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This paper presents the results of the proton irradiation of silicon photomulipliers (SiPMs) by mono-energetic 170 MeV protons with fluence up to 4.6$\times$10$^{9}$ particles/cm$^2$. In our work, three types of silicon photodetectors from Hamamatsu with areas 3$\times$3 mm$^2$ and different subpixel sizes of 25$\times$25 $\mu$m$^2$, 50$\times$50 $\mu$m$^2$, and 75$\times$75 $\mu$m$^2$ were used. The changes in the SiPM dark count rate (DCR) spectrum before and after irradiation in temperatures in the range of 20 $^\circ$C to -65 $^\circ$C are presented. The influence of the DCR changes on the energy resolution of the 662 keV gamma line from the $^{137}$Cs for a non-irradiated GAGG:Ce (1$\%$) scintillator is investigated. The time period of usability of the SiPM detector irradiated by protons in cosmic space was estimated.

A dosimetric experiment was performed at the Medico-Technical Complex in the Joint Institute for Nuclear Research, Dubna, to investigate the effects of metallic dental implants in the treatment of head and neck tumours with proton therapy. The goal of the study was to evaluate the 2D dose distributions of different clinical treatment plans measured in an anthropomorphic phantom, and compare them to predictions from a treatment planning system. The anthropomorphic phantom was sliced into horizontal segments. Two grade 4 Titanium implants were inserted between 2 slices, corresponding to a maxillary area. GafChromic EBT2 films were placed between the segments containing the implants to measure the 2D delivered dose. Two different targets were designed: the first target includes the dental implants in the isocentre, and in the second target, the proton beam is delivered through the implants, which are located at the entrance region of the Bragg curve. The experimental results were compared to the treatment plans made using our custom 3D Treatment Planning System, named RayTreat. To quantitatively determine differences in the isodose distributions (measured and calculated), the gamma index (3 mm, 3%) was calculated for each target for the matrix value in the region of high isodose (> 90%): for the experimental setup, which includes the implants in the SOBP region, the result obtained was 84.3%. When the implants were localised in the entrance region of the Bragg curve, the result obtained was 86.4%. In conclusion, the uncertainties introduced by the clinically planned dose distribution are beyond reasonable limits. The linear energy transfer spectra in close proximity to the implants were investigated using solid state nuclear track detectors (TED). Scattered particles outside the target were detected.