HSC Section 8_April 2017

Wanna et al

comparable to what can be achieved surgically. In a recent multicenter study of 132 patients, 18%with Jackson-Glasscock grade 4 tumors, Gamma Knife achieved tumor control in 93% of cases. 28 A meta-analysis evaluating 869 patients with glomus jugu- lare also lent credence to the utility of radiosurgery for JP. 29 Patients were divided in 4 groups: gross total resection, subtotal resection, subtotal resection followed by radio- surgery, and radiosurgery alone. Although differences in tumor size between the groups were not controlled, the authors found that the radiosurgery alone group had the best rates of tumor control and that gross total resection did not appear to offer significantly improved tumor control versus subtotal resection or subtotal resec- tion followed by radiosurgery. Also noteworthy was the finding that patients who un- derwent gross total resection had significantly worse post-treatment cranial neuropathies when compared with patients undergoing radiosurgery. Although the optimal radiation regimen for JP tumors is not yet standardized, 30 the use of radio- therapy appears to be a valuable addition to the available therapeutic options. Observation The natural history of JP tumors is not well established, but evaluations of the wait- and-scan observation strategy have revealed that intervention may not always be necessary. In 1992, Van der Mey and colleagues 31 were among the first groups to pro- vide evidence to this effect. In a subsequent report on 11 patients from the same cen- ter, it was revealed that 55% of tumors demonstrated radiologic progression, with a median growth rate of 0.8 mm per year. 8 A complicating factor in these series is the possibility that some of the observed tumors were glomus tympanicum rather than jugulare. However, other reports specific to glomus jugulare have since validated these findings. Recently, Prasad and colleagues 32 analyzed the outcomes of 23 Fisch type C and D tumors that were observed for a minimum of 3 years. They demonstrated that 65% of tumors remained stable or even regressed in size over a median follow-up of 61 months. To date this remains one of the largest series on the natural history of JP. The relative paucity of data on tumor observation can be attributed to the rarity of the tumor and historical trends toward intervention after diagnosis. However, although many tumors will potentially grow if left untreated, 7 the slow rate of growth for most tumors and potential complications of intervention make a wait-and-scan policy a worthy consideration after diagnosis.

THE OTOLOGY GROUP OF VANDERBILT EXPERIENCE

The Otology Group of Vanderbilt has been fortunate to be a tertiary referral center for JP tumors over the course of its existence. During this time, the management algo- rithm for these tumors has evolved to include tumor observation and planned subtotal resection, as well as gross total resection and radiation. A compilation of the authors’ experience is described.

Surgery Gross total resection

The Otology Group of Vanderbilt reported previously on 202 jugular paragangliomas treated over a period of 35 years. Total resection was achieved in 90% of cases, with a tumor recurrence rate of 6%. Preoperative cranial neuropathies were seen in 47% of cases, most commonly IX, X, and XII. New postoperative cranial nerve injuries were seen in 60% of patients, most commonly IX followed by XI, X, and XII. Nearly 12% (11.8%) of patients experienced disease recurrence requiring revision surgery. Total resection was possible in 93% of the cases involving recurrence, and 95% of

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