Neurological Disorders and Women's Health: Contribution of Molecular Neuroimaging Techniques.

Sex differences in brain physiology and the mechanisms of drug action have been extensively reported. These biological variances, from structure to hormonal and genetic aspects, can profoundly influence healthy functioning and disease mechanisms and might have implications for treatment and drug development. Molecular neuroimaging techniques may help to disclose sex's impact on brain functioning, as well as the neuropathological changes underpinning several diseases. This narrative review summarizes recent lines of evidence based on PET and SPECT imaging, highlighting sex differences in normal conditions and various neurological disorders.

Comparison between 18F-FDG PET/CT and diffusion-weighted imaging in detection of invasive ductal breast carcinoma.

Objectives: Breast carcinoma is the most common type of cancer in females. This study aims to compare fluorine-18-fluorodeoxyglucose (18F-FDG) uptake pattern and apparent diffusion coefficient (ADC) value for the detection of the primary tumour and axillary metastases of invasive ductal breast carcinoma. Methods: This study included 40 breast carcinoma lesions taken from 39 patients. After staging by positron emission tomography-computed tomography (PET/CT) and diffusion-weighted magnetic resonance imaging (MRI), breast surgery with axillary lymph node dissection or sentinel lymph node biopsy was performed. Results: Primary lesion detection rate for PET/CT and diffusion-weighted MRI was high with 39 of 40 lesions (97.5%). The sensitivity and specificity for the detection of metastatic lymph nodes in axilla were 40.9%, 88.9%, with 18F-FDG PET/CT scans and 40.9%, 83.3%, for dw-MRI, respectively. No significant correlation was detected between ADC and SUVmax or SUVmax ratios. Estrogen receptor (p=0.007) and progesterone receptor (p=0.036) positive patients had lower ADC values. Tumour SUVmax was lower in T1 than T2 tumour size (p=0.027) and progesterone receptor-positive patients (p=0.029). Tumour/background SUVmax was lower in progesterone receptor-positive patients (p=0.004). Tumour/liver SUVmax was higher in grade III patients (p=0.035) and progesterone receptor negative status (p=0.043). Conclusions: This study confirmed the high detection rate of breast carcinoma in both modalities. They have same sensitivity for the detection of axillary lymph node metastases, whereas the PET/CT scan had higher specificity. Furthermore, ADC, SUVmax and SUVmax ratios showed some statistical significance among the patient groups according to different pathological parameters.

How Radioactive Iodine Treatment Affects the Retina.

Objective The aim of this study was to quantitatively assess the macular and retinal nerve fiber layer thicknesses in patients with hyperthyroidism and thyroid cancer undergoing radioactive iodine (RAI) therapy. Study Design This prospective study was conducted in accordance with the principles of the Declaration of Helsinki and approved by the Bagcilar Training and Research Hospital Clinical Research Ethics Committee. Written informed consent was obtained from the patients following a detailed explanation of the study objectives and protocol. Patient selection was randomized. Patients scheduled for RAI treatment in the Nuclear Medicine Clinic were referred to the ophthalmology clinic, respectively. Patients without additional ocular pathology were included in the study. Methods All patients had received RAI therapy using Iodine-131 for hyperthyroidism or thyroid cancer. A complete ophthalmological examination and measurement of macular and retinal nerve fiber layer thickness using optical coherence tomography were performed on all patients before and at the first and sixth months and in first year after RAI treatment. The results were prospectively evaluated. Results The study included 80 eyes of 40 patients. The hyperthyroid group was group 1, and the thyroid cancer group was group 2. There were 25 patients in group 1 and 15 patients in group 2. The mean age was 43.76 ± 11.85 years (range: 22-65 years) in group 1 and 39.87 ± 9.13 years (range: 30-58 years) in group 2. There was no significant difference between the two groups regarding age and sex ( p > 0.05). In both groups, no significant difference was found in the macular thickness and retinal nerve fiber layer thicknesses values obtained in both eyes before and after the RAI treatment. Conclusion As a result of our study, we observed that RAI intake did not harm the retinal layer.

The Impact of Metabolic 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Parameters on the Prognosis of Resectable Pancreatic Adenocarcinoma.

Objectives: 18F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) is a useful staging method in pancreatic cancer. The prognosis of pancreatic adenocarcinoma is affected by the tumor stage and resectable state. Maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of primary tumors are related to prognostic parameters in pancreatic cancer. This study compared 18F-FDG PET/CT findings with prognostic factors and overall survival of patients with pancreatic cancer. Methods: Patients with pancreatic adenocarcinoma, referred to our department between 2015 and 2022 for staging, were retrospectively evaluated. Head-to mid-thigh PET/CT images were obtained 1 h after 18F-FDG injection. Demographic data, survival, and clinical and pathological findings of 39 patients, who underwent surgery after PET/CT imaging, were collected. All primary tumor MTV, SUVmax, background SUVmax, and TLG data have were measured. Results: The images of 39 patients (24 women and 15 men) with a mean age of 66.62±9.60 years were evaluated. The mean SUVmax, MTV 40%, and TLG of the primary tumors in the pancreatic tissue were 6.28±2.33, 19.33±9.77, and 66.56±45.99, respectively. The average survival after disease diagnosis was 18.97±11.47 (2-55) months. MTV and TLG were significantly higher in patients who died during our study. SUVmax has a significant effect on mortality. Conclusion: 18F-FDG PET/CT metabolic parameters of SUVmax, MTV, and TLG could help predicting the prognosis of pancreatic cancer preoperatively and follow-up in patients with resectable tumors. Additionally, in our study group tumor grade and perineural invasion significantly affected overall survival.

The value of radioembolisation therapy on metastatic liver tumours - a single centre experience.

OBJECTIVE: Local treatments used in metastatic liver tumours efficiently control the disease and survival. Transarterial radioembolisation (TARE) is a safely used locoregional treatment method. We aim to investigate the impact of TARE on different kinds of metastatic liver tumours and the effect of pre-treatment clinical findings. MATERIAL AND METHODS: The patients with metastatic liver tumours referred to our department for radioembolisation were retrospectively evaluated. All patients were given a Y-90 glass microsphere after being selected by the appropriate clinical and imaging criteria, lung shunt fraction levels, vascular investigation, and macro aggregated albumin (MAA) scintigraphy performed in the angiography unit. RESULTS: Thirty-four (17 women, 17 men) patients were suitable for the treatment. Patients were treated with 115.88±47.84 Gy Y-90 glass Microspheres. The mean survival rate was 14.59±12.59 months after treatment. Higher survival rates were detected in patients who had higher pre-treatment serum albumin levels. The optimum cut-off value of albumin to predict response to treatment was 4 g/dl with 88.89% sensitivity, 62.50% specificity, 72.73% PPV and 83.33% NPV. Furthermore, one unit increase in age increased mortality 1.152 times in our patient group. CONCLUSION: Radioembolisation is a safe and efficient method for controlling metastatic liver disease. Albumin levels significantly affect predicting response; higher albumin levels are related to higher survival rates. Furthermore, older age positively correlated with mortality rates in our patient group.

Mesenteric Panniculitis Appears as Metastatic Disease on 18F-FDG-PET/CT Scan.

Mesenteric panniculitis is a rare benign inflammatory process involving mesenteric adipose tissue and the pathogenesis is still unknown. It may present 18Fluorine-fluorodeoxyglucose (18F-FDG) uptake and appear like a malign tumor or metastatic disease. We report a case of 47 year-old woman with serous ovarian adenocarcinoma demonstrating intense 18F-FDG uptake and hyperdense nodularity in mesenteric fatty tissue on post-chemotherapy positron emission tomography/computed tomography imaging. The serum tumor marker (CA-125) level was within the normal range. A correlative magnetic resonance imaging highlighted the diagnosis of mesenteric panniculitis that was also confirmed by clinical follow-up.

EANM procedure guidelines for brain PET imaging using [18F]FDG, version 3.

The present procedural guidelines summarize the current views of the EANM Neuro-Imaging Committee (NIC). The purpose of these guidelines is to assist nuclear medicine practitioners in making recommendations, performing, interpreting, and reporting results of [18F]FDG-PET imaging of the brain. The aim is to help achieve a high-quality standard of [18F]FDG brain imaging and to further increase the diagnostic impact of this technique in neurological, neurosurgical, and psychiatric practice. The present document replaces a former version of the guidelines that have been published in 2009. These new guidelines include an update in the light of advances in PET technology such as the introduction of digital PET and hybrid PET/MR systems, advances in individual PET semiquantitative analysis, and current broadening clinical indications (e.g., for encephalitis and brain lymphoma). Further insight has also become available about hyperglycemia effects in patients who undergo brain [18F]FDG-PET. Accordingly, the patient preparation procedure has been updated. Finally, most typical brain patterns of metabolic changes are summarized for neurodegenerative diseases. The present guidelines are specifically intended to present information related to the European practice. The information provided should be taken in the context of local conditions and regulations.

Is there a nonnegligible effect of maximum standardized uptake value in the staging and management of prostate cancer with 68Ga-prostate-specific membrane antigen positron emission tomography/computerized tomography imaging? A single-center experience.

PURPOSE: Prostate-specific membrane antigen (PSMA) positron emission tomography/computerized tomography (PET/CT) has been shown to have significant success in detecting local and distant metastases that cannot not be detected by conventional imaging. Initial staging in intermediate- and high-risk patients with prostate cancer is important for management. In addition, PSMA uptake has been shown to have a relation with grade of disease, and thus could be considered a separate noninvasive prognostic factor. In this study, we aimed to investigate the effect of PSMA PET/CT in the staging and management of prostate cancer patients as well as the relation to maximum standardized uptake value (SUVmax). METHODS: The patients referred to our department for staging prostate cancer were evaluated retrospectively (n = 65). Patients were grouped as positive for lymph node or distant metastatic disease. Primary tumor SUVmax data were compared with the prognostic factors of the disease. In addition, decisions about treatment protocol before and after PSMA PET/CT imaging were noted. RESULTS: All the patients except one were accepted as positive for primary tumor. Of the patients, 46.2% were positive for lymph node and 24.6% for distant metastases. After evaluation by PSMA PET/CT, the clinical choice of treatment changed for 43.1% of our patients. Primary tumor SUVmax and tumor-to-background SUVmax ratios were found to have a significant relation with D'Amico risk classification. We found a positive correlation between SUVmax and prostate-specific antigen, Gleason scores, and age. CONCLUSION: PSMA PET/CT images have a nonnegligible effect on staging, clinical decisions, and change in treatment protocol. SUVmax data have a positive correlation with risk classification and could be identified as a potential independent and non-invasive prognostic factor.

The Use of 18F-FDG PET/CT in Patients with Recurrent Differentiated Thyroid Cancer

Objectives: 18Fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) is used to monitor the recurrence in thyroid cancer patients when there is suspicion of metastases. De-differentiated lesions become 18F-FDG avid with a more aggressive clinical course. The aim of this study was to investigate the use of 18F-FDG PET/CT in differentiated thyroid cancer. Methods: Forty-six patients, either with a negative radioiodine scan or clinical progression and suspicions for metastases with differentiated thyroid cancer that were referred to our department for 18F-FDG PET/CT scan and evaluated retrospectively. PET/CT findings were correlated with clinical and histopathological findings, serum thyroglobulin (Tg), and anti-Tg levels. Results: Twenty-six patients (56.2%) were positive for recurrence in 18F-FDG PET/CT images. Positive 18F-FDG PET/CT findings were significantly correlated with the disease stage and Tg levels. Maximum standardized uptake value did not correlate with other findings or patients' profiles. The cut-off value for Tg was at 52.5 ng/mL having 73.08% sensitivity, 75% specificity, 79.17% positive predictive value, and 68.18% negative predictive value for 18F-FDG PET/CT imaging. Conclusion: 18F-FDG PET/CT is useful for detecting recurrence in differentiated thyroid cancer. Increased Tg levels and stage of the disease were significantly correlated with 18F-FDG positivity. 18F-FDG positivity may also provide information about the de-differentiation process that may support the treatment plan.

Can PSMA-based tumor burden predict response to docetaxel treatment in metastatic castration-resistant prostate cancer?

PURPOSE: We investigated the role of PSMA-derived tumor burden in predicting docetaxel (DTX) therapy response in metastatic castration-resistant prostate cancer (mCRPC). METHODS: Fifty-two mCRPC patients who received at least six cycles of DTX as the first-line treatment following 68Ga-PSMA PET/CT were enrolled in this retrospective study. Total PSMA-derived tumor volume (TV-PSMA) and total lesion PSMA activity (TL-PSMA) were derived from metastatic lesions. A ≥ 50% decline in PSA was defined as a response; a ≥ 25% increase in PSA was defined as progression. Univariate/multivariate logistic and cox regression analyses were performed to predict PSA response, OS, and TTP. RESULTS: Twelve (23%) patients had PSA progression after chemotherapy, while 40 patients (77%) achieved a PSA response. On univariate analysis, a significant association was found between TV-PSMA (p = 0.001), TL-PSMA (p = 0.001), pre-PSA (p = 0.012), LDH (p = 0.003), Hg (p = 0.035), and PSA response to DTX. High TV-PSMA (> 107 cm3) (p = 0.04) and high LDH (> 234 U/L) (p = 0.017) were 8.2 times and 12.2 times more likely for DTX failure in multivariate regression analyses. The median TTP was 16 months, and the median OS was not reached. Patients with high TV-PSMA (p = 0.017), high TL-PSMA (> 1013 cm3) (p = 0.042), high age (> 70 years) (p = 0.016), and high LDH (p ≤ 0.001) had significantly shorter OS, while only high TV-PSMA (p = 0.038) and high age (p = 0.006) were significantly related with shorter TTP. High TV-PSMA (p = 0.017) and high age (p = 0.01) were significant predictors for shorter OS, while only high age (p = 0.006) was a significant predictor for shorter TTP in multivariate analysis. CONCLUSION: Patients with high TV-PSMA had a significantly higher risk for DTX failure. PSMA-based tumor burden prior to DTX therapy seems to be a reliable predictive tool for survival in mCRPC patients.

Factors affecting the response to treatment and survival in hepatocellular carcinoma patients treated with transarterial radioembolisation: a single-centre experience.

OBJECTIVE: Transarterial radioembolisation (TARE) is a promising technique for unresectable primary tumours of the liver. We present our clinical experience and the response to treatment and survival data of patients with hepatocellular carcinoma (HCC) who were treated with Y-90 radioembolisation in our hospital's angiography department. MATERIAL AND METHODS: The data of all the patients with HCC referred to our department for Y-90 treatment were analysed retrospectively. The patients were selected according to the treatment protocol criteria, and lung shunt fraction was evaluated using macroaggregated albumin scintigraphy before radioembolisation. Patients with compatible blood tests and lung shunt fraction rates were chosen for treatment with Y-90 TARE. RESULTS: Twenty-four patients were suitable for Y-90 treatment. The patients were treated with 137 ± 44.6 (80-245) Gy Y-90 glass microspheres. The treatment results were evaluated using modified RECIST criteria, and the partial response, complete response, stable disease and progression rates were found to be 54.2, 16.7, 20.8 and 8.3%, respectively. The median survival rate following treatment was 10 months. Higher alpha-fetoprotein (AFP) levels were related to decreased survival, and posttreatment AFP levels had a significant effect on mortality rates. Higher survival rates were detected in the patients who were treated more selectively than the group treated via a lobar approach. CONCLUSION: Y-90 microsphere radioembolisation is a safe method and may be helpful in treating patients with unresectable hepatocellular tumours. More favourable results were obtained in the patients treated using the more selective approach. AFP levels before and after treatment could predict survival rates.

EANM practice guideline/SNMMI procedure standard for dopaminergic imaging in Parkinsonian syndromes 1.0.

PURPOSE: This joint practice guideline or procedure standard was developed collaboratively by the European Association of Nuclear Medicine (EANM) and the Society of Nuclear Medicine and Molecular Imaging (SNMMI). The goal of this guideline is to assist nuclear medicine practitioners in recommending, performing, interpreting, and reporting the results of dopaminergic imaging in parkinsonian syndromes. METHODS: Currently nuclear medicine investigations can assess both presynaptic and postsynaptic function of dopaminergic synapses. To date both EANM and SNMMI have published procedural guidelines for dopamine transporter imaging with single photon emission computed tomography (SPECT) (in 2009 and 2011, respectively). An EANM guideline for D2 SPECT imaging is also available (2009). Since the publication of these previous guidelines, new lines of evidence have been made available on semiquantification, harmonization, comparison with normal datasets, and longitudinal analyses of dopamine transporter imaging with SPECT. Similarly, details on acquisition protocols and simplified quantification methods are now available for dopamine transporter imaging with PET, including recently developed fluorinated tracers. Finally, [18F]fluorodopa PET is now used in some centers for the differential diagnosis of parkinsonism, although procedural guidelines aiming to define standard procedures for [18F]fluorodopa imaging in this setting are still lacking. CONCLUSION: All these emerging issues are addressed in the present procedural guidelines for dopaminergic imaging in parkinsonian syndromes.