**7.2. New treatment techniques**

because of leakage of the blood–brain barrier due to RT. Intrathecal chemotherapy has higher

Chemotherapeutic agents, such as BCNU, CDDP, cytosine arabinoside, and intrathecal or intravenous methotrexate, have toxic effect to the CNS. Chemotherapy-related cognitive impairment in primary CNS lymphoma was observed in one or more domains: (attention, executive function, memory, psychomotor speed, and language). Other studies have shown that cognitive stability or cognitive improvement during chemotherapy provided that the tumor was responsive to chemotherapy treatment [106, 107]. Uses of high-dose IV methotrex‐ ate or interathecal methotrexate with radiation therapy result in dementia particularly when the radiation is given prior to the methotrexate. Leukoencephalopathy more commonly occurs. MRI shows bilateral periventricular white matter changes. The radiation therapy disrupts the BBB and results in increased permeability of the white matter to the methotrexate [108].

Copeland et al. [109] concluded that chemotherapy had only a slight effect on neurocogni‐ tive status and was confined to perceptual motor skills with observed age effect on perform‐

Chemotherapeutic agents, such as BCNU, cisplatin, and cytarabine, have proved to be more toxic to neural precursor cells than cancer cells [110]. Carmustine, methotrexate, and cytara‐ bine have been found to induce central neurotoxicity to neural stem cell populations located

Prabhu et al. [111] conducted a study on LGG patients and concluded that the addition of chemotherapy procarbazine, lomustine, and vincristine (PCV) to RT for LGGs did not result

Regarding the HRQOL, there is a short-lasting negative impact of PCV chemotherapy on HRQOL during and shortly after treatment, but no long-term effects on HRQOL have been

Patients with previously untreated anaplastic astrocytoma, OA, or oligodendroglioma were evaluated for the long-term efficacy and safety of accelerated fractionated RT combined with intravenous carboplatin. In a phase II study conducted by Levin et al. [113], they found that after RT, patients received procarbazine, lomustine (CCNU), and vincristine (PCV) for 1 year or until tumor progression, 10% of those patients developed serious clinical neurologic

Hilverda et al. [114] reported that glioblastoma patients undergoing RT with concomitant and

In LGG patients, temozolomide is not only successful in terms of extending the survival duration but also has been proven to maintain or even improve HRQOL while patients are on

Patients with recurrent high-grade glioma (HGG), successfully treated with temozolomide, achieved significant improvement in the HRQOL domains, whereas patients with disease

CNS toxicity compared to systemic chemotherapy [105].

252 Neurooncology - Newer Developments

in the subventricular zone and dentate gyrus [99].

in significant MMSE score decline when compared to RT alone.

deterioration and/or dementia requiring full-time caregiver attention.

adjuvant temozolomide treatment did not develop cognitive deterioration.

progression had significant deterioration in most HRQOL domains [116].

ance IQ.

established [112].

treatment [115].

The use of image-guided surgery such as the intraoperative magnetic resonance imaging resulted in improvement in tumor resection and reduction of residual [119]. The use of endoscopic biopsy is a minimally invasive method can be performed safely in conjunction with diversion of cerebrospinal fluid in cases of obstructive hydrocephalus and decrease neuro‐ cognitive decline [120].

New radiation techniques such as IMRT are able to minimize the radiation to healthy brain structures. With using IMRT, hippocampus can be localized and hence the dentate gyrus can be spared, resulting in prevention or decrease neurocognitive decline to some extent [121]. Lin et al. [122] reported significantly lower rates of memory loss posttreatment and with no treatment-related decline in quality of life with IMRT RT.

Insignificant neurocognitive decline was found in a study conducted by Wahba et al. [123] after use of reduced CSI followed by adjuvant chemotherapy in patients with average-risk medulloblastoma.

With proton beam RT, there is less radiation to surrounding normal brain tissues and decrease the area at risk for radiation injury, therefore, sparing of neurocognitive functioning [124].
