Vol 80, No 1 (2021)
Original article
Published online: 2020-03-18

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Comparison of colour difference formulas to best distinguish resected areas of malignant brain tumours from their background using 5-aminolevulinic acid fluorescence

T. Szmuda12, S. Ali2, P. Słoniewski1
Pubmed: 32207850
Folia Morphol 2021;80(1):47-54.


Background: Fluorescence-guided surgery (FGS) with 5-aminolevulinic acid (5-ALA) has been proven to assist neurosurgeons to achieve a more complete brain tumour resection. However, 5-ALA-guided surgery is limited since it is often difficult to distinguish the colour difference between the resected areas of malignant brain tumours from their background. Our aim was to evaluate which colour difference formula was optimal to distinguish between malignant brain tumours and the background healthy tissue using 5-ALA fluorescence.

Materials and methods: Thirty-seven patients with a primary or secondary malignant brain tumour ingested 5-ALA before the surgery. A 400 nm light was used to excite the fluorescence. Surgical videos were recorded for all the patients and a total of 183 samples were obtained from the fluorescent areas and their respective backgrounds. Three colour differences formulas — contrast ratio (CR), CIELab (ΔE*) and CIEDE2000 — were applied to the videos and compared using hot-cold maps. Baseline demographics, the tumour’s location, the tumour’s side, and tumour’s World Health Organization (WHO) grade was also analysed for correlations relating to the fluorescence. Chi-square and the Student’s t-test were used for univariate relations. The three channels of the CIELAB colour space (L*, a* and b*) were analysed together and separately (since L* of fluorescent areas was significantly higher than the background).

Results: ΔE* resulted in good discrimination of a* and b*, and moderate but acceptable discrimination of L*. CIEDE2000 distinguished differences in a* and b*, although not in L*. The CR distinguished only L*, whereas the probability of discriminating a* and b* channels failed. Neither age, sex, tumour location, tumour size nor the WHO grade influenced the a*, b* and L* colour values (p > 0.05). Colour differences measured by ΔE* and CIEDE2000 correlated together (r = 0.99, p < 0.01), whereas CR correlated only with ΔE* (r = 0.21, p = 0.01) but not with CIEDE2000 (r = 0.07, p = 0.32).

Conclusions: ΔE* obtained the best colour discrimination between the resected areas of malignant brain tumours and the background when compared to CR and CIEDE2000. Therefore, ΔE* may be the best formula to help neurosurgeons distinguish the colour differences when operating malignant brain tumours with 5-ALA fluorescence.

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  1. Collaud S, Juzeniene A, Moan J, et al. On the selectivity of 5-aminolevulinic acid-induced protoporphyrin IX formation. Curr Med Chem Anticancer Agents. 2004; 4(3): 301–316.
  2. Eljamel MS, Mahboob SO. The effectiveness and cost-effectiveness of intraoperative imaging in high-grade glioma resection; a comparative review of intraoperative ALA, fluorescein, ultrasound and MRI. Photodiagnosis Photodyn Ther. 2016; 16: 35–43.
  3. Floeth F, Stummer W. The value of metabolic imaging in diagnosis and resection of cerebral gliomas. Nat Clin Pract Neurol. 2005; 1(2): 62–63.
  4. Gómez-Polo C, Montero J, Gómez-Polo M, et al. Comparison of the CIELlab and CIEDE 2000 color difference formulas on gingival color space. J Prosthodont. 2020; 29(5): 401–408.
  5. Gómez-Polo C, Portillo Muñoz M, Lorenzo Luengo MC, et al. Comparison of the CIELab and CIEDE2000 color difference formulas. J Prosthet Dent. 2016; 115(1): 65–70.
  6. Hadjipanayis CG, Widhalm G, Stummer W. What is the surgical benefit of utilizing 5-aminolevulinic acid for fluorescence-guided surgery of malignant gliomas? Neurosurgery. 2015; 77(5): 663–673.
  7. Haj A, Doenitz C, Schebesch KM, et al. Extent of resection in newly diagnosed glioblastoma: impact of a specialized neuro-oncology care center. Brain Sci. 2017; 8(1).
  8. Krakowiak M, Słoniewski P, Dzierżanowski J, et al. Future of the nerve fibres imaging: tractography application and development directions. Folia Morphol. 2015; 74(3): 290–294.
  9. Ling F, Paul E, Furzer R. Colour difference of subcutaneous fat and palmar fat pad in open carpal tunnel release. ANZ J Surg. 2014; 84(11): 856–860.
  10. Lu VM, Jue TR, McDonald KL, et al. The survival effect of repeat surgery at glioblastoma recurrence and its trend: a systematic review and meta-analysis. World Neurosurg. 2018; 115: 453–459.e3.
  11. Roberts DW, Valdés PA, Harris BT, et al. Coregistered fluorescence-enhanced tumor resection of malignant glioma: relationships between δ-aminolevulinic acid-induced protoporphyrin IX fluorescence, magnetic resonance imaging enhancement, and neuropathological parameters. Clinical article. J Neurosurg. 2011; 114(3): 595–603.
  12. Schwake M, Schipmann S, Müther M, et al. 5-ALA fluorescence-guided surgery in pediatric brain tumors: a systematic review. Acta Neurochir (Wien). 2019; 161(6): 1099–1108.
  13. Shonka NA, Aizenberg MR. Extent of resection in glioblastoma. J Oncol Pract. 2017; 13(10): 641–642.
  14. Stummer W, Pichlmeier U, Meinel T, et al. Fluorescence-guided surgery with 5-aminolevulinic acid for resection of malignant glioma: a randomised controlled multicentre phase III trial. Lancet Oncol. 2006; 7(5): 392–401.
  15. Stummer W, Reulen HJ, Meinel T, et al. Extent of resection and survival in glioblastoma multiforme: identification of and adjustment for bias. Neurosurgery. 2008; 62(3): 564–76; discussion 564.
  16. Su X, Huang QF, Chen HL, et al. Fluorescence-guided resection of high-grade gliomas: a systematic review and meta-analysis. Photodiagnosis Photodyn Ther. 2014; 11(4): 451–458.
  17. Suero Molina E, Schipmann S, Stummer W. Maximizing safe resections: the roles of 5-aminolevulinic acid and intraoperative MR imaging in glioma surgery-review of the literature. Neurosurg Rev. 2019; 42(2): 197–208.
  18. Szmuda T, Rogowska M, Słoniewski P, et al. Frontal aslant tract projections to the inferior frontal gyrus. Folia Morphol. 2017; 76(4): 574–581.
  19. Szmuda T, Słoniewski P, Olijewski W, et al. Colour contrasting between tissues predicts the resection in 5-aminolevulinic acid-guided surgery of malignant gliomas. J Neurooncol. 2015; 122(3): 575–584.
  20. Valdés PA, Leblond F, Kim A, et al. Quantitative fluorescence in intracranial tumor: implications for ALA-induced PpIX as an intraoperative biomarker. J Neurosurg. 2011; 115(1): 11–17.
  21. Webster MA, Webster SM, Bharadwaj S, et al. Variations in normal color vision. III. Unique hues in Indian and United States observers. J Opt Soc Am A Opt Image Sci Vis. 2002; 19(10): 1951–1962.
  22. Widhalm G, Wolfsberger S, Minchev G, et al. 5-Aminolevulinic acid is a promising marker for detection of anaplastic foci in diffusely infiltrating gliomas with nonsignificant contrast enhancement. Cancer. 2010; 116(6): 1545–1552.
  23. Yu Qi, Lin K, Liu Y, et al. Clinical uses of diffusion tensor imaging fiber tracking merged neuronavigation with lesions adjacent to corticospinal tract : a retrospective cohort study. J Korean Neurosurg Soc. 2020; 63(2): 248–260.
  24. Zhao S, Wu J, Wang C, et al. Intraoperative fluorescence-guided resection of high-grade malignant gliomas using 5-aminolevulinic acid-induced porphyrins: a systematic review and meta-analysis of prospective studies. PLoS One. 2013; 8(5): e63682.