2.1Whole Brain Radiation Therapy (WBRT)

Abstract

This chapter deals with radiation therapy techniques used for treatment of malignant glioma. It shows how they have become more and more sophisticated over the past decades. Due to this achievement in the planning procedure an exact definition of the target volume has become indispensable and increased the role of imaging in radiotherapy. The pros and cons of various imaging modalities are discussed from the view of a radiation oncologist.

3.4Image-Guided Radiation

I. Goetz • A.-L. Grosu (*) Department of Radiation Oncology, University Medical Center Freiburg,

Robert-Koch-Straße 3, 79106 Freiburg, Germany e-mail: irina.goetz@uniklinik-freiburg.de; anca.grosu@uniklinik-freiburg.de

1Treatment of Gliomas and Radiation Therapy Techniques

Radiotherapy (RT) has played a major role in the treatment of malignant glioma since the 1970s. Adjuvant RT significantly improves local control and survival after resection. The positive effect of postoperative RT was initially demonstrated in patients treated with whole brain RT (WBRT). Three randomized trials documented the efficacy of adjuvant whole brain radiotherapy with significantly increased median survival (Walker et al. 1978, 1980; Andersen 1978). The efficacy of RT improved as advanced imaging techniques enabled more precise radiotherapy planning which focused the treatment on the tumor while minimizing the irradiation of normal brain tissue. Involved field RT (IFRT) superseded WBRT and was subsequently augmented by 3D conformal RT (3D-CRT), intensitymodulated RT (IMRT), and stereotactic radiotherapy.

Despite numerous attempts to combine radiotherapy and chemotherapy, no significant benefit was shown for adjuvant chemotherapy until the advent of temozolomide (Stupp et al. 2005), which remains the current standard therapy for glioblastoma multiforme (GBM).

A large phase III study of the Radiation Therapy Oncology Group (RTOG) and Eastern Cooperative Oncology Group (ECOG) investigated the treatment of malignant gliomas in the 1970s (Chang et al. 1983). The efficacy of four postsurgical treatment options was compared: (1) control radiation of 60 Gy/6–7 weeks to whole brain, (2) control radiation dose plus a booster