Teleoncology in the Department of Defense: a tale of two systems.

Two telemedicine networks were developed for the purpose of conducting multidisciplinary oncology ("teleoncology") conferences. The infrastructure of each system differed: one system was Internet-based; the other was delivered via Integrated Services Digital Network (ISDN) lines. The purpose of this study was to describe the infrastructure and cost, consultative process, technical aspects, and conference format of the two teleoncology programs. The two systems' technical aspects, participant satisfaction with the systems, and conference participation were compared qualitatively. Assessment of the technical aspects of the systems suggested that each had distinct advantages. Survey results indicated that provider satisfaction with the technical and logistical aspects of each type of teleoncology conference was high. The present study may prove helpful for individuals who are considering implementing their own teleoncology programs.

Postoperative irradiation for subtotally resected meningiomas. A retrospective analysis of 140 patients treated from 1967 to 1990.

The authors retrospectively analyzed 140 patients treated at the University of California, San Francisco, from 1967 to 1990 to evaluate the results of radiation therapy (median 5400 cGy) given as an adjuvant to subtotal resection of intracranial meningioma. Of the 140 meningiomas, 117 were benign and 23 were malignant. The median follow-up period was 40 months. The overall survival rate at 5 years was 85% for the benign and 58% for the malignant tumor groups (p = 0.02); the 5-year progression-free survival rates were 89% and 48%, respectively (p = 0.001). For patients with benign meningioma, the 10-year overall and progression-free survival rates were 77%. An improved progression-free survival rate in that group was not related to tumor size but was associated with a younger age (p = 0.01) and treatment after 1980 with innovative technologies (p = 0.002); none of those variables affected the progression-free survival rate in the patients with malignant meningioma. Increased progression-free survival in the benign tumor group was also significantly associated with increasing the minimum radiation dose (p = 0.04). The 5-year progression-free survival rate for patients with benign meningioma treated after 1980 (when computerized tomography or magnetic resonance imaging was used for planning therapy) was 98%, as compared with 77% for patients treated before 1980 (p = 0.002). There were no second central nervous system tumors. Morbidity (3.6%) included sudden blindness or cerebral necrosis and death. When total resection of benign meningioma is not feasible, subtotal resection combined with precise treatment planning techniques and adjuvant radiation therapy can achieve results comparable to those of total resection.

Immobilization improves the reproducibility of patient positioning during six-field conformal radiation therapy for prostate carcinoma.

PURPOSE: To determine the magnitude of patient positioning errors associated with six field conformal therapy for carcinoma of the prostate, and to assess the impact of alpha-cradle immobilization on these errors. METHODS AND MATERIALS: The records of 22 patients, treated at two of the treatment facilities within our department, using computed tomography-planned conformal six field therapy for carcinoma of the prostate, were reviewed. At one facility (UCD), patients were routinely treated with immobilization, while at the other (UCSF) no rigid immobilization was used. Portal films of patients treated at both facilities were subsequently reviewed, and the deviation of each portal from the simulation film was determined (simulation-to-treatment variability). In addition, for each patient, the average deviation of each portal film from the average portal film (treatment-to-treatment variability) was determined. RESULTS: The mean and median simulation-to-treatment variability was 0.4 cm for those patients treated with immobilization, versus 0.6 cm for those treated without immobilization. The 90th percentile of simulation-to-treatment variability was 0.7 cm for those patients treated with immobilization, versus 1.1 cm for those not immobilized. There was a significant reduction in the number of portals observed with errors of > or = 0.50 cm (132/201 vs. 37/87, 66% vs. 43%; p < 0.001), 0.75 cm (184/201 vs. 59/87, 92% vs. 68%; p < 0.001), and 1.0 cm (196/201 vs. 74/87, 98% vs. 85%; p < 0.001) for patients treated with immobilization. There was also a significant reduction in the number of patients with treatment-to-treatment variability > or = 0.5 cm (1/10 vs. 8/12; p = 0.01) for patients treated with immobilization. CONCLUSION: The use of immobilization devices significantly reduces errors in patient positioning, potentially permitting the use of smaller treatment volumes. Immobilization should be a component of conformal radiation therapy programs for prostate carcinoma.

Optic neuropathy after irradiation of meningioma.

Radiation-induced optic neuropathy (RON) is a rare and catastrophic complication of currently employed radiation therapy regimens for meningiomas that have been partially resected and sampled for biopsy. Between 1972 and 1989, 49 patients received postoperative irradiation for partially resected or biopsy sampled meningiomas, with the optic nerve within the treatment field. One patient experienced RON. The latency period for this case was 23 months. A review of the literature disclosed few cases of RON after treatment for meningioma; however, 42 cases of RON have been reported after radiation therapy for other lesions. The authors constructed two approaches to predict optic nerve radiation tolerance. The first is modeled on a previous proposal for a neural tissue nominal standard dose term and enabled accurate prediction of safe treatment regimens and risk of RON. This approach compared favorably with previously employed nominal standard dose terms. The second approach, based on the linear-quadratic model, proved unsuccessful due to its failure to achieve statistical significance.