Routine pregnancy testing compared with asking, before radiotherapy

The rules. In the UK, the Royal College of Radiologists' IR(ME)R guidance for radiotherapy (second edition, 2026) leaves the age range for enquiries and any routine testing to each employer's procedure: it allows routine testing for people with irregular cycles after a risk assessment, says a test should be done if pregnancy cannot be excluded, and, for molecular radiotherapy, that menstrual history alone is not adequate to exclude pregnancy.

What practice looks like. In an international survey of 434 radiation oncologists (69.1 per cent in the United States), 84.8 per cent agreed one should screen for pregnancy before radiotherapy, yet 29.7 per cent said their department had no screening policy and 7.1 per cent did not screen. Of 93 who had treated a known pregnant patient, 17 had done so accidentally, and not screening at simulation was associated with treating a pregnant patient (p = 0.0459).

The catch with testing. Some tumours secrete human chorionic gonadotropin and give a positive pregnancy test in people who are not pregnant; one report describes a gastrointestinal stromal tumour found this way before radiotherapy (Andruska 2020).

What is unknown. No study compares asking alone with routine testing for missed pregnancies, delays or false positives in radiotherapy.