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Table of Contents    
Year : 2018  |  Volume : 66  |  Issue : 2  |  Page : 515-518

Cavernous malformation induced by stereotactic radiosurgery: A report and literature review

Department of Neurosurgery, West Hospital of Sichuan University, Sichuan, China

Date of Web Publication15-Mar-2018

Correspondence Address:
Dr. Xuhui Hui
Department of Neurosurgery, West China Hospital of Sichuan University, Sichuan
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/0028-3886.227308

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How to cite this article:
Wang Q, Zhang S, Hui X. Cavernous malformation induced by stereotactic radiosurgery: A report and literature review. Neurol India 2018;66:515-8

How to cite this URL:
Wang Q, Zhang S, Hui X. Cavernous malformation induced by stereotactic radiosurgery: A report and literature review. Neurol India [serial online] 2018 [cited 2019 Dec 6];66:515-8. Available from:


Cavernous malformations (CMs) are common central nervous system vascular lesions, which may occur sporadically or in a familial form. Rarely, they can be induced by radiation therapy. The majority of these lesions occur in children after they have been subjected to conventional radiation therapy for a medulloblastoma, glioma, and acute lymphocytic leukemia (ALL).[1] Stereotactic radiosurgery-induced CMs are especially rare, with only five cases being reported. They have been reported to develop after administering gamma knife radiosurgery (GKRS) for another CM, or an arteriovenous malformation, metastatic brain tumor, schwannoma, or pineocytoma. In this study, we report the first case of CM formation after stereotactic radiosurgery for a low-grade glioma. We also summarize the clinical features of GKRS-induced CMs, and compare the GKRS induced CMs with the conventional radiation therapy-induced CMs.[2],[3]

A 45-year old man was hospitalized due to a 3-month history of headache and vertigo. Magnetic resonance imaging (MRI) revealed a cystic lesion in the cerebellar vermis. A subtotal resection was achieved due to the unclear boundary of the tumor, and the histopathological diagnosis was a glioma (World Health Organisation grade II) [Figure 1]. As the patient and his relatives refused conventional radiotherapy and chemotherapy, GKRS using a 50% isodose of 14 Gy at the tumor margin was applied. A total of 10 shots were delivered using two 14-mm collimators and eight 8-mm collimator collimators. No recurrence of the residual tumor was observed during the follow-up period; however, some abnormal vessels generated at the site, 2 years after the completion of radiosurgery [Figure 2]a. Since then, the patient was placed under close observation, and a lesion suspected to be a CM was demonstrated on the follow-up magnetic resonance imaging (MRI) performed after 2 years [Figure 2]b. The patient refused a repeat surgery as he had not developed any serious symptoms. Two years later, the patient was hospitalized complaining of severe headache and gait disturbance. MRI showed that the lesion, located at the site where the primary radiation had been given, had presented with a rapid growth [Figure 2]c and [Figure 2]d. Therefore, a microsurgical resection was performed and the lesion as well as the involved brain parenchyma was removed. Histopathological examination confirmed the diagnosis of a CM [Figure 2]f. Postoperatively, the patient recovered uneventfully and the preoperative symptoms improved. The patient was discharged with a Karnofsky score of 90. The follow-up MRI showed that total resection had been achieved [Figure 2]e.
Figure 1: Axial and sagittal magnetic resonance imaging (a-c) demonstrated a lesion in the cerebellum vermis, with no obvious enhancement. Postoperative magnetic resonance imaging depicted no abnormal enhancing signals in the surgical field (d)

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Figure 2: Two years after radiosurgery (August, 2011), some abnormal vessels arose in the previous radiation port (a). In July 2013, a heterogeneous mass with “popcorn-like” sign was noted (b). After admission, this time (August, 2015), the gadolinium-enhanced imaging (c) demonstrated an enhanced mass with surrounding rim of hemosiderin, and T2-weighted imaging (d) revealed the typical “pop-corn” sign of CM. Complete surgical resection was done (e). Postoperative histopathological examination confirmed the diagnosis of cavernous malformation (f)

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Treatment of WHO grade II astrocytomas includes radical surgical resection, radiation therapy, chemotherapy, and conservation therapy. Although stereotactic radiosurgery (SRS) is not a standard treatment therapy for an astrocytoma due to the indistinct borders of the tumor, several studies have investigated the role of radiosurgery in the management of low-grade gliomas, especially in those that are deep-seated and located at critical site, or when radiosurgery is being administered for a residual or recurrent tumor.[4] Our patient received GKRS for the residual glioma after its subtotal surgical resection had been performed; during the follow-up period, a CM (not the initial tumor) was found at the site where previous radiation had ben administered. The newly formed CM in our patient met the diagnostic criteria of radiation-induced neoplasm outlined by Cahan et al.[5] Furthermore, the patient did not have CMs anywhere else in the brain; he also did not have a family history of CMs.

The pathogenesis of GKRS-induced CM remained unknown. Several possible mechanisms have been proposed: (1) Radiation may have initiated the growth of a preexisting tiny cavernoma not previously visible on MRI. (2) Genetic mutations, such as a mutation in the chromosome 22 or p53 tumor suppressor gene; or, exposure to a previously suppressed, oncogenic genetic material that was induced to undergo transformation to its active state by radiation therapy may be responsible. (3) Release of factors including fibroblast growth factor as well as platelet-derived and vascular endothelial growth factors, and impairment of cerebral microcirculation caused by radiation may also contribute.[6] (4) Yoon et al., maintain the belief that SRS-induced CM may just be a hematoma rather than a real CM.[7] In our case, the sequential follow-up data revealed that a de novo CM had been induced by radiation; growth of a preexisting lesion had not taken place; the typical radiological features combined with the histopathological examination confirmed that a real CM, rather than hematoma, was present. We propose that radiation-induced genetic mutations could have been responsible for the generation of the CM, and that radiation-induced vascular parenchymal alterations provided a driving force for its rapid growth.

After reviewing the literature [1],[2],[3],[8],[9] [Table 1], we discovered that GKRS-induced CMs are frequently accompanied by symptomatic hemorrhage and that headache was the most common symptom at presentation. The patients frequently had one identifiable lesion. This lesion may not only appear at the site of the radiation port but also in regions remote from the irradiation site.[2] The mean duration from the administration of radiation to the formation of CM was 6 years. The risks of symptomatic hemorrhage (5/5) and re-hemorrhage (3/5) were high, and surgical intervention was frequently required in GKRS-induced CMs. However, previous studies have shown that the conventional irradiation-induced CMs are frequently asymptomatic and hemorrhagic events occur rarely when they are investigated. The latency time (range: 8.9–12 years) for the occurrence of conventional radiotherapy-induced CMs was of a much longer duration than is seen in GKRS-induced CMs, the lesions were frequently multiple, and conservative treatment with frequent observation was the mainstay of treatment.[10],[11] Therefore, we state that the natural history of GKRS-induced CMs and conventional radiotherapy-induced CMs are different, and that GKRS-induced CMs may share a greater risk of having a hemorrhage and subsequent re-hemorrhage.
Table 1: Summary of reported cases of radiosurgery-induced cavernous malformation

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In conclusion, GKRS may be a useful adjunctive treatment in residual low-grade gliomas; however, a radiation-induced CM has the possibility of occurring at the site of the radiation port. Furthermore, we consider that GKRS-induced CM might be associated with a higher risk of hemorrhage and re-hemorrhage, compared with the conventional radiation-induced CMs. The risk of occurrence of a CM exists not only after conventional radiation but also after radiosurgery. Due to the paucity of cases of radiation induced CM, further investigations in this direction are expected to yield more meaningful conclusions.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that name and initial will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Park YS, Kim SH, Chang JH, Chang JW, Park YG. Radiosurgery for radiosurgery-induced cavernous malformation. World Neurosurg 2011;75:94-8.  Back to cited text no. 1
Sasagawa Y, Akai T, Itou S, Iizuka H. Gamma knife radiosurgery-induced cavernous hemangioma: Case report. Neurosurgery 2009;64:E1006-7.  Back to cited text no. 2
Wang X, Hui XH, Liu JP, Mao Q. Radiation-induced cavernous malformation at the site of arteriovenous malformation following gamma knife radiosurgery: Case report. Clin Neurol Neurosurg 2012;114:1287-89.  Back to cited text no. 3
Lizarraga KJ, Gorgulho A, Lee SP, Rauscher G, Selch MT, DeSalles AA. Stereotactic radiation therapy for progressive residual pilocytic astrocytomas. J Neurooncol 2012;109:129-35.  Back to cited text no. 4
Cahan WG, Woodard HQ, Higinbotham NL, Stewart FW, Coley BL. Sarcoma arising in irradiated bone-Report of eleven cases. Cancer 1998;82:8-34.  Back to cited text no. 5
Amirjamshidi A. Radiation-induced cavernous malformations. J Neurosurg Pediatr 2013;11:734.  Back to cited text no. 6
Cha YJ, Nahm JH, Ko JE, Shin HJ, Chang JH, Cho NH,et al. Pathological evaluation of radiation-induced vascular lesions of the brain: Distinct from de novo cavernous hemangioma. Yonsei Med J 2015;56:1714-20.  Back to cited text no. 7
Iwai Y, Yamanaka K, Yoshimura M. Intracerebral cavernous malformation induced by radiosurgery-Case report. Neurol Med Chir 2007;47:171-3.  Back to cited text no. 8
Pozzati E, Acciarri N, Tognetti F, Marliani F, Giangaspero F. Growth, subsequent bleeding, and de novo appearance of cerebral cavernous angiomas. Neurosurgery 1996;38:662-9.  Back to cited text no. 9
Di Giannatale A, Morana G, Rossi A, Cama A, Bertoluzzo L, Barra S,et al. Natural history of cavernous malformations in children with brain tumors treated with radiotherapy and chemotherapy. J Neurooncol 2014;117:311-20.  Back to cited text no. 10
Cutsforth-Gregory JK, Lanzino G, Link MJ, Brown RD, Jr., Flemming KD. Characterization of radiation-induced cavernous malformations and comparison with a nonradiation cavernous malformation cohort. J Neurosurg 2015;122:1214-22.  Back to cited text no. 11


  [Figure 1], [Figure 2]

  [Table 1]


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