Submit Manuscript | http://medcraveonline.com Abbreviations: WBRT: Whole Brain Radiotherapy; WBRT- HS: Whole Brain Radiotherapy- Hippocampus Sparing; LINAC: Linear Accelerator; IMRT: Intensity Modulated Radiation Therapy; IGRT: Image Guided Radiation Therapy; MRI: Magnetic Resonance Imaging; CT: Computed Tomography; RPA: Recursive Partitioning Analysis; RTOG: Radiation Therapy Oncology Group; SIB: Simultaneous Boost Introduction Brain metastases represent an important issue in oncology due to its high incidence in many malignancies; about 20 to 40 % of patients with cancer develops brain metastases. 1,2 Its incidence is growing due to advances in imaging technologies and treatment of primary 3 and depends in part on the primary cancer: lung, breast cancer and melanoma being the most frequent primary sites that metastasize to that organ. Cerebral hemispheres (80%), followed by the cerebellum (15%) and the brainstem (5%). Palliative Whole Brain Radiation Therapy (WBRT) has been the historical standard of care for these patients, 4 but median overall survival typically is very low with this modality (4-6 months). 5 It has long been demonstrated that patients with limited brain involvement, especially those with only one metastasis, represent a relatively favorable subgroup. Surgical resection followed by WBRT has proven to be a superior treatment modality than WBRT alone or surgical resection alone. 6 However, not all the patients are suitable for surgical resection, so Stereotactic Radio Surgery (SRS) followed by WBRT has become a treatment option for both single 7,8 and oligo-metastatic patients. 9,10 Classically radiation induced toxicity classifed: a. Acute, expressed in days to weeks after irradiation, with intense , nausea and vomiting; b. Early delayed that occurs 1-6 months post-irradiation and can involve transient demyelination with somnolence; c. Late delayed usually observed > 6 months post-irradiation these late delayed injuries have been viewed as irreversible and progressive. Radiation-induced cognitive impairment, the most important late- delayed toxicity, is reported to occur in up to 50-90% of adult brain tumor patients who survive >6 months post-irradiation. WBRT is a powerful way to control the neurological symptoms and quality of life, there has been some recent controversy about whether WBRT afects neurocognitive function; 11,12 the dose of radiation therapy WBRT is 30Gy in 10 patients with neurological symptoms due to metastasis, this treatment improves quality of life, but in asymptomatic patients may instead lead to a deterioration of cognitive function. The Brain damage has several pathogenetic hypotheses: 13 i. Theory of vascular damage, ii. Theory of parenchymal damage, and more recently iii. Theory of neuroanatomical target. 14,15 Peifer et al., 15 indicates that it is not the dose to the whole brain, but rather the dose to the hippocampus and temporal lobes that predicts the subsequent radiation-induced cognitive impairment. These authors proposed a “neuroanatomical target theory”, which suggests that selective damage to certain brain structures may be the cause of cognitive impairment after radiotherapy. This hypothesis has therefore prompted several researchers to investigate the selective avoidance of certain brain areas. The impairment of learning, memory, and motor coordination seem to be linked to irradiation of the hippocampus. 16-20 Despite the fact that these functions are located in diferent brain J Cancer Prev Curr Res. 2015;2(2):28‒30. 28 ©2015 Carcaterra et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and build upon your work non-commercially. Tomotherapy and brain metastases: towards the neuroanatomical target theory Volume 2 Issue 2 - 2015 Maurizio Carcaterra, 1 Cristina Caruso, 2 Vittorio Donato 2 1 Radiation Oncology Department, Belcolle Hospital, Italy 2 Radiation Oncology Department, S Camillo Forlanini Hospital, Italy Correspondence: Maurizio Carcaterra, Belcolle Hospital, Strada sammartinese,Viterbo (VT), Italy, Tel +393335350247, Fax +390761338673, Email Received: October 26, 2014 | Published: March 05, 2015 Abstract Lung, breast cancer and melanoma are the most frequent malignancies that develop brain metastases. Its incidence is growing due to advances in imaging technologies and treatment of the primary tumors. The most important prognostic factors are age, performance status, control of the primary and the number of metastatic brain lesions. Whole Brain Radiation Therapy (WBRT) is the mainstay of treatment for multiple metastatic lesions, but Stereotactic Radiotherapy in addition to WBRT is a valid option for oligometastatic patients. Recently some authors underlined the importance of neurocognitive function preservation in this subgroup of patients by reducing the dose of radiation to hippocampus based upon the “neuroanatomical target” theory. We conducted a study of feasibility and safety adopting Tomo-Therapy to treat oligometastatic brain patients with a maximum of 4 lesions. Advantage of Tomo-Therapy is to perform WBRT with concomitant Stereotactic Radiotherapy to the visible lesions while at the same time sparing the hippocampus. The sensitivity of the central nervous system to radiotherapy closely correlates with the volume of irradiation, the total dose and the dose per fraction. The dose to the region of the hippocampus during WBRT may delay or reduce neurocognitive deterioration. In our series did not observe radiation-related acute or early-delayed toxicity. We argue that the use of Thomo Therapy to avoid selective brain areas, such as the hippocampus, together with lower doses to whole brain may be associated with a low incidence of neurocognitive toxicity. At the same time high doses to the visible lesions may results in best local control. Keywords: radiotherapy, brain cancer, tomotherapy, radiation induced toxicity, brain metastases, stereotactic radiotherapy, neurocognitive function, hippocampus sparing Journal of Cancer Prevention & Current Research Review Article Open Access