Cyberknife Radiosurgery for the Treatment of Head and Neck Cancer: A Systematic Review

Cyberknife radiosurgery is a frameless stereotactic robotic radiosurgery which has shown to deliver better treatment outcomes in the treatment of advanced head and neck (H&N) carcinomas, especially in previously irradiated and recurrent cases. The aim of the study was to perform a systematic review of the available data on the outcomes of Cyberknife radiosurgery for treatment of head and neck cancer and to evaluate its collective outcomes. This systematic review was registered with the university with the registration no. FRP/2019/63 and was approved by the Institutional Review Board (RC/IRB/2019/132). Literature search was performed in the following: PubMed, Science direct, SciELO, MyScienceWork, Microsoft Academ EMBASE, Directory of Open Access Journals, and Cochrane databases with the keywords “Cyberknife,” “oral cancer,” “oropharyngeal cancer,” and “head and neck cancer” and data was extracted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The records identified were 147 manuscripts. Excluded articles included 5 duplicate articles, 33 abstracts, 101 full text articles due to being off-topic, case reports, review, non-English, 1 survey, and 2 other articles containing data extracted from a main study which was already included. A total of 5 articles were evaluated for qualitative synthesis. The mean dose of Cyberknife radiosurgery delivered for previously irradiated recurrent H&N carcinoma patients was 34.57 Gy, with a mean sample size of 5 studied during the period of 2000 to 2016. The available evidence from the systematic review indicates that Cyberknife can be an efficacious treatment option for recurrent previously irradiated H&N carcinoma, especially for nonresectable tumors. There is paucity of homogenous data and studies in this arena; hence, meta-analysis could not be performed. Further standardized studies are essential, especially where the treatment of H&N carcinoma is considered.

Radiosurgery and re-irradiation of brain metastases with cyberknife

Lung cancer is a leading cause of cancer incidence and mortality worldwide with more than 2 million newly diagnosed cases in 2018. The disease is usually diagnosed in stage 3 or 4 with extensive clinical symptoms, which is a bad prognostic factor. Around 40% of patients with brain metastases are with a primary lung cancer, which shows the importance of this pathology. The main treatment option for inoperable lesions is radiosurgery, which can be done more than once in case of progression. This gives an opportunity to deliver a high dose in low volume with a high dose gradient while maintaining healthy tissues. Re-irradiation gives a change for good quality of life for patients with a long life expectancy. This case confirms that two and even three times re-irradiation with CyberKnife is an effective and safe therapeutic option for patients with brain metastases. Keywords: CyberKnife; radiosurgery; re-irradiation; brain metastases; lung cancer.

Robotic assisted CyberKnife radiosurgery for the treatment of iris melanoma

Iris melanoma is a rare form of uveal melanoma with potential metastic spread. Treatment options include surgical resection, enucleation or irradiation. We analysed visual outcome, complication appearance and management in eight patients with iris melanoma following robotic-assisted CyberKnife treatment. Consecutive patients from the Department of Ophthalmology at University of Munich were included in the study if they had an iris melanoma that was treated with CyberKnife and had a minimum follow-up of 12 months. We evaluated tumor thickness, largest diameter, visual acuity and complications. 8 patients were included in this report. The median age was 74 years (range: 53–86 years). The median follow-up was 23 months (range 12–48 months). Tumor thickness decreased from 2.1 to 1.4 mm on average. Four out of eight patients showed stable or increased visual acuity compared to visual acuity at first visit. We did not find a correlation of applied radiation volume or radiation dose on visual outcome. Radiation keratopathy was the most common complication in five patients. No recurrences were noted. Robotic-assisted radiosurgery following CyberKnife is a promising non-invasive, single session treatment option for iris melanoma with comparable results regarding recurrence rate or complications to brachytherapy and proton beam therapy. All included patients showed good visual outcome.

Safety and Efficacy of Hypofractionated Stereotactic Radiosurgery for High-Grade Gliomas at First Recurrence: A Single-Center Experience

Background: The optimal treatment for recurrent high-grade gliomas (rHGG) remains uncertain. This study aimed to investigate the efficacy and safety of CyberKnife radiosurgery as a salvage treatment for in field recurrence of high-grade gliomas at first time.Methods: Between January 2016 and October 2019, seventy patients with rHGG undergone CyberKnife radiosurgery were retrospectively analyzed. The primary endpoint was overall survival (OS), and secondary endpoints included both progression-free survival (PFS) and adverse events which was according to Common Toxicity Criteria Adverse Events (CTCAE) version 5. The prognostic value of key clinical features (age, performance status, planning target volume, dose, use of bevacizumab) were evaluated.Results: A total of 70 patients were included in the study. Forty patients were male and 30 were female. Forty-nine had an initial diagnosis of glioblastoma (GBM), and the rest (21) were confirmed to be WHO grade 3 gliomas. The median planning target volume (PTV) was 16.68 cm3 (0.81 – 121.96 cm3). The median prescribed dose was 24 Gy (12-30 Gy) in 4 fractions (2-6 fractions). Median baseline of Karnofsky Performance Status (KPS) is 70 (40 - 90). With a median follow-up of 12.1 months, the median overall survival after salvage treatment was 17.6 months (19.5 and 14.6 months for grade 3 and 4 gliomas respectively; p = .039). No grade 3 or higher toxicities was recorded. Multivariate analysis showed that concurrent bevacizumab with radiosurgery and KPS>70 were favorable prognostic factors for grade 4 patients with HGG.Conclusions: Salvage CyberKnife radiosurgery showed a favorable outcome and acceptable toxicity for rHGG. A prospective phase II study (NCT04197492) is ongoing to further investigate the value of hypofractionated stereotactic radiosurgery (HSRS) in rHGG.