{'fraction_non_alphanumeric': 0.025839793281653745, 'fraction_numerical': 0.004737295434969853, 'mean_word_length': 5.872781065088757, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Gastrointestinal: Bevacizumab‐induced reversible posterior leukoencephalopathy syndrome in patient with rectal cancer

A 66 year old man, diagnosed with metastatic rectal cancer, presented with blurred vision, gait disturbance, dysarthria, and generalized seizures on the day when his third dose of bevacizumab, oxaliplatin, and capecitabine was administered. The physical examination was normal except for the altered mental status and the elevated blood pressure of 162/99 mm Hg. Laboratory assessment was within normal limits. Magnetic resonance imaging (MRI) of the brain showed patchy T2-hyperintense lesions in the subcortical white matter of the occipital and posterior parietal lobes (Figure 1), which were isointense on diffusion-weighted image. The patient was diagnosed with reversible posterior leukoencephalopathy syndrome (RPLS). The generalized seizures resolved after administration of midazolam and phenytoin. Acccording to the literarture, we attributed the development of RPLS to either oxaliplatin or hypertension; the chemotherapy was switched to bevacizumab and irinotecan, and the hypertension was controlled. Three months later, blurred vision, dysarthria, and gait disturbance were aggravated, and MRI of the brain showed the T2-hyperintense lesions had slightly increased in size. Therefore, bevacizumab was attributed to the development of RPLS; the chemotherapy was switched to panitumumab and irinotecan. Three months later, all the neurologic symptoms resolved, and MRI of the brain revealed resolution of the lesions (Figure 2). RPLS is a distinct clinicoradiological entity manifesting with headache, cortical blindness, and seizures. This syndrome is associated with various conditions: hypertension, eclampsia, chemotherapeutic drugs and immunosuppressants. Both bevacizumab and oxaliplatin were reported to be implicated in the pathogenesis of RPLS. Bevacizumab, however, is often administered in combination with oxaliplatin; it can be difficult to prove which drug is truly involved in the pathogenesis. By the same token, RPLS may be solely related to hypertension induced by chemotherapy. This case proves a causative relationship between bevacizumab and RPLS, because RPLS resolved not by the cessation of oxaliplatin or controlled hypertension, but by the cessation of bevacizumab.