Phase I/II study of stereotactic body radiotherapy for spinal metastasis and its pattern of failure.

OBJECT: The authors report data concerning the safety, effectiveness, and patterns of failure obtained in a Phase I/II study of stereotactic body radiotherapy (SBRT) for spinal metastatic tumors. METHODS: Sixty-three cancer patients underwent near-simultaneous computed tomography-guided SBRT. Spinal magnetic resonance imaging was conducted at baseline and at each follow-up visit. The National Cancer Institute Common Toxicity Criteria 2.0 assessments were used to evaluate toxicity. RESULTS: The median tumor volume of 74 spinal metastatic lesions was 37.4 cm3 (range 1.6-358 cm3). No neuropathy or myelopathy was observed during a median follow-up period of 21.3 months (range 0.9-49.6 months). The actuarial 1-year tumor progression-free incidence was 84% for all tumors. Pattern-of-failure analysis showed two primary mechanisms of failure: 1) recurrence in the bone adjacent to the site of previous treatment, and 2) recurrence in the epidural space adjacent to the spinal cord. Grade 3 or 4 toxicities were limited to acute Grade 3 nausea, vomiting, and diarrhea (one case); Grade 3 dysphagia and trismus (one case); and Grade 3 noncardiac chest pain (one case). There was no subacute or late Grade 3 or 4 toxicity. CONCLUSIONS: Analysis of the data obtained in the present study supports the safety and effectiveness of SBRT in cases of spinal metastatic cancer. The authors consider it prudent to routinely treat the pedicles and posterior elements using a wide bone margin posterior to the diseased vertebrae because of the possible direct extension into these structures. For patients without a history of radiotherapy, more liberal spinal cord dose constraints than those used in this study could be applied to help reduce failures in the epidural space.

Stereotactic radiosurgical treatment of cerebral metastases arising from breast cancer.

OBJECTIVE: This study was undertaken to evaluate the outcome of patients undergoing stereotactic radiosurgery (SRS) as primary or salvage treatment of brain metastases arising from breast cancer. MATERIALS AND METHODS: Between July 2000 and September 2005, the medical records of 49 breast cancer patients who underwent SRS for 84 brain metastases were reviewed retrospectively. Thirty-four patients received SRS as primary brain metastasis treatment and 15 patients received SRS as salvage treatment of brain metastasis recurrence following prior whole-brain radiation therapy. The Kaplan-Meier method, univariate comparisons with log-rank test, and multivariate analysis were performed. RESULTS: Median follow-up was 12 months (range, 5-50 months) and median survival was 19 months for all patients. The 1- and 2-year overall survival (OS) rates were 60%, 56%, and 55%, 23% for initial SRS alone and SRS salvage groups, respectively (P = 0.99). A multivariate analysis showed that a high KPS score (KPS > or =90 vs. <90; P = 0.02), a higher SIR value (SIR > or =6 vs. <6; P = 0.001), postmenopausal status (P = 0.003), and positive estrogen receptor status (P = 0.04) were predictive of better survival. The 1- and 2-year local control rates were 79%, 49%, and 77%, 46% for SRS alone and SRS salvage group, respectively. CONCLUSION: SRS can be used as primary treatment of brain metastases or salvage of recurrences after whole-brain radiation therapy to achieve good local control on the order of close to 80% at 1 year. The median survival of brain metastasis patients with breast cancer of 19 months appears favorable compared with the general brain metastasis population.

A pilot study of neurocognitive function in patients with one to three new brain metastases initially treated with stereotactic radiosurgery alone.

OBJECTIVE: Whether to administer or omit adjuvant whole-brain radiation therapy in conjunction with stereotactic radiosurgery (SRS) in the initial management of patients with one to three newly diagnosed brain metastases is the subject of debate. This report provides data from a pilot study in which neurocognitive function (NCF) was prospectively measured for patients with one to three newly diagnosed brain metastases treated with initial SRS alone. METHODS: Fifteen patients were prospectively treated with initial SRS alone. Assessment of NCF and magnetic resonance imaging scans were performed. RESULTS: At baseline, 67% of the patients had impairment on one or more tests of NCF. The domains most frequently impaired at baseline were executive function, motor dexterity, and learning/memory with an incidence of 50, 40, and 27% respectively. Brain metastasis volume (.3 cm3) measured at the time of initial SRS treatment was associated with worse performance on a measure of attention (P < 0.05). At 1 month, declines in the learning/memory and motor dexterity domains were most common. In a subgroup of five patients still alive 200 days after enrollment, four patients (80%) demonstrated stable or improved learning/memory, three (60%) demonstrated stable or improved executive function, and three (60%) demonstrated stable or improved motor dexterity relative to their baseline evaluation. CONCLUSION: Although two-thirds of the brain metastasis patients had impaired NCF at baseline, the majority of five long-term survivors had stable or improved NCF performance across executive function, learning/memory, and motor dexterity.

Phase I clinical evaluation of near-simultaneous computed tomographic image-guided stereotactic body radiotherapy for spinal metastases.

PURPOSE: To evaluate in a Phase I study the safety, feasibility, and patient-positioning accuracy of treating patients with intensity-modulated, near-simultaneous, computed tomographic (CT) image-guided stereotactic body radiotherapy (SBRT). PATIENTS AND METHODS: Fifteen consecutive patients with metastatic spinal disease who met protocol eligibility criteria were entered into a Phase I clinical trial. Each patient received five treatments of intensity-modulated, near-simultaneous CT image-guided SBRT, for a total of 75 treatments with 90 isocenter setups during the course of the study. Patients uniformly received 30 Gy (if possible) of radiotherapy in 5 fractions to the clinical target volume. The total dose was constrained by limiting the spinal cord to a maximum dose of 10 Gy. To verify correct daily patient positioning before each treatment and to determine the daily treatment setup error after radiation delivery, axial CT scans were taken before and immediately after each treatment without moving the patient from the treatment position, for comparison with the planning CT scan. Toxicity was measured using the Common Toxicity Criteria, the Late Effects of Normal Tissue scoring system and a neurologic function scale. Follow-up was conducted 4 weeks after completion of SBRT, and then 2, 3, 6, 9, 12, and every 6 months thereafter. RESULTS: The procedure was technically feasible to perform in all patients. No neurologic toxicity was observed in any patient. The median follow-up time was 9 months (range 6-16). The Clopper-Pearson upper bound on the probability of paralysis with 95% confidence is no greater than 0.181. The positional setup error was determined to be within 1 mm of planning isocenter. CONCLUSIONS: This Phase I study shows that intensity-modulated, near simultaneous, CT image-guided SBRT is a feasible, and highly precise technique for the noninvasive treatment of spinal metastases. Although no paralysis has developed in the 15 patients treated, continued monitoring for spinal cord toxicity is warranted, as larger numbers of patients will be needed to more precisely define the upper bound on the probability of spinal cord myelopathy.