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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.
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Optic nerve sheath meningiomas (ONSM) are rare but can lead to irreversible blindness. Hybrid imaging may enhance tumor delineation and diagnostic accuracy via receptor binding. However, relevant clinical data for ONSM are lacking. We evaluated the feasibility of receptor-based hybrid imaging prior to robotic radiosurgery (RRS). We retrospectively analyzed all of our institution's patients with suspected ONSM who underwent combined positron emission tomography and magnetic resonance imaging (PET/MRI) with gallium-68-labeled (DOTA0-Phe1-Tyr3) octreotide (Ga68-DOTATOC) before RRS between 2018 and 2019. Eight patients with ten suspected ONSM (female = 7; median age, 51.2 years; IQR, 43.0-66.0) were included. Nine out of ten ONSM were deemed PET-positive with a median standard uptake value (SUV) max of 5.6 (IQR, 2.6-7.8). For all nine ONSM that presented 68Ga-DOTATOC uptake, hybrid PET/MRI was used for target volume contouring prior to RSS. At a median follow-up of 11.7 months (IQR, 9.4-16.4), tumor control was achieved in all patients. Radiosurgery resulted in the improvement of visual acuity in two of eight patients, whereas six showed stable vision. Ga68-DOTATOC-PET/MRI can be used for target volume contouring prior to RRS for ONSM as it enables safe treatment planning and improves diagnostic accuracy.
RESUMEN
The role of robotic radiosurgery (RRS) in the treatment of optic nerve sheath meningiomas (ONSM) remains controversial and it is only performed in specialized institutions due to tight dose constraints. We evaluated the effectiveness and safety of RRS in the management of ONSM. Twenty-five patients with 27 ONSM lesions who underwent RRS using the Cyberknife (CK) system were retrospectively analyzed (median age, 47.9 years; 84.0% women). Multisession RRS was used with 4-5 fractions with a cumulative dose of 20.0-25.0 Gy in 84.0% of patients and a single fraction at a dose of 14.0-15.0 Gy in 16% of patients. Prior to RRS, seven (28%) patients experienced blindness on the lesion side. In those patients with preserved vision prior to radiosurgery, the visual acuity remained the same in 90.0% and improved in 10.0% of the patients. Overall local tumor control was 96.0% (mean follow-up period; 37.4 ± 27.2 months). Neither patient age, previous surgery, or the period from the initial diagnosis to RRS showed a dependency on visual acuity before or after radiosurgery. RRS is a safe and effective treatment for the management of ONSM. Hypofractionation of radiosurgery in patients with preserved vision before CK treatment results in stable or improved vision.
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BACKGROUND: Ependymomas are rare neoplasms of the central nervous system (CNS), usually localized intracranially and most commonly diagnosed in children. Spinal ependymomas are more frequent in young adults. They are either primary lesions or manifest as disseminated seeding of cranial tumors. Data on the management of spinal ependymoma lesions remain scarce, especially concerning stereotactic radiosurgery (SRS) and stereotactic body radiation therapy (SBRT). The purpose of this study is to report the treatment outcomes of two institutions using robotic radiosurgery (RRS) for the treatment of spinal ependymomas. MATERIALS AND METHODS: All patients with a histopathologically confirmed diagnosis of an ependymoma WHO grade II or III who were treated with RRS for one or more spinal lesions were included in this analysis. RESULTS: Twelve patients underwent RRS for the treatment of 32 spinal ependymoma lesions between 2005 and 2020. Two patients were below the age of 18 when treated, whereas nine patients (75%) suffered from a primary spinal ependymoma. The median dose was 15 Gy prescribed to a median isodose of 70%, with 27 lesions (84%) receiving a single-session treatment. The local control (LC) after a median follow-up of 56.7 months was 84%. LC rates at 1, 3, and 5 years were 92, 85, and 77%, respectively. The Kaplan-Meier estimated overall survival after 1, 3, and 5 years were 75, 75, and 64%, respectively. Five patients died, all of them suffering from an anaplastic ependymoma, with widespread CNS tumor progression being the reason for death in four patients. The majority of patients (58%) showed a stable neurological status at the last available follow-up. Overall, the treatment was well tolerated. CONCLUSION: RRS appears to be a safe and efficient treatment modality for managing primary and secondary spinal ependymal tumors in patients with multiple lesions and local recurrences.
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BACKGROUND: Intramedullary metastases are rare and bear a dismal prognosis. Limited data are available on the treatment of such lesions. As surgery may be the mainstay of treatment for patients with resectable and localized metastatic spread, previous case reports and case series suggest radiosurgery to be another viable treatment modality. This multicenter study analyzes the efficacy and safety of robotic radiosurgery (RRS) for intramedullary metastases. METHODS: Patients who received RRS for the treatment of at least one intramedullary metastasis were included. RESULTS: Thirty-three patients with 46 intramedullary metastases were treated with a median dose of 16 Gy prescribed to a median isodose of 70%. The local control was 79% after a median follow-up of 8.5 months. The median overall survival (OS) was 11.7 months, with a 12- and 24-month OS of 47 and 31%. The 12-month progression-free survival was 42% and at 24 months 25%. In addition, 57% of patients showed either an improved or stable neurological function after treatment delivery. Systemic disease progression was the main cause of death. No significant treatment-related toxicities were observed. CONCLUSIONS: RRS appears to be a safe, time-saving and effective treatment modality for intramedullary metastases, especially for patients with unresectable lesions and high burden of disease.
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BACKGROUND: Stereotactic radiosurgery (SRS) has been increasingly applied for up to 10 brain metastases instead of whole brain radiation therapy (WBRT) to achieve local tumor control while reducing neurotoxicity. Furthermore, brain-metastasis incidence is rising due to the increasing survival of patients with cancer. Our aim was to analyze the efficacy and safety of CyberKnife (CK) radiosurgery for elderly patients. METHODS: We retrospectively identified all patients with brain metastases ≥ 65 years old treated with CK-SRS at our institution since 2011 and analyzed data of primary diseases, multimodality treatments, and local therapy effect based on imaging follow-up and treatment safety. Kaplan-Meier analysis for local progression-free interval and overall survival were performed. RESULTS: We identified 97 patients (233 lesions) fulfilling the criteria at the first CK-SRS. The mean age was 73.2 ± 5.8 (range: 65.0-87.0) years. Overall, 13.4% of the patients were > 80 years old. The three most frequent primary cancers were lung (40.2%), kidney (22.7%), and malignant melanoma (15.5%). In 38.5% (47/122 treatments) multiple brain metastases were treated with the CK-SRS, with up to eight lesions in one session. The median planning target volume (PTV) was 1.05 (range: 0.01-19.80) cm3. A single fraction was applied in 92.3% of the lesions with a median prescription dose of 19 (range: 12-21) Gy. The estimated overall survivals at 3-, 6-, and 12 months after SRS were 79, 55, and 23%, respectively. The estimated local tumor progression-free intervals at 6-, 12-, 24-, 36-, and 72 months after SRS were 99.2, 89.0, 67.2, 64.6, and 64.6%, respectively. Older age and female sex were predictive factors of local progression. The Karnofsky performance score remained stable in 97.9% of the patients; only one patient developed a neurological deficit after SRS of a cerebellar lesion (ataxia, CTCAE Grade 2). CONCLUSIONS: SRS is a safe and efficient option for the treatment of elderly patients with brain metastases with good local control rates without the side effects of WBRT. Older age and female sex seem to be predictive factors of local progression. Prospective studies are warranted to clarify the role of SRS treatment for elderly patients.