Giant cell arteritis exclusively detected by 18F-fluorodeoxyglucose positron emission tomography: a case report

INTRODUCTION: This case of giant cell arteritis is noteworthy because it evaded standard diagnostic criteria and only emerged as fever of unknown origin. In this regard, we present (18)F-fluorodeoxyglucose positron emission tomography as a valid diagnostic method. CASE PRESENTATION: This case report describes a 58-year-old Caucasian woman who is a cigarette smoker with a 10-week history of fever of unknown origin, night sweats and weight loss of 12kg. Initially, clinical presentation was suspicious of malignant disease. Laboratory findings detected significantly elevated inflammatory blood parameters including C-reactive protein and elevated erythrocyte sedimentation rate (110mm/hour). Extensive diagnostic workup including microbiological and rheumatological assessment, ultrasonography, endoscopy and computed tomography of abdomen and thorax did not indicate any septic or malignant focus. Eventually, (18)F-fluorodeoxyglucose positron emission tomography was able to reveal arteritis of her aortic arch and supraaortic branches. Subsequently, she commenced steroid and methotrexate therapy that led to sustained remission. CONCLUSIONS: This case of giant cell arteritis may promote discussion regarding a more specific classification for this disease entity. Furthermore, it confirms that (18)F-fluorodeoxyglucose positron emission tomography might serve as a valuable tool for diagnosis of giant cell arteritis, because it could facilitate an accurate and non-invasive detection of lesions of large vessels

Intraoperative 3-D mapping of parathyroid adenoma using freehand SPECT

Background: Freehand single photon emission computed tomography (fSPECT) is a three-dimensional (3-D) tomographic imaging modality based on data acquisition with a handheld detector that is moved freely, in contrast to conventional, gantry-mounted gamma camera systems. In this pilot study, we evaluated the feasibility of fSPECT for intraoperative 3-D mapping in patients with parathyroid adenomas. Methods: Three patients (range 30 to 45 years) diagnosed with hyperparathyroidism (one primary and two tertiary) underwent parathyroid scintigraphy with technetium-99m sestamibi (99mTc-MIBI) to localize parathyroid adenomas. Two patients were referred with persistent hyperparathyroidism after conventional parathyroidectomy. In all three patients, a planar scintigraphy of the neck was performed 10 min after injection (p.i.) followed by SPECT/CT (Symbia T2, Siemens Healthcare) and a correlative ultrasound 2 h p.i. 99mTc-MIBI scan was performed the day before surgery in two patients and at the same day in one patient. fSPECT images were acquired intraoperatively using declipse SPECT (SurgicEyeTM). Results: A total of five parathyroid adenomas were successfully located with SPECT/CT. fSPECT allowed intraoperative detection of all adenomas, and successful parathyroidectomy was accomplished. Parathyroid hormone level decreased intraoperatively in all three patients, on average, by 79% (range 72% to 91%). Conclusion: In this preliminary study, we could demonstrate that intraoperative localization of parathyroid adenomas is feasible using the freehand SPECT technology, thus allowing an image-guided parathyroidectomy

Imaging and liquid biopsy in the prediction and evaluation of response to PRRT in neuroendocrine tumors: implications for patient management

Purpose!#!The aim of this narrative review is to give an overview on current and emerging imaging methods and liquid biopsy for prediction and evaluation of response to PRRT. Current limitations and new perspectives, including artificial intelligence, are discussed.!##!Methods!#!A literature review of PubMed/Medline was performed with representative keywords. The search included articles published online through August 31, 2020. All searches were restricted to English language manuscripts.!##!Results!#!Peptide radio receptor therapy (PRRT) is a prospectively evaluated and approved therapy option in neuroendocrine tumors (NETs). Different ligands targeting the somatostatin receptor (SSTR) are used as theranostic pairs for imaging NET and for PRRT. Response assessment in prospective trials often relies on the morphological RECIST 1.1 criteria, based on lesion size in CT or MRI. The role of SSTR-PET and quantitative uptake parameters and volumetric data is still not defined. Monoanalyte tumor marker chromogranin A has a limited value for response assessment after PRRT. New emerging liquid biopsy techniques are offering prediction of response to PRRT and prognostic value.!##!Conclusions!#!New response criteria for NET patients undergoing PRRT will comprise multiparametric hybrid imaging and blood-based multianalyte markers. This represents tumor biology and heterogeneity

Radioligand therapy using [177Lu]Lu-PSMA-617 in mCRPC: a pre-VISION single-center analysis

Background!#!Radioligand therapy with [!##!Methods!#!A total number of 78 consecutive patients with mCRPC and a history of first-line chemotherapy were included in this retrospective analysis. The outcome of patients treated with 6.0 GBq [!##!Results!#!There was no significant difference comparing the rate of > 50% PSA decline or best PSA response between the 6.0 GBq and 7.5 GBq group (35% vs. 54%, p = 0.065; and - 40.2% vs. - 57.8%, p = 0.329). The median estimated survival and PSA-PFS did not significantly differ between the 6.0 GBq and 7.5 GBq groups as well (11.3 vs. 12.7 months, p = 0.384; and 9.5 vs. 12.3 months, p = 0.258). There was no significant difference regarding the change of kidney, liver, and blood cell parameters under therapy between the treatment groups.!##!Conclusion!#!Higher cumulated doses of

Time after Synthesis and Time after Injection Do Not Affect Diagnostic Quality of [18F]F-PSMA 1007 PET

PET imaging using PSMA ligands is increasingly used for staging in prostate cancer patients in different clinical indications. Unlike [68Ga]Ga-labeled PSMA ligands, fluorinated compounds can be produced in large amounts; thus, they can be used for a higher number of patients. One concern is that in patients studied a long time after synthesis (TaS) or time after injection (TaI), the specific activity may decline; thus, the signal may be lower in these patients. In this study, we investigated a potential effect of TaS and TaI on image quality. In total, 134 consecutive patients were included in this retrospective analysis on the effect of TaS and TaI on uptake in prostate cancer lesions. All the patients underwent [18F]F-PSMA-1007 PET-CT from 99 min up to 549 min after tracer quality control. TaS and TaI were compared to the quantitative tumoral uptake parameters SUVmax and SUVpeak. In a second exploratory part of the analysis, TaS and TaI were correlated to a physiological tracer uptake in different organs. TaS and TaI did not affect the SUVmax and SUVpeak in tumor lesions in [18F]F-PSMA-1007 PET. The physiological uptake in salivary glands, lacrimal glands and the ganglia, spleen and urine was not significantly correlated to TaS or TaI; in contrast to the mean liver uptake, showing a weak, but significant correlation to TaS. The [18F]F-PSMA-1007 uptake in prostate cancer lesions is not significantly dependent on the TaS and TaI. These results are extremely reassuring when performing [18F]F-PSMA-1007 PET a considerable time after synthesis

F-PSMA-1007 PET/CT at 60 and 120 minutes in patients with prostate cancer: biodistribution, tumour detection and activity kinetics.

PURPOSE PSMA-targeted PET in patients with prostate cancer (PCa) has a significant impact on treatment decisions. By far the most frequently used PSMA ligand isGa-labelled PSMA-11. However, due to the availability of larger amounts of activity,F-labelled PSMA ligands are of major interest. The aim of the present study was to evaluate the biodistribution and performance of the novelF-labelled ligand PSMA-1007 at two different time points. METHODS This retrospective analysis included 40 consecutive patients (mean age 68.7 ± 8.1 years) referred for PSMA PET/CT.F-PSMA-1007 PET/CT was performed for localization of biochemical relapse, primary staging or therapy follow-up. Circular regions of interest were placed on representative slices of the liver, spleen, kidney, abdominal aortic blood pool, bone marrow (fourth lumbar vertebral body), urinary bladder and gluteus muscle at 60 and 120 min after injection. In malignant lesions the maximum standardized uptake (SUV) was measured within volumes of interest at both time points. All SUVs at 60 min were compared with those at 120 min after injection. RESULTS The activity in the blood pool, urinary bladder and gluteus muscle was very low and decreased significantly over time (P < 0.001). Uptake in the liver, spleen and kidney showed a significant increase over time and uptake in the bone marrow remained stable. Overall, 135 PCa lesions were detected at 60 min and 136 lesions at 120 min after injection. The median SUVincreased significantly (P < 0.001) from 10.98 to 15.51 between 60 and 120 min. CONCLUSION PCa lesions show a significant increase inF-PSMA-1007 uptake at 120 min compared with 60 min after injection. In addition, accumulation of the tracer in the urinary bladder was very low leading to improved contrast of adjacent PCa lesions. Increasing accumulation in the liver may limit the sensitivity of the tracer in detecting liver metastases