Faculty Bibliography

BACKGROUND: Although whole-brain radiation therapy (WBRT) has been a standard palliative management for brain metastases from renal cell carcinoma, its benefit has been elusive because of radiobiological resistance. OBJECTIVE: To evaluate the role of stereotactic radiosurgery (SRS) in the management of brain metastases from renal cell carcinoma. METHODS: We reviewed records from 158 consecutive patients (men = 111, women = 47) who underwent SRS for 531 brain metastases from renal cell carcinoma. The median patient age was 61 years (range, 38-83 years), and the median number of tumors per patient was 1 (range, 1-10). Seventy-nine patients (50%) had solitary brain metastasis. Fifty-seven patients (36%) underwent prior WBRT. The median total tumor volume for each patient was 3.0 cm3 (range, 0.09-47 cm). RESULTS: The overall survival after SRS was 60%, 38%, and 19% at 6, 12, and 24 months, respectively, with a median survival of 8.2 months. Factors associated with longer survival included younger age, longer interval between primary diagnosis and brain metastases, lower recursive partitioning analysis class, higher Karnofsky performance status, smaller number of brain metastases, and no prior WBRT. Median survival for patients with < 2 brain metastases, higher Karnofsky performance status (> 90), and no prior WBRT was 12 months after SRS. Sustained local tumor control was achieved in 92% of patients. Symptomatic adverse radiation effects occurred in 7%. Overall, 70% of patients improved or remained neurologically stable. CONCLUSION: Stereotactic radiosurgery is an especially valuable option for patients with higher Karnofsky performance status and smaller number of brain metastases from renal cell carcinoma.

BACKGROUND: Nonfunctional pituitary adenomas (NFPAs) represent approximately 50% of all pituitary tumors. OBJECTIVE: To evaluate the long-term outcomes of stereotactic radiosurgery for NFPAs. METHODS: We evaluated the management outcomes of Gamma Knife radiosurgery in 125 patients with NFPAs over an interval of 22 years. The median patient age was 54 years (range, 16-88 years). One hundred ten patients (88%) had residual or recurrent tumors after >/= 1 surgical procedures, and 17 (14%) had undergone prior fractionated radiation therapy. The median target volume was 3.5 cm3 (range, 0.4-28.1 cm3), and the median tumor margin dose was 13.0 Gy (range, 10-25 Gy). RESULTS: Tumor volume decreased in 66 patients (53%), remained stable in 46 (37%), and increased in 13 (10.4%) during a median of 62 months (maximum, 19 years) of imaging follow-up. The actuarial tumor control rates at 1, 5, and 10 years were 99%, 94%, and 76%, respectively. Factors associated with a reduced progression-free survival included larger tumor volume (>/= 4.5 cm3) and >/= 2 prior recurrences. Of 88 patients with residual pituitary function, 21 (24%) suffered new hormonal deficits at a median of 24 months (range, 3-114 months). Prior radiation therapy increased the risk of developing new pituitary hormonal deficits. One patient (0.8%) had a decline in visual function, and 2 (1.6%) developed new cranial neuropathies without tumor progression. CONCLUSION: Stereotactic radiosurgery can provide effective management for patients with newly diagnosed NFPAs and for those after prior resection and/or radiation therapy.

BACKGROUND: Patients with small-cell lung cancer have a high likelihood of developing brain metastases. Many of these patients will have prophylactic cranial irradiation (PCI) or eventually undergo whole brain radiation therapy (WBRT). Despite these treatments, a large number of these patients will have progression of their intracranial disease and require additional local therapy. Stereotactic radiosurgery (SRS) is an important treatment option for such patients. METHODS: We retrospectively reviewed the charts of 44 patients with brain metastases from small-cell lung cancer treated with gamma knife SRS. Multivariate analysis was used to determine significant prognostic factors influencing survival. RESULTS: The median follow-up from SRS in this patient population was 9 months (1-49 months). The median overall survival (OS) was 9 months after SRS. Karnofsky performance status (KPS) and combined treatment involving WBRT and SRS within 4 weeks were the two factors identified as being significant predictors of increased OS (p = 0.033 and 0.040, respectively). When comparing all patients, patients treated with a combined approach had a median OS of 14 months compared to 6 months if SRS was delivered alone. We also compared the OS times from the first definitive radiation: WBRT, WBRT and SRS if combined therapy was used, and SRS if the patient never received WBRT. The median survival for those groups was 12, 14, and 13 months, respectively, p = 0.19. Seventy percent of patients had follow-up magnetic resonance imaging available for review. Actuarial local control at 6 months and 12 months was 90% and 86%, respectively. Only 1 patient (2.2%) had symptomatic intracranial swelling related to treatment, which responded to a short course of steroids. New brain metastases outside of the treated area developed in 61% of patients at a median time of 7 months; 81% of these patients had received previous WBRT. CONCLUSIONS: Stereotactic radiosurgery for small-cell lung carcinoma brain metastases provided safe and effective local tumor control in the majority of patients.