Inside database
The INSIDE PET/Tracker system has been used in the last few years to monitor hadron beams and treatment plans at the Centro Nazionale di Adroterapia Oncologica (CNAO) synchrotron facility in Pavia. Its in-beam PET was tested during 2016 with polymethyl methacrylate (PMMA) and anthropomorphic phantoms [Piliero et al., 2016; Bisogni et al., 2017] and its response was thoroughly characterised. The same setup was also used in December 2016 to perform the first online monitoring test during a conventional patient treatment session.
Early results obtained with the INSIDE project have raised clinical interest in the possibility of monitoring in real time the anatomical modification in the context of the planning target volume (PTV) and near organs at risk (OAR). The envisaged clinical impact comes from having a feedback on the goodness of the treatment plan, i.e., on the coverage completeness of the target, for each treatment fraction. In particular, the system would allow interveningin time on the PTVin case of unexpected monitoring feedback, thus preventing any undesired collateral effects.
At the state of the art, clinicians compare the simulated CT (baseline) with the re-evaluation CT acquired during the radiotherapy(RT) in order to find any possible anatomical modification that could affectthe distribution of the planned dose. This comparison is not done at each treatment fraction. Modifications could be caused by patient weight loss, mucus stagnation or inflammatory (e.g., radio-induced) processes. The same response to the disease and to the treatment could induce anatomical modifications in unexpected ways. For example, there are new clinical evidences that show how the regression of adenoid cystic carcinoma and squamous-cell carcinoma, is particularly rapid when the two diseases are treated with carbon and proton ions, respectively. Their fast regression must be monitored during each treatment fraction. Therefore,these kinds of disease are good candidates for testing the enhanced monitoring features provided by the INSIDE system.
The CNAO is planning for conducting a longitudinal study to assess systematically the early response of disease during the treatment and any anatomical modifications that have significant degrading effects on the goodness of the dose distribution. The study will be conducted on conventional clinical treatments in 2018.
The CNAO longitudinal study is not the first one conducted with in-vivo PET imagers, see, e.g., the MIRANDA study [Nischwitz et al., 2015]. However, it presents the following unique features: 1) it is the first one that uses in-beam PET data, which can provide additional statistics and hence better signal-to-noise ratios without any additional room occupancy; 2) it will be cross-validated with the integrated particle tracker; 3) it will use TOF-grade PET data for reduced artefact due to incomplete angular coverage.
Such a study involves professionals and researchers from different research bodies for several months. A large amount of data is being collected and analysed by the involved partners. These data are anonymised and stored in the database accessible from this website.
To request access please write an email to: insidedb-support@lists.pi.infn.it