Early neurological complications after stereotactic radiosurgery/radiotherapy.

OBJECTIVE: To evaluate the neurological complications after stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT). MATERIAL AND METHOD: The Ramathibodi Radiosurgery Unit started its service in August 1997, using the linear-accelerator based system. There were 144 patients treated from August 1997 to October 1999. Single fraction SRS was performed in 56 cases consisting of 46 arteriovenous malformations (AVMs), 4 cranial nerve (CN) schwannomas, 3 pituitary adenomas, 2 meningiomas, and 1 multiple hemangioblastomas. Eighty eight patients received multifractionated SRT, including 27 meningiomas, 17 pituitary adenomas, 13 benign and malignant gliomas, 8 brain metastasi(e)s, 5 CA nasopharynx, 5 craniopharyngiomas, 5 CN schwannomas, 2 AVMs, 2 chordomas, and 4 others. After treatment the patients were clinically evaluated every 1-6 months and MRI was scheduled at 6 or 12-month interval or when there were abnormal clinical signs/symptoms. The complications included any new neurological complaints or findings during and after treatment. RESULTS: Median follow-up time was 9.5 (0-20) months. Of 138 patients with available follow-up data, there were 23 (13 SRS and 10 SRT) cases who experienced new neurological symptoms at 3 weeks - 20 months (median = 3 months) from the time treatment started. Symptoms included headache, seizure, weakness, decreased vision, vertigo with/without ataxia, diplopia, dizziness, impaired memory, hemifacial spasm, decreased sensation and facial palsy. Three AVM patients had intraventricular hemorrhage from the patent nidi. After symptomatic treatment there were 15 cases with complete recovery (including seizure control) and 6 with partial recovery. There were 2 deaths from ruptured AVM and progressive metastatic brain lesion. There were 79 patients who had at least 1 follow-up MRI, and changes were detected in T2-weighted images in 19 cases at 3-18 months after treatment. Ten cases had symptoms corresponding to the image changes, the other 9 patients were asymptomatic. CONCLUSIONS: Longer follow-up time is needed to fully evaluate the complications after SRS/SRT, however, preliminary results showed that most of the complications were mild and transient. There was a tendency of a higher complication rate in the SRS group. Not all patients with post treatment image changes developed symptoms.

Medical physics is alive and well and growing in South East Asia.

In recent years there has been a significant economic growth in South East Asia, along with it a concurrent development of medical physics. The status of four countries--Malaysia, Thailand, the Philippines and Indonesia are presented. Medical physicists in these countries have been experiencing the usual problems of lack of recognition, low salaries, and insufficient facilities for education and training opportunities. However the situation has improved recently through the initiative of local enthusiastic medical physicists who have started MS graduate programs in medical physics and begun organizing professional activities to raise the profile of medical physics. The tremendous support and catalytic roles of the American Association of Physicists in Medicine (AAPM) and international organizations such as International Organization for Medical Physics (IOMP), International Atomic Energy Agency (IAEA), World Health Organization (WHO), and International Center for Theoretical Physics (ICTP) have been instrumental in achieving progress. Contributions by these organizations include co-sponsorship of workshops and conferences, travel grants, medical physics libraries programs, and providing experts and educators. The demand for medical physicists is expected to rise in tandem with the increased emphasis on innovative technology for health care, stringent governmental regulation, and acceptance by the medical community of the important role of medical physicists.

Prognostic factors among 130 patients with osteosarcoma.

One hundred thirty patients with high grade osteosarcoma were enrolled in a randomized prospective multidisciplinary treatment that included intraarterial chemotherapy, local irradiation, limb salvage surgery, and prophylactic whole lung irradiation. The patients were evaluated to stage the prognostic factors. In a multivariate analysis, a minimal level of serum lactic acid dehydrogenase less than 300 IU/L showed a significant prognostic value. The history of trauma before diagnosis of disease, local irradiation of the affected site, histologic response to preoperative multidisciplinary therapy, and prophylactic whole lung irradiation were associated with significantly better prognosis in the log rank test. Patient age, site of the primary tumor, presentation of fracture, pathologic subtype, signs and symptoms, serum alkaline phosphatase level, and erythrocyte sedimentation rate were not found to be prognostic factors. The 9-year survival rate of the whole group was 55%.