In the treatment of keloids, the recurrence after surgical excision is relatively high. Various types of adjuvant therapy such as radiotherapy and corticosteroid injection have been used to reduce the recurrence.

The aim of this study was to determine the appropriate time for initiating postoperative radiotherapy and to analyze factors associated with the occurrence and recurrence of keloids.

Of these 37 lesions, 22 were located in the ear lobe, 6 in the helix of the auricle, 4 on the shoulder, 3 on the chest wall, and 2 on the abdomen. Causative factors were piercings (n=24), trauma (n=5), previous surgical lesions or bacillus Calmette-Guerin vaccination lesions (n=3) and acne (n=2). Radiation therapy was initiated within 24 h in 24 lesions, between 24 and 72 h in 6 lesions, and after more than 72 h in 7 lesions.

Seven lesions recurred, including 5 recurrences in high stretch-tension regions (p=0.010). Initial treatments were administered within 24 h in 1 lesion and more than 72 h after surgical excision in 6 lesions (p<0.0001). In the 19 patients with family histories, maternal and paternal genetic predispositions were present in 14 and 5 patients, respectively (p=0.033).

Radiotherapy should be initiated within 72 h of surgical excision. Location in a high stretch-tension region was significantly associated with recurrence. Patients with a family history showed a significant tendency toward maternal genetic predisposition. Therefore, combination therapy should be considered to reduce the occurrence and recurrence of keloids, and careful observation is required.