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Purpose Thyroid nodules frequently coexist with primary hyperparathyroidism (pHPT). Because of the increasing use of 18F-fluorocholine (18F-FCH) PET/CT in patients with pHPT, evaluation of its clinical utility for thyroid nodules characterization in this population is of paramount importance. Herein, we investigate the value of dual-point 18F-FCH PET/CT in the diagnosis of thyroid cancer in patients referred for pHPT imaging who have thyroid nodules. Patients and methods All pHPT patients who underwent a dual-time point 18F-FCH PET/CT (at 5 and 60 minutes postinjection) between July 2019 and December 2020 were analyzed. Only those with a thyroid nodule greater than 10-mm and pathological analysis (criterion standard) were included. Nodule-to-thyroid SUVmax ratio was calculated at the 2 study points, as well as the 18F-FCH washout index (WO%). Results Twenty-seven patients (32 nodules) were included in this study. The final diagnoses were as follows: 27 benign nodules including 2 NIFTPs (noninvasive follicular thyroid neoplasm with papillary-like nuclear features) and 5 cancers of follicular origin. Early uptake ratio was significantly higher in malignant lesions than in benign nodules (P = 0.0008). Thyroid cancers were also characterized by a marked 18F-FCH washout index (WO% benign vs cancer: 2.9% ± 4.1% vs 45.5% ± 13.4%, P = 0.0001). Using a WO% threshold of 22.1%, 25/27 benign nodules and 5/5 malignant lesions were accurately classified (sensitivity of 100%, specificity of 92.6%, positive predictive value of 71.4%, and negative predictive value of 100%). The false-positive findings were related to the 2 NIFTPs that share similarities with thyroid cancer. Conclusions Our preliminary results suggest to perform a dual-time-point PET/CT acquisition protocol in pHPT patients with uncharacterized centimeter thyroid nodules. However, the real impact of these promising results should be assessed by prospective studies on a larger cohort of patients.

Background Oligodendroglioma is a rare type of primary brain tumor which, like other malignant gliomas, metastasizes very rarely even when in high-grade form. Case report A 36-year-old white man diagnosed 29 months previously as having 1p/19q codeleted anaplastic oligodendroglioma presented bilateral cruralgia and lower limb motor deficits. A computed tomography scan showed multiple osteoblastic bone lesions. The presence of oligodendroglial cells was revealed by bone marrow biopsy and confirmed by immunohistochemical analyses. A positon emission tomography-computed tomography scan confirmed the exclusive involvement of bones. Conclusion This case joins less than 20 other reported cases of oligodendroglioma bone marrow metastasis, and is one of only a handful of cases of diffuse bone metastases beyond the axial skeleton. To the best of our knowledge, the early relapse of 1p/19q codeleted anaplastic oligodendroglioma with this distribution of metastases has never been described in the literature.

The goal of this study was to validate high-frequency (24 MHz) ultrasound imaging techniques for early detection and follow-up of renal tumors in a murine Wilms’ tumor model (n = 26). For 11 mice, maximum tumor dimensions were estimated from images along three orthogonal axes for comparison with posteuthanasia caliper and histologic measurements. Tumor size in the 15 remaining mice was checked biweekly. The mice were then euthanized and histologic study assessed tumor position and nature. Tumors were detected in vivo between 7 to 14 days after injection of tumor-inducing cells. Tumor maximum cross-sectional area varied from 0.07 mm2 to 5.7 mm2 at the time of initial detection. The relative r.m.s. error between ultrasonic and histologic estimations of maximum cross-sectional area was estimated to be 19%. Results demonstrate feasibility of noninvasive ultrasound biomicroscopy early detection and characterization of renal tumor development for longitudinal monitoring of the same animal. (E-mail: bridal@lip.bhdc.jussieu.fr )

TPS646 Background: For patients with early HER2+ breast cancer at diagnosis, addition of trastuzumab (T) to 6 cycles of preoperative docetaxel (D) can reach a pathological complete response (pCR) in ~50% of cases, and a high rate of conservative surgery. pCR can be predicted by changes of Fluorodeoxyglucose (FDG) tumor uptake evaluated by Positon Emission Tomography (PET) after one cycle of therapy. In order to increase this pCR rate, adding an antiangiogenic compound could be considered. Pre-clinical and phase I-II data support that the combination of bevacizumab (B) and T is synergistic and safe when patients are chemotherapy naïve. The neoadjuvant AVATAXHER trial (EUDRACT 2009-013410-26) investigates the potential increase of pCR rate by combining B with T and D for patients with HER2+ breast cancer who are not predicted for pCR by FDG PET. Methods: In this multicenter, open-label, phase II trial, 2 phases are planned after a selection period: phase I: all patients receive two cycles of therapy combining T (8 mg/kg at the first cycle, then 6 mg/kg) and D (100 mg/m2). FDG PET is also performed within 7 days before cycle 1 (baseline) and less than 3 days before cycle 2 in order to calculate changes of the tumor FDG uptake between baseline and after cycle 1 (ΔSUV). Phase 2: if ΔSUV≥70%, patients will continue to receive T and D for (cycles 3 to 6: D 100 mg/m2 + T 6 mg/kg); if ΔSUV2 + T 6 mg/kg + B 15 mg/kg) or arm B ( cycles 3 to 6: D 100 mg/m2 + T 6 mg/kg). The primary endpoint is pCR rate evaluated post-surgery 4 to 6 weeks after the last treatment of cycle 6. Enrolment began in May 2010 and 125 patients were to be recruited in 26 sites. According to the hypothesis that 60% of patients will have a ΔSUV

Purpose To analyze the outcome and dose distribution of intensity-modulated radiation therapy (IMRT) by helical tomotherapy in women treated for large supradiaphragmatic Hodgkin’s disease. Material and methods A total of 13 patients received adjuvant radiation at a dose of 30 Gy to the initially involved sites with a boost of 6 Gy to those areas suspected of harboring residual disease on the simulation CT scan. Results With a median follow-up of 23 months, the two-year progression-free survival was 91.6%, and the 2- and 3-year overall survivals were 100%. We did not report any heart or lung acute side effects. The conformity index of PTV (Planning Target Volume) was better for IMRT than for 3D-CRT (p=0.001). For the breasts, lungs, heart, thyroid and esophagus, the volume distributions favored the IMRT plans. For the breasts, the V20Gy, V25Gy and V30Gy were 1.5, 2.5 and 3.5 times lower, respectively, for IMRT than for 3D-CRT. For the lung tissues, the V20Gy and V30Gy were 2 times and 4.5 times lower, respectively, for IMRT than for 3D-CRT. For the heart, the V20Gy and V30Gy were 1.4 and 2 times lower, respectively, for IMRT than for 3D-CRT. For the esophagus, the V35Gy was 1.7 lower for IMRT than for 3D-CRT, and for the thyroid, the V30Gy was 1.2 times lower for IMRT. Conclusion IMRT by helical tomotherapy improved the PTV coverage and dramatically decreased the dose in organs at risk. The treatment was well tolerated, but a longer follow-up is necessary to prove a translation of these dosimetric improvements in the outcome of the patients.