The use of single-timepoint images to link administered radioiodine activity (MBq) to a prescribed lesion radiation-absorbed dose (cGy): a regression-based prediction interval tool for the management of well-differentiated thyroid cancer patients.

PURPOSE: To introduce a biomarker-based dosimetry method for the rational selection of a treatment activity for patients undergoing radioactive iodine 131I therapy (RAI) for metastatic differentiated thyroid cancer (mDTC) based on single-timepoint imaging of individual lesion uptake by 124I PET. METHODS: Patients referred for RAI therapy of mDTC were enrolled in institutionally approved protocols. A total of 208 mDTC lesions (in 21 patients) with SUVmax > 1 underwent quantitative PET scans at 24, 48, 72, and 120 h post-administration of 222 MBq of theranostic NaI-124I to determine the individual lesion radiation-absorbed dose. Using a general estimating equation, a prediction curve for biomarker development was generated in the form of a best-fit regression line and 95% prediction interval, correlating individual predicted lesion radiation dose metrics, with candidate biomarkers ("predictors") such as SUVmax and activity in microcurie per gram, from a single imaging timepoint. RESULTS: In the 169 lesions (in 15 patients) that received 131I therapy, individual lesion cGy varied over 3 logs with a median of 22,000 cGy, confirming wide heterogeneity of lesion radiation dose. Initial findings from the prediction curve on all 208 lesions confirmed that a 48-h SUVmax was the best predictor of lesion radiation dose and permitted calculation of the 131I activity required to achieve a lesional threshold radiation dose (2000 cGy) within defined confidence intervals. CONCLUSIONS: Based on MIRD lesion-absorbed dose estimates and regression statistics, we report on the feasibility of a new single-timepoint 124I-PET-based dosimetry biomarker for RAI in patients with mDTC. The approach provides clinicians with a tool to select personalized (precision) therapeutic administration of radioactivity (MBq) to achieve a desired target lesion-absorbed dose (cGy) for selected index lesions based on a single 48-h measurement 124I-PET image, provided the selected activity does not exceed the maximum tolerated activity (MTA) of < 2 Gy to blood, as is standard of care at Memorial Sloan Kettering Cancer Center. TRIAL REGISTRATION: NCT04462471, Registered July 8, 2020. NCT03647358, Registered Aug 27, 2018.

Restaging [18F] fludeoxyglucose positron emission tomography/computed tomography scan in recurrent cutaneous squamous cell carcinoma: Diagnostic performance and prognostic significance.

BACKGROUND: There are no specific recommendations for [18F] fludeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in assessing recurrent cutaneous squamous cell carcinoma (cSCC). OBJECTIVE: To evaluate FDG-PET/CT in recurrent cSCC. METHODS: FDG-PET/CT scans were retrospectively reviewed. Sites of abnormal uptake were noted and correlated with biopsy/histopathology studies, where available, and with follow-up imaging or clinical data in others. Comparison with available CT/magnetic resonance imaging was performed. The prognostic significance of PET/CT parameters was evaluated, and PET/CT-based change in management was recorded. RESULTS: A total of 115 FDG-PET/CT scans were analyzed in 100 consecutive patients with cSCC. Of these, 96 (84%) scans were positive for recurrence, and 25 showed distant metastases. PET/CT detected unsuspected disease sites in 39 of 115 scans (34%), locoregional disease in 14, distant metastases in 11, both locoregional disease and distant metastases in 8, additional local cutaneous disease in 5, and second malignancy in 1. Comparison of 78 PET/CT scans with available CT/magnetic resonance imaging showed 37 additional abnormalities on 23 PET/CT scans, predominantly including skin/subcutaneous lesions and nodes. PET/CT led to change in management in 28% of patients. On univariate/multivariate analysis, increased number of FDG-positive lesions and lung metastases on PET/CT was associated with increased risk of death/disease progression. LIMITATIONS: Retrospective study. CONCLUSIONS: FDG-PET/CT was sensitive in detecting recurrent disease in cSCC, led to change in management for 28% of patients, and proved to be of prognostic value.

Reexamination of the chromium-51-labeled posttransfusion red blood cell recovery method.

BACKGROUND: The chromium-51-labeled posttransfusion recovery (PTR) study has been the gold-standard test for assessing red blood cell (RBC) quality. Despite guiding RBC storage development for decades, it has several potential sources for error. METHODS: Four healthy adult volunteers each donated an autologous, leukoreduced RBC unit, aliquots were radiolabeled with technetium-99m after 1 and 6 weeks of storage, and then infused. Subjects were imaged by single-photon-emission computed tomography immediately and 4 hours after infusion. Additionally, from subjects described in a previously published study, adenosine triphosphate levels in transfusates infused into 52 healthy volunteers randomized to a single autologous, leukoreduced, RBC transfusion after 1, 2, 3, 4, 5, or 6 weeks of storage were correlated with PTR and laboratory parameters of hemolysis. RESULTS: Evidence from one subject imaged after infusion of technetium-99m-labeled RBCs suggests that, in some individuals, RBCs may be temporarily sequestered in the liver and spleen immediately following transfusion and then subsequently released back into circulation; this could be one source of error leading to PTR results that may not accurately predict the true quantity of RBCs cleared by intra- and/or extravascular hemolysis. Indeed, adenosine triphosphate levels in the transfusates correlated more robustly with measures of extravascular hemolysis in vivo (e.g., serum iron, indirect bilirubin, non-transferrin-bound iron) than with PTR results or measures of intravascular hemolysis (e.g., plasma free hemoglobin). CONCLUSIONS: Sources of measurement error are inherent in the chromium-51 PTR method. Transfusion of an entire unlabeled RBC unit, followed by quantifying extravascular hemolysis markers, may more accurately measure true posttransfusion RBC recovery.

Targeted Radiopharmaceutical Therapy for Bone Metastases.

Radiopharmaceutical approaches for targeting bone metastasis have traditionally focused on palliation of pain. Several agents have been clinically used over the last several decades and have proven value in pain palliation providing pain relief and improving quality of life. The role is well established across several malignancies, most commonly used in osteoblastic prostate cancer patients. These agents have primarily based on targeting and uptake in bone matrix and have mostly included beta emitting isotopes. The advent alpha emitter and FDA approval of 223Ra-dichloride has created a paradigm shift in clinical approach from application for pain palliation to treatment of bone metastasis. The approval of 223Ra-dichloride given the survival benefit in metastatic prostate cancer patients, led to predominant use of this alpha emitter in prostate cancer patients. With rapid development of radiopharmaceutical therapies and approval of other targeted agents such as 177Lu-PSMA the approach to treatment of bone metastasis has further evolved and combination treatments have increasingly been applied. Novel approaches are needed to improve and expand the use of such therapies for treatment of bone metastasis. Combination therapies with different targeting mechanisms, combining chemotherapies and cocktail of alpha and beta emitters need further exploration.

False-Positive Uptake in Splenic Hemangioma on 68 Ga-DOTATATE PET/CT.

ABSTRACT: Somatostatin receptor imaging using 68 Ga-DOTATATE PET is widely popular for evaluation of neuroendocrine tumors. 68 Ga-DOTATATE PET/CT shows highest physiologic uptake in spleen followed by other organs such as kidneys, adrenal glands, and liver. Hemangiomas, although rare, are the most common primary benign neoplasm of the spleen, composed of endothelial-lined vascular channels. We present a case of 77-year-old man who underwent 68 Ga-DOTATATE PET/CT scan for evaluation of pancreatic neuroendocrine tumor and incidentally demonstrated intense radiotracer uptake in splenic hemangiomata.

The Evaluation of the Efficacy and Safety of Midazolam Nasal Spray in Patients With Seizure Clusters: A Systematic Review and Meta-Analysis.

Midazolam nasal spray (MDZ-NS) is a new emerging rescue medication that suppresses epileptic seizures. Until now, few studies, pharmacokinetic (PK) and pharmacodynamic (PD) profiles, and clinical trials have shown that midazolam nasal spray could become an effective and promising alternative to conventional routes (intravenous {IV}/rectal). Therefore, we thought of conducting a systematic review and meta-analysis of midazolam (MDZ) to assess its potential outcomes. The analysis was also evaluated based on the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of midazolam nasal spray. A systematic literature search was carried out through various databases to identify studies of accounted outcomes of midazolam nasal spray (MDZ-NS). Randomized and other studies of patients (12 years or older) with seizure clusters (SCs) were included. A total of three full-text articles were considered for systematic review and meta-analysis as per the inclusion and exclusion criteria. The 5 mg MDZ-NS was observed to be equally safe as a placebo, and the risk ratio (RR) was 1.01 (95% confidence interval (CI): 0.67-1.53). After the administration of MDZ-NS, either the patients remained seizure-free for six hours or more or the seizure was terminated within 10 minutes and had no recurrence between 10 minutes and six hours. The risk ratio (RR) obtained was 1.54 (95% CI: 1.25-1.91). The result was statistically significant as a higher success rate was observed with the use of 5 mg midazolam nasal spray compared to placebo (p < 0.0001). Heterogeneity was not observed in the results of the included studies (inconsistency index {I2}: 0%). The present systematic review and meta-analysis demonstrated that 5 mg midazolam nasal spray was efficacious in treating patients with seizure clusters and is well-tolerated. Also, its use is relatively safe.

Paxlovid: A promising drug for the challenging treatment of SARS-COV-2 in the pandemic era.

Coronavirus infection is a pandemic threat and the most dangerous disease of the 21st century. Despite the rigorous exertion of world-class researchers, there is no perfect cure for it. It has been seen in presently available studies that Paxlovid prevents the progression of diseases and reduces severity in patients tremendously who are at high risk of hospitalization and death. It is a safe oral antiviral drug and has the potential to treat infections from multiple corona variants including omicron which affects humans. Paxlovid is comparatively less expensive than other available effective medicines. Consequently, it reduces hospitalization and death and helps to plummet the economic burden on patients and the health-care system globally. This medicine is still under investigation, and numerous clinical trials are still underway. Its potential side effects are minor and well tolerated by research study participants. Studies show its benefits outweigh the risk, and it is an effective and good alternative for the treatment of coronavirus disease.

Assessment of salivary gland function after 177Lu-PSMA radioligand therapy: Current concepts in imaging and management.

Prostate specific membrane antigen (PSMA) is a transmembrane protein that is highly expressed on prostate epithelial cells and is strongly upregulated in prostate cancer. Radioligand therapy using beta-emitting Lutetium-177 (177Lu)-labeled-PSMA-617, a radiolabeled small molecule, has gained attention as a novel targeted therapy for metastatic prostate cancer, given its high affinity and long tumor retention, and rapid blood pool clearance. In March 2022, the United States Food and Drug administration has granted approval to the targeted 177Lu-PSMA-617 therapy for treatment of patients with PSMA-positive metastatic castration resistant prostate cancer, who have been previously treated with an androgen-receptor pathway inhibitor and taxane-based chemotherapy. Studies have demonstrated the adverse effects of this treatment, mainly encountered due to radiation exposure to non-target tissues. Salivary glands show high PSMA-ligand uptake and receive increased radiation dose secondary to accumulation of 177Lu-PSMA-617. This predisposes the glands to radiation-mediated toxicity. The exact mechanism, scope and severity of radiation-mediated salivary gland toxicity are not well understood, however, the strategies for its prevention and treatment are under evaluation. This review will focus on the current knowledge about salivary gland impairment post 177Lu labeled PSMA-based radioligand therapies, diagnostic methodologies, and imaging with emphasis on salivary gland scintigraphy. The preventive strategies and known treatment options would also be briefly highlighted.

Improvement in Quality of Life of Postmenopausal Women with Depression with commonly used Antidepressants (Escitalopram vs. Desvenlafaxine): A Randomized Controlled Trial in a Tertiary Care Teaching Hospital of North India.

Introduction: The postmenopausal symptoms affect the quality of life (QoL) of women. Depression and anxiety too have been associated with diminished QoL. It is known that antidepressants escitalopram and desvenlafaxine are effective in the treatment of depression and anxiety. However, to the best of our knowledge, their comparative effect on the QoL of postmenopausal women with depression and anxiety has not been studied in the Indian setup. Materials and Methods: The present study was a randomized, intention to treat, open-label trial undertaken in North India's a tertiary care teaching hospital. Postmenopausal women attending the psychiatry outpatient department and newly diagnosed with depression and anxiety were randomized in two groups to receive Tab. Escitalopram 10-20 mg and Tab. Desvenlafaxine 50-100 mg. Their QoL was assessed using the WHOQOL BREF scale at baseline, 3 weeks and 6 weeks. Results: Escitalopram was observed to be statistically better than desvenlafaxine in improving the overall QoL score of the WHOQOL-BREF scale. Individually, escitalopram significantly improved the scores of the physical health domain, psychological and environmental domains except for the social relationship domain. Desvenlafaxine significantly improved scores of all four domains. Conclusion: Escitalopram was observed to be significantly better than desvenlafaxine in improving the overall QoL scores. Both the drugs were well tolerated.

Efficacy, tolerability and safety of perampanel in population with pharmacoresistant focal seizures: A systematic review and meta-analysis.

BACKGROUND: Focal seizures are associated with various co-morbidities. Seizure disorders also affect the quality of life of the patients. A huge proportion of patients continue to have uncontrolled seizures despite the availability of numerous antiepileptic drugs. Novel therapeutic targets too, have failed to overcome this problem. Therefore, drugs acting on conventional targets are being explored. Perampanel is one such drug. The present study aimed to assess its efficacy, safety, and effect on quality of life and cognition in patients aged 12 years and above. METHODS: Database search was conducted using keywords perampanel, partial seizures and randomized controlled trials (RCTs). Single and double blinded RCTs were included in the analysis. The primary outcomes assessed were 50% responder rate and seizure freedom rates. Secondary outcomes assessed were Improvement in Clinical Global Improvement for Change (CGI-C), number of patients who experienced adverse events, number of patients who withdrew from trials, adverse drug reaction (ADR) profile from Vigibase, long term safety, quality of Life (QoL) assessment and cognitive assessment, especially in adolescents. The Risk ratios (RR) were calculated for these parameters. RESULTS: 24 full text articles were obtained out of a total 421 studies. From these seven double blind randomized controlled trials were included in the meta-analysis. Perampanel treated patients showed higher 50% responder rates than those treated with placebo. The Risk Ratios (RRs) were 1.39 [95% confidence interval (CI) 1.08-1.79], 1.83 [95% CI 1.51 - 2.22] and 1.81 [95% CI 1.45-2.27] for the 4 mg per day, 8 mg once daily and 12 mg once daily subgroups of perampanel respectively. The RRs for the seizure freedom rates were 4.52 [95% CI 1.30-15.73], 3.65 [95% CI 1.40-9.52] and 2.14 [95% CI 1.11-4.11] for 4 mg per day, 8 mg once daily and 12 mg once daily subgroups of perampanel respectively. There was a significantly higher risk of TEAEs with the 8 mg and 12 mg doses of perampanel as compared to that with placebo. Number of patients who withdrew from the trials due to adverse events was statistically significant in only the 12 mg subgroup of perampanel in comparison to that with placebo group. CONCLUSION: Perampanel was observed to be an effective add on drug for treating pharmacoresistant focal seizures. The patients achieved higher 50% response rates and freedom from seizures with its use. Tolerability of perampanel was more at lower doses.

18F-FDG PET/CT for Posttreatment Surveillance Imaging of Patients with Stage III Merkel Cell Carcinoma.

The purpose of this study was to investigate the diagnostic and prognostic value of 18F-FDG PET/CT for surveillance imaging in patients treated for stage III Merkel cell carcinoma (MCC). Methods: This retrospective study included 61 consecutive stage III MCC patients who were clinically asymptomatic and underwent surveillance 18F-FDG PET/CT. Findings were correlated with either pathology or clinical/imaging follow-up. The median follow-up period was 4.8 y. Statistical analyses were performed. Results:18F-FDG PET/CT detected unsuspected recurrences in 33% patients (20/61) with lesion-based sensitivity, specificity, and accuracy of 92%, 93%, and 93%, respectively. The mean ± SD SUV for malignant and benign lesions was 7.5 ± 3.9 and 3.8 ± 2.0, respectively. Unknown distant metastases, as first recurrence site, were noted in 12 of 61 patients. Those with positive disease on 18F-FDG PET/CT within 1 y of definitive treatment had relatively worse overall survival (P < 0.0001). After adjustment on stage, risk of death increased with a higher SUVmax (hazard ratio for 1 unit = 1.17; P = 0.006) and with a higher number of positive lesions on 18F-FDG PET/CT (hazard ratio for 1 additional lesion = 1.60; P < 0.001). Conclusion: Postdefinitive treatment surveillance 18F-FDG PET/CT scanning detects unsuspected recurrences and has prognostic value. Inclusion of 18F-FDG PET/CT within the first 6 mo after definitive treatment would be appropriate for surveillance and early detection of recurrence. Our data merit further studies to evaluate the prognostic implications.

18F-Fluciclovine Uptake in Thymoma Demonstrated on PET/MRI.

ABSTRACT: A 68-year-old man with a history of prostate cancer post-primary treatment presented with rising prostate-specific antigen levels and was referred for 18F-fluciclovine PET/MRI to localize recurrent disease. PET/MRI revealed a solitary focus of uptake in a soft tissue nodule in the anterior mediastinum, which was resected and found to be a type B2 thymoma. 18F-fluciclovine uptake is mediated by amino acid transporters, primarily alanine-serine-cysteine transporter 2 and l-type amino acid transporter 1, previously demonstrated to be expressed on thymic carcinomas. This case highlights the possibility of overexpression of amino acid transporters in thymomas as well, rarely described before.

Repurposing Potential of Ketamine: Opportunities and Challenges.

Ketamine is a noncompetitive antagonist of the N-methyl-D-aspartate (NMDA) receptor which also interacts with various other receptors that account for its myriad actions. Originally approved as a general anesthetic, it is being explored to be repurposed for numerous other indications such as depressive disorders, suicidal ideation, substance-use disorders, anxiety disorders, chronic pain, refractory status epilepticus, and bronchial asthma exacerbations. Numerous trials are ongoing for the same. The nasal spray of esketamine, a more potent S (+) enantiomer of ketamine, has been approved by the United States Food and Drug Administration (USFDA) for treatment-resistant depression along with the oral antidepressants. However, there are concerns about its safety on long term use, given its psychedelic effects and potential abuse. In this review, we discuss repurposing ketamine for potential therapeutic use and about the safety concerns related to ketamine and esketamine.

Rosai-Dorfman Disease-Utility of 18F-FDG PET/CT for Initial Evaluation and Follow-up.

BACKGROUND: The role of imaging in the management of Rosai-Dorfman disease (RDD), a rare non-Langerhans cell histiocytosis, is not clearly defined. We present an analysis of FDG PET/CT findings obtained for initial disease characterization, follow-up evaluation, and treatment planning for this disease. METHODS: From an institutional pathology database (2001-2018), we identified RDD patients who underwent FDG PET/CT scans either as part of clinical care or when done as part of clinical trials. For all scans, sites of abnormal FDG uptake were assessed, and SUVmax was measured. Comparison of PET/CT findings was made with anatomic (CT/MRI-based) imaging, where available. Instances of changing treatment based on PET/CT were recorded. RESULTS: We reviewed 109 FDG PET/CT scans in 27 patients with RDD. Five of 27 patients had only nodal/cutaneous disease, whereas 22 patients had extranodal disease, most commonly in bone (n = 9) and central nervous system (n = 7). PET/CT identified sites of active disease in 24 of 27 patients. All identified bone and extraskeletal lesions, except for a brain lesion in 1 patient, were FDG-avid. In 6 of 20 patients (30%) with available prior CT or MRI, PET/CT demonstrated additional RDD lesions (bones: n = 5, pleura: n = 1) that were not apparent on anatomic imaging; 3 of these lesions were outside the CT field of view, and 3 were not recognized on CT. Overall, 13 of 109 PET/CT scans led to a change in management, affecting 41% (11/27) of patients. CONCLUSION: FDG PET/CT was valuable in defining disease extent and optimizing treatment strategy in patients with RDD.

Preserving Radiology Resident Education During the COVID-19 Pandemic: The Simulated Daily Readout.

RATIONALE AND OBJECTIVES: The educational value of the daily resident readout, a vital component of resident training, has been markedly diminished due to a significant decrease in imaging volume and case mix diversity. The goal of this study was to create a "simulated" daily readout (SDR) to restore the educational value of the daily readout. MATERIALS AND METHODS: To create the SDR the following tasks were performed; selection of cases for a daily worklist for each resident rotation, comprising a combination of normal and abnormal cases; determination of the correct number of cases and the appropriate mix of imaging modalities for each worklist; development of an "educational" environment consisting of separate "instances" of both our Picture Archive Communication System and reporting systems; and the anonymization of all of the cases on the worklists. Surveys of both residents and faculty involved in the SDR were performed to assess its effectiveness. RESULTS: Thirty-two residents participated in the SDR. The daily worklists for the first 20 days of the SDR included 3682 cases. An average of 480 cases per day was dictated by the residents. Surveys of the residents and the faculty involved in the SDR demonstrated that both agreed that the SDR effectively mimics a resident's daily work on rotations and preserves resident education during the Coronavirus Disease 2019 crisis. CONCLUSION: The development of the SDR provided an effective method of preserving the educational value of the daily readout experience of radiology residents, despite severe decreases in imaging exam volume and case mix diversity during the Coronavirus Disease 2019 pandemic.

Systematic Review of the Effects of Phosphodiesterase-5 Inhibitors and Dexamethasone on High Altitude Pulmonary Edema (HAPE).

OBJECTIVE: To review and synthesize the current available evidence of the effects of phosphodiesterase-5 inhibitors and dexamethasone on the outcomes of individuals affected by acute mountain sickness symptoms and High Altitude Pulmonary Edema (HAPE). METHODS: In 2015, two authors independently performed separate searches using three different databases (PubMed, Ovid and Web of Science) later reviewed by the third author. The searches used the following terms "High Altitude Pulmonary Edema" and "Phosphodiesterase-5 Inhibitors" while the second search used "High Altitude Pulmonary Edema" and "Dexamethasone". The following exclusion criteria were utilized: patients < 18 years old, non-human studies, studies at altitudes < 2,000 meters. The search included articles from year 2000 to current. RESULTS: A total of 237 manuscripts were initially reviewed. The search involving phosphodiesterase-5 inhibitors initially yielded 37 manuscripts, four of which met inclusion criteria. A total of 101 patients were included in these articles. For the Dexamethasone search, 200 manuscripts were retrieved. Three of these studies met the inclusion criteria, reporting data on a total of 66 patients. None of the studies reported significant improvements in outcomes of patients from the use of either phosphodiesterase-5 inhibitors or dexamethasone. CONCLUSIONS: According to the current available literature, neither phosphodiesterase -5 inhibitors or dexamethasone significantly alter the outcome of individuals affected by HAPE.

Clinical value of 18F-FDG-PET/CT in staging cutaneous squamous cell carcinoma.

BACKGROUND: Cutaneous squamous cell carcinoma (cSCC) is the second most common skin malignancy. Computed tomography (CT) and/or MRI are commonly used for staging, however, the role of fluorine-18-fluorodeoxyglucose (F-FDG)-PET is not clearly established. In this study, we evaluated F-FDG-PET/CT imaging for initial staging of cSCC. PATIENTS AND METHODS: F-FDG-PET/CT scans performed in patients with newly diagnosed cSCC were reviewed retrospectively. Images were visually assessed for lesions and F-FDG uptake [standardized uptake value (SUV)] in primary and secondary sites was measured. Suspected lesions on F-FDG-PET/CT were correlated with histopathology when available, follow-up imaging or clinical data in others. RESULTS: Twenty-three cSCC patients who underwent F-FDG-PET/CT at diagnosis were evaluated. Primary sites were in head/neck (n=21), chest (n=1), and foot (n=1). All patients had F-FDG-positive scans with a total of 51 F-FDG-positive lesions. All primary lesions (n=24) were F-FDG-positive (SUV: 2.3-22.8; mean 10.2), and additional 27 F-FDG-positive lesions, including 21 nodes, four cutaneous, one osseous and one lung lesion, were noted in 13 patients. Mean size of F-FDG-positive nodes was 0.9 cm (range: 0.4-2.5 cm), predominantly clinically impalpable. Pathology was available for 40/51 lesions; 31 sites positive for malignancy. SUV (mean±SD) was 9.2±6.2 for malignant and 2.7±1.2 for benign lesions. Sensitivity, positive predictive value, and accuracy of F-FDG-PET/CT scan were 100, 77.5, and 77.5%, respectively. F-FDG detected seven additional lesions in three patients, compared to CT/MRI. Overall, staging F-FDG-PET/CT detected nine prior unknown lesions in five patients that were proven metastatic disease by histopathology or follow-up; F-FDG-PET/CT modified management in 5/23 (21.7%) patients. CONCLUSION: F-FDG-PET/CT has high sensitivity in the detection of cSCC lesions, including small cutaneous and nodal disease, and has a potential role in initial staging and management.

Enchondroma of Tibia as Potential False-positive Finding on 68Ga-DOTATOC PET/CT Scan.

A 70-year-old man with a history of carcinoid tumor of small bowel was referred for Ga-DOTATOC study to evaluate the extent of disease. PET/CT scan revealed known metastatic disease in the liver, with other sites of involvement including pancreas, peritoneum, and bones. In addition, moderately intense uptake was noted in proximal right tibia and further correlation on CT showed metaphyseal lesion with "rings and arcs" calcification suggestive of enchondroma. This case highlights the possibility of overexpression of somatostatin receptors in enchondromas, which has been little explored in literature.

Integrating Early Rapid Post-Peptide Receptor Radionuclide Therapy Quality Assurance Scan into the Outpatient Setting.

OBJECTIVE: To understand value of early rapid, quality-assurance (QA), post-therapy whole-body scan (Tx-WBS) in patients receiving peptide receptor radionuclide therapy (PRRT) in outpatient setting. METHODS: Sixteen patients with metastatic neuroendocrine tumors received PRRT and underwent Tx-WBS after each cycle. Early imaging (3 hour post-injection) was favored. Planar-images obtained on dual-headed gamma camera (speed 30 cm/min) were visually assessed and qualitatively compared with pre-therapy diagnostic scans. Retention% and lesion/spleen (L/S) ratios were calculated. RESULTS: Fifty three Tx-WBS were analyzed. No cutaneous contamination, extravasation or unexpected tracer distribution was observed. 46/53 (87%) Tx-WBS in 14/16 (88%) patients demonstrated uptake in metastatic lesions. No significant correlation was seen between L/S ratios and response on follow-up imaging. Qualitative assessment of follow-up images during four-cycles of PRRT provided preliminary estimate of disease course in 11/16 patients; with unexpected findings in 2. CONCLUSION: In daily practice, especially in outpatient setting, an early QA post-PRRT scan proved effective for validating successful treatment and allowing preliminary disease monitoring, at no additional cost.