Proton-beam therapy or photon-beam radiosurgery for WHO grade I meningiomas?

Excerpt

Proton-beam therapy (PBT) has been in use since the early 1960s [1]. Typically, PBT has been applied in rare or paediatric neoplasms because of its costs, its specific physical properties and its rare availability. PBT’s share of radiotherapy was 0.6% in the US in 2012 [4]. In this issue of Acta Neurochirurgica, Vlachogiannis et al. [3] present their experience with PBT in 170 patients with WHO grade I meningiomas. As opposed to the classical use of PBT, their patients have neither a rare tumour type nor do they belong to the paediatric age group. Reports on PBT for more common tumours from a neurosurgical viewpoint such as meningiomas add to the competitive field of non-invasive treatments for such tumours. Until recently, PBT did not have to stand much competition from other non-invasive treatment options such as stereotactic single-session photon-beam radiosurgery (RS) because of the rarity of the tumours treated or the paediatric age group undergoing PBT. Accordingly, PBT has been considered as part of radiation oncology, performed by radiation oncologists dealing with a rather narrow niche in terms of tumours and patients. This is going to change with the inroad of PBT into the field of more common neurosurgical neoplasms in adult patients. With the treatment of classical neurosurgical neoplasms, PBT will have to face competitive challenges and critical questions, which so far it may not have confronted. The neurosurgeon Lars Leksell developed the concept of RS and the first dedicated machine for such treatments, the Gamma Knife (GK). The neurosurgeon John R. Adler developed the second dedicated machine for RS, the CyberKnife (CK). RS was introduced by neurosurgeons against the resistance of radiation oncologists. Because of that resistance and in advocacy of their new concept, neurosurgeons amassed an unparalleled knowledge and experience in RS for intracranial neoplasms. As a consequence, RS is nowadays one of the best-documented medical treatments, with more than 15,000 publications on Gamma Knife radiosurgery (GKRS) alone. Ideally, neurosurgeons approach tumours such as intracranial meningiomas with a concept in mind including microsurgery, RS or the combination of both. Therefore, any new treatment for classical neurosurgical neoplasms of adult patients will have to prove at least equality of results with well-established neurosurgical treatment options such as RS, stand the test of everyday clinical practice and compete with the comparably low costs of RS. …