Hypofractionation in radiotherapy. An investigation of injured Swedish women, treated for cancer of the breast

Abstract

Background. The Swedish Insurance Company for Patient Injuries asked the two authors of this report to identify the Swedish women with cancer of the breast who had been injured by radiotherapy with a hypofractionated schedule. The purpose was to provide a basis on which the Company could decide if indemnification could be given. Material and methods. We define hypo-fractionation as any fraction dose exceeding 2.0 gray (Gy) per day. We set the lower limit for the “late effect” at 53.0 Gy with 2 Gy/fraction. All departments of radiotherapy in Sweden were asked to identify women who had developed brachial plexus neuropathy (BPN). Their medical records were obtained. The clinical picture of their injuries was recorded, and the absorbed dose was calculated or reconstructed. All doses, no matter in what way they were expressed, were recalculated to “late effect”, presented in EQD_2Gy (Equalized Total Dose in 2 Gy/fraction). The latency period from therapy to onset of symptoms was also noted. Results. A variety of treatment techniques was used, fractions ranging in size from 2.5 to 6.0 Gy. Absorbed doses up to a Biologically Equivalent Dose (BED) 146 EQD_2Gy in late effects were recorded (6 Gy×13). More than 95% of the injured women had a combination of stiff shoulder, paralysis, pain, oedema and atrophy of the muscles to the arm and/or hand. Latency from end of radiotherapy to onset of symptoms could be as long as 30 years. Discussion. Hypofractionated radiotherapy has injured severely numerous patients. The lesions have become a medico-legal issue in some countries. The life of many of these women has been ruined: physically, mentally, socially and economically. Conclusion. Hypofractionated radiotherapy can cause injuries if the target volume is not exact, or the total dose is not adjusted to a tolerable level as compared to conventional treatments employing 2 Gy/day fractions.

Notes

EQD (Equalized Total Dose) is Estro nomenclatura. The corresponding American term is NTD (Normal Total Dose)