Glioblastoma multiforme (GBM), the most common and malignant primary brain tumor in adults is classified as a World Health Organisation (WHO) grade 4. Surgical removal of the tumor is the primary method of treatment. Unfortunately, because GBM is a disease of the entire brain, total resection is not possible. Therefore, the use of radiotherapy and/or chemotherapy is considered as Stupp protocol. Patients with recurrent GBM will be included in the ANCHIALE study. The goal of the trial is to evaluate the efficacy and tolerance of using the NanoTherm therapy system in recurrent GBM. The main questions it aims to answer are: 1. how NanoTherm therapy influences overall survival, and progression free survival; 2. what is the tolerance of NanoTherm therapy in terms of side effects (allergies, intracranial bleeding, infections, brain edema, increased intracranial pressure) and quality of life. Participants will undergo: * initial visit, considering the inclusion/exclusion criteria, neurological examination, and surveys regarding daily functioning and quality of life; * standard neurosurgical operation aimed, if possible, complete removal of the recurrent GBM and administration of NanoTherm ASI - a sterile suspension of iron oxide nanoparticles. A catheter will be implanted allowing for measurement of temperature during the first activation in the magnetic field; * between the 6th and 10th day after tumor resection, a standard computerized tomography (CT) scan of the head will be performed for routine postoperative evaluation; * after the first activation (10th day), the catheter will be removed; * subsequently, for 6 times, the patient will be subjected to the variable magnetic field of the NanoActivator® to induce hyperthermia - activations will be conducted on the 10th, 14th, 17th, 21st, 24th, and 28th day; * for up to 2 years post-procedure, a CT scan with an evaluation of treatment efficacy will be performed; * during follow-up visits for up to 2 years after the surgical procedure, a neurological examination, assessment of adverse symptoms, number of hospitalizations, number of medical visits, clinimetric assessment regarding quality of life, neurological deficit and degree of disability will be conducted. Researchers will compare NanoTherm group with patients undergoing Stupp protocol treatment for the abovementioned effects.