastatic head and neck PGL (HNPGL) or multifocal extraadrenal PGL, and seven patients had nonmetastatic extraadrenal disease. Comparative evaluation included morphological imaging with CT, functional imaging with (68)Ga-DOTATOC PET, and (123)I-MIBG imaging. The imaging results were analysed on a per-patient and on a per-lesion basis. RESULTS: On a per-patient basis, the detection rate of (68)Ga-DOTATOC PET was 100 %, whereas that of planar (123)I-MIBG imaging was 10.0 % and with SPECT/CT 20.0 % for both nonmetastatic and metastatic/multifocal extraadrenal PGL. On a per-lesion basis, the overall sensitivity of (68)Ga-DOTATOC PET was 100 % (McNemar p < 0.5), that of planar (123)I-MIBG imaging was 3.4 % (McNemar p < 0.001) and that of SPECT/CT was 6.9 % (McNemar p < 0.001). Both (68)Ga-DOTATOC PET and anatomical imaging identified 27 lesions. Planar (123)I-MIBG imaging identified only one lesion, and SPECT/CT two lesions. Two additional lesions were detected by (68)Ga-DOTATOC PET but not by either (123)I-MIBG or CT imaging. CONCLUSION: Our analysis in this patient cohort indicated that (68)Ga-DOTATOC PET/CT is superior to (123)I-MIBG SPECT/CT, particularly in head and neck and bone lesions, and provides valuable information for staging extraadrenal PGL, particularly in patients with surgically inoperable tumours or multifocal/malignant disease.

(68)Ga-PSMA PET/CT for restaging recurrent prostate cancer: which factors are associated with PET/CT detection rate?

PURPOSE: To assess the association between PSA levels, PSA kinetics and other factors and a pathological (68)Ga-PSMA PET/CT scan in patients with recurrent prostate cancer (rPCa) with biochemical relapse (BR) after radical therapy. METHODS: Seventy consecutive rPCA patients referred for (68)Ga-PSMA PET/CT, matching all the following criteria, were retrospectively evaluated: (a) previous radical prostatectomy or primary radiotherapy with curative intent; (b) BR or persisting high PSA levels after primary treatment; and (c) complete clinical and imaging information. The mean ± SD PSA level was 3.5 ± 5.3 ng/mL (median 1.7, range 0.2 - 32.2 ng/mL), the mean ± SD PSA doubling time (PSAdt) was 6.5 ± 5.5 months (median 5.5, range 1.3 - 31.6 months), and the mean ± SD PSA velocity was 7.9 ± 20.5 (median 2.1, range 0.2 - 147.5 ng/mL/year). Statistical analysis was performed to assess which factors were associated with the detection of rPCa on (68)Ga-PSMA PET/CT. RESULTS: (68)Ga-PSMA PET/CT was positive in 52 of 70 patients (74.2%). In 30 patients (42.8%) lesions limited to the pelvis were detected. Distant lesions were observed in 8 of patients (11.4%). Local plus systemic lesions were detected in 14 patients (20%). PSA level (p = 0.017) and PSAdt (p = 0.0001) were significantly different between PET-positive patients (higher PSA level, shorter PSAdt) and PET-negative patients (lower PSA, longer PSAdt). ROC analysis showed that PSAdt 6.5 months and PSA 0.83 ng/mL were optimal cut-off values. In multivariate analysis PSAdt was associated with (68)Ga-PSMA PET/CT positivity. (68)Ga-PSMA PET/CT was positive in 17 of 20 patients (85%) with PSA <2 ng/mL and PSAdt <6.5 months, and in 3 of 16 patients (18.7%) with PSA <2 ng/mL and PSAdt ≥6.5 months. CONCLUSION: The great potential of (68)Ga-PSMA PET/CT in patients with rPCa and BR was confirmed. PSA and PSAdt were valuable predictors of pathological (68)Ga-PSMA PET/CT findings.

Unrecognized paraganglioma of the urinary bladder as a cause for basilar-type migraine.

Extra-adrenal paraganglioma with isolated localization in the urinary bladder is a rare neuroendocrine tumor. Although the typical symptoms like headache, nausea, weight loss, flushing, heart palpitation or paroxysmal hypertension during micturition are well established, we present an unusual case of bladder paraganglioma, 'misdiagnosed' with basilar-type migraine due to headache for the past 8 years. As urologists linked the presence of a tumor (by CT) and symptoms connected with micturition, no cystoscopy and no transurethral resection of the bladder was performed prior to detailed diagnostic workup. After diagnosis of an extra-adrenal paraganglioma, the patient was scheduled for open partial cystectomy. In consideration of the fact that bladder paraganglioma is an infrequent genitourinary cancer, this case report clearly points out the importance of an exact anamnesis and clinical examination to minimize the probability of misdiagnosis with possible fatal consequences in any case with clinical suspicion of bladder paraganglioma.

Investigating patient eligibility for anti-amyloid monoclonal antibody treatment of Alzheimer's disease: real-world data from an Austrian psychiatric memory clinic population.

BACKGROUND: Pharmacological treatment options for patients with dementia owing to Alzheimer's disease are limited to symptomatic therapy. Recently, the US Food and Drug Administration approved the monoclonal antibody lecanemab for the treatment of amyloid-positive patients with mild cognitive impairment (MCI) and early Alzheimer´s dementia. European approval is expected in 2024. Data on the applicability and eligibility for treatment with anti-amyloid monoclonal antibodies outside of a study population are lacking. AIMS: This study examined eligibility criteria for lecanemab in a real-world memory clinic population between 1 January 2022 and 31 July 2023. METHOD: We conducted a retrospective, single-centre study applying the clinical trial eligibility criteria for lecanemab to out-patients of a specialised psychiatric memory clinic. Eligibility for anti-amyloid treatment was assessed following the phase 3 inclusion and exclusion criteria and the published recommendations for lecanemab. RESULTS: The study population consisted of 587 out-patients. Two-thirds were diagnosed with Alzheimer's disease (probable or possible Alzheimer's disease dementia in 43.6% of cases, n = 256) or MCI (23%, n = 135), and 33.4% (n = 196) were diagnosed with dementia or neurocognitive disorder owing to another aetiology. Applying all lecanemab eligibility criteria, 11 (4.3%) patients with dementia and two (1.5%) patients with MCI would have been eligible for treatment with this compound, whereas 13 dementia (5.1%) and 14 (10.4%) MCI patients met clinical inclusion criteria, but had no available amyloid status. CONCLUSIONS: Even in a memory clinic with a good infrastructure and sufficient facilities for dementia diagnostics, most patients do not meet the eligibility criteria for treatment with lecanemab.

Correlation of 99mTc-DPD bone scintigraphy with histological amyloid load in patients with ATTR cardiac amyloidosis.

BACKGROUND: The significance of measuring 99mTc-labelled-3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) in transthyretin (ATTR) cardiac amyloidosis has not been adequately studied. This single-centre observational study evaluated the correlation between 99mTc-DPD scintigraphy and histological amyloid load in endomyocardial biopsy (EMB). METHODS: Twenty-eight patients with biopsy-proven ATTR amyloidosis and concomitantly available 99mTc-DPD scintigraphy were included. Visual Perugini scoring, and (semi-)quantitative analysis of cardiac 99mTc-DPD uptake by planar whole-body imaging and single photon emission computed tomography (SPECT/CT) using regions of interest (ROI) were performed. From this, heart-to-whole-body ratio (H/WB) and heart-to-contralateral-chest ratio (H/CL) were calculated. The histological amyloid load was quantified using two different staining methods. RESULTS: Increased cardiac tracer uptake was documented in all patients (planar: ROImean 129 ± 37 cps; SPECT/CT: ROImean 369 ± 142 cps). Histological amyloid load (19 ± 13%) significantly correlated with Perugini score (r = 0.69, p < .001) as well as with cardiac 99mTc-DPD uptake (planar: r = 0.64, p < .001; H/WB: r = 0.50, p = .014; SPECT/CT: r = 0.53, p = .008; H/CL: r = 0.43, p = .037) (results are shown for correlations with Congo Red-staining). CONCLUSION: In ATTR, cardiac 99mTc-DPD uptake significantly correlated with histological amyloid load in EMB. Further studies are needed to implement thresholds in cardiac 99mTc-DPD uptake measurements for risk stratification and guidance of therapy.

A retrospective comparison between 68Ga-DOTA-TOC PET/CT and 18F-DOPA PET/CT in patients with extra-adrenal paraganglioma.

PURPOSE: (18)F-Fluoro-L-dihydroxyphenylalanine ((18)F-DOPA) PET offers high sensitivity and specificity in the imaging of nonmetastatic extra-adrenal paragangliomas (PGL) but lower sensitivity in metastatic or multifocal disease. These tumours are of neuroendocrine origin and can be detected by (68)Ga-DOTA-Tyr(3)-octreotide ((68)Ga-DOTA-TOC) PET. Therefore, we compared (68)Ga-DOTA-TOC and (18)F-DOPA as radiolabels for PET/CT imaging for the diagnosis and staging of extra-adrenal PGL. Combined cross-sectional imaging was the reference standard. METHODS: A total of 5 men and 15 women (age range 22 to 73 years) with anatomical and/or histologically proven extra-adrenal PGL were included in this study. Of these patients, 5 had metastatic or multifocal lesions and 15 had single sites of disease. Comparative evaluation included morphological imaging with CT and functional imaging with (68)Ga-DOTA-TOC PET and (18)F-DOPA PET. The imaging results were analysed on a per-patient and a per-lesion basis. The maximum standardized uptake value (SUVmax) of each functional imaging modality in concordant tumour lesions was measured. RESULTS: Compared with anatomical imaging, (68)Ga-DOTA-TOC PET and (18)F-DOPA PET each had a per-patient and per-lesion detection rate of 100% in nonmetastatic extra-adrenal PGL. However, in metastatic or multifocal disease, the per-lesion detection rate of (68)Ga-DOTA-TOC was 100% and that of (18)F-DOPA PET was 56.0%. Overall, (68)Ga-DOTA-TOC PET identified 45 lesions; anatomical imaging identified 43 lesions, and (18)F-DOPA PET identified 32 lesions. The overall per-lesion detection rate of (68)Ga-DOTA-TOC PET was 100% (McNemar, P < 0.5), and that of (18)F-DOPA PET was 71.1% (McNemar, P < 0.001). The SUVmax (mean ± SD) of all 32 concordant lesions was 67.9 ± 61.5 for (68)Ga-DOTA-TOC PET and 11.8 ± 7.9 for (18)F-DOPA PET (Mann-Whitney U test, P < 0.0001). CONCLUSION: (68)Ga-DOTA-TOC PET may be superior to (18)F-DOPA PET and diagnostic CT in providing valuable information for pretherapeutic staging of extra-adrenal PGL, particularly in surgically inoperable tumours and metastatic or multifocal disease.

Somatostatin receptor PET in neuroendocrine tumours: 68Ga-DOTA0,Tyr3-octreotide versus 68Ga-DOTA0-lanreotide.

PURPOSE: The aim of this study was to evaluate the impact of (68)Ga-labelled DOTA(0)-lanreotide ((68)Ga-DOTA-LAN) on the diagnostic assessment of neuroendocrine tumour (NET) patients with low to moderate uptake on planar somatostatin receptor (SSTR) scintigraphy or (68)Ga-labelled DOTA(0),Tyr(3)-octreotide ((68)Ga-DOTA-TOC) positron emission tomography (PET). METHODS: Fifty-three patients with histologically confirmed NET and clinical signs of progressive disease, who had not qualified for peptide receptor radionuclide therapy (PRRT) on planar SSTR scintigraphy or (68)Ga-DOTA-TOC PET (n = 38) due to lack of tracer uptake, underwent (68)Ga-DOTA-LAN PET to evaluate a treatment option with (90)Y-labelled lanreotide according to the MAURITIUS trial. The included patients received 150 ± 30 MBq of each radiopharmaceutical intravenously. PET scans were acquired 60-90 min after intravenous bolus injection. Image results from both PET scans were compared head to head, focusing on the intensity of tracer uptake in terms of treatment decision. CT was used for morphologic correlation of tumour lesions. To further evaluate the binding affinities of each tracer, quantitative and qualitative values were calculated for target lesions. RESULTS: (68)Ga-DOTA-LAN and (68)Ga-DOTA-TOC both showed equivalent findings in 24/38 patients when fused PET/CT images were interpreted. The sensitivity, specificity and accuracy of (68)Ga-DOTA-LAN in comparison to CT were 0.63, 0.5 and 0.62 (n = 53; p < 0.0001) and for (68)Ga-DOTA-TOC in comparison to CT 0.78, 0.5 and 0.76 (n = 38; p < 0.013), respectively. (68)Ga-DOTA-TOC showed a significantly higher maximum standardized uptake value (SUV(max)) regarding the primary tumour in 25 patients (p < 0.003) and regarding the liver in 30 patients (p < 0.009) compared to (68)Ga-DOTA-LAN. Corresponding values of both PET scans for tumour and liver did not show any significant correlation. (68)Ga-DOTA-TOC revealed more tumour sites than (68)Ga-DOTA-LAN (106 vs 53). The tumour to background ratios for tumour and liver calculated from SUV(max) measurements were significantly higher for (68)Ga-DOTA-TOC than (68)Ga-DOTA-LAN (p < 0.02). CONCLUSION: (68)Ga-DOTA-TOC PET imaging is an established imaging procedure for accurate staging of NET patients. (68)Ga-DOTA-LAN should only be considered as a PET tracer of second choice in patients with no pathologic tracer uptake on (68)Ga-DOTA-TOC PET. In these patients, (68)Ga-DOTA-LAN PET can provide valuable information when evaluating PRRT as the treatment option, as a broader spectrum of human SSTR subtypes can be detected.

Screening for osteoporosis in people with MS: A new risk score.

BACKGROUND: Due to the demographic development and improved treatment options, the role of comorbidities is of increasing importance in the medical care of people with MS (pwMS). A higher risk of osteoporosis is well known in chronic autoimmune diseases, and is also described in MS. While there are several screening guidelines in the elderly or in patients with rheumatoid arthritis, there are no generally accepted recommendations when to perform bone mineral testing in pwMS under the age of 65 years. We aimed to determine risk factors of osteoporosis in pwMS and to develop a risk score which can be applied in daily clinical routine. METHODS: Densitometry (hip and lumbar spine) was performed in 159 pwMS aged ≤65 years and in 81 age- and sex-matched healthy controls (HC). Osteoporosis was defined according to WHO criteria as a bone density 2.5 standard deviation or more below the mean of young adults. Risk factors were identified by logistic regression analysis. RESULTS: Osteoporosis occurred more frequently in postmenopausal pwMS and male pwMS as compared to HC. Besides age, sex, menopausal status in females, body-mass-index and smoking, a higher degree of disability - as assessed by the Expanded Disability Status Scale - was identified as MS specific risk factor for osteoporosis, whereas the cumulative glucocorticoid dose was not associated with osteoporosis risk. Based on these risk factors, we developed an MS-specific risk score which allows to estimate the individual probability of osteoporosis. CONCLUSION: This risk score enables individual screening recommendation for pwMS and, subsequently, early prevention of osteoporosis which probably should result in reduction of fractures and morbidity.