ABSTRACT
A 35-year-old woman with history of breast cancer was referred to our department for restaging by F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scan. Aside from multiple other FDG-avid metastatic lesions, a segmental increased FDG uptake was visualized along the asymmetrically thicker left first sacral nerve root, highly concerning for metastatic disease, which was confirmed by the subsequently performed magnetic resonance imaging. Our case highlights the capability of FDG PET/CT scan in the correct diagnosis of the extremely rare phenomenon of nerve root metastasis as well as the importance of differentiating FDG-avid lumbosacral nerve roots from adjacent skeletal metastases.
Subject(s)
Leiomyosarcoma , Thrombosis , Uterine Neoplasms , Female , Humans , Positron Emission Tomography Computed Tomography , Fluorodeoxyglucose F18 , Leiomyosarcoma/diagnostic imaging , Leiomyosarcoma/pathology , Vena Cava, Inferior , Uterine Neoplasms/diagnostic imaging , Uterine Neoplasms/pathologyABSTRACT
Introduction: This study was conducted to evaluate the predictive values of volumetric parameters and radiomic features (RFs) extracted from pretreatment 68Ga-PSMA PET and baseline clinical parameters in response to 177Lu-PSMA therapy. Materials and methods: In this retrospective multicenter study, mCRPC patients undergoing 177Lu-PSMA therapy were enrolled. According to the outcome of therapy, the patients were classified into two groups including positive biochemical response (BCR) (≥ 50% reduction in the serum PSA value) and negative BCR (< 50%). Sixty-five RFs, eight volumetric parameters, and also seventeen clinical parameters were evaluated for the prediction of BCR. In addition, the impact of such parameters on overall survival (OS) was evaluated. Results: 33 prostate cancer patients with a median age of 69 years (range: 49-89) were enrolled. BCR was observed in 22 cases (66%), and 16 cases (48.5%) died during the follow-up time. The results of Spearman correlation test indicated a significant relationship between BCR and treatment cycle, administered dose, HISTO energy, GLCM entropy, and GLZLM LZLGE (p<0.05). In addition, according to the Mann-Whitney U test, age, cycle, dose, GLCM entropy, and GLZLM LZLGE were significantly different between BCR and non BCR patients (p<0.05). According to the ROC curve analysis for feature selection for prediction of BCR, GLCM entropy, age, treatment cycle, and administered dose showed acceptable results (p<0.05). According to SVM for assessing the best model for prediction of response to therapy, GLCM entropy alone showed the highest predictive performance in treatment planning. For the entire cohort, the Kaplan-Meier test revealed a median OS of 21 months (95% CI: 12.12-29.88). The median OS was estimated at 26 months (95% CI: 17.43-34.56) for BCR patients and 13 months (95% CI: 9.18-16.81) for non BCR patients. Among all variables included in the Kaplan Meier, the only response to therapy was statistically significant (p=0.01). Conclusion: This exploratory study showed that the heterogeneity parameter of pretreatment 68Ga-PSMA PET images might be a potential predictive value for response to 177Lu-PSMA therapy in mCRPC; however, further prospective studies need to be carried out to verify these findings.
ABSTRACT
ABSTRACT: Recently imaging with new PET radiotracers that act as fibroblast activation protein inhibitors (FAPIs) showed promising results in oncology and even nononcology imaging. Here we report a case of advanced pancreatic adenocarcinoma, imaged with both 18 F-FDG and 68 Ga-FAPI-46 PET/CT scans. The result indicated that imaging with 68 Ga-FAPI-46 showed significant improvement in detection of metastases as well as local malignancy recurrence. Moreover, the intensity and SUVs of the lesions were higher in 68 Ga-FAPI-46 scan compared with 18 F-FDG.
Subject(s)
Adenocarcinoma , Pancreatic Neoplasms , Adenocarcinoma/diagnostic imaging , Fluorodeoxyglucose F18 , Gallium Radioisotopes , Humans , Neoplasm Recurrence, Local , Pancreatic Neoplasms/diagnostic imaging , Positron Emission Tomography Computed Tomography/methods , QuinolinesABSTRACT
ABSTRACT: A 59-year-old prostate cancer patient, status post radical prostatectomy, was referred to our department for restaging with 68Ga-prostate-specific membrane antigen (PSMA) PET/CT scan. Aside multiple metastatic lesions involving pelvic lymph nodes as well as the right femoral trochanter, a PSMA-positive rectal wall thickening was detected. Colonoscopy correlation and tissue diagnosis, recommended to rule out accompanying primary malignancy, confirmed the presence of rectal adenocarcinoma. This case signifies the importance of requesting pathological correlation for unexplained PSMA-positive lesions, emphasizing the potential role PSMA ligands may play in detecting occult second primary malignancies, especially synchronous/metachronous colorectal cancers.
Subject(s)
Adenocarcinoma , Prostatic Neoplasms , Adenocarcinoma/diagnostic imaging , Edetic Acid , Gallium Isotopes , Gallium Radioisotopes , Humans , Male , Middle Aged , Positron Emission Tomography Computed Tomography , Prostatectomy , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/surgery , RadiopharmaceuticalsABSTRACT
ABSTRACT: A 52-year-old woman with metastatic pancreatic adenocarcinoma underwent imaging with 18F-FDG PET/CT and 68Ga-FAPI-46 PET/CT, which demonstrated malignancy recurrence in the surgical bed with multiple metastatic lesions, more extensive on 68Ga-FAPI-46 PET/CT. The patient was a candidate for therapy with 177Lu-FAPI-46 due to high uptake of lesions in 68Ga-FAPI-46 images and no other available therapeutic option. Posttreatment 177Lu-FAPI-46 scans showed rather rapid washout of the radiopharmaceutical from tumoral lesions. This case report suggests that, although 68Ga-FAPI-46 is a promising agent for tumor imaging, 177Lu-FAPI-46 may not be an optimal compound for theranostic applications.