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Abstract: Schwannomas are usually benign, rare, and slow-growing nerve sheath tumor composed of Schwann cells. They develop in the head and neck area in approximately 25% to 40% of cases, of which 1% in the oral cavity, where the tongue remains the preferred site. Malignant transformation occurs in approximately 8% to 10% cases. We report a unique case of a histologically proven FDG-avid schwannoma of the left mobile portion of the tongue, showing an 18F-FDG avidity on PET/CT, which was a false-positive result for local recurrence in a patient followed for squamous cell carcinoma., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: Recent advances in the development of innovative treatments for MM (metastatic melanoma) significantly improved survival. BRAF inhibitor-targeted therapies are also indicated in stage IV BRAF-mutant melanoma, especially dabrafenib and trametinib in combination. The authors present here an impressive rapid (1 month) complete metabolic response on FDG PET/CT to BRAF inhibitors of an MM with a massive tumor burden estimated at more than 10 kg., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: A 67-year-old man was referred to our department to undergo a 68Ga-DOTATOC PET/CT during the systematic follow-up of a small intestine neuroendocrine tumor. PET revealed an incidental focal increased uptake of 68Ga-DOTATOC matching with a left intraparotid lesion on the combined contrast-enhanced CT, suggestive of a benign salivary tumor. An MRI was performed to characterize this lesion, and finally, the patient underwent surgery. Histological analysis confirmed the presence of a basal cell adenoma., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Patients and Methods: Patients with WD-GEP-NET who benefited from a pretherapeutic 68Ga-DOTATOC PET/CT and a 177Lu-DOTATATE SPECT/CT after the cycle 1 of peptide receptor radionuclide therapy were prospectively included. SPECT/CT acquisitions were performed on a system calibrated with a conversion factor of 9.48 counts/MBq per second and were reconstructed with an iterative algorithm allowing quantification using the SPECTRA Quant software (MIM Software, Cleveland, OH). For each patient, different SUV parameters were recorded on both PET/CT (Ga parameters) and SPECT/CT (Lu parameters) for comparison: physiological uptakes (liver/spleen), tumor uptake (1-10/patient; SUVmax, SUVmean, SUVpeak, MTV), tumor-to-liver and tumor-to-spleen ratios according to liver/spleen SUVmax and SUVmean (TLRmax, TLRmean, TSRmax, and TSRmean, respectively)., Results: Ten patients (8 female; 2 male) aged from 50 to 83 years presenting with a metastatic progressive WD-GEP-NET (7 small intestine, 2 pancreas, 1 rectum) were included. Median values of lesional Lu-SUV were significantly lower than the corresponding Ga-SUV (P < 0.001), whereas median values of lesional Lu-MTV, Lu-TLR, and Lu-TSR were significantly higher than the corresponding Ga-MTV, Ga-TLR, and Ga-TSR (P < 0.02). Pearson correlation coefficients were strong for both SUV and MTV parameters (0.779-0.845), weak for TLR parameters (0.365-0.394), and moderate-to-strong for TSR parameters (0.676-0.750)., Conclusions: Our results suggest the feasibility of 177Lu-DOTATATE SPECT/CT quantification in clinical practice and show a strong correlation of several SUV-based parameters with the corresponding in 68Ga-DOTATOC PET/CT., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Abstract: We report an increased uptake of 18F-choline in the right cerebellopontine angle area in a 73-year-old man with biochemical failure prostate cancer after radical prostatectomy, potentially suggestive of bone metastasis in the base of the skull. A brain MRI was also performed showing an intense gadolinium enhancement focus in the same area, concordant with a right vestibular schwannoma, subsequently histologically proven. This case underlines that schwannoma is a diagnostic pitfall in 18F-choline PET/CT, suggesting this radiolabeled tracer as a promising tool for brain tumors characterization due to its higher signal-to-background ratio than 18F-FDG., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Triplet chemotherapy (FOLFOXIRI) + bevacizumab regimen is indicated as first-line treatment of BRAF-mutated metastatic colorectal cancer (mCRC). Nevertheless, its proven therapeutic efficacy in clinical trials was solely based on partial morphologic responses assessed by CT. To date, only 1 case of complete response assessed by FDG PET/CT was reported in literature in BRAF-mutated mCRC, but treated with doublet chemotherapy (FOLFIRI) + cetuximab regimen. We report a complete metabolic response assessed by FDG PET/CT, maintained over time (13 months) in a 60-year-old woman with BRAF-mutated mCRC treated by FOLFOXIRI-bevacizumab. This also confirms that FDG PET/CT is emerging as a useful approach for therapeutic assessment of targeted drugs in mCRC.

Paclitaxel-ramucirumab chemotherapy is indicated in second line of metastatic gastroesophageal junction cancer (mGEJC) after progression under platinum-5-FU chemotherapy. Nevertheless, the reported common response after treatment is only partial within series. To date, only 1 case report of negative posttreatment FDG PET/CT was published without baseline examination from RAINBOW trial. We illustrated the interest of FDG PET/CT to evaluate treatment especially paclitaxel-ramucirumab with 2 examples of complete metabolic responses in 2 patients having different HER2 biomarker profiles of mGEJC. As illustrated, FDG PET/CT emerges as a useful approach for therapeutic assessment of targeted drugs in mGEJC.

FOLFIRI-aflibercept chemotherapy is indicated in second-line treatment of metastatic colorectal cancer (mCRC) after progression under FOLFOX (±bevacizumab). Nevertheless, its proven therapeutic efficacy in clinical trials was based on partial responses. And to date, only 2 cases of complete response assessed by CT were reported in literature. We report a complete metabolic response assessed by FDG PET/CT in a 50-year-old woman with mCRC treated by FOLFIRI-aflibercept. This also confirms that FDG PET/CT is emerging as a useful approach for therapeutic assessment of targeted drugs in mCRC.

We report the case of a 27-year-old woman referred to our department for the characterization of a 7 × 6-cm left ischio-anal fossa mass by Ga-DOTATOC PET/CT. Several diagnoses were previously mentioned, in particular, myxoid sarcoma but also pelvic paraganglioma. Urinary methoxylated derivates and blood chromogranin A tests were negative. PET/CT showed a high Ga-DOTATOC uptake of the mass that was strongly consistent with paraganglioma diagnosis. Histopathological analysis surprisingly revealed a solitary fibrous tumor without aggressive criteria.

A 49-year-old man was referred to our department for an assessment of a cerebral metastasis of unknown primary with F-FDG PET/CT. This imaging led to detection of a suspected pulmonary primary carcinoma, as well as an incidental left focal thyroid uptake. An ultrasonography, performed a month later, revealed a thyroiditis aspect. An anti-PD1 immunotherapy was also proposed 2 months later after confirmation of a lung adenocarcinoma. A second baseline FDG PET/CT surprisingly showed a diffuse thyroid uptake. A fine-needle aspiration biopsy of thyroid parenchyma finally revealed a diffuse involvement from lung adenocarcinoma (ie, primary lung metastasis to the thyroid gland).

A 51-year-old man referred to our department to undergo an F-FDG PET/CT to detect primary tumor 7 days after diagnosis of one left brain metastasis on MRI in the aftermath of acute right-sided hemiparesis. F-FDG PET/CT was performed without sufficient fasting period. It showed abnormal uptake in the left apical lung nodule, suspicious for primary tumor. Moreover, F-FDG PET/CT showed extensive skeletal muscle accumulation which was more significant as expected but concerning only the left side of the body. So, acute right-sided hemiparesis was responsible for no muscle uptake, probably explained by denervation and altered muscle energetics.

Background: The diagnosis of wrist fractures, especially scaphoid fractures, remains a challenge because of nonunion risk. Currently, new hybrid technologies are emerging such as SPECT/CT systems, which combine functional and anatomical data sets. So, we wanted to evaluate the utility of SPECT/CT in the management of occult carpal fractures., Methods: In this study, all patients addressed at the orthopedic department at Brest University Hospital for wrist pain after trauma with initial normal plain radiographs were prospectively included. Patients with normal radiographs but with signs strongly suggestive of clinical fracture underwent a bone SPECT/CT and an MRI of the wrist. Therapeutic management took into account the results of all modalities, and all patients were followed up for at least 6 months and reviewed by the same surgeon. SPECT/CT findings were compared with those of the other modalities and follow-up., Results: From December 2009 to May 2011, 57 patients were enrolled. Fifty-seven SPECT/CT and 52 MRI scans were obtained. Twenty-eight patients had normal imaging results, whereas 29 patients presented bone bruise and/or fractures. Ten patients were concordant according to SPECT/CT and MRI; 2 patients presented fractures on SPECT/CT without MRI performed; 17 patients had partially discordant results. Only 1 patient presented a nonunion at the follow-up, whereas both investigations were positive., Conclusions: This study highlights the good performances of SPECT/CT, which allows the detection of most occult carpal fractures. When a carpal occult fracture is strongly suspected clinically, SPECT/CT might be proposed at first intention after normal radiographs.