FLEX January 2024

10976817, 2021, 2, Downloaded from https://aao-hnsfjournals.onlinelibrary.wiley.com/doi/10.1177/0194599820938660 by UNIVERSITY OF MINNESOTA 170 WILSON LIBRARY, Wiley Online Library on [24/09/2023]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creative Commons License

Manzoor et al

395

Seventeen patients (41%) underwent postsurgical therapy, including radiation in 13 patients (77%), salvage surgery in 2 patients (12%), and salvage surgery followed by radiation in 2 patients (12%). Radiation was planned preoperatively to be delivered in the adjuvant setting in 4 cases, although most radiation was in the salvage setting (n = 11). Of patients treated with radiation, 12 (80%) were treated with SRS and 3 (20%) were treated with IMRT ( Table 2 ). The median SRS dose was 25 Gy (IQR, 18-25 Gy) delivered in a median of five fractions (IQR, 2-5 fractions) with a median biologic equivalent dose (BED) of 68 Gy (IQR, 67-79 Gy). The median IMRT dose was 45 Gy (IQR, 45-54 Gy) delivered in a median of 25 fractions (IQR, 25-27 fractions) with a median BED of 72 Gy (IQR 72-90 Gy). The median time from surgery to salvage therapy was 49 months (IQR, 8-23 months; Figure 5 ). Binary logistic regression did not demonstrate any significant clinical, dis ease, or surgical predictors of the need for radiation after GTRor STR ( Table 4 ). Cox proportional hazards regression models did not reveal any significant association between single variable predictors and post-STR salvage-free survival ( Figure5 ). All patients who received combined modality treatment (surgery plus adjuvant or salvage therapy) had controlled disease at the time of last follow-up; therefore, no analyses were done to analyze for predictors of adjuvant/salvage ther apy success. STR and Cranial Nerve Outcomes Single predictor binary logistic regression did not find any statistically significant associations between STR type and postoperative cranial neuropathy. Type 1 STR was not asso ciated with increased risk of new-onset cranial neuropathy compared with type 2, type 3, or type 2 and 3 collectively (OR 1.06, 95% CI 0.16-6.94, P = .95). Lower Cranial Nerve Outcomes At presentation, the most common LCN involved was CN XII (n = 11, 27%), followed by CN X (n = 10, 24%; Table 5 ). New postoperative LCN was uncommon, involving CN

Table2. Details of Microsurgical and Radiation Treatment.

Median/ incidence

IQR/ frequency

Variable

Grouping GTR with no preop CN deficits GTR with preop CN deficits STR with no preop CN deficits STR with preop CN deficits

6 3

15%

7%

22 10

54% 24%

Indications for surgery Tumor growth

7

17% 39% 20% 39% 51%

Cranial nerve involvement

16

Other

8

Patient preference

16 21

Presurgical embolization

Type of STR Type 1: Extended STR with LC preservation

19

59%

Type 2: Posterior fossa decompression

5

16%

Type 3: Limited middle ear STR

8

25%

Neurotology procedure ITF with FN transposition ITF with fallopian bridge Tympanomastoidectomy

4

10% 39% 26%

16 11

TEES

3 7

7%

Posterior fossa craniotomy

17%

Radiotherapy technique Stereotactic radiosurgery

12

80% 20%

Intensity-modulated radiotherapy Radiation dose Stereotactic radiosurgery dose (Gy) Biologically effective dose (Gy) Intensity-modulated radiotherapy dose (Gy) Biologically effective dose (Gy)

3

25 68 45

18-25 67-79 45-54

72

72-90

Abbreviations: CN, cranial nerve; FN, facial nerve; IQR, interquartile range; ITF, infratemporal fossa; GTR, gross total resection; LCN, lower cranial neu ropathy; PGL, paraganglioma; STR, subtotal resection; TEES, transcanal endoscopic approach.

Table3. Clinical and Radiographic Differences in STR Cohorts.

Type 1 STR

Type 2/3 STR

P

Variable

Median/incidence

IQRor %

Median/incidence

IQRor%

Age (years)

41

35-60

56

34-66

.37 .21

Glasscock-Jackson Staging

I-II

3 5

16% 26% 58%

6 2 5

46% 15% 38%

III IV

11 12

Preoperative tumor volume (cm 3 ) Postoperative tumor volume (cm 3 )

6.7-27.7 2.6-16.6

5.7 5.4

3.4-27.1 2.6-8.2

.18 .88 .16

4.2

EOR (%)

47.5

25-69

29

5-46.7

Abbreviations: EOR, extent of resection; IQR, interquartile range; STR, subtotal resection.