The role of basal metabolic and volumetric 18F-FDG PET/CT parameters and their changes in predicting pathological complete response in breast cancer patients receiving neoadjuvant chemotherapy.

OBJECTIVE: The aim of this study is to investigate the roles of pre- and post- treatment quantitative fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) parameters including maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) and their rate of change in predicting pathological complete response (pCR) in patients with local and locally advanced invasive breast cancer receiving neoadjuvant chemotherapy (NAC). SUBJECTS AND METHODS: Ninety-eight patients who received NAC after being diagnosed with local and locally advanced invasive breast cancer between January 2017 and September 2021 were retrospectively included in our study. Molecular subtypes of all patients were determined. Maximum SUV, MTV, TLG, percent change in SUVmax (ΔSUVmax), ΔMTV, and ΔTLG obtained from PET/CT scans performed before and after NAC were calculated. The cut-off, AUC, sensitivity, and specificity values of these parameters in predicting pCR were calculated using receiver operating characteristic (ROC) curves. RESULTS: ΔTMTV (cut-off 94.01%, AUC: 0.846), ΔTTLG (cut-off 97.36%, AUC: 0.870), B2MTV (cut-off<1.75, AUC: 0.764), B2TLG (cut-off<2.11, AUC: 0.764), B2SUVmax (cut-off<1.58, AUC: 0.767), ΔBMTV (cut-off 93.67%, AUC: 0.851), ΔBTLG (cut-off 97.22%, AUC: 0.870), ΔBSUVmax (cut-off 84.99%, AUC: 0.846) calculated using ROC curves were found to significantly predict pCR with high sensitivity and specificity. CONCLUSION: We concluded that metabolic and volumetric PET/CT parameters, the rates of their change, and metabolic response during NAC may be important variables in predicting pCR in patients with breast cancer.

68Ga-FAPI-04 PET/CT Versus 18F-FDG PET/CT in Malignant Peritoneal Mesothelioma.

ABSTRACT: An 83-year-old man presented with abdominal pain, vomiting, and bloating. His abdominal CT revealed heterogeneous peritoneal thickening in the lower quadrants, which was more prominent in the pelvic region. 18F-FDG PET/CT performed to locate the primary tumor showed irregular peritoneal and omental thickening with low to moderate FDG uptake. 68Ga-FAPI (fibroblast activation protein-specific inhibitor)-04 PET/CT of the patient, whose primary tumor could not be detected using FDG, showed high radiopharmaceutical uptake in the areas of heterogeneous thickening on peritoneal and serosal surfaces. Peritoneal Tru-Cut biopsy revealed malignant tumoral infiltration indicating mesothelioma. This case showed that 68Ga-FAPI-04 PET/CT could be a promising radiopharmaceutical in the evaluation of peritoneal mesothelioma.

A Case with 68Ga-FAPI Positive and 18F-FDG Negative Breast Cancer

A female patient diagnosed of infiltrative breast carcinoma using tru-cut biopsy underwent 18flourine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) for staging. The tumor was located in the superior external quadrant of the right breast, and did not exhibit pathological uptake in 18F-FDG PET/CT. Later, gallium-68 (68Ga) fibroblast activation protein-specific inhibitor (FAPI)-04 PET/CT imaging was performed and the primary tumor showed intense radiotracer accumulation. This presumes that 68Ga-FAPI PET/CT imaging is superior to 18F-FDG imaging in detecting the primary tumor in breast cancer, thereby suggesting the replacement of FAPI by 18F-FDG in breast-cancer staging in the future.

Nivolumab-Related Dry Mouth and Dry Eye: Cross-Sectional Study.

To evaluate ICIs related dry eye and dry mouth in nivolumab therapy, 24 patients receiving nivolumab (group 1), 30 patients in remission without treatment for 6 months (group 2), 30 healthy participants (group 3) were cross-sectionally examined. Schirmer's 1, 2, TSH blood tests, serological analysis, salivary flow scintigraphy and minor-salivary gland biopsy were performed. Schirmer's tests were performed with anesthetic (1) and without anesthetic (2). Schirmer's scores were lower in group 1 with more frequent reduced tear production (p < 0.001). TSH levels negatively correlated with Schirmer's scores. Functional insufficiency was detected by salivary flow scintigraphy in 7 out of 10 patients with Schirmer's test positivity. In Schirmer's positive patients, lymphocytic sialadenitis was confirmed in 4 patients (focus score > 1) and CD4 T lymphocyte precipitation was observed in 6 patients. Nivolumab therapy may be associated with ICIs related immune sicca.