The new generation of synthetic diamonds grown as a CVD single crystal on a high pressure high temperature substrate offers a wide range of applications. In particular, because of the near tissue equivalence and its small size (good spatial resolution), CVD single crystal diamond finds applicability in radiotherapy as a dosemeter of ionizing radiation. In this paper we report the electrical and dosimetric properties of a new diamond detector which was fabricated at IFJ based on a single crystal detector-grade CVD diamond provided with a novel contact metallization. Diamond properties were assessed at IFJ using a Theratron 680E therapeutic 60Co gamma rays unit and at COOK with 6 and 18 MV x-rays Varian Clinac CL2300 C/D accelerator. The new dosemeter showed high electric and dosimetric performances: low value of dark current, high current at the level of some nanoamperes during irradiation, very fast dynamic response with a rise time amounting to parts of a second, good stability and repeatability of the current and linearity of the detector signal at different dose and dose rate levels typically applied in radiotherapy. The results confirm the potential applicability of diamond material as a dosemeter for applications in radiotherapy.
We investigated the relationship between RBE-weighted dose (DRBE) calculated with constant (cRBE) and variable RBE (vRBE), dose-averaged linear energy transfer (LETd) and the risk of radiographic changes in skull base patients treated with protons. Clinical treatment plans of 45 patients were recalculated with Monte Carlo tool FRED. Radiographic changes (i.e. edema and/or necrosis) were identified by MRI. Dosimetric parameters for cRBE and vRBE were computed. Biological margin extension and voxel-based analysis were employed looking for association of DRBE(vRBE) and LETd with brain edema and/or necrosis. When using vRBE, Dmax in the brain was above the highest dose limits for 38% of patients, while such limit was never exceeded assuming cRBE. Similar values of Dmax were observed in necrotic regions, brain and temporal lobes. Most of the brain necrosis was in proximity to the PTV. The voxel-based analysis did not show evidence of an association with high LETd values. When looking at standard dosimetric parameters, the higher dose associated with vRBE seems to be responsible for an enhanced risk of radiographic changes. However, as revealed by a voxel-based analysis, the large inter-patient variability hinders the identification of a clear effect for high LETd.
Fracture of the femur is the most frequent late complication in patients with soft tissue sarcomas (STS) who receive external beam radiotherapy after limb-sparing surgery. To reduce the risk of bone fracture following radiotherapy of STS of the thigh, we minimized the dose to the femur and to surrounding normal tissues by applying intensity modulated radiation therapy (IMRT). We report preliminary results of post-surgery IMRT of the thigh in patients with STS in this extremity. 10 adult patients undergoing post-operative radiotherapy of STS of the thigh were treated using IMRT. Clinical IMRT plans with simultaneous integrated boost (SIB) and 3-phase three-dimensional conformal radiotherapy (3D-CRT) were designed to adequately treat the planning target volume and to spare the femur to the largest extent possible. Dose distributions and dose-volume histograms were compared. For either technique, a comparable target coverage was achieved; however, target volume was better covered and critical structures were better spared in IMRT plans. Mean and maximum doses to OAR structures were also significantly reduced in the IMRT plans. On average, the mean dose to the femur in 3D-CRT plans was about two times higher than that in IMRT plans. Compared with 3D-CRT, the application of IMRT improves the dose distribution within the concave target volumes and reduces dose to the OAR structures without compromising target coverage.
Glioblastoma multiforme remains one of the most aggressive and treatment-resistant brain tumors that necessitate innovative therapeutic approaches. Nanomedicine has emerged as a promising strategy to enhance radiation therapy by improving drug delivery, radiosensitization, and real-time treatment monitoring. Stimuli-responsive nanoparticles can overcome limitations of the blood–brain barrier, modulate tumor microenvironment, and facilitate targeted therapeutic interventions. The integration of nanotechnology with proton and X-ray radiotherapy offers improved dose precision, enhanced radiosensitization, and adaptive treatment strategies. Furthermore, Artificial Intelligence-driven nanoparticle designs are optimizing therapeutic outcomes by tailoring formulations to tumor-specific characteristics. While promising, clinical translation remains a challenge that requires rigorous validation to ensure safety and efficacy. This review highlights advancements in nanomedicine-enhanced radiotherapy and future directions for glioblastoma multiforme treatment.