Kent E. Wallner

Intracranial ependymomas: results of treatment with partial or whole brain irradiation without spinal irradiation

Twenty patients with intracranial ependymoma (16) or anaplastic ependymoma (4) received post-operative radiation therapy at the University of California, San Francisco from 1959 through 1981. No patient received prophylactic spinal irradiation. The actuarial survival at 5, 10, and 15 years for 15 patients with ependymoma who received greater than 45 Gy was 67, 57, and 46%, respectively. Only one patient (7%) developed clinically recognized spinal metastases; this patient was eventually shown to have tumor at the primary site, within the irradiated volume. Six of 11 patients treated with partial brain irradiation had an intracranial recurrence, versus 1 of 4 patients treated with whole brain irradiation. Three patients were autopsied after failing partial brain irradiation for an ependymoma and the site of failure was within the irradiated volume of each patient. Partial brain irradiation was used to treat 4 patients with anaplastic ependymoma. One developed a local recurrence within the irradiated volume. The other three survived longer than 10 years. At UCSF, most patients with low grade ependymomas are presently treated with partial brain irradiation, but whole brain plus spinal irradiation is used for anaplastic tumors.

Effect of cisplatin resistance on cellular radiation response.

Cisplatin-resistant tumors of the head and neck are generally resistant to irradiation. To determine whether the association between cisplatin (DDP) resistance and radiation resistance is a cellular phenomenon, we developed DDP-resistant Chinese hamster fibroblasts and studied their response to radiation. DDP resistance did not confer cross resistance to radiation. DDP-resistant cells did not demonstrate altered ability to repair sublethal or potentially lethal radiation damage. However, an isodose concentration of DDP did not inhibit repair of radiation damage in drug-resistant cells as readily as it did in drug-sensitive cells. The results suggest that cross resistance of tumors between DDP and radiation may be a result of the tumor microenvironment, rather than being a cellular phenomenon. Additionally, DDP may not inhibit the repair of radiation damage in DDP-resistant tumors.

Adriamycin resistance, heat resistance and radiation response in Chinese hamster fibroblasts.

We have investigated the effect of heat, radiation or Adriamycin (ADR) on Chinese hamster fibroblasts (HA-1), their heat resistant variants, and their ADR resistant variants. Heat or ADR resistance did not confer cross resistance to radiation. Cells resistant to heat did show cross resistance to ADR. Cells selected for ADR resistance were not cross resistant to heat and they did not exhibit drug potentiation by hyperthermia, characteristic of ADR sensitive cells. Cytofluorometric measurement showed decreased ADR uptake in both heat and ADR resistant cells. The possibility of cross resistance between heat and ADR should be considered when designing treatment protocols involving combined modality trials.

Radiation therapy for the treatment of non-eighth nerve intracranial neurilemmoma

The records of 19 patients treated for intracranial neurilemmomas, other than of the eighth nerve, at the University of California, San Francisco from 1945 through 1983 were reviewed. One patient who died within 30 days following surgery was excluded from the analysis. The 5th and the 9/10/11th nerve complex were the most common sites of tumor origin. Patients were classified by the extent of surgical resection: total (90-99% resection, NTR), subtotal (less than 90% resection, STR) and biopsy. Five patients had total excision of their tumor without post-operative irradiation and none had recurred. One of the 2 patients who had STR and did not receive post-operative irradiation recurred, while 2 of the 3 patients who received post-operative irradiation following STR recurred. One of the 2 patients who had NTR and did not receive post-operative irradiation recurred, while 1 of the 3 patients who received post-operative irradiation following NTR recurred. Two patients were treated with post-operative irradiation following biopsy and one recurred. One patient was treated with planned preoperative irradiation to reduce tumor vascularity, followed by total resection. Because of the small number of patients, no firm conclusion regarding the efficacy of irradiation for non-eighth nerve intracranial neurilemmoma can be made.

Squamous cell carcinoma of the head and neck after radiation therapy for Hodgkin's disease a report of two cases and a review of the literature

Squamous cell carcinoma (SCC) of the head and neck developed in two patients 12 and 22 years, respectively, after radiation treatment for Hodgkins disease (HD). Both tumors arose in previously irradiated fields. Sixteen reported cases of SCC of the head and neck occurring after treatment for HD are summarized. Details of treatment were lacking in most instances. The authors suspect that cases similar to the two reported here will be seen more frequently with longer follow‐up of patients cured of HD.

Retreatment of pediatric brain tumors with radiation and misonidazole: results of a CCSG/RTOG phase I/II study

Twenty‐nine patients with recurrent pediatric brain tumors after full‐dose treatment with radiation were retreated with misonidazole (9 gm/m2) and whole‐brain irradiation (300 rad × 10). Seventeen of 29 patients (59%) experienced nausea and vomiting with misonidazole administration and 6 patients (21%) developed peripheral neuropathy. Serum levels of misonidazole were similar to those reported for adults. One patient died of trauma shortly after retreatment. For the remaining 28 patients, the median time‐to‐progression was 5.5 months. Median survival was 13 months. Six patients (21%) developed radiation toxicity, two of whom died from the toxicity. Whereas the results on this study are similar to reported series of patients receiving salvage chemotherapy for recurrent pediatric brain tumors, more effective treatment clearlv is needed.