P14.93 Partial stiff-person syndrome, cerebral lymphoma, and HIV infection

BACKGROUND Stiff person syndrome (SPS) is a rare entity, characterized by rigidity or stiffness of the muscles. It is usually autoimmune, but it can also appear as a paraneoplastic (5%) or cryptogenic disorder. This study aims to establish a potential connection between what appears to be a partial SPS, an advanced HIV infection, and a primary central nervous system (CNS) lymphoma in a young adult. MATERIAL AND METHODS We present the case of a 42-year-old male, who, in the course of approximately five months developed dizziness, impairment of manual dexterity, ataxia, postural instability, hallucinations, weight loss, and fever. He was admitted to our clinic, after a progressive deterioration of his mental status, presenting global aphasia, and increased left hemibody muscle tone, with persistent left torticollis. According to the blood tests and cerebral MRIs he was diagnosed with HIV infection, thrombophilia, and a left frontal mass, of unknown etiology. RESULTS His neurocognitive deterioration was suggestive of a primary CNS lymphoma and the ipsilateral abnormal increased muscular tone raised the suspicion of a partial SPS. It appeared most likely in the context of the brain lesion, even if its nature remained unknown, due to the deteriorated status, that made biopsy impossible. The diagnosis of cerebral lymphoma was based on the IRM characteristics and the change in appearance after corticosteroid therapy. CONCLUSION Even if it represents a rare diagnosis, partial SPS can appear as a paraneoplastic entity, our patient’s evolution and clinical examination being suggestive for this pathology.

RADI-15. Radiotheranostic Approach in Brain Tumor

Purpose The aim of this study is feasibility and potential treatment of targeted radionuclide theranostic approach for patients with brain tumors. Methods For the period 2020–2021, 6 child and adult patients who had been diagnosed with brain tumors were treated using theranostic approach followed by refractory to conventional therapy. Two patients that were presented with HER-2 positive, ER and PR negative breast cancer and brain metastases as well as a history of several cycles of chemotherapy sessions and radiotherapy using gamma knife were treated with 177Lu-Trastuzumab (Herceptin). Three other patients with primary brain tumor underwent peptide receptor radionuclide therapy (PRRT) with 177Lu-DOTATATE. The last case was a patient with refractory primary cerebral lymphoma to standard therapy with confirmed CD20-positive B-cell lymphoma who underwent 177Lu-Rituximab. Results A two women with HER-2 positive breast cancer and brain metastasis underwent two cycles of 177Lu-trastuzumab. Post-therapy assessment showed some improvement. Next, a man with a high-grade glioma tumor in the left frontal lobe with history of debunking surgery in combination with chemoradiation received 177Lu-DOTATATE that resulted in a short-term stable situation. Another patient presented with a right cerebellopontine angle meningioma underwent PRRT with 177Lu-DOTATATE. She had a stable disease with some improvement in the clinical status. Also, a girl with an astrocytoma in suprasellar cistern underwent 2 cycles of 177Lu-DOTATATE. The complete response was designed. Finally, a patient with refractory primary cerebral lymphoma received 177Lu-Rituximab. Conclusion Nuclear oncology in the field of neuro-oncology (neuroradiotheranostics) has been toward a personalized approach, effective and safe therapy. These preliminary studies might demonstrate feasibility and therapeutic potential of theranostics in patients with primary, relapsed or metastasis brain tumors. Further studies preferentially well-designed multicenter international clinical trial is warranted.

Levamisole-induced leukoencephalopathy

A medical case of an acute demyelinating process in cerebrum caused by taking levamisole is presented. The issues of pathogenesis and differential diagnosis of levamisole-induced leukoencephalopathy with acute disseminated encephalomyelitis, multiple sclerosis, progressive multifocal leukoencephalopathy, and cerebral lymphoma are discussed.