A previously healthy 56-year-old man developed gradual left- side hemiparesis, more accentuated in the lower limb (July 2016). A brain computerized tomography (CT)-scan and complementary magnetic resonance imaging (MRI) showed a solitary metastatic lesion (Met 1) in the right central sulcus (11.95 cc) with extensive perilesional edema [ and ]. The investigative tumor screening, including a CT- scan of the thorax and abdomen, revealed a suspect primary tumor in the left kidney as well as multiple, disseminated metastatic lesions in the lungs, liver, peri-aortic abdominal nodes, and left adrenal gland. A thrombotic mass positioned within the boundaries of the left renal vein was also reported. The subsequent biopsy revealed a clear cell renal cancer, Fuhrman Grade 2, as the primary. Due to the underlying extension of metastatic activity, nephrectomy was not indicated. Because of his relatively young age and previous healthy condition, the patient was accepted for upfront RRR- treatment of Met 1, structured on three separate fractions (GKRS 1–3) over a 7-day period [ and ]. This strategy aimed to sustain the patient’s performance status by avoiding further neurological deterioration while providing a window to start first-line targeted therapy (sunitinib). The rationale behind RRR can be found elsewhere in the literature.[-,]\nFollow-up MRI at 1, 3, and 6 months confirmed subsequent tumor volume reduction of Met 1 with ensuing significant improvement of the patient’s motor function []. Notably, a discrete, nonsymptomatic adverse radiation effect (ARE) around Met 1 was reported at 3 months, however, this subsequently resolved at 6 and 10 months. Despite the positive evolution of Met 1, the corresponding follow-up MRI at 10 months demonstrated a new, large metastatic lesion (17.3 cc) with extensive perilesional edema within the confinements of the left frontotemporal region, threatening the area of Broca and the insular region (Met 2). A parasagittal micrometastasis in the posterior boundaries of the left temporal lobe was also reported (Met 3). Despite further thoracic disease progression on anti-PD1 treatment (nivolumab), the patient’s clinical condition remained stable (Karnofsky Performance Scale [KPS] 90, recursive partitioning analysis [RPA] Class II); it was, therefore, decided to treat Met 2 with RRR and Met 3 with SF-GKRS [ and ] before switching systemic treatment to axitinib.\nMet 2 decreased in volume by 15% between GKRS 1 and GKRS 3. Follow-up MRI at 14 months after RRR-treatment of Met 1 (=2 months after RRR-treatment of Met 2) showed further tumor volume reduction of Met 2 while Met 1 and Met 3 remained unchanged [-]. However, edema increment around Met 2 was also reported, suggesting an additional focal (yet asymptomatic) ARE. Due to further radiological evidence of extracranial disease progression (CT-scan thorax and abdomen, October 2017), low- tolerance to axitinib and the patient’s own choice, further systemic therapy was altogether disrupted 14 months post- RRR of Met 1. Last follow-up MRI (20 months after RRR of Met 1) showed almost complete ablation of all GKRS-treated lesions and a reduction in perifocal edema surrounding Met 2, without major corticosteroid intervention [- and -]. Despite remaining free from motor-sensory deficits, epileptic seizures (Engel score of 1) or cognitive impairment, the patient promptly deteriorated at this stage due to extracranial disease progression (KPS 50, RPA 3). The patient succumbed to his disease 21 months post-RRR-treatment of Met 1.
A 67-year-old previously healthy male presented in September 2011 with a 3-week history of fatigue, dizziness, balance impairment, left-sided motor/sensory deficits, and transient mainly right-sided headache. Brain CT and MRI demonstrated a 25-mm large metastasis in the superior left cerebellar hemisphere (M1) with slight compression of the brainstem in addition to three smaller metastases in the right frontal lobe and one in the left occipital lobe. Further investigations revealed a small pulmonary lesion which was deemed unlikely to be the primary tumor. A stereotactic biopsy was, therefore, performed on one of the frontal lesions to establish a definitive diagnosis; the microscopic evaluation demonstrated a metastasis from malignant melanoma with underlying BRAF-mutation.\nThree weeks after the biopsy, the patient underwent GKRS for all metastases. At the time of treatment, his neurological condition had deteriorated with increasing paresis of the left leg requiring assisted mobilization by wheelchair (KPS 60–70; RPA 2–3). The stereotactic MRI at GKRS 1 revealed a short-interval significant size increase of M1 to 37 mm (approximately 15 cm3) with central necrosis and slight surrounding edema despite ongoing corticosteroid therapy. V4 proved now deformed and partially compressed though without radiological evidence of hydrocephalus. The lesion was assessed as inaccessible for microsurgical decompression. Due to the size of the lesion and high risk for ARE in the brainstem, M1 was adaptively treated by means of 3R []; the remaining four lesions were treated with SF-GKRS. During the three-part treatment time M1 experienced a tumor reduction of almost 10% (from 15.1 at GKRS 1 to 13.8 cm3 at GKRS 3); V4 volume increased slightly (from 0.83 cm3 at GKRS 1 to 0.93 cm3 at GKRS 3). The dose fractionation schedule is described in . The first follow-up MRI was planned 4 weeks after the third GKRS; because of increased headache/dizziness and to assess the need for post-GKRS systemic treatment the examination was performed 10 days earlier than planned (MRI at 3 weeks).\nAlthough volume assessments by LGP were technically not possible on this particular MRI due to image artefacts, M1 had higher signal on T2 with a more necrotic appearance whereas V4 remained almost unchanged. However, with supportive/ongoing corticosteroid therapy, the patient recovered some balance and strength in his left leg shortly after his examination; systemic antitumoral treatment (BRAF inhibitor dabrafenib) was started at this stage. A new follow-up MRI at 8 weeks revealed decreased volume of M1 (41% compared to MRI at GKRS 1) and diminished compression of V4 (volume of V4 increased from 0.83 cm3 at GKRS 1 to 1.43 cm3 at 8 weeks) []. Local edema had diminished. The remaining treated lesions were under control. However, a CT scan at 10 weeks was performed due to general deterioration over the previous few weeks; the examination demonstrated new areas of hemorrhage and surrounding edema adjacent to two frontal metastases which were treated with SF-GKRS, and slightly increased edema surrounding M1 although with stable V4 conditions. He died 2 weeks later (10 weeks after GKRS) in palliative care. No autopsy was performed. According to the available medical data, the patient might have died of extracranial tumor activity and possible intracranial complications.