The effective dose from computed tomography of the maxillofacial complex has been estimated and used for an assessment of risk. For each scan sequence 64 TLDs were placed in 27 selected sites in the upper portion of a tissue-equivalent human phantom to record the equivalent dose in radiosensitive organs/tissues. Equivalent doses ranged from 0.11 mSv (bone marrow, maxillary scan) to 20 mSv (salivary glands, mandibular scan). By the use of a calculation that included the salivary glands as part of the remainder, two contiguous 1 cm axial slices of the maxilla were found to result in an effective dose of 0.1 mSv, and four contiguous 1 cm axial slices of the mandible in an effective dose of 0.76 mSv. Effective doses of this magnitude represent a probability of stochastic effects of the order of 8 X 10(-6) and 56 X 10(-6) respectively.

Despite the emergence of sophisticated technologies in treatment planning and administration, routine determination of delivered radiation doses remains a challenge due to limitations associated with conventional dosimeters. Here, we describe a gel-based nanosensor for the colorimetric detection and quantification of topographical radiation dose profiles in radiotherapy. Exposure to ionizing radiation results in the conversion of gold ions in the gel to gold nanoparticles, which render a visual change in color in the gel due to their plasmonic properties. The intensity of color formed in the gel was used as a quantitative reporter of ionizing radiation. The gel nanosensor was used to detect complex topographical dose patterns including those administered to an anthropomorphic phantom and live canine patients undergoing clinical radiotherapy. The ease of fabrication, operation, rapid readout, colorimetric detection, and relatively low cost illustrate the translational potential of this technology for topographical dose mapping in radiotherapy applications in the clinic.

There are no data relating complex film tomography with effective dose that may be used to estimate the relative risk associated with dental implant diagnostics. The purpose of this study was to calculate the effective dose and estimate risk from the use of the Scanora multimodal imaging system. With the use of a tissue equivalent human phantom and thermoluminescent dosimetry, panoramic radiography was found to result in an effective dose of 26 microSv, while complex film tomography resulted in an effective dose of< 1 microSv to 30 microSv depending on the anatomical location of the imaging plane and the collimation option. An effective dose of this magnitude for panoramic radiography was estimated to represent a probability for stochastic effects on the order of 1.9 x 10(-6). Similarly, the effective dose associated with film tomography may be estimated to be equal to a probability for stochastic effects in the range of << 1 x 10(-6) to 2.2 x 10(-6).

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