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Introduction: Current guidelines don't support the use of pretreatment imaging in patients with favorable intermediate-risk prostate cancer. 68Ga-prostate-specific membrane antigen positron emission tomography/computed tomography (PSMA PET/CT) is more accurate than conventional imaging for preoperative staging. We aimed to evaluate whether pretreatment 68Ga-PSMA PET/CT is beneficial for identifying pathological lymph node involvement (LNI) and adverse pathology among patients with favorable intermediate-risk prostate cancer. Methods: We reviewed 88 patients with favorable intermediate-risk prostate cancer who underwent 68Ga-PSMA PET/CT prior to radical prostatectomy and lymph node dissection from 2016-2020. The primary endpoint was the presence of pathological LNI. Association between pretreatment characteristics and outcomes were evaluated. Results: Preoperative 68Ga-PSMA PET/CT showed suspicious uptake in lymph nodes in 4/88 patients (5%), hence, 20 patients would need to be scanned to identify a patient with a positive lymph node on imaging. Two patients had pathological LNI, only one of whom showed 68Ga-PSMA PET/CT uptake prior to surgery. The sensitivity, specificity, positive predictive value, and negative predictive values of 68Ga-PSMA PET/CT for identifying LNI were 50%, 97%, 25%, and 99%, respectively. After surgery, four patients had evidence of prostate-specific antigen (PSA) persistence. The rate of PSA persistence was higher among patients with LNI on preoperative 68Ga-PSMA PET/CT (2/4, 50% vs. 2/84, 2%, p=0.009). Conclusions: Preoperative imaging of favorable intermediate-risk prostate cancer patients using 68Ga-PSMA PET/CT showed a low yield for identifying patients at higher risk. Consistent with current guidelines, our findings do not support the routine use of PET/CT in this group of patients. Future prospective studies are needed to validate our findings. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the study was to elaborate the incidence and type of skeletal involvement in a large cohort of patients with newly diagnosed prostate cancer (PCa) referred for Ga-68 PSMA-11 PET/CT staging in a single center. Methods: Study cohort included 963 consecutive patients with newly diagnosed PCa referred for Ga-68 PSMA-11 PET/CT study for staging. The incidence of bone involvement, type of bone metastases, and extent of disease were determined and correlated with the ISUP Grade Group (GG) criteria and PSA levels. Results: Bone metastases were found in 188 (19.5%) of 963 patients. Bone metastases were found in 10.7% of patients with PSA < 10 ng/dL and in 27.4% of patients with PSA > 10 ng/dL and in 6.1% of patients with GG ≤ 2/3 and in 8.9% of patients with GG 4/5. In 7.6% of the patients, skeletal involvement was extensive, while 11.9% of patients had oligometastatic disease. Osteoblastic type metastases were the most common type of bone metastases presented in 133 of the patients with malignant bone involvement (70.7%). More than half of them had only osteoblastic lesions (72 patients (38.3%)), while the other (61 patients (32.5%)) had also intramedullary and/or osteolytic type lesions. Intramedullary metastases were found in 97 patients (51.6%), while 41 (21.8%) of them were only intramedullary lesions. Osteolytic metastases were detected in 36 patients (19.2%), of which 8 were only osteolytic lesions. Conclusion: Although traditionally bone metastases of PCa are considered osteoblastic, osteolytic and intramedullary metastases are common, as identified on PET with labeled PSMA. Skeletal spread may be present also in patients with GG ≤ 2/3 and PSA < 10 ng/dL. [ABSTRACT FROM AUTHOR]

Background: [18F]-Fluorodeoxyglucose (FDG) positron emission tomography–computed tomography (PET/CT) may sometimes be suboptimal for imaging gastric adenocarcinoma. The recently introduced [68Ga]Ga-FAPI-04 (FAPI) PET/CT targets tumor stroma and has shown considerable potential in evaluating the extent of disease in a variety of tumors. Methods: We performed a head-to-head prospective comparison of FAPI and FDG PET/CT in the same group of 13 patients with gastric adenocarcinoma who presented for either initial staging (n = 10) or restaging (n = 3) of disease. Lesion detection and maximum standardized uptake value (SUVmax) were compared between the two types of radiotracers. Results: All ten primary gastric tumors were FAPI-positive (100% detection rate), whereas only five were also FDG-positive (50%). SUVmax was not significantly different, but the tumor-to-background ratio was higher for FAPI (mean, median, and range of 4.5, 3.2, and 0.8–9.7 for FDG and 12.9, 11.9, and 2.2–23.9 for FAPI, P = 0.007). The level of detection of regional lymph node involvement was comparable. FAPI showed a superior detection rate for peritoneal carcinomatosis (100% vs. none). Two patients with widespread peritoneal carcinomatosis underwent a follow-up FAPI scan after chemotherapy: one showed partial remission and the other showed progressive disease. Conclusions: The findings of this pilot study suggest that FAPI PET/CT outperforms FDG PET/CT in detecting both primary gastric adenocarcinoma and peritoneal carcinomatosis from gastric cancer. FAPI PET/CT also shows promise for monitoring response to treatment in patients with peritoneal carcinomatosis from gastric cancer; however, larger trials are needed to validate these preliminary findings. [ABSTRACT FROM AUTHOR]

Purpose: Over recent years, peptide receptor radiotherapy (PRRT) has been recognized as an effective treatment for patients with metastatic neuroendocrine tumors (NETs). Personalized dosimetry can contribute to improve the outcome of peptide receptor radiotherapy (PRRT) in patients with metastatic NETs. Dosimetry can aid treatment planning, ensuring that absorbed dose to vulnerable normal organs (kidneys and bone marrow) does not exceed safe limits over serial treatments, and that absorbed dose to tumor is sufficient. Absorbed dose is estimated from a series of post-treatment SPECT/CT images. Total self-dose is proportional to the integral under the time activity concentration curve (TACC). Method dependence of image-based absorbed dose calculations has been previously investigated, and we set out here to extend previous work by examining implications of number of data points in the TACC and the numerical integration methods used in estimating absorbed dose. Methods: In this retrospective study, absorbed dose estimates and effective half-lives were calculated by fitting curves to TACCs for normal organs and tumors in 30 consecutive patients who underwent a series of 4 post-treatment SPECT/CT scans at 4 h, 24 h, 4–5 days, and 1 week following 177Lu-DOTATATE PRRT. We examined the effects of including only 2 or 3 rather than all 4 data points in the TACC, and the effect of numerical integration method (mono-exponential alone or in combination with trapezoidal rule) on the absorbed dose and half-life estimates. Our current method is the combination of trapezoidal rule over the first 24 h, with mono-exponential fit thereafter extrapolated to infinity. The other methods were compared to this current method. Results: Differences in absorbed dose and effective half-life between the current method and estimates based only on the second, third, and fourth scans were very small (mean differences < 2.5%), whereas differences between the current method and 4-point mono-exponential fit were higher (mean differences < 5%) with a larger range. It appears that in a 4-point mono-exponential fit the early (4 h) time point may skew results, causing some large errors. Differences between the current method and values based on only 2 time points were relatively small (mean differences < 3.5%) when the 24 h and 1 week scans were used, but when the 24 h and 4–5 days scans, or the 4–5 days and 1 week scans were used, differences were greater. Conclusion: This study indicates that for 177Lu-DOTATATE PRRT, accurate estimates of absorbed dose for organs and tumors may be estimated from scans at 24 h, 72 h, and 1 week post-treatment without an earlier scan. It may even be possible to cut out the 72 h scan, though the uncertainty increases. However, further work on more patients is required to validate this. [ABSTRACT FROM AUTHOR]

Objectives: To investigate whether scopolamine, an anticholinergic agent which induces hyposalivation, represents a risk factor for the occurrence of dental caries. Materials and methods: A retrospective cohort study was carried out among sailors treated with scopolamine for seasickness. The study population included 370 young healthy male adults (18–30 years old) who served in the Israel Navy between 2012 and 2016. Of these, 66 subjects who were chronically treated with intermittent administration of scopolamine, either by the oral or transdermal route, were assigned to the study group. Documented subject characteristics included age, socioeconomic status, level of education, body mass index, smoking history, and dental hygiene. Follow-up lasted 1 to 3.5 years. Results: Two- to 3.5-year follow-up revealed a higher risk of dental caries in 15 of 16 subjects (93.8%) treated with an average of 50.9 mg scopolamine, in contrast to only 71 of 108 control subjects (65.7%) (RR = 1.43, p = 0.02 [95% CI = 1.18–1.72]). Follow-up for 1–1.5 years revealed a lower occurrence of dental caries in both the study group (11/22, 50.0%) and the control group (46/104, 44.2%). Follow-up of 1.5–2 years also revealed less dental caries, in 16/28 subjects (57.1%) in the study group and 51/92 subjects (55.4%) in the control group. The differences were not statistically significant. Conclusions: In healthy young adults, prolonged intermittent use of scopolamine was found to be a risk factor for the development of dental caries. Clinical significance: Dental care and hygiene should be intensified when administering hyposalivatory anticholinergic agents. [ABSTRACT FROM AUTHOR]

Anaplastic ganglioglioma (AGG) is a rare tumor. A PubMed database search yielded only a few case reports and fewer case series. An even rarer entity is AGG arising in the spinal cord. We present a case of a pediatric patient with a pathological diagnosis of spinal AGG. Copyright © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Central nervous system metastases from nasopharyngeal carcinoma (NPC) are uncommon. The patient presented was diagnosed with aggressive advanced NPC resistant to treatment and complicated by a solitary brain metastasis. A Pub Med database search was conducted to review the existing literature regarding brain metastases of NPC, using the search terms "nasopharyngeal neoplasia," "nasopharyngeal carcinoma," "nasopharynx," "radiotherapy," "central nervous system," and "brain" in section of "Title/Abstract." The articles were first evaluated by title and then by abstract, and thereafter appropriate manuscripts were evaluated by full text. References of the published papers were also reviewed. [ABSTRACT FROM AUTHOR]

Bone metastases from prostate cancer (PCa) often show an increase in density on computed tomography (CT) after successful androgen deprivation therapy (ADT). Density may be reduced, however, as the disease progresses or, contrarily, when disease is no longer active. The current study investigated the role of 68Ga-PSMA-11 positron emission tomography/computed tomography (PET/CT) in differentiating between these two conditions. Methods: The study cohort included 15 PCa patients with sclerotic/blastic bone metastasis in whom reduction in bone density of metastasis was noted on follow-up 68Ga-PSMA-11 PET/CT after ADT. Each patient had two PET/CT scans. Prior to the first scan, six patients were castration naïve and nine patients were already treated. All patients had ADT between the two PET/CT scans. PET parameters (SUVmax and tumor-to-background ratio), and CT parameters (HUmax) were determined and compared for each lesion on both scans. Patient's response was based on prostate-specific antigen (PSA) levels and appearance of new lesions. The Kolmogorov–Smirnov test was used to evaluate normal distribution of the continuous variables. Results: Post-ADT reduction in bone density was identified in 37 lesions. The mean HUmax was 883.9 ± 175.1 on the first scan and 395.6 ± 157.1 on the second scan (p < 0.001). Twenty-one of the 37 lesions showed no increased tracer uptake on the second PET/CT scan raising the likelihood of a response. The other 16 lesions were associated with increased uptake suggestive of an active resistant disease. Bone density was not different in lesions that no longer showed an increased uptake as compared with those that did. Seven of the study patients responded to therapy, and none of the 16 lesions found in these patients showed increased 68Ga-PSMA-11 uptake. In eight patients with progressive disease, all 12 lesions in five of them showed increased 68Ga-PSMA-11 uptake, there was mixed response in two patients (having two lesions with increased uptake and one without) and although all three lesions no longer showed an increased uptake, new lesions were detected in the eighth patient. Conclusion: A decrease in density of bone lesions may reflect clinical progression, or contrarily, a response to therapy in patients with PCa and skeletal involvement treated with ADT. Uptake of 68Ga-PSMA-11 may separate between these two vastly opposing conditions. [ABSTRACT FROM AUTHOR]

Introduction: Data on the accuracy of 68Ga-PSMA positron emission tomography/computed tomography (PET/CT) in patients with intermediate/high-risk prostate cancer are being accumulated. Its role in assessing the extent of local disease has not been fully elaborated.Aim: To determine the performance characteristics of 68Ga-PSMA PET/CT in identifying local disease extension in patients with intermediate/high risk prostate cancer.Methods: 68Ga-PSMA PET/CT studies of 61 consecutive patients with intermediate/high-risk prostate cancer who underwent radical prostatectomy were reviewed by nuclear medicine specialists. Tumor location, extraprostatic extension (EPE), seminal vesicle invasion (SVI), and lymph nodes involvement (LNI) were compared to pathological findings. The incremental value of 68Ga-PSMA PET/CT to established nomograms was determined.Results: Two patients without pathologic uptake of 68Ga-PSMA were excluded. Seventeen patients were diagnosed with EPE (29%), 12(20%) had SVI and 3(5%) LNI. The concordance between tumor location and 68Ga-PSMA PET/CT findings was 48%, and EPE was not indicated by PET in any of the patients. The sensitivity, specificity, positive, and negative predictive value for SVI were 58%, 96%, 78%, 90%, respectively (area under the receiver operating characteristic curve = 0.77) and for LNI 67%, 98%, 67%, 98%, respectively (area under the receiver operating characteristic curve = 0.82). Incorporating imaging findings into the MSKCC-SVI nomogram enhanced the diagnostic accuracy from 0.84 to 0.95 (Integrated Discrimination Increment 0.24, P = 0.004).Conclusion: In patients with intermediate/high-risk prostate cancer, 68Ga-PSMA PET/CT provides information regarding intraprostatic tumor location, SVI and LNI but has no role in assessment for EPE. This information might be useful for pretreatment counseling, decision-making and possibly preoperative planning. [ABSTRACT FROM AUTHOR]

Background: The aim of the current study was to assess whether and to what extent monitoring response to treatment using prostate-specific membrane antigen (PSMA)-based positron-emitting tomography/computerized tomography (PET/CT) studies contribute clinically relevant data to routine clinical follow-up during treatment of patients with metastatic prostate cancer (PCa). Results: Fifty-two patients with metastatic PCa who underwent [68Ga]Ga-PSMA-11 PET/CT imaging and serum prostate-specific antigen (PSA) level measurements before and during treatment were investigated. Response was categorized by serum PSA dynamics according to improvement, stable disease, and disease progression and compared to change in imaging findings on pre- and post-treatment PET/CTs. McNemar's test was used to assess agreement between PET/CT- and PSA-based responses to treatment. Thirty-four patients (65.4%) had compatible biochemical- and imaging-based response to treatment. However, the imaging and biochemical responses were discrepant in 18/52 patients (34.6%). PET/CT showed progressive disease in 5/52 patients (9.6%) and improvement/stable disease in 13/52 (25%) compared to biochemical assessment results. Discrepancy between imaging and biochemical response was most prominent in biochemically stable patients (90.9%), followed by patients with biochemical progression (33.3%), and in only few (8.7%) patients with biochemical improvement. The imaging-based response was suitable for choosing subsequent treatment in 22 of 30 patients (73.3%) with longer follow-up (median time of 10.3 months (IQR 6.3–18.2)). The relevance of the imaging methodology was reflected by its ability to assess individual lesions in cases of heterogeneous lesion responses, reveal the appearance of new lesions, and identify lesions that required specific consideration, such as targeted radiotherapy. Conclusions: Results of this retrospective analysis showed that biochemical responses to treatment and [68Ga]Ga-PSMA-11 PET/CT-based responses to treatment differ in one third of metastatic PCa patients. The latter additionally enabled lesion-based and not solely patient-based analysis. Monitoring response during treatment by [68Ga]Ga-PSMA-11 PET/CT is suitable for decision-making in patient management and choice of treatment in the majority of patients. [ABSTRACT FROM AUTHOR]