Growth of untreated vestibular schwannoma: a prospective study

Clinical article

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Object

Small vestibular schwannomas (VSs) are often conservatively managed and treated only upon growth. Growth is usually reported in mm/year, but describing the growth of a 3D structure by a single diameter has been questioned. As a result, VS growth dynamics should be further investigated. In addition, baseline clinical parameters that could predict growth would be helpful. In this prospective study the authors aimed to describe growth dynamics in a cohort of conservatively managed VSs. They also compared different growth models and evaluated the ability of baseline parameters to predict future growth.

Methods

Between 2000 and 2006, 178 consecutive patients with unilateral de novo small-sized VSs identified among the Norwegian population of 4.8 million persons were referred to a tertiary care center and were included in a study protocol of conservative management. Tumor size was defined by MR imaging–based volume estimates and was recorded along with clinical data at regular visits. Mixed-effects models were used to analyze the relationships between observations. Three growth models were compared using statistical diagnostic tests: a mm/year–based model, a cm3/year–based model, and a volume doubling time (VDT)-based model. A receiver operating characteristic curve analysis was used to determine a cutoff for the VDT-based model for distinguishing growing and nongrowing tumors.

Results

A mean growth rate corresponding to a VDT of 4.40 years (95% CI 3.49–5.95) was found. Other growth models in this study revealed mean growth rates of 0.66 mm/year (95% CI 0.47–0.86) and 0.19 cm3/year (95% CI 0.12–0.26). Volume doubling time was found to be the most realistic growth model. All baseline variables had p values > 0.09 for predicting growth.

Conclusions

Based on the actual measurements, VDT was the most correct way to describe VS growth. The authors found that a cutoff of 5.22 years provided the best value to distinguish growing from nongrowing tumors. None of the investigated baseline predictors were usable as predictors of growth.

Abbreviations used in this paper:ROC = receiver operating characteristic; VDT = volume doubling time; VS = vestibular schwannoma.

Article Information

Address correspondence to: Jobin K. Varughese, M.D., Institute of Surgical Sciences, University of Bergen, Haukeland University Hospital, N-5021 Bergen, Norway. email: jobinv@gmail.com.

Please include this information when citing this paper: published online January 20, 2012; DOI: 10.3171/2011.12.JNS111662.

© AANS, except where prohibited by US copyright law.

Headings

Figures

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    Graphs demonstrating fitted values for 3 growth models: mm/year–based model (A), cm3/year–based model (B), and VDT-based model (C). A growth model is more realistic the more it adheres to the modeling assumptions. The more ideal the growth model, the more the plot type should show a uniform spread for all values. The fan shapes of A and B show that the mm/year–based model supports this requirement poorly and that the cm3/year–based model supports it even worse.

  • View in gallery

    Graphs demonstrating 3 growth models: mm/year–based model (A), cm3/year–based model (B), and VDT-based model (C). A growth model is more realistic the more it adheres to the modeling assumptions. The more ideal the growth model, the more the plot type should show a straight line. The cm3/year–based model in B shows the least straight line and thus supports the assumption the worst.

  • View in gallery

    Histogram showing the distribution of VDTs. Note that the smallest tumors show the most rapid VDTs. V = mean volume at the time of diagnosis for the tumors in that respective bar, in cm3.

  • View in gallery

    Graph showing the ROC curve for determining an appropriate VDT cutoff for distinguishing between growth and no growth (as classified by the mm/year–based model). A VDT cutoff of 5.22 years has a sensitivity of 0.81 and a specificity of 0.84.

  • View in gallery

    Graph depicting relative changes in tumor volume. The ratio between the final and initial tumor volume for each patient (y axis) is related to the duration of the follow-up (x axis). Dotted lines indicate where a data point would be expected after a certain period if it had a given VDT; this allows us to visually interpret treatment statistics and growth rates along a time axis. Note that the VDT estimates are sensitive to the interval between MR imaging studies, that is, the sampling density. The vertical axis is logarithmic. + = treated tumors; ο = untreated tumors; × = patients lost to follow-up.

References

1

Artz JCTimmer FCMulder JJCremers CWGraamans K: Predictors of future growth of sporadic vestibular schwannomas obtained by history and radiologic assessment of the tumor. Eur Arch Otorhinolaryngol 266:6416462009

2

Bakkouri WEKania REGuichard JPLot GHerman PHuy PT: Conservative management of 386 cases of unilateral vestibular schwannoma: tumor growth and consequences for treatment. Clinical article. J Neurosurg 110:6626692009

3

Battaglia AMastrodimos BCueva R: Comparison of growth patterns of acoustic neuromas with and without radiosurgery. Otol Neurotol 27:7057122006

4

Beenstock M: Predicting the stability and growth of acoustic neuromas. Otol Neurotol 23:5425492002

5

Bozorg Grayeli AKalamarides MFerrary EBouccara DEl Gharem HRey A: Conservative management versus surgery for small vestibular schwannomas. Acta Otolaryngol 125:106310682005

6

Caye-Thomasen PHansen SDethloff TStangerup SEThomsen J: Sublocalization and volumetric growth pattern of intracanalicular vestibular schwannomas. Laryngoscope 116:1131 11352006

7

Gardner GRobertson JH: Hearing preservation in unilateral acoustic neuroma surgery. Ann Otol Rhinol Laryngol 97:55 661988

8

Hajioff DRaut VVWalsh RMBath APBance MLGuha A: Conservative management of vestibular schwannomas: third review of a 10-year prospective study. Clin Otolaryngol 33:2552592008

9

Herwadker AVokurka EAEvans DGRamsden RTJackson A: Size and growth rate of sporadic vestibular schwannoma: predictive value of information available at presentation. Otol Neurotol 26:86922005

10

Kanzaki JTos MSanna MMoffat DAMonsell EMBerliner KI: New and modified reporting systems from the consensus meeting on systems for reporting results in vestibular schwannoma. Otol Neurotol 24:6426492003

11

Martin TPSenthil LChavda SVWalsh RIrving RM: A protocol for the conservative management of vestibular schwannomas. Otol Neurotol 30:3813852009

12

Mick PWesterberg BDNgo RAkagami R: Growing vestibular schwannomas: what happens next?. Otol Neurotol 30:101 1042009

13

Mirz FPedersen CBFiirgaard BLundorf E: Incidence and growth pattern of vestibular schwannomas in a Danish county, 1977–98. Acta Otolaryngol Suppl 543:30332000

14

Modugno GCPirodda AFerri GGFioravanti ACalbucci FPezzi A: Small acoustic neuromas: monitoring the growth rate by MRI. Acta Neurochir (Wien) 141:106310671999

15

Moffat DAHardy DGBaguley DM: Strategy and benefits of acoustic neuroma searching. J Laryngol Otol 103:51591989

16

Mohyuddin AVokurka EAEvans DGRamsden RTJackson A: Is clinical growth index a reliable predictor of tumour growth in vestibular schwannomas?. Clin Otolaryngol Allied Sci 28:85902003

17

Møller PMyrseth EPedersen PHLarsen JLKrakenes JMoen G: Acoustic neuroma—treatment modalities. Surgery, gammaknife or observation?. Acta Otolaryngol Suppl 543:34372000

18

Myrseth EMøller PWentzel-Larsen TGoplen FLund- Johansen M: Untreated vestibular schwannomas: vertigo is a powerful predictor for health-related quality of life. Neurosurgery 59:67762006

19

Myrseth EPedersen PHMøller PLund-Johansen M: Treatment of vestibular schwannomas. Why, when and how?. Acta Neurochir (Wien) 149:6476602007

20

Nedzelski JMSchessel DAPfleiderer AKassel EERowed DW: Conservative management of acoustic neuromas. 1992. Neurosurg Clin N Am 19:207216v2008

21

Nikolopoulos TPFortnum HO'Donoghue GBaguley D: Acoustic neuroma growth: a systematic review of the evidence. Otol Neurotol 31:4784852010

22

Nutik SLBabb MJ: Determinants of tumor size and growth in vestibular schwannomas. J Neurosurg 94:9229262001

23

Ogawa KKanzaki JOgawa SYamamoto MIkeda SShiobara R: The growth rate of acoustic neuromas. Acta Otolaryngol Suppl 487:1571631991

24

Park SHGoo JMJo CH: Receiver operating characteristic (ROC) curve: practical review for radiologists. Korean J Radiol 5:11182004

25

Pinheiro JCBates DM: Mixed-Effects Models in S and SPlus New YorkSpringer Verlag2000

26

Rosenberg SI: Natural history of acoustic neuromas. Laryngoscope 110:4975082000

27

Smouha EEYoo MMohr KDavis RP: Conservative management of acoustic neuroma: a meta-analysis and proposed treatment algorithm. Laryngoscope 115:4504542005

28

Stangerup SECaye-Thomasen PTos MThomsen J: The natural history of vestibular schwannoma. Otol Neurotol 27:547 5522006

29

Strasnick BGlasscock ME IIIHaynes DMcMenomey SOMinor LB: The natural history of untreated acoustic neuromas. Laryngoscope 104:111511191994

30

Timmer FCHanssens PEvan Haren AEvan Overbeeke JJMulder JJCremers CW: Follow-up after gamma knife radiosurgery for vestibular schwannomas: volumetric and axial control rates. Laryngoscope 121:135913662011

31

Tos MStangerup SECayé-Thomasen PTos TThomsen J: What is the real incidence of vestibular schwannoma?. Arch Otolaryngol Head Neck Surg 130:2162202004

32

Tschudi DCLinder TEFisch U: Conservative management of unilateral acoustic neuromas. Am J Otol 21:7227282000

33

van de Langenberg Rde Bondt BJNelemans PJBaumert BGStokroos RJ: Follow-up assessment of vestibular schwannomas: volume quantification versus two-dimensional measurements. Neuroradiology 51:5175242009

34

Varughese JKWentzel-Larsen TVassbotn FMoen GLund- Johansen M: Analysis of vestibular schwannoma size in multiple dimensions: a comparative cohort study of different measurement techniques. Clin Otolaryngol 35:971032010

35

Winn RH: Youmans Neurological Surgery ed 5PhiladelphiaWB Saunders2003

36

Yamamoto MHagiwara SIde MJimbo MArai YOno Y: Conservative management of acoustic neurinomas: prospective study of long-term changes in tumor volume and auditory function. Minim Invasive Neurosurg 41:86921998

37

Yoshimoto Y: Systematic review of the natural history of vestibular schwannoma. J Neurosurg 103:59632005

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