Stereotactic radiosurgery vs. fractionated radiotherapy for tumor control in vestibular schwannoma patients: a systematic review.

OBJECTIVE: Repeated controlled studies have revealed that stereotactic radiosurgery is better than microsurgery for patients with vestibular schwannoma (VS) <3 cm in need of intervention. In this systematic review we aimed to compare results from single-fraction stereotactic radiosurgery (SRS) to fractionated stereotactic radiotherapy (FSRT) for patients with VS. DATA SOURCES AND ELIGIBILITY CRITERIA: We systematically searched MEDLINE, Web of Science, Embase and Cochrane and screened relevant articles for references. Publications from 1995 through 2014 with a minimum of 50 adult (>18 years) patients with unilateral VS, followed for a median of >5 years, were eligible for inclusion. After screening titles and abstracts of the 1094 identified articles and systematically reviewing 98 of these articles, 19 were included. INTERVENTION: Patients with unilateral VS treated with radiosurgery were compared to patients treated with fractionated stereotactic radiotherapy. RESULTS: No randomized controlled trial (RCT) was identified. None of the identified controlled studies comparing SRS with FSRT were eligible according to the inclusion criteria. Nineteen case series on SRS (n = 17) and FSRT (n = 2) were included in the systematic review. Loss of tumor control necessitating a new VS-targeted intervention was found in an average of 5.0% of the patients treated with SRS and in 4.8% treated with FSRT. Mean deterioration ratio for patients with serviceable hearing before treatment was 49% for SRS and 45% for FSRT, respectively. The risk for facial nerve deterioration was 3.6% for SRS and 11.2% for FSRT and for trigeminal nerve deterioration 6.0% for SRS and 8.4% for FSRT. Since these results were obtained from case series, a regular meta-analysis was not attempted. CONCLUSION: SRS and FSRT are both noninvasive treatment alternatives for patients with VS with low rates of treatment failure in need of rescue therapy. In this selection of patients, the progression-free survival rates were on the order of 92-100% for both treatment options. There is a lack of high-quality studies comparing radiation therapy alternatives for patients with VS. Finally, 19 articles reported long-term tumor control after SRS, while only 2 articles reported long-term FSRT results, making effect estimates more uncertain for FSRT.

Long-term quality of life and tumour control following gamma knife radiosurgery for vestibular schwannoma.

INTRODUCTION: Gamma knife radiosurgery (GKRS) has for the last decades been an established treatment option for patients with small- or medium-sized vestibular schwannomas (VS), although little data is reported on long-term outcome regarding quality of life (QOL) and tumour control in this patient category. The objective of this study was to investigate long-term QOL and tumour control in GKRS-treated VS patients at our institution. METHODS: Data was reviewed from a consecutive cohort of 128 patients, 62 men and 66 women, diagnosed with VS and treated with GKRS at Karolinska University Hospital between 1997 and 2003. Patients previously treated for VS, patients from abroad, and patients with neurofibromatosis were excluded from the study. Median age at the time of treatment was 66 years (range 23-89), with a median follow-up time of 104 months (range 11-165) and radiological median follow-up of 86 months (range 5-170). Five patients were lost to follow-up. RESULTS: Data on QOL (EQ-5D score) was obtained in 90 % (98/109) of all cases at the end of follow-up, showing low morbidity and a high QOL with median index of 0.91 (max. score 1.0) in these patients. Tumour control was achieved in 92 % (118/128) of patients after a single GKRS treatment. Ten patients had loss of tumour control, either radiologically seen as growth progression, or due to the need for salvage treatment. Neither pre-treatment growth of the vestibular schwannoma, or a large tumour size (Koos grade 3 & 4) was correlated with a higher degree of treatment failure (p = 0.695 and p = 0.647, respectively). There was no difference in tumour control in young (<60 y/o) vs. elderly (≥60 y/o) patients (p = 0.167). CONCLUSION: We report a high QOL and low morbidity at long-term follow-up after GKRS treatment in VS patients. Furthermore, a high tumour control rate was achieved independent of tumour size, patient age or pre-treatment evidence of tumour growth.

Adaptive hybrid surgery analysis (AHSA) for adjuvant gamma knife radiosurgery treatment of vestibular schwannoma residuals.

OBJECTIVES: Adaptive Hybrid Surgery Analysis (AHSA, Brainlab, Munich, Germany) is a software application generating in real-time conceptual dose plans for tumor residuals but has so far not been assessed for usability in a Gamma Knife (Elekta, Stockholm, Sweden) radiosurgery practice. We aimed to compare AHSA stereotactic radiosurgery dose plans with Leksell Gamma Plan (LGP, Elekta, Stockholm, Sweden) plans for adjuvant radiosurgical treatment of Vestibular Schwannoma (VS) residuals. PATIENTS AND METHODS: In this retrospective comparative study, we compared the automatically calculated AHSA dose plans with clinical LGP treatment plans in 13 patients radiosurgically treated for VS residuals. We first created an LGP template based on our specific constraints to organs at risk (OAR), and a tumor prescription volume coverage of minimum 98%. As most proximal anatomy at risk is not manually contoured in our practice, OARs (i.e. brainstem, optic apparatus and cochlea) in the planning images were automatically segmented in Elements Anatomical Mapping and imported into the AHSA software for re-planning and comparison with the LGP dose plans. RESULTS: There was no significant difference in tumor coverage and conformity index between the LGP and AHSA dose planning data, with the mean and maximal dose to the brainstem slightly higher in the latter. CONCLUSION: The AHSA dose plans for adjuvant radiosurgical treatment of VS residuals were comparable to those of LGP used in our Gamma Knife practice, confirming the usability of AHSA in the management of Vestibular Schwannoma in a Gamma Knife practice.

Short-Term Surgical Outcome for Vestibular Schwannoma in Sweden: A Nation-Wide Registry Study.

Background: Vestibular Schwannoma (VS) is a benign neoplasm arising from the 8th cranial nerve, with surgery one of the treatment modalities. In a nation-wide registry study, we describe the baseline, treatment characteristics, and short-term outcome in patients surgically treated for VS. Methods: We performed a nationwide study with data from the Swedish Brain Tumor Registry (SBTR) for all adults diagnosed with VS 2009-2015. Patient symptoms, tumor characteristics, and postoperative complications were analyzed. Results: In total 348 patients underwent surgery for VS. Mean age was 50.6 ± 14.5 years and 165 patients (47.4%) were female. The most common symptom was focal neurological deficit (92.0%), with only 25 (7.2%) being asymptomatic prior to surgery, and 217 (63.6%) had no restriction in activity. Following surgery, 100 (28.7%) patients developed new deficit(s). In terms of postoperative complications; 11 (3.2%) had a hematoma, 35 (10.1%) an infection, 10 (2.9%) a venous thromboembolism, and 23 (6.6%) had a reoperation due to complication. There were no deaths within 30-days after surgery. When grouped according to tumor size (< 4 vs. ≥4 cm), those with ≥4 cm tumors were more often males (p = 0.02), had more often ICP related symptoms (p = 0.03) and shorter time from imaging to surgery (p < 0.01). Analysis of the younger (< 65 years) vs. elderly (≥65 years) revealed no difference in outcome except increased 1-year mortality (p = 0.002) in elderly. Conclusion: In this nation-wide registry-study, we benchmark the 30-day complication rate after VS surgery as collected by the SBTR. Further, we present the current neurosurgical outcome data from both VS smaller than 40 mm compared to larger tumors, as well as younger vs. elderly VS patients. Since surgical decision making is a careful consideration of short term risk vs. long term benefit, this information can be useful in clinical decision making.