Treatment outcomes of radiotherapy for malignant psoas syndrome: A single-center retrospective study.

INTRODUCTION: The efficacy of radiotherapy for symptomatic relief of malignant psoas syndrome (MPS) remains unknown because there are limited publications with high level evidence, including analyses with sufficient number of cases, clinical trials, and systematic reviews about radiotherapy for MPS. We aimed to investigate the characteristics of and symptom relief rates in patients treated with radiotherapy for MPS in palliative intent. METHODS: In this single-center retrospective study, we analyzed data of 22 consecutive patients treated with radiotherapy for MPS at our institution in Japan between 2012 and 2022. We recorded patient characteristics, including primary site, invasion pattern, recognition of MPS by the attending physician, radiation regimen, biological effective dose with α/ß = 10 Gy (BED10), and adverse events. Since no objective evaluation index for palliative radiotherapy for non-bone metastases has been established, we modified and used an International Consensus on Palliative Radiotherapy Endpoint, which was originally used for bone metastases, to evaluate symptom relief in the present retrospective study. "Response" was defined as symptom relief described in medical records or the use of analgesic medications reduced by ≥25% within 3 months post-initiation of radiotherapy. RESULTS: Genitourinary organs (41%) were the most common primary-tumor sites. MPS was caused by metastasis in the iliopsoas muscle in 14 patients (64%) and by direct invasion of the primary tumor in eight patients (36%). Since the optimal radiation dose for MPS has not been established, the radiation dose varied from low dose, which are used in palliative radiotherapy for painful bone metastases, to high dose with conventional fraction using 1.8 to 2 Gy per fraction, with a median BED10 of 48 Gy (range, 10.6-79.2 Gy). Fifteen patients (68%) achieved a response. No acute nor late adverse events of grade 2 or higher, according to Common Terminology Criteria for Adverse Events version 5.0, were reported during the observation period. CONCLUSION: Radiotherapy for symptomatic MPS might be an effective treatment option with a high response rate (68%) and minimal adverse events. Since the present study is a retrospective study with small number of cases, a prospective study with a larger sample size is required.

Glioblastoma, IDH-wildtype with leptomeningeal metastasis to Meckel's cave: A case report.

Meckel's cave or the trigeminal cistern is a subarachnoid space near the apex of the petrous portion of the temporal bone and contains cerebrospinal fluid and the Gasserian ganglion, which divides into the ophthalmic (V1), maxillary (V2), and mandibular (V3) nerves. Infectious, inflammatory, congenital, and neoplastic lesions can occur in Meckel's cave. Leptomeningeal metastasis of glioblastoma (GBM), IDH-wildtype to Meckel's cave is rare. We encountered a case of leptomeningeal metastasis of GBM to Meckel's cave in an elderly female patient who presented with pain around her right eye. Magnetic resonance imaging revealed enhancing lesions in the right temporal lobe and cervical spinal cord. The pathological diagnosis of GBM was confirmed after biopsy of the cervical spinal cord lesion, which showed hyperaccumulation of fluorodeoxyglucose (FDG) on FDG-positron emission tomography. This case indicates that metastatic lesions can also occur in Meckel's cave.

Adult-Onset Acute Disseminated Encephalomyelitis with Epstein-Barr Virus Infection.

We present the case of a 22-year-old man who was diagnosed with tonsillitis and treated with antibiotics. Although the symptoms subsided, 1 week later, he presented with weakness in the lower limbs and was hospitalized. The weakness in the lower limbs worsened; he developed difficulty speaking and was transferred to our hospital. Laboratory tests showed a white blood cell count of 10,600/µL (24% atypical lymphocytes). Positive results were obtained for immunoglobulin M (IgM) antibody against Epstein-Barr virus (EBV) viral capsid antigen. EBV-deoxyribonucleic acid quantification in blood yielded positive results. Magnetic resonance imaging (MRI) revealed a hyperintensity in the spinal cord at the Th11 level of the lower spine on T2-weighted imaging (T2WI). In addition, T2WI and fluid-attenuated inversion recovery imaging showed hyperintense lesions on the right cerebral peduncle, bilateral thalami, posterior leg of the left internal capsule, and right corona radiata. We diagnosed acute disseminated encephalomyelitis (ADEM) with EBV and initiated steroid pulse therapy. Symptoms, along with the lesions seen on MRI, subsequently ameliorated. This case suggests that ADEM can be difficult to diagnose, but careful diagnosis is crucial since appropriate treatment is necessary to improve the symptoms.