From January 1970 to June 1982, among 4, 294 patients with malignant neoplasms, herpes zoster (HZ) occurred in 87 (2.0%) after irradiation. The incidence of HZ infection was rather high in patients with malignant lymphoma (8.3%), epipharyngeal cancer (8.2%), ovarial tumor (4.8%) and testicular tumor (4.2%). Most of these patients received extensive radiation therapy along the spinal cord and/or nerve root.
The location of HZ infection was devided as follows : HZ infectious lesion located in the area of (I-A) innervated segment of the irradiated nerve root (74%), (I-B) irradiated dermatome (3%) and (II) not associated with radiation field (23%).
In 55 (86%) of 64 patients of I-A, HZ infection occurred within one year, particularly in six months (41 cases (64%)) after the complesion of radiation therapy. This incubation period between completing irradiation and the manifestation of HZ infection was likely to be compatible with the period between radiation therapy and earlier radiation injury. Among 20 patients in Group II, 12 patients (60%) developed HZ infection over a year after irradiation.
The cumulative 5-year survival of these patients except for the patients with malignant lymphoma was 42% and HZ infection was considered to have no prognostic significance.
In 19 cases treated with 3-Germylopropionic acid sesquioxide (Biositon-8), all were free of severe neuralgia and 11 patients were cured within 2 weeks. Ongoing clinical trial investigating the use of Biositon-8 appears promising against HZ infection.
