Radiotherapy in Prostate Brain Metastases: A Review of the Literature

Brain Metastases in Prostate Cancer

The presence of brain metastases in patients with prostate cancer is infrequent. Intracranial dissemination of prostate cancer usually occurs in the late stage of the disease. It most commonly involves the epidural space as a result of local invasion of cranial metastases (6). However, since the dura mater serves as a barrier to the spread of tumor cells, intradural spread is most likely the result of hematogenous spread. Some risk factors for the development of brain metastases have been identified including elevated Gleason Score as well as long-standing disease (7). Magnetic resonance imaging (MRI) is the optimal method used to evaluate the location, number, size, and pattern of brain metastases (7).

The prognosis of patients with prostate cancer who develop brain metastases is poor, as is that of other brain metastases from other types of cancer. In addition, it is common for patients to have concurrent distant metastases. In the Tremont-Lukats et al. series of patients, they reported a median treatment-free survival of 1 month (8). The median survival time of prostate cancer patients with brain metastases has ranged from 1 to 7.7 months (5, 8-11).

Leptomeningeal dissemination. Lynes et al. described that the most common intracranial location of prostate cancer metastases was the meninges (65%), cerebrum (25%), and cerebellum (8%). However, many patients were diagnosed only by autopsy and/or computed tomography (CT) rather than MRI, and it is possible that before the introduction of MRI into clinical practice many intraparenchymal lesions in the brain went undetected (7, 11). In more modern studies, the development of dural metastases in prostate cancer is very rare, with an incidence of less than 0.1% (12). In the study by Kanilmaz et al., 60% of patients had pure intraparenchymal metastases, 20% had pure extensive dural metastases, and 20% had both. The exact mechanism of leptomeningeal dissemination is unknown, although several theories have been proposed. As the survival of metastatic castration-resistant prostate cancer (mCRPC) improves, the incidence of dural metastases is likely to increase, thus a differential diagnosis should be considered in those patients with mCRPC who present with neurological symptoms (13).

Intraparenchymal metastases. Intraparenchymal brain metastases are more frequent in men with prostate cancer with aggressive phenotypes such as mCRPC. The most common symptoms are dysphasia, dysarthria, diplopia, facial numbness, headache, weakness, delirium, and confusion (14-16).

In the Kayolmaz study, 75% of patients with intraparenchymal metastases had multiple metastatic lesions (7). As in the Memorial-Sloan-Kettering Cancer Center study, 71% of their patients had multiple intraparenchymal metastatic lesions (9). Bhambhvani et al. reported data from 31 patients with a median number of brain metastases of 2 (1-5). In this study, 61% of metastases were supratentorial, 10% infratentorial, and 29% were both supratentorial and infratentorial (16).

Brain metastasis from prostate cancer presenting as a cystic tumor is even rarer. Twelve cases of prostate cancer patients with cystic or partially cystic brain metastases have been published (17).

This post was last modified on Tháng mười một 29, 2024 5:32 chiều