Pollock, Bruce E.

Object The decline in cranial nerve morbidity after radiosurgery for vestibular schwannoma (VS) correlates with dose reduction and other technical changes to this procedure. The effect these changes have had on tumor control has not been well documented. Methods The authors performed a retrospective review of 293 patients with VSs who underwent radiosurgery between 1990 and 2004 and had a minimum of 24 months of imaging follow-up (90% of the entire series). The median radiation dose to the tumor margin was 13 Gy. Treatment failure was defined as progressive tumor enlargement noted on 2 or more imaging studies. The mean postradiosurgical follow-up was 60.9 ± 32.5 months. Results Tumor growth was noted in 15 patients (5%) at a median of 32 months after radiosurgery. Radiographically demonstrated tumor control was 96% at 3 years and 94% at 7 years after radiosurgery. Univariate analysis revealed 2 factors that correlated with failed radiosurgery for VS: an increasing number of isocenters (p = 0.03) and tumor margin radiation doses ≤ 13 Gy (p = 0.02). Multivariate analysis showed that only an increasing number of isocenters correlated with failed VS radiosurgery (hazard ratio 1.1, 95% CI 1.02–1.32, p < 0.05). The tumor margin radiation dose (p = 0.22) was not associated with tumor growth after radiosurgery. Conclusions Distortion of stereotactic MR imaging coupled with increased radiosurgical conformality and progressive dose reduction likely caused some VSs to receive less than the prescribed radiation dose to the entire tumor volume.

Object The best approach to the management of vestibular schwannoma (VS) remains controversial. The aim of this study is to analyze the initial and follow-up costs of resection and stereotactic radiosurgery for patients with VS. Methods Initial and follow-up costs in 53 cases in which patients with unilateral, previously unoperated VSs > 3 cm underwent resection (21 cases) or radiosurgery (32 cases) at the Mayo Clinic from June 2000 until July 2002 were analyzed for 36 months. Follow-up treatment-specific utilization records were gathered prospectively for patients not returning to the Mayo Clinic after treatment. Six-month moving averages of incremental follow-up costs were calculated for the 2 patient groups. Results The mean cost of surgery in the microsurgery group was $23,788 (95% confidence interval $22,280–$24,842) compared with $16,143 (95% confidence interval $15,277–$17,545) for the radiosurgical group. Mean incremental follow-up costs per month for patients in the microsurgery group started just > $1000 per month, decreased steadily, and remained < $70 per month by the 10th month of follow-up. Mean incremental follow-up costs per month for patients in the radiosurgery group were <$10 per month for the first few months and thereafter increased to as much as $200 per month. Conclusions Although the total cost of microsurgery is higher due to the costs of hospitalization, follow-up costs for radiosurgery are greater in general. From a societal perspective, radiosurgery is less expensive than microsurgical resection provided that the rate of tumor progression after radiosurgery remains low with long-term follow-up.

Object Patients with trigeminal neuralgia (TN) and persistent or recurrent facial pain after microvascular decompression (MVD) typically undergo less invasive procedures in the hope of providing pain relief. The outcomes and risks of repeat posterior fossa exploration (PFE) for these patients are not clearly understood. Methods From September 2000 to November 2006, 29 patients (14 men, 15 women) underwent repeat PFE. The mean number of surgeries per patient at the time of repeat PFE was 3.2 (range 1–6). The mean follow-up duration after surgery was 33.7 months. Results Compression of the trigeminal nerve was noted in 24 patients (83%) by an artery (13 patients, 45%), vein (4 patients, 14%), or Teflon (7 patients, 24%). Four patients (14%) who underwent operations elsewhere had incorrect cranial nerves decompressed at their first surgery. Only MVD was performed in 18 patients (62%) and a partial nerve section (PNS) was performed in 11 patients (38%). An excellent facial pain outcome (no pain, no medications required) was achieved and maintained for 80% and 75% of patients at 1 and 3 years after surgery, respectively. Patients with Burchiel Type 1 TN were pain free without medications (91% at 1 year and 85% at 3 years) more frequently than patients with Burchiel Type 2 TN (27% at both 1 and 3 years; hazard ratio = 5.4, 95% confidence interval 1.4–21.1, p = 0.02). Fifteen patients (52%) had new or increased facial numbness. Two patients (7%) developed anesthesia dolorosa; both had undergone PNS. Two patients (7%) had hearing loss after surgery. Conclusions Repeat PFE for patients with idiopathic TN has facial pain outcomes that are comparable with both percutaneous needle-based techniques and stereotactic radiosurgery. Patients with persistent or recurrent TN should be considered for repeat PFE, especially if other less invasive surgeries have not relieved their facial pain.

Object The authors reviewed outcomes after stereotactic radiosurgery for patients with acromegaly and analyzed factors associated with biochemical remission. Methods Retrospective analysis was performed for 46 consecutive cases of growth hormone (GH)–producing pituitary adenomas treated by radiosurgery between 1991 and 2004. Biochemical remission was defined as a fasting GH less than 2 ng/ml and a normal age- and sex-adjusted insulin-like growth factor–I (IGF-I) level while patients were not receiving any pituitary suppressive medications. The median follow up after radiosurgery was 63 months (range 22–168 months). Twenty-three patients (50%) had biochemical remission documented at a median of 36 months (range 6–63 months) after one radiosurgical procedure. The actuarial rates of biochemical remission at 2 and 5 years after radiosurgery were 11 and 60%, respectively. Multivariate analysis showed that IGF-I levels less than 2.25 times the upper limit of normal (hazard ratio [HR] 2.9, 95% confidence interval [CI] 1.2–6.9, p = 0.02) and the absence of pituitary suppressive medications at the time of radiosurgery (HR 4.2, 95% CI 1.4–13.2, p = 0.01) correlated with biochemical remission. The incidence of new anterior pituitary deficits was 10% at 2 years and 33% at 5 years. Conclusions Discontinuation of pituitary suppressive medications at least 1 month before radiosurgery significantly improved endocrine outcomes for patients with acromegaly. Patients with GH–producing pituitary adenomas should not undergo further radiation therapy or surgery for at least 5 years after radiosurgery because GH and IGF-I levels continue to normalize over that interval.

ABSTRACTOBJECTIVE:To describe the quality of life (QOL) over time for adults with newly diagnosed high-grade gliomas and to examine the relationship between QOL and outcome data collected in three prospective cooperative group clinical trials.METHODS:The QOL study was a companion protocol for three Phase II high-grade glioma protocols. Five self-administered forms were completed by patients to assess QOL at study entry, 2 months, and 4 months after enrollment.RESULTS:QOL data were available for baseline, first, and second subsequent follow-up evaluations for 89%, 71%, and 69% of patients, respectively. A significant proportion of patients (47.1%) experienced impaired QOL (QOL ≤ 50) in at least one measure at subsequent evaluations, whereas most patients (88%) with impaired QOL at baseline continued to have impaired QOL at subsequent evaluations. On multivariable analyses, baseline QOL measures were predictive of QOL at the time of follow-up. In addition, patients who underwent a gross total resection were much less likely to have impaired QOL (P = 0.006), were less likely to experience worsening depression (P = 0.0008), and were more likely to have improved QOL (P = 0.003) at their first follow-up evaluation. Changes in QOL measures over time were not found to be associated with survival in multivariable analyses that adjusted for known prognostic variables; variables that were independently associated with improved survival were better performance status (P &lt; 0.001), younger age (P &lt; 0.001), and greater extent of resection (P &lt; 0.001).CONCLUSION:Baseline QOL was predictive of QOL over time. Gross total resection was associated with longer survival and improved QOL over time for patients with high-grade gliomas.

Abstract OBJECTIVE: To evaluate the efficacy and toxicity of radiosurgery in the treatment of cranial base chordoma and chondrosarcoma. METHODS: We reviewed 29 patients with cranial base chordoma (n = 25) or chondrosarcoma (n = 4) who underwent stereotactic radiosurgery between September 1990 and December 2002. The median patient age was 45 years (range, 10–81 yr). Nineteen patients also had radiation therapy before or in conjunction with radiosurgery (median dose, 50.4 Gy). The median tumor volume was 14.4 cm3 (range, 0.6–65.1 cm3). The median tumor margin dose was 15 Gy (range, 10–20 Gy); the median maximum radiation dose was 30 Gy (range, 20–40 Gy). Median clinical and imaging follow-up periods were 4.8 and 4.5 years, respectively. RESULTS: Seven chordoma patients (28%) had tumor progression (in-field, n = 3; out-of-field, n = 4), whereas 18 had stable disease or tumor shrinkage. No patient with a chondroid chordoma had tumor enlargement. The actuarial tumor control rates were 89 and 32% at 2 and 5 years, respectively. All 4 patients with chondrosarcoma had tumor control. Clinically, 7 patients (24%) had improvement of pretreatment symptoms, 16 (55%) remained stable, and 6 (21%) worsened. Three patients with tumor progression died. Ten patients (34%) had radiation-related complications. Complications included cranial nerve deficits (n = 6), radiation necrosis (n = 5), and pituitary dysfunction (n = 3). Patients having radiosurgery alone had no toxicity. CONCLUSION: Cranial base chordomas and chondrosarcomas remain a formidable management challenge. Radiosurgery as an adjunct to surgical resection provides in-field tumor control for some patients, but radiation-related complications are relatively high, especially when radiosurgery is combined with fractionated radiation therapy.