Abstract
Background
Volumetric natural history studies specifically on large vestibular schwannomas (VSs), commonly classified as Koos grade 4, are lacking. The aim of the current study is to present the volumetric tumor evolution in sporadic Koos grade 4 VSs and possible predictors for tumor growth.
Methods
Volumetric tumor measurements and tumor evolution patterns from serial MRI studies were analyzed from selected consecutive patients with Koos grade 4 VS undergoing initial wait-and-scan management between January 2001 and July 2020. The significant volumetric threshold was defined as a change in volume of ≥10%.
Results
Among 215 tumors with a median size (IQR) of 2.7cm3 (1.8-4.2), 147 tumors (68%) demonstrated growth and 75 tumors (35%) demonstrated shrinkage during follow-up. Growth-free survival rates (95% CI) at 1, 2, 5, and 10 years were 55% (48-61), 36% (29-42), 29% (23-36), and 28% (21-34), respectively and did not significantly differ in tumors >20 mm (Chi-square=.40; P-value=.53). Four tumor evolution patterns (% of total) were observed: continued growth (60); initial growth then shrinkage (7); continued shrinkage (27); and stability (5). Good hearing (adjusted HR 2.21, 95% CI 1.48-3.30; P<.001) and peritumoral edema (adjusted HR 2.22, 95% CI 1.18-4.13; P.01) at diagnosis were significantly associated with an increased likelihood of growth.
Conclusions
Koos grade 4 VSs show a wide variety in size and growth. Due to variable growth patterns, an initial wait-and-scan strategy with short scan intervals may be an acceptable option in selected tumors, if no significant clinical symptoms of mass effect that warrant treatment are present.
Volumetric natural history studies specifically on large vestibular schwannomas (VSs), commonly classified as Koos grade 4, are lacking. The aim of the current study is to present the volumetric tumor evolution in sporadic Koos grade 4 VSs and possible predictors for tumor growth.
Methods
Volumetric tumor measurements and tumor evolution patterns from serial MRI studies were analyzed from selected consecutive patients with Koos grade 4 VS undergoing initial wait-and-scan management between January 2001 and July 2020. The significant volumetric threshold was defined as a change in volume of ≥10%.
Results
Among 215 tumors with a median size (IQR) of 2.7cm3 (1.8-4.2), 147 tumors (68%) demonstrated growth and 75 tumors (35%) demonstrated shrinkage during follow-up. Growth-free survival rates (95% CI) at 1, 2, 5, and 10 years were 55% (48-61), 36% (29-42), 29% (23-36), and 28% (21-34), respectively and did not significantly differ in tumors >20 mm (Chi-square=.40; P-value=.53). Four tumor evolution patterns (% of total) were observed: continued growth (60); initial growth then shrinkage (7); continued shrinkage (27); and stability (5). Good hearing (adjusted HR 2.21, 95% CI 1.48-3.30; P<.001) and peritumoral edema (adjusted HR 2.22, 95% CI 1.18-4.13; P.01) at diagnosis were significantly associated with an increased likelihood of growth.
Conclusions
Koos grade 4 VSs show a wide variety in size and growth. Due to variable growth patterns, an initial wait-and-scan strategy with short scan intervals may be an acceptable option in selected tumors, if no significant clinical symptoms of mass effect that warrant treatment are present.
| Original language | English |
|---|---|
| Article number | vdad144 |
| Number of pages | 10 |
| Journal | Neuro-Oncology Advances |
| Volume | 6 |
| Issue number | 1 |
| Early online date | 3 Nov 2023 |
| DOIs | |
| Publication status | Published - 2024 |
Funding
S.M.S., S.C., and P.P.H.J.L. are funded by the Highly Specialised Care & Research programme (TZO programme), (partly) financed by the Netherlands Organisation for Health Research and Development (ZonMw) [grant number: 10070012010006].
| Funders | Funder number |
|---|---|
| ZonMw : Dutch Organisation for Health Research and Development | 10070012010006 |
Keywords
- vestibular schwannoma
- volumetric growth
- observation
- Koos grade 4
- wait-and-scan