Stereotactic body radiotherapy for a large arteriovenous malformation of the head and neck

The addition of adjuvant radiotherapy in the management of extracranial arterio-venous malformations: a case discussion

Introduction:

The management of extracranial arterio-venous malformations (AVMs) is complex and often requires a multidisciplinary approach. Currently, treatment includes surgical resection and embolotherapy.

Methods:

We present the case of a foot AVM that was managed with adjuvant radiotherapy after previous surgery and embolotherapy had been attempted, and we discuss the role of radiotherapy in the management of extracranial AVMs.

Results:

The malformation was successfully eradicated with complete obliteration of the nidus and no recurrence.

Conclusions:

The addition of radiotherapy in the management of extracranial arterio-venous malformations offers promising results using similar doses to those used in brain AVMs.

Stereotactic Body Radiotherapy (SBRT) for an Extracranial Arteriovenous Malformation of the Pelvis

Extracranial arteriovenous malformations (AVMs) are rare pathological, benign conditions that are characterized by aberrantly connected arteries and veins without normal intervening capillary vasculature. Although stereotactic radiosurgery is an established, efficacious, safe treatment for intracranial AVMs, there is no known published data on the use of stereotactic body radiotherapy (SBRT) for the treatment of abdominopelvic AVMs. One patient with an extracranial AVM in the pelvis that was only partially responsive to embolization was treated with SBRT to a dose of 21 Gy, delivered in three fractions over six calendar days. At presentation, the patient was non-ambulatory due to neuropathic pain from a sciatic impingement of the AVM. The patient underwent two prior catheter-based embolization procedures that had achieved partial obliteration, but with the persistence of neuropathic pain and symptoms. After SBRT to the pelvic AVM, the patient had marked improvement in pain over 10 months and was able to ambulate again. Follow-up angiography and CT demonstrated the obliteration of previously visualized AVM. We describe the first known report of pelvic AVM successfully treated with a combination of embolization and SBRT. Three-fraction SBRT to a total dose of 21 Gy appears to be safe and effective for extracranial AVMs arising in the pelvis. This strategy may be considered for patients with pelvic AVMs that are refractory to standard interventional therapies. However, these findings should be validated in larger cohorts.

Stereotactic Gamma Knife Radiosurgery for Extracranial Arteriovenous Malformations

INTRODUCTION

Head and neck extracranial arteriovenous malformations (AVMs) are rare pathological conditions which pose diagnostic and reconstruction challenges. Stereotactic radiosurgery (SRS) is nowadays an established treatment method for brain AVMs, with high obliteration and low complication rates. Here we describe the first report of head extracranial AVMs successfully treated by Gamma Knife (GK) as a retrospective historical cohort.

METHODS

Over a 9-year period, 2 cases of extracranial AVMs were treated by GK Perfexion (Elekta Instruments AB, Stockholm, Sweden) at a single institution. A stereotactic frame and multimodal imaging, including digital subtraction angiography (DSA), were used. The prescribed dose was 24 Gy at the 50% isodose line.

RESULTS

The first case was of a patient with pulsating tinnitus and left superficial parotido-condylian AVM. Embolization achieved partial obliteration. Tinnitus disappeared during the following 6 months after GK. The second case was a patient with repetitive gingival hemorrhages and right superior maxillary AVM, fed by the right internal maxillary and facial arteries. Embolization achieved partial obliteration with recurrence of symptoms. GK was further performed. DSA confirmed complete obliteration in both patients.

CONCLUSIONS

Single-fraction GK radiosurgery appears to be safe and effective for extracranial AVMs. We recommend prescribing doses that are comparable to the ones used for brain AVMs (i.e., 24 Gy). A stereotactic frame is an important tool to ensure higher accuracy in the context of these particular locations. However, in selected cases, a mask could be applied either for single fraction purposes (if in a non-mobile location) or for hypofractionation, in case of larger volumes. These findings should be validated in larger cohorts, inclusively in terms of dose prescription.

Spontaneous Regression of Parapharyngeal Arteriovenous Malformation

Arteriovenous malformations (AVMs) are fast-flow vascular malformations that mostly occur in the head and neck region. They are typically progressive and their spontaneous regression is almost never seen. We present a case with pulsatile tinnitus and a parapharyngeal AVM. It resolved completely after diagnostic catheter-based angiography alone.