Instrumentation for medical physics applications Barbara Camanzi, PPD/RAL Instrumentation for radiotherapy Imaging: 1. Fast Time Of Flight PET 2. Electron Portal Imaging Devices In-vivo dosimetry Other non medical activities Conclusions

Instrumentation for radiotherapy UK government is supporting expansion of radiotherapy for cancer treatment. New advanced instrumentation is needed => plenty of possibilities to apply particle physics techniques in the field of radiotherapy. Many thanks to RM/ICR colleagues. Instrumentation => Looking at the treatment from the patient end = to make sure that the right dose is delivered at the right side (tumour location). Right location = imaging P: Better and faster imaging of tumours (organs with high degree of movement) is needed to precisely located them in respect to the therapeutic beam. S: Development of a fast Time Of Flight PET. Development of fast Electron Portal Imaging Devices (EPIDs) with higher quantum efficiency than ones currently available (few %). Right dose = dosimetry P: EU directive for performing online dosimetry measurements for every patient and every treatment fraction. S: Development of an online in-vivo dosimetry system.

Imaging: Fast Time Of Flight PET Fast high quality imagines to precisely locate the tumour: fast Time Of Flight PET that achieves sub-cm position resolution (50 ps timing resolution). Candidate technologies: fast scintillators coupled to SiPMs. 1. Fast and bright scintillators: new lanthanum halide materials by Saint- Gobain Crystals 2. SiPMs: fast and insensitive to magnetic fields => PET/MRI combined R&D required: 1. Preparation of scintillating material samples and coupling to SiPM. 2. Measurement of system performance: response time, light yield, energy resolution. 3. Design and optimisation of a simple demonstrator system: 2 channels. 4. Measurement of performance of demonstrator system: time of flight. Funds: 1. Just received some CLIK funds (£82.5k) for R&D stages 1. and Another application in with NHS (New and Emerging Applications of Technology call), outcome by end of May.

Imaging: Electron Portal Imaging Devices (EPIDs) High quality radiography images taken during treatment using therapeutic beam to centre beam on tumour: fast and high quantum efficiency EPIDs placed behind patient. Candidate technologies: fast scintillators coupled to SiPMs. 1. fast scintillators: lanthanum halides, CsI, etc. 2. SiPMs: multipixels = high spatial resolution R&D required: 1. Design of an EPID based on scintillators coupled to SiPMs: dimensions, number of channels, etc. 2. Preparation of the scintillators and SiPMs matrixes and coupling of the two matrixes. 3. Measurement of the system performance: quantum efficiency, images. Funds: None yet. Planning to find a suitable funding scheme and apply during this year.

In-vivo dosimetry (See also Giulio Villani presentation) In-vivo dosimetry at the tumour site: implantable + intracavitary applications. Candidate dosimeters: SiO 2 devices sensitive to radiation = shift in threshold voltage following irradiation when biased with constant current. 1. Floating gate devices (see Giulio Villani talk) 2. RadFETs (Radiation sensitive MOSFETs; already used in particle physics experiments, for ex. BaBar and LHC) R&D required: 1. Characterisation of dosimeters under irradiation of “therapeutic” beams. 2. Implanted: development of a wireless miniaturised sensor combined with position sensor. 3. Intracavitary: development of a miniaturised sensor to fit in catheters. 4. Clinical trials. Funds: some CLIK funds to test floating gate devices (see Giulio Villani talk) and collaborations with Brunel (Akram Khan + PhD student) and possibly R.E.M. (Andrew Holmes-Siedle). Possibly look for other funds during this year.

Other non medical activities Following invited talk at RADECS 2006, paper on dosimetry for particle accelerators and nuclear fusion reactors published in May 2008 issue of Nature Materials.

Conclusions Wealth of exciting projects to further take technologies developed for particle physics into the medical physics (radiotherapy) world. My plans: get for the moment three projects going. Potentials in other fields: nuclear fusion.