Search Results (22)

Background/Objectives: The lung is the most common site of metastases, regardless of the cancer subtype. Treating oligometastatic disease with surgery or stereotactic ablative radiotherapy (SABR) may improve patient survival. Methods: We retrospectively analyzed 41 patients with limited (one or two lesions, max dimension <3 cm) lung-only metastatic disease that were treated with the CK M6 robotic radiosurgery system in our Department, in terms of treatment efficacy and toxicity. Results: Acute and late toxicity was negligible (4 out of 41 patients developed grade 2 or 3 lung fibrosis). Six months post-SABR, complete response was achieved in 18 out of 41 patients (43.9%), while the rest of the cases exhibited major responses. A biological effective dose (BED_α/β=10) in the range of 100 Gy appears to be equally effective with higher doses. Within a median follow-up of 34 months, only three patients (7.3%) progressed locally, while three patients progressed to distal sites. Two-year local progression-free survival (LPFS) rates were 92.6% (95% CI 78.5–97%). Conclusions: SABR for low-burden lung oligometastases is an effective treatment modality that yields high local control and survival rates. Toxicity is negligible, regardless of the performance status of patients. Early referral of such patients to radiation oncology departments may be critical for patient survival and quality of life. Full article

Precise patient positioning is paramount in radiosurgery to ensure the accurate targeting of tumors while minimizing damage to surrounding healthy tissues. This study focuses on the development and validation of a robust forward kinematics (FK) model for a robotic patient positioning system, specifically designed to handle emergency interruptions such as power loss or emergency stops. The FK model integrates data from high-resolution primary encoders within the actuators and secondary encoders post-load on each axis, providing real-time feedback and ensuring sub-millimeter positional accuracy. The control architecture leverages a dual-loop feedback system to enhance precision and stability during operation and recovery. The simulation and experimental results demonstrate that the FK model, combined with encoder feedback, reliably determines the patient bed’s exact position during interruptions and guides the system’s safe and accurate resumption of treatment. These findings underscore the critical role of FK and encoder integration in improving the safety, reliability, and precision of robotic radiosurgery systems, addressing key challenges in medical robotics for radiation therapy. Full article

Pediatric cancers, while rare, pose unique challenges due to the heightened sensitivity of developing tissues and the increased risk of long-term radiation-induced effects. Radiotherapy (RT) is a cornerstone in pediatric oncology, but its application is limited by concerns about toxicity, particularly secondary malignancies, growth abnormalities, and cognitive deficits. CyberKnife (CK), an advanced robotic radiosurgery system, has emerged as a promising alternative due to its precision, non-invasiveness, and ability to deliver hypofractionated, high-dose RT while sparing healthy tissues. This narrative review explores the existing evidence on CK application in pediatric patients, synthesizing data from case reports, small series, and larger cohort studies. All the studies analyzed reported cases of tumors located in the skull or in the head and neck region. Findings suggest CK’s potential for effective tumor control with favorable toxicity profiles, especially for complex or inoperable tumors. However, the evidence remains limited, with the majority of studies involving small sample sizes and short follow-up periods. Moreover, concerns about the “dose-bath” effect and limited long-term data on stochastic risks warrant cautious adoption. Compared to Linac-based RT and proton therapy, CK offers unique advantages in reducing session numbers and enhancing patient comfort, while its real-time tracking provides superior accuracy. Despite these advantages, CK is associated with significant limitations, including a higher potential for low-dose scatter (often referred to as the “dose-bath” effect), extended treatment times in some protocols, and high costs requiring specialized expertise for operation. Emerging modalities like π radiotherapy further underscore the need for comparative studies to identify the optimal technique for specific pediatric cases. Notably, proton therapy remains the benchmark for minimizing long-term toxicity, but its cost and availability limit its accessibility. This review emphasizes the need for balanced evaluations of CK and highlights the importance of planning prospective studies and long-term follow-ups to refine its role in pediatric oncology. A recent German initiative to establish a CK registry for pediatric CNS lesions holds significant promise for advancing evidence-based applications and optimizing treatment strategies in this vulnerable population. Full article

Objectives: Accurate target definition, treatment planning and delivery increases local tumor control for radiotherapy by minimizing collateral damage. To achieve this goal for uveal melanoma (UM), tantalum fiducial markers (TFMs) were previously introduced in proton and photon beam radiotherapy. However, TFMs cause pronounced scattering effects in imaging that make the delineation of small tumors difficult. The aim of this study was to evaluate silicone fiducial markers (SFMs) for the guiding of stereotactic radiosurgery (SRS) for UM. Methods: In this retrospective interventional pilot case series, three patients with small UMs 3 mm or less in tumor thickness and ≤10 mm in largest basal diameter received silicone fiducial markers. The fiducial markers were punched out (3 mm) from conventional silicone encircling bands for buckle surgery. The markers were sutured onto the sclera at the tumor margins according to the use of TFMs. MRI and CT images were used for the localization of the tumor and the markers before robotic-guided SRS. Results: The silicone fiducial markers were punched out easily from the original band, better to handle than TFMs and easy to suture onto the sclera. They could be visualized in both MRI and CT, but were more visible in CT. In the absence of scattering effects, both the markers and thus the tumor boundaries could be clearly delineated. Conclusions: This is the first report that introduces fiducial markers intraoperatively shaped from conventional silicone encircling bands usually used for retinal detachment surgery. The SFMs allow more accurate tumor delineation, resulting in the more precise planning and administration of SRS when compared to TFMs. This simple modification has a major impact on a well-known treatment approach. Full article

Background: Vestibular symptoms can severely affect patients with vestibular schwannomas (VSs). Studies assessing vestibular symptoms beyond clinical routine assessment in patients with VS treated by stereotactic radiosurgery (SRS) are scarce. Therefore, we employed the standardized questionnaire Dizziness Handicap Inventory (DHI) to systematically evaluate vestibular symptoms prior to and after SRS. Methods: For this retrospective single center study, we included patients who received Cyberknife^® SRS for newly diagnosed unilateral VS between 2012 and 2022, and who had a minimum of two follow-up (FU) visits. Besides clinical assessment, the presence and severeness of vestibular symptoms before and after treatment was recorded by using the DHI. Overall DHI symptom scores (1–100) were classified into four grades (0 = “none”, 1 = “mild”, 2 = “moderate” and 3 = “severe”). The results were correlated with tumor-, patient-, and treatment-related characteristics. Results: We analyzed 128 patients with a median age of 60 years (range: 20–82) and a median FU of 36 months (range: 11–106 months). The median tumor volume was 0.99 cm³ (range: 0.04–7.1 cm³). A median marginal dose of 13 Gy (range: 12–14 Gy) was administered. The crude rate of local tumor control was 99.2%. The mean DHI total score at last follow-up (LFU, 25.5 ± 24.7; range 0–92) was significantly lower than before SRS (29.4 ± 25.3; range:0–92, p = 0.026), which was reflected in a higher proportion of patients with DHI grade “none” and a lower proportion of patients with DHI grade “severe” at LFU. Chi-square tests showed a significant correlation of the DHI grades (DHI 0–1 vs. DHI 2–3) with the absence or presence of vestibular symptoms both before SRS (p < 0.001, CI 95%) and at LFU (p = 0.038). Conclusions: The DHI is a feasible and valid instrument for measuring vestibular symptoms after SRS. In addition, the DHI enables the quantification of symptoms and can therefore serve as an important tool for outcome assessment after SRS of VS. In the present cohort, DHI scores improved significantly during FU. Full article

Background/Objectives: Surgery is the primary treatment for early-stage lung cancer. Patients with medically inoperable lung carcinomas and patients who refuse to undergo surgery are treated with definite radiotherapy. Stereotactic ablative radiotherapy (SABR) is a compelling non-invasive therapeutic modality for this group of patients that confers promising results. Methods: We report an interim analysis of an ongoing trial. Eighty-one patients with medically inoperable early-stage (T1,2N0) lung cancer underwent SABR in our institution. SABR was delivered via the CyberKnife M6 robotic radiosurgery system. The endpoints of the analysis were treatment efficacy and tolerance. Results: There were no acute or late toxicities from the skin or the connective tissue of the thorax. A grade 2/3 lung injury of non-clinical significance was noted in 6% of patients, which was directly related to a higher biologically effective dose (BED_{α/β = 3}) and larger irradiation lung volumes in both univariate and multivariate analyses. A local control (LC) was achieved in 100% of the patients at the first follow-up, and the projected 24-month local progression-free survival (LPFS) rate was 95%. The projected 24-month disease-specific overall survival (OS) was 94%. Conclusions: High LC and OS rates can be achieved with SABR for early-stage lung cancer, with minimal toxicity. This study continues to recruit patients. Full article

This paper offers a comprehensive examination of the development and implementation of advanced safety protocols in the Patient Positioning System (PPS) for radiosurgery. In an era where precision and safety are increasingly crucial in medical procedures, particularly radiosurgery, the implementation of sophisticated safety measures in PPS is vital. This research delves into the detailed design of the system, emphasizing the sensor and controller mechanisms employed. A significant focus is placed on comparing single-loop and dual-loop control systems, assessing their impact on the precision, accuracy, and repeatability of the PPS. The study showcases how dual-loop control demonstrates superior performance in these areas, leading to enhanced patient safety and treatment outcomes. Additionally, the paper discusses the integration of these safety protocols within the system’s architecture, underscoring the practical implications of these advanced measures in augmenting patient safety and treatment effectiveness. Full article

The landscape of cranial base surgery has undergone monumental transformations over the past several decades. This article serves as a comprehensive survey, detailing both the historical and current techniques and technologies that have propelled this field into an era of unprecedented capabilities and sophistication. In the prologue, we traverse the historical evolution from rudimentary interventions to the state-of-the-art neurosurgical methodologies that define today’s practice. Subsequent sections delve into the anatomical complexities of the anterior, middle, and posterior cranial fossa, shedding light on the intricacies that dictate surgical approaches. In a section dedicated to advanced techniques and modalities, we explore cutting-edge evolutions in minimally invasive procedures, pituitary surgery, and cranial base reconstruction. Here, we highlight the seamless integration of endocrinology, biomaterial science, and engineering into neurosurgical craftsmanship. The article emphasizes the paradigm shift towards “Functionally” Guided Surgery facilitated by intraoperative neuromonitoring. We explore its historical origins, current technologies, and its invaluable role in tailoring surgical interventions across diverse pathologies. Additionally, the digital era’s contributions to cranial base surgery are examined. This includes breakthroughs in endoscopic technology, robotics, augmented reality, and the potential of machine learning and AI-assisted diagnostic and surgical planning. The discussion extends to radiosurgery and radiotherapy, focusing on the harmonization of precision and efficacy through advanced modalities such as Gamma Knife and CyberKnife. The article also evaluates newer protocols that optimize tumor control while preserving neural structures. In acknowledging the holistic nature of cranial base surgery, we advocate for an interdisciplinary approach. The ecosystem of this surgical field is presented as an amalgamation of various medical disciplines, including neurology, radiology, oncology, and rehabilitation, and is further enriched by insights from patient narratives and quality-of-life metrics. The epilogue contemplates future challenges and opportunities, pinpointing potential breakthroughs in stem cell research, regenerative medicine, and genomic tailoring. Ultimately, the article reaffirms the ethos of continuous learning, global collaboration, and patient-first principles, projecting an optimistic trajectory for the field of cranial base surgery in the coming decade. Full article

(1) Background: Transient increase in volume of vestibular schwannomas (VS) after stereotactic radiosurgery (SRS) is common and complicates differentiation between treatment-related changes (pseudoprogression, PP) and tumor recurrence (progressive disease, PD). (2) Methods: Patients with unilateral VS (n = 63) underwent single fraction robotic-guided SRS. Volume changes were classified according to existing RANO criteria. A new response type, PP, with a >20% transient increase in volume was defined and divided into early (within the first 12 months) and late (>12 months) occurrence. (3) Results: The median age was 56 (range: 20–82) years, the median initial tumor volume was 1.5 (range: 0.1–8.6) cm³. The median radiological and clinical follow-up time was 66 (range: 24–103) months. Partial response was observed in 36% (n = 23), stable disease in 35% (n = 22) and PP in 29% (n = 18) of patients. The latter occurred early (16%, n = 10) or late (13%, n = 8). Using these criteria, no case of PD was observed. (4) Conclusion: Any volume increase after SRS for vs. assumed to be PD turned out to be early or late PP. Therefore, we propose modifying RANO criteria for SRS of VS, which may affect the management of vs. during follow-up in favor of further observation. Full article

Objective: To analyze, in a cohort of acromegalic patients, the results of the efficiency and safety of radiosurgery (CyberKnife), as well as the prognostic factors associated with disease remission. Material and methods: Observational, retrospective, longitudinal, and analytical study that included acromegalic patients with persistent biochemical activity after initial medical–surgical treatment, who received treatment with CyberKnife radiosurgery. GH and IGF-1 levels at baseline after one year and at the end of follow-up were evaluated. Results: 57 patients were included, with a median follow-up of four years (IQR, 2–7.2 years). The biochemical remission rate was 45.6%, 33.33% achieved biochemical control, and 12.28% attained biochemical cure at the end of follow-up. A progressive and statistically significant decrease was observed in the comparison of the concentrations of IGF-1, IFG-1 x ULN, and baseline GH at one year and at the end of follow-up. Both cavernous sinus invasion and elevated baseline IGF-1 x ULN concentrations were associated with an increased risk of biochemical non-remission. Conclusion: Radiosurgery (CyberKnife) is a safe and effective technique in the adjuvant treatment of GH-producing tumors. Elevated levels of IGF x ULN before radiosurgery and invasion of the cavernous sinus by the tumor could be predictors of biochemical non-remission of acromegaly. Full article

The IBA myQA^® SRS high-resolution solid-state detector was evaluated in the context of robotic radiosurgery delivered using CyberKnife^®. The performance was investigated for periodic machine delivery quality assurance (DQA) and patient-specific treatment verification. myQA^® SRS is a 140 × 120 mm CMOS matrix with 400 µm resolution, allocated in a cylindrical ABS phantom topped by a hemispheric cap. Evaluations included: periodic DQA tests, angular response, dose-rate dependence and Iris variable aperture collimator field size measurements. For patient-specific QA various intracranial targets were studied (Gamma Index, 3%/1 mm agreement criteria), taking into account also the detector’s angular response. Results for periodic DQA were in accordance with the machine commissioning data. Dose-rate dependence was confirmed, and angular response tests resulted in a signal decay >5% when beams were delivered outside a ±50° amplitude cone with respect to the vertical direction. Concerning patient-specific QA, >50° angled beams elimination led to a Gamma Index passing rates improvement ranging between +3% and +115%. IBA myQA^® SRS proved to be a suitable device for many CyberKnife^® constancy DQA checks, providing high-resolution real-time results. Patient-specific Gamma tests showed high passing rates once angular dependence corrections were performed, even in high complexity treatments such as those for trigeminal neuralgia targets. Full article

Background: CyberKnife-based robotic radiosurgery (RRS) is a widely used treatment modality for various benign and malignant tumors of the central nervous system (CNS) in adults due to its high precision, favorable safety profile, and efficacy. Although RRS is emerging in pediatric neuro-oncology, scientific evidence for treatment indications, treatment parameters, and patient outcomes is scarce. This systematic review summarizes the current experience and evidence for RRS and robotic stereotactic radiotherapy (RSRT) in pediatric neuro-oncology. Methods: We performed a systematic review based on the databases Ovid Medline, Embase, Cochrane Library, and PubMed to identify studies and published articles reporting on RRS and RSRT treatments in pediatric neuro-oncology. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were applied herein. Articles were included if they described the application of RRS and RSRT in pediatric neuro-oncological patients. The quality of the articles was assessed based on their evidence level and their risk for bias using the original as well as an adapted version of the Newcastle Ottawa Quality Assessment Scale (NOS). Only articles published until 1 August 2021, were included. Results: A total of 23 articles were included after final review and removal of duplicates. Articles reported on a broad variety of CNS entities with various treatment indications. A majority of publications lacked substantial sample sizes and a prospective study design. Several reports included adult patients, thereby limiting the possibility of data extraction and analysis of pediatric patients. RRS and RSRT were mostly used in the setting of adjuvant, palliative, and salvage treatments with decent local control rates and acceptable short-to-intermediate-term toxicity. However, follow-up durations were limited. The evidence level was IV for all studies; the NOS score ranged between four and six, while the overall risk of bias was moderate to low. Conclusion: Publications on RRS and RSRT and their application in pediatric neuro-oncology are rare and lack high-quality evidence with respect to entity-related treatment standards and long-term outcomes. The limited data suggest that RRS and RSRT could be efficient treatment modalities, especially for children who are unsuitable for surgical interventions, suffer from tumor recurrences, or require palliative treatments. Nevertheless, the potential short-term and long-term adverse events must be kept in mind when choosing such a treatment. Prospective studies are necessary to determine the actual utility of RRS and RSRT in pediatric neuro-oncology. Full article

Pulmonary metastases are the most frequent site of metastases in renal cell carcinoma (RCC). Metastases directed treatment remains an important treatment option despite advances in systemic therapies. However, the safety and efficacy of robotic radiosurgery (RRS) for the treatment of lung metastases of RCC remains unclear. Patients with metastatic RCC and lung metastases treated by RRS were retrospectively analyzed for overall survival (OS), progression-free survival (PFS), local recurrence free survival (LRFS) and adverse events. The Kaplan–Meier method was used for survival analysis and the common terminology criteria for adverse events (CTCAE; Version 5.0) classification for assessment of adverse events. A total of 50 patients were included in this study. Median age was 64 (range 45–92) years at the time of RRS. Prior to RRS, 20 patients (40.0%) had received either tyrosine kinase inhibitors or immunotherapy and 27 patients (54.0%) were treatment naïve. In our patient cohort, the median PFS was 13 months (range: 2–93). LRFS was 96.7% after two years with only one patient revealing progressive disease of the treated metastases 13 months after RRS. Median OS was 35 months (range 2–94). Adverse events were documented in six patients (12%) and were limited to grade 2. Fatigue (n = 4) and pneumonitis (n = 2) were observed within 3 months after RRS. In conclusion, RRS is safe and effective for patients with metastatic RCC and pulmonary metastases. Radiation induced pneumonitis is specific in the treatment of pulmonary lesions, but not clinically relevant and survival rates seem favorable in this highly selected patient cohort. Future directions are the implementation of RRS in multimodal treatment approaches for oligometastatic or oligoprogressive disease. Full article

Background: Foramen magnum meningiomas (FMMs) represent a considerable neurosurgical challenge given their location and potential morbidity. Stereotactic radiosurgery (SRS) is an established non-invasive treatment modality for various benign and malignant brain tumors. However, reports on single-session or multisession SRS for the management and treatment of FMMs are exceedingly rare. We report the largest FMM SRS series to date and describe our multicenter treatment experience utilizing robotic radiosurgery. Methods: Patients who underwent SRS between 2005 and 2020 as a treatment for a FMM at six different centers were eligible for analysis. Results: Sixty-two patients met the inclusion criteria. The median follow-up was 28.9 months. The median prescription dose and isodose line were 14 Gy and 70%, respectively. Single-session SRS accounted for 81% of treatments. The remaining patients received three to five fractions, with doses ranging from 19.5 to 25 Gy. Ten (16%) patients were treated for a tumor recurrence after surgery, and thirteen (21%) underwent adjuvant treatment. The remaining 39 FMMs (63%) received SRS as their primary treatment. For patients with an upfront surgical resection, histopathological examination revealed 22 World Health Organization grade I tumors and one grade II FMM. The median tumor volume was 2.6 cubic centimeters. No local failures were observed throughout the available follow-up, including patients with a follow-up ≥ five years (16 patients), leading to an overall local control of 100%. Tumor volume significantly decreased after treatment, with a median volume reduction of 21% at the last available follow-up (p < 0.01). The one-, three-, and five-year progression-free survival were 100%, 96.6%, and 93.0%, respectively. Most patients showed stable (47%) or improved (21%) neurological deficits at the last follow-up. No high-grade adverse events were observed. Conclusions: SRS is an effective and safe treatment modality for FMMs. Despite the paucity of available data and previous reports, SRS should be considered for selected patients, especially those with subtotal tumor resections, recurrences, and patients not suitable for surgery. Full article

Fiducial markers (FM) inserted into tumors increase the precision of irradiation during robotic radiosurgery (RRS). This retrospective study evaluated the clinical complications, marker migration, and motion amplitude of FM implantations by analyzing 288 cancer patients (58% men; 63.1 ± 13.0 years) who underwent 357 FM implantations prior to RRS with CyberKnife, between 2011 and 2019. Complications were classified according to the Society of Interventional Radiology (SIR) guidelines. The radial motion amplitude was calculated for tumors that moved with respiration. A total of 725 gold FM was inserted. SIR-rated complications occurred in 17.9% of all procedures. Most complications (32.0%, 62/194 implantations) were observed in Synchrony^®-tracked lesions affected by respiratory motion, particularly in pulmonary lesions (46.9% 52/111 implantations). Concurrent biopsy sampling was associated with a higher complication rate (p = 0.001). FM migration occurred in 3.6% after CT-guided and clinical FM implantations. The largest motion amplitudes were observed in hepatic (20.5 ± 11.0 mm) and lower lung lobe (15.4 ± 10.5 mm) lesions. This study increases the awareness of the risks of FM placement, especially in thoracic lesions affected by respiratory motion. Considering the maximum motion amplitude, FM placement remains essential in hepatic and lower lung lobe lesions located >100.0 mm from the spine. Full article