接受放射核素治疗的患者通常需要在治疗后一段时间内限制某些活动，以优化公众保护并确保不超过法定剂量限制。软件可以根据自放射性药物使用时的纵向剂量率测量，计算个人所需的限制期。在澳大利亚医院，电子表格程序已被用于此目的已经有20年。然而，该电子表格在计算接触模式下的剂量时使用近似值，这会影响计算出的限制期。因此，开发了一款名为Dorn的计算机程序，可提供与电子表格相同的功能，但无需使用此近似值。对比了Dorn和电子表格提供的辐射安全建议。样本为55例接受碘-131治疗分化型甲状腺癌患者。无论是照顾婴儿、与儿童密切接触还是与伴侣共眠的限制期，在Dorn中通常比电子表格长约13小时，但在某些情况下，限制期可能会短至一周甚至长达一月。如果临床上使用Dorn代替电子表格，一些患者的限制期将更短，并且治疗提供者可以更自信地遵守法规要求和最佳实践。Dorn可以在https://doi.org/jg5f 给予免费下载。©2023年辐射防护协会。由IOP Publishing Limited代表SRP出版。保留所有权利。

Patients treated with radionuclide therapy usually require restrictions on certain activities for a period of time following treatment to optimise protection of the public and ensure the legal dose limit is not exceeded. Software may be used to calculate necessary restriction periods for an individual based on longitudinal dose rate measurements from the time of radiopharmaceutical administration. A spreadsheet program has been used for this purpose in Australian hospitals for the last two decades. However, this spreadsheet has a limitation in that it uses an approximation in the calculation of dose from a contact pattern, which affects the calculated restriction period. A computer program called Dorn was developed that provides the same functionality as the spreadsheet but without this approximation. Proffered radiation safety advice from Dorn and the spreadsheet were compared.Advice from the spreadsheet and Dorn were compared for 55 patients who underwent iodine-131 therapy for differentiated thyroid cancer.The restriction periods for caring for infants, close contact with children and sleeping with a partner were typically about 13 hours longer in Dorn than in the spreadsheet, but in some cases were over a week shorter or a month longer.If the Dorn program is used clinically in place of the spreadsheet, some patients will enjoy shorter restriction periods and the therapy provider can be more confident in their compliance with regulatory requirements and best practice. Dorn is freely available from https://doi.org/jg5f.© 2023 Society for Radiological Protection. Published on behalf of SRP by IOP Publishing Limited. All rights reserved.