Calibration test of PET scanners in a multi-centre clinical trial on breast cancer therapy monitoring using 18F-FLT.

UNLABELLED: A multi-centre trial using PET requires the analysis of images acquired on different systems We designed a multi-centre trial to estimate the value of 18F-FLT-PET to predict response to neoadjuvant chemotherapy in patients with newly diagnosed breast cancer. A calibration check of each PET-CT and of its peripheral devices was performed to evaluate the reliability of the results. MATERIAL AND METHODS: 11 centres were investigated. Dose calibrators were assessed by repeated measurements of a 68Ge certified source. The differences between the clocks associated with the dose calibrators and inherent to the PET systems were registered. The calibration of PET-CT was assessed with an homogeneous cylindrical phantom by comparing the activities per unit of volume calculated from the dose calibrator measurements with that measured on 15 Regions of Interest (ROIs) drawn on 15 consecutive slices of reconstructed filtered back-projection (FBP) images. Both repeatability of activity concentration based upon the 15 ROIs (ANOVA-test) and its accuracy were evaluated. RESULTS: There was no significant difference for dose calibrator measurements (median of difference -0.04%; min = -4.65%; max = +5.63%). Mismatches between the clocks were less than 2 min in all sites and thus did not require any correction, regarding the half life of 18F. For all the PET systems, ANOVA revealed no significant difference between the activity concentrations estimated from the 15 ROIs (median of difference -0.69%; min = -9.97%; max = +9.60%). CONCLUSION: No major difference between the 11 centres with respect to calibration and cross-calibration was observed. The reliability of our 18F-FLT multi-centre clinical trial was therefore confirmed from the physical point of view. This type of procedure may be useful for any clinical trial involving different PET systems

Construction and tests of an in-beam PET-like demonstrator for hadrontherapy beam ballistic control

International audienc

Dosimétrie chez le lapin d'[131I]ICF01012 en vue de son utilisation pour le traitement du mélanome métastatique par radiothérapie interne vectorisée

National audienc

A multicenter prospective phase II study of postoperative hypofractionated stereotactic body radiotherapy (SBRT) in the treatment of early-stage oropharyngeal and oral cavity cancers with high risk margins: the STEREO POSTOP GORTEC 2017-03 trial.

Primary surgery is usually the mainstay treatment in early-stage oropharyngeal and oral cavity cancer. Typically, neck surgery is performed. Negative tumor margins are recommended (> 5 mm). If feasible, re-resection of any positive margin is preferred. Otherwise, postoperative radiotherapy is required. Adjuvant postoperative radiotherapy can be limited to the primary site for patients with pT1-T2 tumors and negative neck exploration. Currently, both fractionated external beam radiotherapy and brachytherapy can have a role in the postoperative management of early-stage oropharyngeal and oral cavity cancer with high risk margins. Another possible alternative could be postoperative stereotactic body radiotherapy (SBRT). The aim of this study is to evaluate postoperative SBRT in the treatment of early-stage oropharyngeal and oral cavity cancer with high risk margins. The STEREO POSTOP study is a national, open-label, non-randomized phase II trial within the GORTEC network. Patients with early-stage oropharyngeal and oral cavity cancers with high risk margins indicating the need for postoperative radiation are eligible for enrollment. SBRT consists of a total dose of 36 Gy in 6 fractions over 2 weeks. The primary endpoint is severe late toxicity defined as 2-year toxicity of grade ≥ 3 according to CTCAE V4.03 classification. The secondary endpoints include acute toxicity (≤ 3 months), local and locoregional control, disease-free and overall survival, quality of life of patients, nutritional impact and predictive factors of toxicity. The experimental design chosen is a one-step Fleming plan design without interim analysis as the primary endpoint will be evaluated at a 2-year follow-up. Ninety patients will be recruited. The study was started in January 2018 with a 4-year enrollment period and an estimated completion in January 2024. This study is the first prospective trial to evaluate head and neck cancer postoperative SBRT in the setting of early-stage oropharyngeal and oral cavity cancers with high risk margins. SBRT is an attractive option because it delivers a highly conformal dose of radiation in a limited number of fractions (like brachytherapy but with less contraindication), with steep dose gradients resulting in reduced normal tissue irradiation and with a short overall treatment time. Clinicaltrials.gov : NCT03401840 , registered on 17-1-2018. Identifier in French National Agency for the Safety of Medicines and Health Products (ANSM): N°ID - RCB 2017-A02058-45, registered on July 2017. Protocol version: Version 3 dated from 25th November 2019

Présentation de l’étude Gortec 2017-03 : radiothérapie en conditions stéréotaxiques postopératoire des cancers localisés de l’oropharynx et de la cavité buccale avec marges à risque (PHRC-K-16-164) [Description of the GORTEC 2017-03 study: Postoperative stereotactic radiotherapy for early stage oropharyngeal and oral cavity cancer with high risk margin (PHRC-K-16-164)]

The GORTEC 2017-03-Stereo-postop study is a phase 2, multicentric, nationwide study, funded by the hospital clinical research program (PHRC). The sponsor is Centre Jean-Perrin in Clermont-Ferrand, in partnership with the GORTEC. The principal investigators are Dr J Biau and Dr M Lapeyre. The main objective is to study severe late toxicity of postoperative stereotactic radiotherapy (6×6Gy) for early stage oropharyngeal and oral cavity cancer with high risk margins. The secondary objectives include acute toxicity, efficacy, nutritional impact and quality of life. The population is adult patients, with pT1 or pT2 squamous cell carcinoma of the oropharynx or oral cavity (except lips), without indication of neck irradiation or concomitant chemotherapy, with at risk margin (R1, less than 5mm or uncertain). Ninety patients will be included over a 2-year period; this was calculated to limit the rate of 2-year severe toxicity at 5 to 15%, with a 2-year local control of at least 80 to 90%. If this study is considered as positive, stereotactic radiotherapy (6×6Gy) could become the third therapeutic option, with brachytherapy and normofractionated intensity-modulated radiotherapy (IMRT), for postoperative irradiation of oropharyngeal and oral cavity cancer with high risk margins

Construction and tests of an in-beam PET-like demonstrator for hadrontherapy beam ballistic control

International audienceWe present the first results obtained with a detector, called Large Area Pixelized Detector (LAPD), dedicated to the study the ballistic control of the beam delivered to the patient by in-beam and real time detection of secondary particles, emitted during its irradiation in the context of hadrontherapy. These particles are 511 keV γ from the annihilation of a positron issued from the β+ emitters induced in the patient tissues along the beam path. The LAPD basic concepts are similar to a conventional PET camera. The 511 keV γ are detected and the reconstructed lines of response allow to measure the β+ activity distribution. Nevertheless, when trying to use γ from positron annihilation for the ballistic control in hadrontherapy, the large prompt γ background should be taken into account and properly rejected. First reconstruction results, obtained with a phantom filled with a high intensity FDG source at the cancer research centre of Clermont-Ferrand are shown. We also report results of measurements performed at the Heidelberg Ion-Beam Therapy Centre with one third of the detector, using proton and carbon ion beams