Positive FAPI PET/CT in a Bilateral Mammary Angiosarcoma Patient With Less Impressive FDG PET/CT Images

Nomogram construction for overall survival in breast angiosarcoma based on clinicopathological features: a population-based cohort study

BACKGROUND

Breast angiosarcoma (BAS) is a rare, aggressive malignancy with a poor prognosis, often challenging to assess due to its unique biology. This study aimed to develop a nomogram to predict 3- and 5-year overall survival (OS) for BAS patients using key clinicopathological factors.

METHODS

Data from 450 BAS patients diagnosed between 2000 and 2021 were extracted from SEER database. Key variables, including age, tumor size, tumor grade, and distant metastasis status, were identified through univariate and multivariate Cox regression analyses. These factors were incorporated into a nomogram for OS prediction. The model was validated internally and externally using the concordance index (C-index), calibration curves, and decision curve analysis (DCA) to assess its predictive accuracy and clinical utility.

RESULTS

The nomogram demonstrated good predictive accuracy, with a C-index of 0.68 in the training set and 0.72 in the test set. ROC analysis indicated strong short-term predictive power, with AUC values of 0.81 and 0.75 for 1-year survival in the training and test sets, respectively, though predictive performance declined over time. DCA showed substantial clinical benefit for 12-month predictions, which diminished over longer time frames. The model effectively distinguished high-risk BAS patients and provided individualized survival estimates, supporting its potential use in clinical decision-making.

CONCLUSION

This study presents the first BAS nomogram for OS prediction, showing robust short-term accuracy. The long-term utility is limited by heterogeneity and sample size, highlighting the need for external validation to confirm generalizability and clinical applicability.

18 F-FAPI PET/CT Imaging in a Case of Synovial Sarcoma

ABSTRACT

Synovial sarcoma is a rare malignancy of mesenchymal origin, known for its propensity for metastasis and challenging early diagnosis, primarily affecting adolescents and young adults. This case report illustrates the utility of 18 F-fibroblast activation protein inhibitor PET/CT in an 18-year-old woman with synovial sarcoma primarily located in the left calf and metastases in the left thoracic cavity.

Significantly Higher 68 Ga-FAPI Than 18 F-FDG Uptake by Hidradenocarcinoma of Head and Neck on PET/CT

ABSTRACT

Hidradenocarcinoma is quite rare in clinical practice. Herein, we describe the 68 Ga-FAPI and 18 F-FDG PET/CT findings of hidradenocarcinoma of the head and neck in a 75-year-old man. In the present case, the primary tumor and secondary lesions showed intense accumulation of 68 Ga-FAPI but only slight 18 F-FDG uptake. This case demonstrates that 68 Ga-FAPI PET/CT might be used as a helpful tool for evaluating hidradenocarcinoma.

Comparison of 18 F-FDG and 18 F-FAPI PET/CT Findings of Signet-Ring Cell Carcinoma of the Stomach

ABSTRACT

A 66-year-old man with gastric signet-ring cell carcinoma underwent both 18 F-FDG and 18 FAl-NOTA-FAPI PET/CT imaging. There was no abnormal FDG activity in the stomach, but there was diffuse intense 18 FAl-NOTA-FAPI uptake in the known lesion and an adjacent metastasis.

18 F-FDG PET/CT Versus 18 F-FAPI PET/CT in a Case of Recurrent Malignant Phyllodes Breast Tumor

ABSTRACT

A 52-year-old woman with medical history of surgery for left malignant phyllodes breast tumor found a mass on the left chest 3 months ago. A suspicion of recurrent malignant phyllodes breast tumor was made. The patient was enrolled in the clinical trial of 18 F-FAPI PET/CT in recurrent sarcoma (no. NCT05485792). 18 F-FAPI PET/CT and 18 F-FDG PET/CT were performed, and the images demonstrated intense uptake in a huge mass in the left anterior chest wall. Then the patient underwent extended resection of left chest wall tumor. The tumor proved to be recurrent malignant phyllodes breast tumor pathologically.

Fibroblast Activation Protein Inhibitor (FAPI)-PET Imaging in Sarcoma

Advances in histopathologic and molecular genetic subtyping of sarcoma will potentially allow identification of novel diagnostic and therapeutic targets for specific subtypes, but a "pan-sarcoma" target is needed. This article provides an overview on expression of one potential candidate, fibroblast activation protein alpha in soft tissue and bone sarcoma, and the resulting application of 68Ga-FAPI as novel imaging probes in these rare tumor entities. Current preclinical and clinical data on 68Ga-FAPI-PET/CT in sarcomas are summarized. 68Ga-FAPI-PET-CT potentially offers important complementary information to be used in diagnostic work-up, assessment of therapy response, and prognostication of soft tissue and bone sarcomas.

Complex Fibroadenoma Mimicking Breast Cancer on 68Ga-FAPI-04 and 18F-FDG PET/CT

ABSTRACT

A 47-year-old woman had complaint of palpable swelling in the left breast for the last 3 weeks. 18F-FDG PET/CT for staging of concomitant invasive carcinoma in the right breast and 68Ga-labeled fibroblast activation protein inhibitor 04 PET/CT imaging in an ongoing study were performed. Increased radiopharmaceutical uptake was observed in both PET/CT imaging in complex fibroadenoma located in the left breast.

PET-CT in Clinical Adult Oncology-VI. Primary Cutaneous Cancer, Sarcomas and Neuroendocrine Tumors

PET-CT is an advanced imaging modality with many oncologic applications, including staging, therapeutic assessment, restaging and surveillance for recurrence. The goal of this series of six review articles is to provide practical information to providers and imaging professionals regarding the best use of PET-CT for specific oncologic indications, the potential pitfalls and nuances that characterize these applications, and guidelines for image interpretation. Tumor-specific clinical information and representative PET-CT images are provided. The current, sixth article in this series addresses PET-CT in an evaluation of aggressive cutaneous malignancies, sarcomas and neuroendocrine tumors. A discussion of the role of FDG PET for all types of tumors in these categories is beyond the scope of this review. Rather, this article focuses on the most common malignancies in adult patients encountered in clinical practice. It also focuses on Food and Drug Agency (FDA)-approved and clinically available radiopharmaceuticals rather than research tracers or those requiring a local cyclotron. This information will serve as a guide to primary providers for the appropriate role of PET-CT in managing patients with cutaneous malignancies, sarcomas and neuroendocrine tumors. The nuances of PET-CT interpretation as a practical guide for imaging providers, including radiologists, nuclear medicine physicians and their trainees, are also addressed.