Table 5.
Literature Review of Principal iLGG Surgical Studies
| Authors | No. of Cases | Comparison With Symptomatic Group | Histological Diagnosis | Preoperative Tumoral Volume (cm3) | EOR | PFS | Dead Patients | MPFS | Postoperative Deficits | Second Surgery | Median FU (yr) | Risk Factors From Comparative Analysis With Symptomatic Group |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pallud et al 20108 |
47 | Yes 47 incidental on 1249 (3.76% of cases) |
Astrocytoma 7 Oligodendroglioma 31 Oligoastrocytoma 9 |
17.2 | GTR = 14 STR = 12 PR = 1 Biopsy = 16 |
68 mo (8-152) | 4 | NA | NA | NA | 6.6 | iLGGs have a female predominance (P = .05), smaller initial tumor volumes (P < .001), lower incidence of contrast enhancement (P = .009), and are more likely to undergo gross total surgical removal (P < .001) |
| Potts et al 20129 | 35 | Yes 35 incidental on 197 (17.76% of cases) |
Astrocytoma 16 Oligodendroglioma 12 Oligoastrocytoma 6 Ganglioglioma 1 |
20.2 | GTR = 21 STR = 14 |
29 (5-70) | 1 | n/a | 3 recorded operative morbidities among patients with incidental lesions (8.6%) | 6 | 5.1 | iLGGs have a significantly lower preoperative tumor volumes than sLGGs(20.2 vs 53.9 cm3, P = .001), less likely to have tumors in eloquent locations (14.3% vs 61.9%, P = .001), and a higher prevalence of females (57.1% vs 36%, P = .02). In addition, patients with iLGGs were also more likely to undergo gross total resection (60% vs 31.5%, P = .001) and had improved overall survival on Kaplan-Meier analysis (P = .039) |
| Duffau et al 201211 | 11 | No | Glioma WHO grade II | 32.6 | sTR = 3 GTR = 4 STR = 14 |
64 28-73 |
0 | NA | Transient = 7 Permanent = 0 |
NA | 1.7 | NA |
| Zhang et al 201414 |
23 | Yes 23 incidental on 196 (11.73% of cases) |
Astrocytoma 6 Oligodendroglioma 6 Oligoastrocytoma 11 |
23.8 | GTR = 21 STR = 0 PR = 2 |
85 34-108 |
5 | 22 95.6% |
NA | 6/23 | 9.3 | iLGGs had higher preoperative KPS (P < .001), smaller tumor volume (P = .014), lower frequency of eloquent areas involvement (P < .001) and higher rate of complete resection (P = .037) comparing to those with sLGGs |
| Lima et al 201618 | 19 | No | Glioma WHO grade II | 51.4 | sTR = 5 GTR = 4 STR = 7 PR = 2 |
28 3-79 |
0 | NA | Transient = 7 Permanent = 0 |
NA | 5.1 | NA |
| Opoku-Darko et al 201820 |
34 | No | Astrocytoma IDH1/2 mutated 12 Oligodendroglioma 16 Astrocytoma IDH wild-type 3 Others 3 |
36.8 | EOR 100%= 8 EOR75-99%= 11 EOR <75% = 15 |
Transient = 1 Permanent = 1 |
5.1 | NA | ||||
| Ius et al 202022 | 34 | Yes 34/223 10.2% |
Astrocytoma IDH1/2 mutated 28 Oligodendroglioma 14 Astrocytoma IDH wild-type 4 |
16 cm3 | EOR 100% = 34 | 4/34 78-mo 38-98 |
0 | NA | Transient = 3 Permanent = 0 |
4 | 5.8 | iLGGs had higher preoperative Karnofsky performance scale (KPS) (P = .003), smaller tumor volume (P = .0001), lower frequency of eloquent areas involvement (P = .0001), and higher rate of complete resection (P = .0001) compared to those with sLGGs |
| Gogos et al 20207 | 113 | Yes 113/657 17.2% |
Astrocytoma IDH1/2 mutated 26 Oligodendroglioma 48 Astrocytoma IDH wild-type 11 |
22.5% | EOR 100% = 113 | NA | 11 | Transient = 25 Permanent = 5 |
6.6 | Complete resection of the FLAIR abnormality was achieved in 57% of patients with incidental lesions but only 23.8% of symptomatic lesions (P < .001), and the residual volumes were smaller for iLGGs (2.9 vs 13.5 cm3, P < .0001). Overall survival was significantly longer for patients with incidental tumors (median survival not reached for patients with iLGGs vs 14.6 yr for those with sLGGs, P < .0001) | ||
| Boetto et al 20206 | 101 | No | Astrocytoma IDH1/2 mutated 28 Oligodendroglioma 36 IDH wild-type 13 Others 5 |
16 | Supratotal resection in all cases | NA | NA | NA | NA | 3.2 | NA | |
| Present study 2021 | 267 | No | Molecular data in 232 cases Astrocytoma IDH1/2 mutated 83 Oligodendroglioma 115 IDH wild-type 34 |
26 | EOR 100% = 135 Supratotal resection = 24 EOR <100% = 99 |
NA | 47/70 (67.15%) | Permanent deficits were detected in 3.01% of cases 6 mo after surgery | 16/70 (22.85%) | 7.3 | NA |
Abbreviations: EOR, extent of resection; FU, follow-up; GTR, gross total resection; iLGGs, incidental low-grade gliomas; MPFS, malignant progression-free survival; NA, not applicable; PFS, progression-free survival; PR, partial resection; sLGGs, symptomatic low-grade gliomas; STR, subtotal resection; sTR, supratotal resection.