Volumetric growth rate of incidental asymptomatic meningiomas: a single-center prospective cohort study

Volumetric growth rate of incidentally found meningiomas on immunotherapy

PURPOSE

The expression of PD-L1 in high-grade meningiomas made it a potential target for immunotherapy research in refractory cases. Several prospective studies in this field are still on going. We sought to retrospectively investigate the effects of check-point inhibitors (CI) on meningiomas that had been naïve to either surgical or radiation approaches by following incidental meningiomas found during treatment with CI for various primary metastatic cancers.

METHODS

We used the NYU Perlmutter Cancer Center Data Hub to find patients treated by CI for various cancers, who also had serial computerized-tomography (CT) or magnetic-resonance imaging (MRI) reports of intracranial meningiomas. Meningioma volumetric measurements were compared between the beginning and end of the CI treatment period. Patients treated with chemotherapy during this period were excluded.

RESULTS

Twenty-five patients were included in our study, of which 14 (56%) were on CI for melanoma, 5 (20%) for non-small-cell lung cancer and others. CI therapies included nivolumab (n = 15, 60%), ipilimumab (n = 11, 44%) and pembrolizumab (n = 9, %36), while 9 (36%) were on ipilimumab/nivolumab combination. We did not find any significant difference between tumor volumes before and after treatment with CI (1.31 ± 0.46 vs. 1.34 ± 0.46, p=0.8, respectively). Among patients beyond 1 year of follow-up (n = 13), annual growth was 0.011 ± 0.011 cm3/year. Five patients showed minor volume reduction of 0.12 ± 0.10 cm3 (21 ± 6% from baseline). We did not find significant predictors of tumor volume reduction.

CONCLUSION

Check-point inhibitors may impact the natural history of meningiomas. Additional research is needed to define potential clinical indications and treatment goals.

Evaluation of four tumour growth models to describe the natural history of meningiomas

BACKGROUND

The incidence of newly diagnosed meningiomas, particularly those diagnosed incidentally, is continually increasing. The indication for treatment is empirical because, despite numerous studies, the natural history of these tumours remains difficult to describe and predict.

METHODS

This retrospective single-centre study included 294 consecutive patients with 333 meningiomas who underwent three or more brain imaging scans. Linear, exponential, power, and Gompertz models were constructed to derive volume-time curves, by using a mixed-effect approach. The most accurate model was used to analyse tumour growth and predictors of rapid growth.

FINDINGS

The Gompertz model provided the best results. Hierarchical clustering at the time of diagnosis and at the end of follow-up revealed at least three distinct groups, which can be described as pseudoexponential, linear, and slowing growth with respect to their parameters. Younger patients and smaller tumours were more frequent in the pseudo-exponential clusters. We found that the more "aggressive" the cluster, the higher the proportion of patients with grade II meningiomas and who have had a cranial radiotherapy. Over a mean observation period of 56.5 months, 21% of the tumours moved to a cluster with a lower growth rate, consistent with the Gompertz's law.

INTERPRETATION

Meningiomas exhibit multiple growth phases, as described by the Gompertz model. The management of meningiomas should be discussed according to the growth phase, comorbidities, tumour location, size, and growth rate. Further research is needed to evaluate the associations between radiomics features and the growth phases of meningiomas.

FUNDING

No funding.

Growth dynamics of incidental meningiomas: A prospective long-term follow-up study

Background

There is no consensus on the management of incidental meningiomas. The literature on long-term growth dynamics is sparse and the natural history of these tumors remains to be illuminated.

Methods

We prospectively assessed long-term tumor growth dynamics and survival rates during active monitoring of 62 patients (45 female, mean age 63.9 years) harboring 68 tumors. Clinical and radiological data were obtained every 6 months for 2 years, annually until 5 years, then every second year.

Results

The natural progression of incidental meningiomas during 12 years of monitoring was growth (P < .001). However, mean growth decelerated at 1.5 years and became insignificant after 8 years. Self-limiting growth patterns were seen in 43 (63.2%) tumors, non-decelerating in 20 (29.4%) and 5 (7.4%) were inconclusive due to  ≤ 2 measurements. Decelerating growth persisted once established. Within 5 years, 38 (97.4%) of 39 interventions were initiated. None developed symptoms prior to intervention. Large tumors (P < .001) involving venous sinuses (P = .039) grew most aggressively. Since inclusion 19 (30.6%) patients have died of unrelated causes and 2 (3%) from grade 2 meningiomas.

Conclusion

Active monitoring seems a safe and appropriate first-line management of incidental meningiomas. Intervention was avoided in  > 40% with indolent tumors in this cohort. Treatment was not compromised by tumor growth. Clinical follow-up seems sufficient beyond 5 years if self-limiting growth is established. Steady or accelerating growth warrant monitoring until they reach a stable state or intervention is initiated.

Volumetric Growth and Growth Curve Analysis of Residual Intracranial Meningioma

BACKGROUND

After meningioma surgery, approximately 1 in 3 patients will have residual tumor that requires ongoing imaging surveillance. The precise volumetric growth rates of these tumors are unknown.

OBJECTIVE

To identify the volumetric growth rates of residual meningioma, growth trajectory, and factors associated with progression.

METHODS

Patients with residual meningioma identified at a tertiary neurosurgery center between 2004 and 2020 were retrospectively reviewed. Tumor volume was measured using manual segmentation, after surgery and at every follow-up MRI scan. Growth rates were ascertained using a linear mixed-effects model and nonlinear regression analysis of growth trajectories. Progression was defined according to the Response Assessment in Neuro-Oncology (RANO) criteria (40% volume increase).

RESULTS

There were 236 patients with residual meningioma. One hundred and thirty-two patients (56.0%) progressed according to the RANO criteria, with 86 patients being conservatively managed (65.2%) after progression. Thirteen patients (5.5%) developed clinical progression. Over a median follow-up of 5.3 years (interquartile range, 3.5-8.6 years), the absolute growth rate was 0.11 cm 3 per year and the relative growth rate 4.3% per year. Factors associated with residual meningioma progression in multivariable Cox regression analysis were skull base location (hazard ratio [HR] 1.60, 95% CI 1.02-2.50) and increasing Ki-67 index (HR 3.43, 95% CI 1.19-9.90). Most meningioma exhibited exponential and logistic growth patterns (median R 2 value 0.84, 95% CI 0.60-0.90).

CONCLUSION

Absolute and relative growth rates of residual meningioma are low, but most meet the RANO criteria for progression. Location and Ki-67 index can be used to stratify adjuvant treatment and surveillance paradigms.

Growth risk classification and typical growth speed of convexity, parasagittal, and falx meningiomas: a retrospective cohort study

OBJECTIVE

Meningiomas are the most common primary intracranial tumors, and their clinical and biological characteristics vary by location. Convexity, parasagittal, and falx meningiomas account for approximately 50%-65% of intracranial meningiomas. Focusing only on these locations, the aim of this study was to determine the typical speed of tumor growth, to assess the growth risk, and to show the possible tumor volume that many lesions can reach after 5 years.

METHODS

Patients with radiologically suspected convexity, parasagittal, or falx meningiomas at the authors' institution were studied retrospectively. The relative growth rate (RGR) and annual volume change (AVC) were calculated from MRI at more than 3-month intervals. Based on sex, age, and signal intensity on T2-weighted MRI, the cases were classified into three groups: extremely high-growth, high-growth, and low-growth groups.

RESULTS

The data of 313 cases were analyzed. The median RGR and AVC for this entire cohort were 6.1% (interquartile range [IQR] 2.4%-16.0%) and 0.20 (IQR 0.04-1.18) cm3/year, respectively. There were significant differences in sex (p = 0.018) and T2-weighted MRI signal intensity (p < 0.001) for RGR, and T2-weighted MRI signal intensity (p < 0.001), tumor location (p = 0.025), and initial tumor volume (p < 0.001) for AVC. The median RGR and AVC were 17.5% (IQR 8.3%-44.1%) and 1.05 (IQR 0.18-3.53) cm3/year, 8.2% (IQR 2.9%-18.6%) and 0.33 (IQR 0.06-1.66) cm3/year, and 3.4% (IQR 1.2%-5.8%) and 0.04 (IQR 0.02-0.21) cm3/year for the extremely high-growth, high-growth, and low-growth groups, respectively, with a significant difference among the groups (p < 0.001). A 2.24-times, or 5.24 cm3, increase in tumor volume over 5 years was typical in the extremely high-growth group, whereas the low-growth group showed little change in tumor volume even over a 5-year follow-up period.

CONCLUSIONS

For the first time, the typical speed of tumor growth was calculated, focusing only on patients with convexity, parasagittal, and falx meningiomas. In addition, the possible tumor volume that many lesions in these locations can reach after 5 years was shown based on objective indicators. These results may allow clinicians to easily detect lesions that require frequent follow-up or early treatment by determining whether they deviate from the typical range of the growth rate, similar to a growth chart for children.

Natural history and volumetric analysis of meningiomas in neurofibromatosis type 2

OBJECTIVE

The objective of this paper was to describe the volumetric natural history of meningiomas in patients with neurofibromatosis type 2 (NF2).

METHODS

The authors performed a retrospective descriptive study by reviewing NF2 patients with meningiomas at their institution between 2000 and 2019. Demographic data were collected from the electronic medical records. Tumor volume was collected using volumetric segmentation software. Imaging characteristics including peritumoral brain edema (PTBE) and tumor calcification were collected for each patient from their first to most recent MRI at the authors’ institution. An increase of 15% or more per year from original tumor size was used as the cutoff to define growth.

RESULTS

A total of 137 meningiomas from 48 patients were included in the analysis. The average number of tumors per person was 2.9. Ninety-nine (72.3%) tumors were in female patients. The median length of follow-up from first imaging to last imaging was 32 months (IQR 10.9, 68.3 months). Most tumors were located in the cerebral convexity (24.8%), followed by the falcine region (18.2%) and spine (10.2%). The median tumor growth was 0.12 cm3/yr (IQR 0.03, 0.52 cm3/yr). At the time of first imaging, 21.9% of tumors had calcifications, while 13.9% of meningiomas had PTBE. Of 137 tumors, 52 showed growth. Characteristics associated with tumor growth included PTBE (OR 9.12, 95% CI 1.48–56.4), tumor volume (per cm3) at first imaging (OR 0.91, 95% CI 0.83–0.99), and 10-year increased age at first imaging (OR 0.57, 95% CI 0.43–0.74). PTBE had the shortest median time to growth at 9.2 months.

CONCLUSIONS

Although the majority of NF2-associated meningiomas do not grow in the short term, a wide range of growth patterns can be seen. Younger age at first imaging and presence of PTBE are associated with growth. Patients with these characteristics likely benefit from closer follow-up.