Dose-effect relationships for recurrence of keloid and pterygium after surgery and radiotherapy.

PURPOSE: To show radiation dose-response relationships for recurrence of keloid and pterygium after radiotherapy following surgery.

METHODS AND MATERIALS: Using PubMed, we performed a retrospective review of articles reporting incidences and/or dose-response relationships for recurrence of keloid and pterygium after radiotherapy following surgery. The irradiation regimens identified were normalized by use of the linear-quadratic model; biologically effective doses (BEDs) were calculated.

RESULTS

For keloid recurrence after radiotherapy following keloid removal, with either teletherapy or brachytherapy, the recurrence rate after having delivered a BED greater than 30 Gy is less than 10%. For pterygium recurrence after bare sclera surgery and (90)Sr beta-irradiation, a BED of about 30 Gy seems to be sufficient also to reduce the recurrence rate to less than 10%.

CONCLUSIONS

Most of the doses in the radiotherapy schemes used for prevention of keloid recurrence after surgery are too low. In contrast, the doses applied in most regimens to prevent pterygium recurrence are too high. A scheme with a BED of 30 to 40 Gy seems to be sufficient to prevent recurrences of keloid as well as pterygium.