A calculator based program to optimize the simulation of breast irradiation

The simulation of breast fields using an isocentric set-up technique can be a lengthy process involving the placement of the isocentre, the determination of the gantry angles, and the selection of the lung shields, which in our center is one of six standard blocks. We show that with a body contour taken through central axis, five measurements and a calculator program, it is possible to significantly decrease the amount of time required to simulate a breast patient. We have developed a program for an HP48GX handheld calculator to determine the gantry angles, the isocentre, the field width, the standard angled block, and the couch and collimator rotation. The calculations are based on measurements of the field length, the horizontal distance between midline and mid axillary line, and the vertical distances from the mid axillary line to the inferior and superior beam border and central axis at midline. We use spherical geometry to perform the calculations to reflect the true environment and do not make any assumptions about the average patient's shape. For the simulation process a jig was developed that is inserted into the tray holder of the simulator to show the optical and radiological shadow of the calculated shielding along the patient's midline for clinical assessment during simulation and on the simulation film. The jig also has a holder for an aluminum wedge to improve the image quality of the simulation film. We admit that the lung shield increases the dose to the contralateral breast because of increased scatter and transmission through the shield; however, the block decreases the volume of irradiated lung while keeping the beam edge along the midline of the patient. The technique has been in use for two years and has resulted in time savings of up to 30% per patient. It has proven to be an easy and accurate way of setting up isocentric treatments to the breast.     

Interfacing a programmable desk calculator to a hard-wired data system.

The primary disadvantage of hard-wired data systems for use in nuclear medicine is the fact that that the data contained in the memory bank are not accessible to the user and often must be processed mathematically before they can be employed in interpretation, particularly in dynamic studies. The authors describe a relatively inexpensive programmable device which can be used in conjunction with the data system and overcomes these limitations to a great extent.     

Use of a programmable pocket calculator in radiotherapy treatment planning.

Software packages for a programmable pocket calculator have been developed for use in dosimetry. Using a field equation and a mathematical model of the beam profile, one can find the dose delivered to any point within the irradiated volume. Use of these programs for simple field calculations allows the radiologist to concentrate on more complex treatment plans.     

PopAffiliator: online calculator for individual affiliation to a major population group based on 17 autosomal short tandem repeat genotype profile

Because of their sensitivity and high level of discrimination, short tandem repeat (STR) maker systems are currently the method of choice in routine forensic casework and data banking, usually in multiplexes up to 15?C17 loci. Constraints related to sample amount and quality, frequently encountered in forensic casework, will not allow to change this picture in the near future, notwithstanding the technological developments. In this study, we present a free online calculator named PopAffiliator (http://cracs.fc.up.pt/popaffiliator) for individual population affiliation in the three main population groups, Eurasian, East Asian and sub-Saharan African, based on genotype profiles for the common set of STRs used in forensics. This calculator performs affiliation based on a model constructed using machine learning techniques. The model was constructed using a data set of approximately fifteen thousand individuals collected for this work. The accuracy of individual population affiliation is approximately 86%, showing that the common set of STRs routinely used in forensics provide a considerable amount of information for population assignment, in addition to being excellent for individual identification.