Introduction
Methods
Systematic review
Search strategy
Inclusion criteria
Year | Criteria | Patients (tumors) | NF 2 | Prior microsurgery | Follow-up (months) Mean (median; range) | Male: Female | Age (years) Mean (median; range) | |
---|---|---|---|---|---|---|---|---|
Series including patients with prior surgery | ||||||||
Inoue et al | 2005 | > 3 cm | 18 (20) | 2/20 | 11/20 | > 72 | 6:12 | 33–81 |
Chung et al | 2010 | > 3 cm | 21 | 0/21 | 14/21 | 66 (53; 12–155) | 9:12 | – |
Yang et al | 2011 | > 3cm median 9 mL | 65 | 0/65 | 17/65 | − (36; 1–146) | 37:28 | 51 (19–89) |
Zeiler et al | 2012 | 3–4 cm | 28 | 2/28 | 12/28 | 34.5 (-; 6–99) | 13:12 | − (56; 26–85) |
Williams et al | 2013 | > 3 cm | 24 | 0/24 | 9/24 | − (48.5;7–211) | 16:8 | 61.5 (62; 32–87) |
Iorio-Morin et al | 2016 | > 4 mL | 68 | 0/68 | 13/68 | − (47; 6–125) | 1.4:1 | − (58; 16–85) |
Lefranc et al | 2018 | Koos IV | 86 | 0/86 | 14/86 | 74.4 (-; 36–192) | 0.4:0.6 | 54.6 (23–84) |
Huang et al | 2018 | > 3 cm & > 10 Ml | 35 | 0/35 | 9/35 | − (48; 6–156) | 20:15 | 49.7 (-; 21–74) |
Watanabe et al | 2019 | > 8 cc | 19 | 0/19 | 9/19 | − (98; 49–204) | 8:11 | − (71;29–91) |
Stastna et al | 2020 | > 4 mL | 73 | 0/73 | 4/73 | − (66; 25.2–177.6) | 29:44 | − (61;23–84) |
Mezey et al | 2020 | > 10 mL | 103 | 0/103 | 18/103 | 74.4(-; 1.2–226.8) | 46:57 | 61.5(-;20–88) |
Hasegawa et al | 2021 | Koos IV | 203 | 0/203 | 153/203 | − (152; 12–277) | 86:117 | − (58;13–83) |
Umekawa et al | 2022 | Koos IV | 50 | 0/50 | 22/50 | 63(63;24–178) | – | 57(-;28–86) |
Series excluding patients with prior surgery | ||||||||
Van de Langenberg | 2011 | > 6 mL, BS indent | 33 | 0/33 | 0/33 | − (30; 12–72) | 15:18 | 54.8 (30–83) |
Milligan et al | 2012 | > 2.5 cm | 22 | 0/22 | 0/22 | − (66; 26–121) | 13:9 | 61 ± 15 |
Bailo et al | 2016 | > 25 mm | 59 | 0/59 | 0/59 | 74.9 (79;36–164) | 21:38 | 63.8 (-; 24–85) |
Huo et al | 2020 | > 3.5 mL | 19 | 0/19 | 0/19 | 28.7 | 10:9 | 57(-;38–73) |
Ogino et al | 2020 | > 5 mL | 170 | 0/170 | 0/170 | − (61.2; 4.8–296.4) | 93:77 | − (61;21.1–39) |
Pikis et al | 2022 | median 8.7 mL | 627 | 0/627 | 0/627 | Median 36 | 283:344 | Median 54 (-; –-) |
Dose (Gy) Mean (median; range) | TV mean (median; range) | Radiological: Overall control; stable volume; decrease | Further surgery, SRS or shunt (time point if given) | |
---|---|---|---|---|
Series including patients with prior surgery | ||||
Inoue et al | 10 (4/20); 11 (2/20); 12 (14/20) | 15.2 (-; 5.3–28.5) | 14/15; 6/15; 8/15 | Resection: 1/15 resection (2 years after) |
Chung et al | 11.9 (12; 11–14) | 17.3 (17.1; 12.7–25.2) | 18/21; 17/21; 1/21 | Resection: 2/21 (8 and 72 months after) Shunt: 2/21 (7, 17 months after) Omaya: 1/21 (11 months after) |
Yang et al | − (12;11–15) | 9 (-;5–22) | 58/65; 18/65; 38/65 | Resection: 7/65 (2 at 6 months and 5 at 2.5 years) Shunt: 3/65 |
Zeiler et al | 12.5 (-;12–13) | 9.7 (-; 6.9–10.6) | 23/25; 9/25; 14/25 | Resection: 1/25 Shunt: 3/25 (5, 11 and 24 months after) |
Williams et al | − (11; 8–20) | − (9.5; 3.1–24.7) | 16/18; 6/18; 10/18 | Resection: 3/24 (at a mean of 46 months (6–102) after) SRS: 3/24 Shunt: 2/24 |
Iorio-Morin et al | 12 (-;11–13) | -(7.4; 4–19) | 64/68 | Resection: 3/68 (4, 13, 36 months after) Shunt: 3/68 |
Lefranc et al | 11(-; 10–12) | 4.46 (-; 1.38–8.69) | 78/86; 26/86; 60/86 | Resection: 7/86 Shunt: 1/86 |
Huang et al | − (11;10–12) | − (14.8;10.3–24.5) | 30/35; 5/35; 25/35 | Resection: 5/35 (9 months-6 years after) Cysto-peritoneal shunt: 2/35 |
Watanabe et al | − (12, 10–12) minimum − (12;10–12) | − (11.5; 8–30.6) | 15/19; 2/19; 13/19 | Resection: 3/19 (2 surgeries and 1 combined) Shunt: 3/19 |
Stastna | − (12;11.5–12) | − (6.5; 4–14.2) | 64/73; 3/73; 61/73 | Resection: 6/73 SRS: 1/73 VP shunt: 4/73 Cystic puncture plus SRS: 1/73 |
Mezey et al | 12.5(-;12–18) | 12.4(-;7.8–21.5) | 81/103; 60/103; 21/103 | Resection:17/103 Shunt: 13/103 Ventriculostomy: 2/103 |
Hasegawa et al | − (12;9–13) | − (6.7;2–28.9) | 168/203; 34/203; 134/203 | Resection: 35/203 SRS: 6/203 VP shunt: 6/203 |
Umekawa et al | 12(-;12–14) | 5.3(-;4.1–6.8) | 46/50 | Resection: 2/50 Shunt: 2/50 |
Series excluding patients with prior surgery | ||||
Van de Langenberg | 12.6 (-; 12.5–13) | − (8.8; 6.1–17.7) | 29/33; 7/33; 22/33 | Resection: 5/33 (combined) SRS: 2/33 s Shunt: 2/33 (6 and 12 months after) |
Milligan et al | − (12; 12–14) | − (9.4; 5.3–19.1) | 18/22; 0/22; 18/22 | Resection: 2/22 (median 32 (14–90) after) Shunt: 2/22 |
Bailo et al | − (13;11–15) | 6.0 (5.6; 2.5–14.9) 25–30 mm vs > 30 | 54/59 | Resection: 1/59 (48 months after) Shunt: 10/59 |
Huo et al | − (12.5;12–13.5) | − (4.06;3.5–6.99) | 18/19 | Resection: 1/19 Shunt: 3/19 |
Ogino et al | − (12.5; 10.5–22) | − (7.4;5–20) | Actuarial rates (not numbers) | MS:7/170 SRS:1/170 Shunt:8/170 after a median 7.2 (1.3–32.7) |
Pikis et al | Median 12 | Median 8.7 | 590/627; 299/627; 291/627 | Resection:18/627 SRS and rhizotomy:1/627 SRS: 6/627 Cyst aspiration:1/627 Shunt: 7/627 |
Exclusion criteria
Outcome measures
Establishment of evidence based guidelines
Results
Tumor control
Tumor control (stability or decrease)
Tumor stability
Tumor reduction
Transient-tumor-expansion (pseudoprogression)
Post-SRS procedures
Salvage resection
Post-SRS shunting for hydrocephalus
Further salvage SRS
Cranial nerve toxicities and hearing preservation
Worsened facial palsy (preexisting) | New facial palsy /hemifacial spasm | Hearing preservation | Disturbance in balance | Other CN new deficit | |
---|---|---|---|---|---|
Series including patients with prior surgery | |||||
Inoue et al | 0/9 | 0/9 | 4/5 up to 13 years | – | 0/20 |
Chung et al | 0/21 | 0/21 | – | 5/21 | 1 case of malignant transformation 1 case of cerebellar infarction |
Yang et al | – | 1/65 HB II at 6 months | 18/22 | – | 4/65 sensory dysfunction |
Zeiler et al | – | 1/25 worsening hemifacial spasm | – | 7/28 (temporary) | 2/25 sensory dysfunction |
Williams et al | 2/24 | 6/24 worsening of preexisting | – | – | 3/11 worsened sensory dysfunction |
Iorio-Morin et al | – | 0/68 | – | 8/68 | 4/68 sensory dysfunction |
Lefranc et al | – | 0/86 | 25/38 | – | – |
Huang et al | 0/7 | 0/28 | 1/3 | – | – |
Watanabe et al | – | 0/7 | 0/6 | – | 2/19 transient trigeminal neuropathy |
Stastna | – | 3/73 (stated as worsened of preexistent or new) | 11/27 | – | 6/73 facial paresthesias 5/73 trigeminal neuralgia |
Mezey et al | 3/103 | 3/103 facial palsy 5/103 hemifacial spasm | – | 12/103 | 6/103 facial paresthesias 3/103 trigeminal neuralgia |
Hasegawa et al | – | 0/203 | 11/28 | – | 11/203 trigeminal neuralgia 2 tumor-related deaths (one malignant transformation) |
Umekawa et al | – | 2/50 | 18/42 | 0/50 | 3/50 |
Series excluding patients with prior surgery | |||||
Van de Langenberg et al | – | 2/33 transient facial palsy (HB II) | 7/12 | 1/33 | 3/33 facial paresthesias |
Milligan et al | – | 3/22 facial palsy 1/22 hemifacial spasm | 3/10 | – | 3/22 trigeminal neuralgia |
Bailo et al | – | 3/59 | 1/59 transient worsening at 6 months | 5/16 | 4/59 new/worsened trigeminal deficit |
Huo et al | – | – | – | – | – |
Ogino et al | – | 7/170 | 24/42 | 10/170 | 15/170 |
Pikis et al | – | 19/627 | 116/205 | 9/81 | 48/627 |
All series together | P value | Series including patients with prior surgery | P value | Series not including patients with prior surgery | P value | |
---|---|---|---|---|---|---|
Tumor control | ||||||
Tumor control (stability or decrease) | 89% (86.1–91.9%) | < 0.001 | 87.7% (84.6–90.9%) | < 0.001 | 93.7% (91.9–95.4%) | < 0.001 |
Tumor stability | 29.7% (17.7–41.7%) | < 0.001 | 31.2% (18.7–43.8%) | < 0.001 | 23.8% | 0.16 |
Tumor reduction | 57% (44.4–69.6%) | < 0.001 | 55.1% (37.8–72.3%) | < 0.001 | 64% (40.9–87%) | < 0.001 |
Further intervention | ||||||
Further microsurgery | 7.7% (5.3–10.1%) | < 0.001 | 9.6% (6.5–12.6%) | < 0.001 | 3.3% (1.7–4.9%) | < 0.001 |
Further shunt | 5% (3.2–6.8%) | < 0.001 | 4.7% (2.7–6.6%) | < 0.001 | 6.4% (2–10.7%) | < 0.001 |
Further SRS | 10% (0.5–1.4%) | < 0.001 | 1% (0.03–1.7) | 0.004 | 0.9% (0.2–1.5%) | 0.007 |
Cranial nerve outcomes | ||||||
Facial nerve palsy | 2.3% (1.2–3.4%) | < 0.001 | 1.3% (0.3–2.3%) | 0.01 | 3.4% (2.2–4.6%) | < 0.001 |
Hearing preservation | 37.9% (21.6–54.3%) | < 0.001 | 34.2% (24.3–44.1%) | < 0.001 | 40.4% (7.0–73.9%) | 0.01 |
Discussion
Summary (level C evidence) | |
---|---|
Tumor control | |
Lower | Previous resection |
Volumes exceeding 10 mL | |
Large Koos IV | |
Progression of residual VS prior to SRS | |
Middle cerebellar peduncle compression | |
Higher | Marginal dose of at least 12 Gy |
Smaller volumes | |
Facial nerve preservation (better) | Volume less than 10 mL |
Non-cystic VS | |
Marginal dose lower than 13 Gy | |
Hearing preservation (better) | Age < 60 years |
Gardner-Robertson 1 at treatment | |
Cochlear dose less than 4 Gy | |
Recommendations | |
Ideal candidates: Patients • Without disabling symptoms, • With serviceable hearing, • With comorbidities that make resection riskier • Those who wish to avoid a resection, • With no symptomatic mass effect | |
Marginal dose prescription: Between 11 and 13 Gy |