REVIEW The role of brachytherapy in the treatment of glioblastoma multiforme Eric Barbarite 1 & Justin T. Sick 2 & Emmanuel Berchmans 1 & Amade Bregy 1 & Ashish H. Shah 1 & Nagy Elsayyad 3 & Ricardo J. Komotar 1 Received: 31 May 2014 /Revised: 6 March 2016 /Accepted: 7 March 2016 # Springer-Verlag Berlin Heidelberg 2016 Abstract Brachytherapy (BT) for glioblastoma multiforme (GBM) involves the use of radioactive isotopes to deliver ionizing radiation directly into the tumor bed. Its application as a means to prolong survival in GBM patients over the past few decades has come with variable success. The objective of this review is to describe the utility of BT in GBM, and to report the outcomes and adverse events associated with its use in different multimodal treatment approaches. A search of the literature was conducted using the PubMed database. The most recent search was performed in September 2015. Thirty-two series involving 1571 patients were included in our review. The longest median overall survival (MOS) fol- lowing BT for newly diagnosed GBM reached 28.5 months. Overall, 1-, 2-, and 3-year survival rates were 46–89 %, 20– 57 %, and 14–27 %. For recurrent GBM, the longest reported MOS after BT was 15.9 months. One-, 2- and 3-year survival rates for recurrent GBM were 10–66 %, 3–23 %, and 9–15 %. Adverse events were reported in 27 % of patients. Reoperation for radiation necrosis occurred in 4 and 27 % of patients fol- lowing low- and high-dose rate BT, respectively. BT is a fea- sible option for extending survival in carefully selected GBM patients. As patient outcomes and overall survival improve with more aggressive radiotherapy, so does the risk of radiation-related complications. The most effective use of BT is likely as a part of multimodal treatment with other novel therapies. Keywords Glioblastoma . Brachytherapy . Outcomes . Side effects . Systematic analysis Introduction Glioblastoma multiforme (GBM) is the most common prima- ry CNS malignancy. Its incidence has been reported between 3.17 and 3.4/100,000 person-years with a temporal increase over the past five decades [11, 49]. Despite multimodal stan- dard of care, the median survival of patients with GBM re- mains short at 14 months [30, 36]. Almost all GBM patients experience recurrence, which commonly occurs at or within 2 cm of the primary tumor bed. As a result, adjuvant radio- therapy to the surgical bed has evolved as a standard postop- erative treatment. In the past, such treatment involved whole brain radiation therapy but has since been refined with dose- fractionated external beam radiotherapy (EBRT), as well as other modalities such as brachytherapy (BT). BT for GBM involves the use of radioactive isotopes that produce indirect ionizing radiation [33]. As unstable nuclei break down to more stable forms, high-energy gamma rays are released into the surrounding tissue. Energy transfer to the surrounding tissue results in the production of electrons by the Comptom and photoelectric effects, which ultimately disrupt atomic bonds. Isotopes most relevant to the treatment of GBM are iodine-125 (I-125) and iridium-129 (192-Ir). The energy content of photons is dependent upon the parent isotope, with I-125 representing a low-energy isotope (27–32 keV) and 192-Ir representing a high-energy isotope (380 keV). * Ricardo J. Komotar rkomotar@med.miami.edu 1 Department of Neurological Surgery, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, 2nd Floor, Miami, FL, USA 2 The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA 3 Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, FL, USA Neurosurg Rev DOI 10.1007/s10143-016-0727-6