Intraoperative radiotherapy to treat newly diagnosed solitary brain metastasis: initial experience and long-term outcomes

Abstract

abbreviatioNs BrM = brain metastasis; GPA = Graded Prognostic Assessment; IORT = intraoperative radiotherapy; KPS = Karnofsky Performance Scale; LMD = leptomeningeal (metastatic) disease; NSCLCa = non-small cell lung cancer; RPA = recursive partitioning analysis; SRS = stereotactic radiosurgery; WBRT = whole-brain radiation therapy; XRS = radiation source. submitted January 30, 2014. accepted November 13, 2014. iNclude wheN citiNg Published online January 23, 2015; DOI: 10.3171/2014.11.JNS1449. disclosure The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper. obJect The authors assessed the feasibility of intraoperative radiotherapy (IORT) using a portable radiation source to treat newly diagnosed, surgically resected, solitary brain metastasis (BrM). methods In a nonrandomized prospective study, 23 patients with histologically confirmed BrM were treated with an Intrabeam device that delivered 14 Gy to a 2-mm depth to the resection cavity during surgery. results In a 5-year minimum follow-up period, progression-free survival from the time of surgery with simultaneous IORT averaged (± SD) 22 ± 33 months (range 1-96 months), with survival from the time of BrM treatment with surgery+IORT of 30 ± 32 months (range 1-96 months) and overall survival from the time of first cancer diagnosis of 71 ± 64 months (range 4-197 months). For the Graded Prognostic Assessment (GPA), patients with a score of 1.5-2.0 (n = 12) had an average posttreatment survival of 21 ± 26 months (range 1-96 months), those with a score of 2.5-3.0 (n = 7) had an average posttreatment survival of 52 ± 40 months (range 5-94 months), and those with a score of 3.5-4.0 (n = 4) had an average posttreatment survival of 17 ± 12 months (range 4-28 months). A BrM at the treatment site recurred in 7 patients 9 ± 6 months posttreatment, and 5 patients had new but distant BrM 17 ± 3 months after surgery+IORT. Six patients later received whole-brain radiation therapy, 7 patients received radiosurgery, and 2 patients received both treatments. The median Karnofsky Performance Scale scores before and 1 and 3 months after surgery were 80, 90, and 90, respectively; at the time of this writing, 3 patients remain alive with a CNS progression-free survival of > 90 months without additional BrM treatment. coNclusioNs The results of this study demonstrate the feasibility of resection combined with IORT at a dose of 14 Gy to a 2-mm peripheral margin to treat a solitary BrM. Local control, distant control, and long-term survival were comparable to those of other commonly used modalities. Surgery combined with IORT seems to be a potential adjunct to patient treatment for CNS involvement by systemic cancer. Clinical trial registration no.: NCT00107367 (clinicaltrials.gov)

Stereotactic radiosurgery versus whole-brain radiotherapy after intracranial metastasis resection: a systematic review and meta-analysis

“…Traditionally, the standard of care for patients with solitary brain metastasis has been resection plus whole-brain radiotherapy (WBRT) [4, 7]. Resection allows for histopathological examination of the tissue and has been shown to improve neurological symptoms, functional independence, and survival [5].…”

“…Given that patients with systemic cancer are now living longer due to improved extracranial anti-tumor strategies, concerns related to these delayed, radiation-induced neurotoxic effects are prompting neuro-oncologists to assess alternatives to WBRT [4, 14]. Many centers are therefore using targeted techniques with limited radiation exposure, such as stereotactic radiosurgery (SRS).…”

“…Many centers are therefore using targeted techniques with limited radiation exposure, such as stereotactic radiosurgery (SRS). SRS is associated with fewer global cognitive side effects, CNS preservation, and better quality-of-life [2, 4, 7, 15]. …”

Intraoperative radiotherapy for the treatment of thyroid cancer: a pilot study

“…IORT was also used to safely treat locally advanced and recurrent rectal cancer, producing effects similar other intraoperative radiotherapy techniques but with a shorter operative time [6]. In addition, Weil et al [7] reported the feasibility of using IORT to treat brain metastases, and Wenz et al [22] reportedly used IORT to treat advanced thoracic spinal metastases, with good results. Finally, Rutkowski et al [9] reported the feasibility using IORT to treat early oral cancer.…”

Neurosurgical management of brain metastases

“…Preliminary results are comparable to other current treatment paradigms. 43 Local therapy with intraoperative radiation or brachytherapy may be a particularly attractive option for lesions that result in resection cavities too large to be treated safely with SRS such as those great than 15 ml in volume. 44,45 Local radiation to the resection cavity, either via SRS or intraoperative radiotherapy, has been associated with an increased rate of distant failure and leptomeningeal disease in comparison to adjuvant WBRT.…”