MIRD pamphlet no. 16: Techniques for quantitative radiopharmaceutical biodistribution data acquisition and analysis for use in human radiation dose estimates

This report describes recommended techniques for radiopharmaceutical biodis tribution data acquisition and analysis in human subjects to estimate radia tion absorbed dose using the Medical Internal Radiation Dose (MIRD) schema. The document has been prepared in a format to address two audiences: indiv iduals with a primary interest in designing clinical trials who are not exp erts in dosimetry and individuals with extensive experience with dosimetry- based protocols and calculational methodology. For the first group, the gen eral concepts involved in biodistribution data acquisition are presented, w ith guidance provided for the number of measurements (data points) required . For those with expertise in dosimetry, highlighted sections, examples and appendices have been included to provide calculational details, as well as references, for the techniques involved. This document is intended also to serve as a guide for the investigator in choosing the appropriate methodol ogies when acquiring and preparing product data for review by national regu latory agencies. The emphasis is on planar imaging techniques commonly avai lable in most nuclear medicine departments and laboratories. The measurement of the biodistribution of radiopharmaceuticals is an import ant aspect in calculating absorbed dose from internally deposited radionucl ides, Three phases are presented: data collection, data analysis and data p rocessing. In the first phase, data collection, the identification of sourc e regions, the determination of their appropriate temporal sampling and the acquisition of data are discussed. In the second phase, quantitative measu rement techniques involving imaging by planar scintillation camera, SPECT a nd PET for the calculation of activity in source regions as a function of t ime are discussed. In addition, nonimaging measurement techniques, includin g external radiation monitoring, tissue-sample counting (blood and biopsy) and excreta counting are also considered. The third phase, data processing, involves curve-fitting techniques to integrate the source lime-activity cu rves (determining the area under these curves). For some applications, comp artmental modeling procedures may be used. Last, appendices are included th at provide a table of symbols and definitions, a checklist for study protoc ol design, example formats for quantitative imaging protocols, temporal sam pling error analysis techniques and selected calculational examples. The ut ilization of the presented approach should aid in the standardization of pr otocol design for collecting kinetic data and in the calculation of absorbe d dose estimates.