Background
18
F-Fluorodeoxyglucose (FDG) positron emission tomography–computed tomography (PET/CT) may sometimes be suboptimal for imaging gastric adenocarcinoma. The recently introduced
68
...GaGa-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 (SUV
max
) 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%). SUV
max
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.
The adult mouse prostate has a seemingly endless capacity for regeneration, and sonic hedgehog (SHH) signaling has been implicated in this stem cell-driven process. However, it is not clear whether ...SHH acts on the epithelium or stromal cells that secrete factors required for epithelial expansion. Because little is known about stromal stem cells compared with their epithelial counterparts, we used in vivo mouse genetics tools to characterize four prostate stromal subtypes and their stem cells. Using knockin reporter alleles, we uncovered that SHH signals from prostate basal epithelial cells to adjacent stromal cells. Furthermore, the SHH target gene Gli1 is preferentially expressed in subepithelial fibroblast-like cells, one of four prostate stromal subtypes and the subtype closest to the epithelial source of SHH. Using Genetic Inducible Fate Mapping to mark adult Gli1 - or Smooth muscle actin -expressing cells and follow their fate during regeneration, we uncovered that Gli1 -expressing cells exhibit long-term self-renewal capacity during multiple rounds of androgen-mediated regeneration after castration-induced involution, and depleted smooth muscle cells are mainly replenished by preexisting smooth muscle cells. Based on our Genetic Inducible Fate Mapping studies, we propose a model where SHH signals to multiple stromal stem cells, which are largely unipotent in vivo.
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.
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.
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 (
< 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.
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.
The goal of Identity, Formation, Agency, and Culture is to lay the basis of a theory with which to better understand the difficulties and complexities of identity formation. It provides an extensive ...understanding of identity formation as it relates to human striving (agency) and social organization (culture). James E. Côté and Charles G. Levine have compiled state-of-the-art psychological and sociological theory and research into a concise synthesis. This volume utilizes a vast, interdisciplinary literature in a reader-friendly style. Playing the role of narrators, the authors take readers through the most important theories and studies of self and identity, focusing on pragmatic issues of identity formation--those things that matter most in people's lives.
Identity, Formation, Agency, and Culture is intended for identity-related researchers in the behavioral and social sciences, as well as clinicians, counselors, and social workers dealing with identity-related disorders. It also serves as a main or supplemental text in advanced courses on identity, identity and human development, social development, moral development, personality, the sociology of identity, and the individual and society taught in departments of psychology, sociology, human development, and family studies.
Contents: Preface. Part I: A Critical Analysis of Approaches to Self and Identity. Identity Theory in Perspective. Psychological Approaches to the Concepts of Self and Identity. The Identity Concept in Sociology. Integrating Sociological and Psychological Perspectives on Identity: Toward a Social Psychology of Identity. Issues in Definition and Critique. Part II: A Return to a Formal Theory of Ego Identity Formation. Erikson Revisited: The Basis of a Formal Theory of Identity Formation. Identity, Agency, and Social Structure. Part III: Theoretical and Empirical Elaborations for a Social Psychology of Identity in Late Modernity. Identity Capital. Assessing the Adequacy of Identity Stage Resolution in Late Modernity. Identity and Late Modern Society: Ongoing Concerns and Future Research.
Our purpose was to retrospectively evaluate the cases of patients with surgically proven appendicitis that was misdiagnosed on abdominal CT to determine the causes of the missed diagnosis.
Increased ...awareness of the underlying factors common to most cases of the missed diagnosis of appendicitis on CT and increased radiologic vigilance in cases of atypical abdominal pain may enable us to further improve our diagnostic accuracy.
Although prostate-specific membrane antigen (PSMA) PET/CT has been shown valuable for staging biopsy-proven B(+) high-risk prostate cancer, elderly patients are occasionally referred for PSMA PET/CT ...without a preimaging confirming biopsy B(−). The current study evaluated the rate, clinical characteristics, and PET-based stage of elderly B(−) patients and explored whether biopsy status affects therapeutic approach. Methods: One hundred consecutive patients at least 80 y old who underwent staging 68Ga-PSMA-11 PET/CT were included. For each patient, we documented whether preimaging biopsy was performed, the clinical parameters, the PET-based staging parameters, and the primary therapy received. Results: Thirty-four (34%) of the elderly patients included in the study had no preimaging biopsy. Compared with B(+) patients, B(−) patients were older (median age, 87 vs. 82 y; P < 0.01), with worse performance status (P < 0.01) and higher prostate-specific antigen (PSA) levels (median, 57 vs. 15.4 ng/mL; P < 0.01). On 68Ga-PSMA-11 PET/CT, all B(−) patients had avid disease, with trends toward higher rates of bone metastases (47.1% vs. 28.8%) and overall advanced disease (50% vs. 33.3%) than in B(+) patients. Among patients with localized (n = 36) or locally advanced (n = 25) disease, B(−) patients were less commonly referred than B(+) patients for definitive therapies (P < 0.01). However, higher age, Eastern Cooperative Oncology Group performance status, and PSA were other probable factors determining their therapeutic approach. Among 39 patients with advanced disease, 38 received hormonal therapy irrespective of their biopsy status. Among B(−) patients with advanced disease who were referred for hormonal therapy, 12 of 13 with follow-up data showed a biochemical or imaging-based response. Conclusion: Real-life experience with 68Ga-PSMA-11 PET/CT indicates that around one third of elderly patients are referred for imaging without a preimaging confirming biopsy. These patients are likely to be older, with a worse clinical status and higher PSA levels. Advanced disease might be more likely to be identified on their 68Ga-PSMA-11 PET/CT images, and if it is, their biopsy status does not preclude them from receiving hormonal therapy.
Although prostate-specific membrane antigen (PSMA) PET/CT has been shown valuable for staging biopsy-proven B(+) high-risk prostate cancer, elderly patients are occasionally referred for PSMA PET/CT ...without a preimaging confirming biopsy B(-). The current study evaluated the rate, clinical characteristics, and PET-based stage of elderly B(-) patients and explored whether biopsy status affects therapeutic approach.
One hundred consecutive patients at least 80 y old who underwent staging
Ga-PSMA-11 PET/CT were included. For each patient, we documented whether preimaging biopsy was performed, the clinical parameters, the PET-based staging parameters, and the primary therapy received.
Thirty-four (34%) of the elderly patients included in the study had no preimaging biopsy. Compared with B(+) patients, B(-) patients were older (median age, 87 vs. 82 y;
< 0.01), with worse performance status (
< 0.01) and higher prostate-specific antigen (PSA) levels (median, 57 vs. 15.4 ng/mL;
< 0.01). On
Ga-PSMA-11 PET/CT, all B(-) patients had avid disease, with trends toward higher rates of bone metastases (47.1% vs. 28.8%) and overall advanced disease (50% vs. 33.3%) than in B(+) patients. Among patients with localized (
= 36) or locally advanced (
= 25) disease, B(-) patients were less commonly referred than B(+) patients for definitive therapies (
< 0.01). However, higher age, Eastern Cooperative Oncology Group performance status, and PSA were other probable factors determining their therapeutic approach. Among 39 patients with advanced disease, 38 received hormonal therapy irrespective of their biopsy status. Among B(-) patients with advanced disease who were referred for hormonal therapy, 12 of 13 with follow-up data showed a biochemical or imaging-based response.
Real-life experience with
Ga-PSMA-11 PET/CT indicates that around one third of elderly patients are referred for imaging without a preimaging confirming biopsy. These patients are likely to be older, with a worse clinical status and higher PSA levels. Advanced disease might be more likely to be identified on their
Ga-PSMA-11 PET/CT images, and if it is, their biopsy status does not preclude them from receiving hormonal therapy.
Purpose
The recent introduction of integrated PET-MRI systems into practice seems promising in oncologic imaging, and efforts are made to specify their added values. The current study evaluates the ...added values of PET-MRI over PET-CT in detecting active malignant hepatic lesions.
Methods
As part of an ongoing prospective study in our institution that assesses the added values of PET-MRI, subjects undergo PET-CT and subsequent PET-MRI after single radiotracer injection. The current study included 97 pairs of whole-body PET-CT and liver PET-MRI scans, of 61 patients (19/61 had ≥ 2 paired scans), all performed with
18
FFDG and interpreted as showing active malignant hepatic involvement. Primary malignancies were of colorectal/biliary/pancreatic/breast/other origins in 19/9/9/7/17 patients. Monitoring response to therapy was the indication in 86/97 cases. When PET-MRI detected additional malignant lesions over PET-CT, lesions size, their characteristics on PET-MRI, and the influence on the final report were recorded.
Results
In 37/97 (38.1%) cases, a total of 78 malignant lesions were identified on PET-MRI but not on PET-CT: 19 lesions (11 cases) were identified on PET of PET-MRI but not on PET of PET-CT; 37 lesions (14 cases) were small (≤ 0.8 cm) and identified on MRI only; 22 lesions (12 cases) were > 0.8 cm, had low/no
18
FFDG uptake, but were categorized as viable based on MRI. These 78 lesions caused major effect on final reports in 11/97 (11.3%) cases, changing reported response assessment category (10/86 cases) or defining malignant hepatic disease on staging/restaging scans (1/11 cases).
Conclusion
PET-MRI offers several advantages over PET-CT in assessing the extent and response to therapy of malignant hepatic involvement. Additional malignant lesions detected on PET-MRI are attributed to superior PET performance (compared with PET of PET-CT), greater spatial resolution provided by MRI, and improved multi-parametric viability assessment. In around one-tenth of cases, findings identified on PET-MRI but not on PET-CT significantly change the final report’s conclusion.
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