Radiosurgery for Arteriovenous Malformations Using Micro–Multi-leaf Collimators: Analyses of Outcome

Abstract

Aim To assess the outcome of patients with AVMs treated using micro-MLC–based radiosurgery at Regional Cancer Centre (RCC), Thiruvananthapuram.

Materials and Methods During January 1 to December 31, 2012, 24 patients were treated with stereotactic radiosurgery (SRS) at RCC. The median age was 28 years (range: 8–58 years). There were 11 males and 13 females. Fifteen patients had prior embolization. All patients were treated with a frameless radiosurgery system using micro-MLC–based linear accelerator (LINAC). Obliteration of the lesion was assessed with either magnetic resonance angiogram (MRA) or digital subtraction angiography (DSA).

Results Nineteen patients who underwent an assessment procedure were evaluable for this study. At median follow-up of 12 months, nearly two-thirds of patients had complete obliteration of the AVM and the rest had partial obliteration. Among patients with complete obliteration, seven patients had an AVM volume of ≤ 3 cc and three-fourths of the patients had AVM score of < 1.5. Further, marginal dose of > 18 Gy resulted in higher obliteration. One patient had an episode of seizure after SRS. No complications or bleed was seen in any of the patients after treatment.

Conclusion Our experience correlates with the existing literature reports, without any significant complications. Longer follow-up is required to assess the complete obliteration and late complications.

Keywords

venous malformation - stereotactic radiosurgery - LINAC - micro–multi-leaf collimators

• References

• 1 Sun DQ, Carson KA, Raza SM. , et al. The radiosurgical treatment of arteriovenous malformations: obliteration, morbidities, and performance status. Int J Radiat Oncol Biol Phys 2011; 80 (02) 354-361
• 2 Kubo HD, Wilder RB, Pappas CTE. Impact of collimator leaf width on stereotactic radiosurgery and 3D conformal radiotherapy treatment plans. Int J Radiat Oncol Biol Phys 1999; 44 (04) 937-945
• 3 Lomax NJ, Scheib SG. Quantifying the degree of conformity in radiosurgery treatment planning. Int J Radiat Oncol Biol Phys 2003; 55 (05) 1409-1419
• 4 Ma L, Xia P, Verhey LJ, Boyer AL. A dosimetric comparison of fan-beam intensity modulated radiotherapy with Gamma knife stereotactic radiosurgery for treating intermediate intracranial lesions. Int J Radiat Oncol Biol Phys 1999; 45 (05) 1325-1330
• 5 Steiner L, Lindquist C, Adler JR, Torner JC, Alves W, Steiner M. Clinical outcome of radiosurgery for cerebral arteriovenous malformations. J Neurosurg 1992; 77 (01) 1-8
• 6 Friedman WA, Bova FJ, Spiegelmann R. Linear accelerator radiosurgery at the University of Florida. Neurosurg Clin N Am 1992; 3 (01) 141-166
• 7 Touboul E, Al Halabi A, Buffat L. , et al. Single-fraction stereotactic radiotherapy: a dose-response analysis of arteriovenous malformation obliteration. Int J Radiat Oncol Biol Phys 1998; 41 (04) 855-861
• 8 Flickinger JC, Pollock BE, Kondziolka D, Lunsford LD. A dose-response analysis of arteriovenous malformation obliteration after radiosurgery. Int J Radiat Oncol Biol Phys 1996; 36 (04) 873-879
• 9 Friedman WA, Bova FJ, Bollampally S, Bradshaw P. Analysis of factors predictive of success or complications in arteriovenous malformation radiosurgery. Neurosurgery 2003; 52 (02) 296-307 , discussion 307–308
• 10 Pollock BE, Flickinger JC. A proposed radiosurgery-based grading system for arteriovenous malformations. J Neurosurg 2002; 96 (01) 79-85
• 11 Andrade-Souza YM, Zadeh G, Ramani M, Scora D, Tsao MN, Schwartz ML. Testing the radiosurgery-based arteriovenous malformation score and the modified Spetzler-Martin grading system to predict radiosurgical outcome. J Neurosurg 2005; 103 (04) 642-648
• 12 Flickinger JC, Kondziolka D, Lunsford LD. , et al. A multi-institutional analysis of complication outcomes after arteriovenous malformation radiosurgery. Int J Radiat Oncol Biol Phys 1999; 44 (01) 67-74