title: Report on the clinical effects of inadvertent radiation underdosage in 1045 patients.
abstract: Between Autumn 1982 and Winter 1991, 1045 patients received lower doses of radiation than were prescribed for the treatment of their cancers because of a miscalculation of radiation doses. This occurred as a result of the introduction of a new technique of treatment planning. An error in the application of the planning system lead to an underdosage of radiation of between 5 and 35%. In patients who received radiation alone for radical treatment a dose reduction of 20% or more resulted in a lower than expected local control rate. The effects were less marked in patients who were treated by combinations of surgery and radiation and in those with a very high rate of distant metastases. In 1991, a new computer planning system was installed and a discrepancy was discovered between the new plans and those from the previous system. Further investigation revealed that the original planning system already contained within it a correction factor for the tumour to skin distance and that systematically reapplying this correction had resulted in underdoses of radiation being delivered to patients for nearly 10 years. During the 9-year period of this dose miscalculation only 6% of patients treated in the department were treated with the isocentric technique; for many of those it formed only a part of their treatment.
authors.affiliation: Yorkshire Regional Centre for Cancer Treatment, Cookridge Hospital, Leeds, UK.
authors.forename: D
authors.initials: D
authors.lastname: Ash
authors.forename: T
authors.initials: T
authors.lastname: Bates
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003131:Combined Modality Therapy; D016889:Endometrial Neoplasms / Q000532:radiotherapy; D004938:Esophageal Neoplasms / Q000532:radiotherapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000532:radiotherapy; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control; D009369:Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D010166:Palliative Care; D011471:Prostatic Neoplasms / Q000532:radiotherapy; D011830:Radiation Effects; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D012004:Rectal Neoplasms / Q000532:radiotherapy; D015996:Survival Rate; D016896:Treatment Outcome; D001749:Urinary Bladder Neoplasms / Q000532:radiotherapy; D002583:Uterine Cervical Neoplasms / Q000532:radiotherapy