Impact of Cochlear Dose on Hearing Preservation Following Stereotactic Radiosurgery in Treatment of Vestibular Schwannomas: A Multi-Center Study.

OBJECTIVE: Stereotactic radiosurgery (SRS) is a well-established treatment for vestibular schwannomas (VS). Hearing loss remains a main morbidity of VS and its treatments, including SRS. The effects of radiation parameters of SRS on hearing remain unknown. The goal of this study is to determine the effect of tumor volume, patient demographics, pretreatment hearing status, cochlear radiation dose, total tumor radiation dose, fractionation, and other radiotherapy parameters on hearing deterioration. METHODS: Multicenter retrospective analysis of 611 patients who underwent SRS for VS from 1990-2020 and had pre- and post-treatment audiograms. RESULTS: Pure tone averages (PTAs) increased and word recognition scores (WRSs) decreased in treated ears at 12-60 months while remaining stable in untreated ears. Higher baseline PTA, higher tumor radiation dose, higher maximum cochlear dose, and usage of single fraction resulted in higher post radiation PTA; WRS was only predicted by baseline WRS and age. Higher baseline PTA, single fraction treatment, higher tumor radiation dose, and higher maximum cochlear dose resulted in a faster deterioration in PTA. Below a maximum cochlear dose of 3 Gy, there were no statistically significant changes in PTA or WRS. CONCLUSIONS: Decline of hearing at one year in VS patients after SRS is directly related to maximum cochlear dose, single versus 3-fraction treatment, total tumor radiation dose, and baseline hearing level. The maximum safe cochlear dose for hearingtbrowd preservation at one year is 3 Gy, and the use of 3 fractions instead of one fraction was better at preserving hearing.

Local Recurrence in Choroidal Melanomas following Robotic-Assisted Radiosurgery (CyberKnife).

Introduction: Tumor recurrence in choroidal melanoma has been associated with decreased overall survival due to metastatic spreading. To detect risk factors of local recurrence and side effects, we analyzed tumor planning and treatment parameters in patients with recurrence of choroidal melanoma after treatment with robotic-assisted radiosurgery (CyberKnife). Methods: Six hundred ninety-four patients treated with CyberKnife between 2005 and 2019 were retrospectively reviewed. Age, gender, best-corrected visual acuity, tumor height, and diameter were recorded. Treatment planning and radiation doses were reviewed. Salvage therapy, overall survival, metastasis, and complications were recorded. Results: Seventy-four patients showed local recurrence. Local recurrence occurred after 42.1 months post CyberKnife treatment (mean; range: 5-100 months). Fourteen out of 74 patients (18.9%) died during follow-up. Recurrence treatment included enucleation in 51 patients (68.9%) and radiosurgery in 19 patients (25.7%). Treatment planning without contrast medium MRI, radiation dose of less than 21 Gy, and insufficient margin delineation were identified as risk factors incrementing local control. Discussion: Robotic-assisted radiosurgery (CyberKnife) is a suitable treatment option for large choroidal melanoma up to 12 mm. Patients with significantly better visual acuity received repeat CyberKnife treatment as salvage therapy and showed an eye retention rate of 81%.

Robotic CyberKnife Radiosurgery for the Treatment of Choroidal and Ciliary Body Melanoma.

PURPOSE: To present the results of robotic-assisted radiosurgery in choroidal and ciliary body melanomas treated at the Department of Ophthalmology of Ludwig-Maximilians-University and the European CyberKnife Center in Munich, Germany. DESIGN: Interventional case series METHODS: This retrospective study included 594 consecutive patients referred to our clinic for the treatment of choroidal and ciliary body melanomas with robotic radiosurgery (CyberKnife) from 2005 to 2019. Eye retention, local control and disease-specific survival rates were calculated as Kaplan-Meier and actuarial estimates. The impact of prescription dose, tumor size, and ciliary body involvement was assessed by likelihood ratio tests and Cox regression. RESULTS: Among all patients who were staged according to the TNM classification system (8th edition), 22.7% were I, 57.9% were II, 18.9% were III, and 0.5% were IV. Median apical tumor height and base diameter were 5.8 and 11.4 mm. The mean follow-up was 41.7 months. Local control after 3 and 5 years was 92.0% (95% CI = 88.2%-94.7%) and 84.3% (95% CI = 77.9%-89.0%), respectively, for 21 to 22 Gy and 86.9% (95% CI = 79.7%-91.7%) and 77.7% (95% CI = 68.5%-84.6%), respectively, when treated with 20 Gy or less. Eye retention was achieved in 89.9% and 81.0% after 3 and 5 years with 21 to 22 Gy and 85.9% and 80.0% for 20 Gy or less. Disease-specific survival rates were 93.1% (95% CI = 90.2%-95.2%) after 3 years, 89.8% (95% CI = 86.0%-92.6%) after 5 years, and 87.8% (95% CI = 82.8%-91.4%) after 7 years. CONCLUSIONS: This is the largest series of patients treated for choroidal and ciliary body melanomas with CyberKnife. Our results reflect an improvement in the outcome of CyberKnife therapy for patients with choroidal and ciliary body melanoma treated with single-session radiosurgery in the last decade.

Robotic CyberKnife radiosurgery for small choroidal melanomas.

Plaque brachytherapy is the most common procedure for the treatment of small choroidal melanoma, especially in posteriorly located tumors. However, there is only little information on outcome after treatment with stereotactic radiosurgery, for example, CyberKnife radiosurgery. We reviewed patients with choroidal melanoma (maximum tumor height 4 mm) treated with CyberKnife radiosurgery. Demographic information, tumor dimension, complications, metastasis and overall survival during the whole follow-up were tracked and analyzed with a specific focus on local tumor control and potential risk factors. One hundred eighty-eight patients (102 female, 54.2%) with a median age of 63 years [interquartile range (IQR): 54-73 years] were analyzed over a median of 46 months (IQR: 24-62 months). Metastasis occurred in 14 patients (7.4%) in median of 18 months after treatment (IQR: 13-47 months) and survival was achieved in 178 patients (94.7%). Within the observation period, eye retention was observed in 166 patients (88.3%). Superior local control was achieved in patients who received a prescription dose of at least 21 Gy or more (91.6%; P = 0.04). Other potential risk factors incrementing local control were treatment planning with missing MRI in advance and too small target delineation during the planning process. Radiosurgery (CyberKnife) in a single, outpatient procedure is suitable for the treatment of small choroidal melanoma. We found local control rate after 3 years compared to the standard treatment with plaque brachytherapy. On the study side, 15 years of CyberKnife treatment allowed to identify risk factors that might increment local control and thus improve treatment regimens.

Robotic assisted CyberKnife radiosurgery for the treatment of choroidal metastasis.

PURPOSE: Choroidal metastases occur in many patients with systemic cancer and limit quality of life due to visual deterioration or pain. The limited prognosis of these patients demand treatment approaches that aim at a quick response and easy application. We evaluated a robotic assisted radiosurgery device, the CyberKnife, in the treatment of choroidal metastasis. METHODS: Following retrobulbar anaesthesia, target volume was defined by an interdisciplinary team using gadolinium-contrast-enhanced MRI, computer tomography (CT) as well as all previously obtained clinical data. Radiation was delivered in a single fraction with a CyberKnife at a radiation dose of 21 Gy with a 70% isodose. We evaluated tumour height, reflectivity, visual acuity and side effects over the course of the follow-up. RESULTS: A total of four patients were included in this report. Mean follow-up time was 31 months, and all patients showed decreased tumour volume and signs of fibrosis during follow-up. One patient remained stable in terms of visual acuity, two patients lost visual acuity and one patient improved and had a functional visual acuity at last follow-up. One patient developed radiation retinopathy with subsequent neovascular glaucoma that needed further management. All other patients did not show any signs of radiation induced side effects. CONCLUSION: We report on the outcome of robotic CyberKnife radiosurgery in the treatment of uveal metastasis. We believe that single session, outpatient treatment delivery that can be facilitated with CyberKnife radiosurgery offer some benefits for this particularly sick group of patients.

Robotic-assisted radiosurgery for the treatment of vasoproliferative tumours.

PURPOSE: Vasoproliferative tumours (VPT) are a rare but benign entity that can lead to severe visual acuity deterioration. There is no standard of care, and depending on the degree of clinical features, including tumour size and dissemination, visual acuity and subretinal fluid, treatment options include observation, cryotherapy and brachytherapy. Particularly in larger tumours, brachytherapy has advantages over other options, although higher radiation doses and the need for surgical application are disadvantages of this otherwise effective treatment option. CyberKnife radiosurgery might represent an alternative therapeutic option as no surgical intervention is needed and radiation doses are lower. METHODS: All patients diagnosed with vasoproliferative tumors who were treated with CyberKnife radiosurgery with a minimum follow-up time of 12 months were included in this case series. We recorded visual acuity, number of lesions, central retinal thickness with optical coherence tomography (OCT) and reflectivity using A-scan standardizes echography every three months. RESULTS: A total of four patients with a median age of 34 years (range: 24 - 51) who were observed over an average of 26.5 months (range: 17 - 49 months) matched our inclusion criteria. We appreciated stabilization or increase in visual acuity in all four patients and a regression in tumour thickness with subsequent increase in internal reflectivity as a marker of increasing fibrosis. CONCLUSION: We observed good visual and functional outcome following CyberKnife therapy for VPT. We believe that further studies should be pursued to evaluate CyberKnife therapy for the treatment of VPT not treatable with cryo- or lasertherapy.

Incidence of secondary glaucoma after treatment of uveal melanoma with robotic radiosurgery versus brachytherapy.

PURPOSE: Different modalities of radiation therapy nowadays allow for effective treatment of uveal melanoma combined with the advantage of eye preservation. However, this advantage can secondarily be impaired by radiation-related side effects. After local recurrence, secondary glaucoma (SG) has been described as second most frequent complication leading to need of enucleation. This study compares the incidence of SG after conventional Ruthenium (Ru)-106 brachytherapy (BT) versus CyberKnife robotic radiosurgery (RRS) which has been gaining importance lately as an efficient treatment option offering improved patient comfort. METHODS: Medical records of all patients diagnosed with uveal melanoma in the Eye Clinic of the Ludwig-Maximilians-University Munich between 2007 and 2013 were reviewed. A total of 268 eyes of 268 patients treated with Ru-106 BT or CyberKnife-RRS as monotherapy were entered in this retrospective cohort study. Incidence of SG was correlated with treatment modality and baseline tumour characteristics. RESULTS: Fifty-three patients (19.8%) developed SG. At 5 years, SG was significantly more frequent after RRS (46.7%) than BT (11.1%); however, tumour thickness (maximum apical height) as a marker of tumour progress was more pronounced in the RRS group. Subgroup analysis of 178 patients for tumours amenable to both BT and RRS (thickness ≤6 mm) revealed comparable results at 3 years (RRS: 13.8 versus BT: 11.2%), but a trend towards increased incidence after RRS beyond year three. However, this difference was not significant at 5 years (28.2% versus 11.2%, p = 0.138). Tumour thickness was significantly associated with incidence of SG. CONCLUSION: In tumours ≤6 mm thickness, RRS and BT seem to offer a comparable safety profile in terms of SG. Beyond year three, SG was tendentially, but not significantly more frequent after RRS. Increasing tumour thickness is associated with risk of SG.

Percutaneous radiofrequency ablation (RFA) or robotic radiosurgery (RRS) for salvage treatment of colorectal liver metastases.

BACKGROUND: Stereotactic radiation therapy is an evolving modality to treat otherwise unresectable liver metastases. In this analysis, two local therapies: 1) single session robotic radiosurgery (RRS) and 2) percutaneous radiofrequency ablation (RFA) were compared in a total of 60 heavily pretreated colorectal cancer patients. METHODS: Thirty patients with a total of 35 colorectal liver metastases not qualifying for surgery that were treated in curative intent with RRS were prospectively followed. To compare efficacy of both treatment modalities, patients treated with RFA during the same period of time were matched according to number and size of the treated lesions. Local tumor control, local disease free survival (DFS), and freedom from distant recurrence (FFDR) were analyzed for efficacy. Treatment-related side effects were recorded for comparison. RESULTS: The median diameter of the treated lesions was 33 mm (7-53 mm). Baseline characteristics did not differ significantly between the groups. One- and two-year local control rates showed no significant difference but favored RRS (85% vs. 65% and 80% vs. 61%, respectively). A significantly longer local DFS of patients treated with RRS compared to RFA (34.4 months vs. 6.0 months; p < 0.001) was found. Both, median FFDR (11.4 months for RRS vs. 7.1 months for RFA p = 0.25) and the recurrence rate (67% for RRS and 63% for RFA, p > 0.99) were comparable. CONCLUSION: Single session RRS is a safe and effective method to treat colorectal liver metastases. In this analysis, a trend towards longer DFS was seen in patients treated with RRS when compared to RFA.