The inverse problem formulation of the depth dose curve estimation is applied to sparse non-equally spaced measurement grid and the subsequent solution as well as the selection of measurement depths are discussed. The performance of the proposed estimation method is evaluated with real 6 MeV and 18 MeV photon data. These studies show that the proposed method allows the estimation of the depth d...

In this clinical study, we have compared routine diagnostic dose (131)I scan and (99m)TcO4(-) thyroid scintigraphy with therapeutic dose (131)I imaging for accurate thyroid remnant estimation after total thyroidectomy. We conducted a retrospective review of the patients undergoing total thyroidectomy for differentiated thyroid carcinoma (DTC) and subsequently receiving radioactive iodine (RAI) ...

Background For radiological protection and control, the International Commission on Radiological Protection (ICRP) provides nominal risk coefficients related to radiation exposure, which can be extrapolated using excess relative absolute obtained from Life Span Study of atomic bomb survivors in Hiroshima Nagasaki with dose dose-rate effectiveness factor (DDREF). Materials Methods Since it is im...

Purpose To investigate the impact of radiation dose on breast density estimation in digital mammography. Materials and Methods With institutional review board approval and Health Insurance Portability and Accountability Act compliance under waiver of consent, a cohort of women from the American College of Radiology Imaging Network Pennsylvania 4006 trial was retrospectively analyzed. All patien...

Dosage estimation for conformation radiotherapy applied to cervical cancer was discussed. Field size and shape in conformation therapy was freely change able according to the shape and size of tumor. When the same size and shape of the field for therapy by Co 60 gamma ray was applied to each case, tissue-air ratio TAR was given by an equation, T=-0.00326d+1.035, where T is TAR and d an average ...

Knowledge of what dose-volume histograms can be expected for a previously unseen patient could increase consistency and quality in radiotherapy treatment planning. We propose a machine learning method that uses previous treatment plans to predict such dose-volume histograms. The key to the approach is the framing of dose-volume histograms in a probabilistic setting.The training consists of esti...

In a clinical dose finding study with active control a new drug with several dose levels is compared with an active comparator drug. The main focus of such studies often lies on the estimation of a target dose that leads to the same efficacy as the control. This article investigates the finite sample properties of the maximum likelihood estimation of the target dose and compares several approac...

A recent series of experiments aimed to determine the amount salt can be reduced in food products without losing too much of their original taste; this is called the benchmark dose. In this study, a logistic model was used, however, it did not to include some features of the experiment and also used the data in an inefficient way. To improve the model, we borrowed the idea of risk assessment fr...

Computed Tomography (CT) procedures constitute the 5% of the total diagnostic radiology and provide more than the 40% of the total dose. Patient dose depends on many factors; most of them depend on the way the procedure is performed. All around the world, there is a growing interest in studying patient dose in CT procedures in order to optimize them. If the patient is pregnant, conceptus absorb...