Review Article

Raman Spectroscopy for Clinical Oncology

Table 2

A summary of the recent in vivo applications of Raman spectroscopy for cancer diagnosis discussed in the present paper. Type of cancer, number of patients (and/or number of spectra if reported), data analysis methods, and diagnostic outcome are presented for each reference. The studies utilizing the rat model for brain cancer are presented in this table, although these were not human clinical trials, for comparison with the state of current technology.

Type of cancerNumber of patientsData analysisOutcomeReference

Breast9 (31 spectra acquired)Fitting of spectra based on linear combination model coefficients from ex vivo tissue samplesSensitivity: 100%
Specificity: 100%
Accuracy: 93.3%
[31]

Skin19 (21 tissue sites with total of 42 spectra)Nonlinear maximum representation and discrimination (MRDF) and Sparse linear multinomial logistic regression (SMLR)Sensitivity: 100%
Specificity: 91%
Accuracy: 95%
[45]

BrainRat model (C6 glioma cells for glioblastoma model)Prinicipal component analysis (PCA), Ward’s Clustering algorithm and square Euclidian distance measuresIn vivo classification based on ex vivo model with 100% accuracy[51]

BrainRat model (cortical and subcortical melanotic tumor model)k-means cluster analysisDevelopment of false-color tissue map of brain tumors;tumor margins delineated[54]

Gastric*67 (238 total tissue sites)Nonnegative constrained least squares minimization with Classification and Regression Tree (CART) modelSensitivity: 94.0%
Specificity: 93.4%
Accuracy: 93.7%
[61]

Gastric*71 (1102 spectra acquired)Partial least squares and linear discriminant analysis (PLS-DA)Sensitivities: 93.8, 84.7, 82.1%
Specificities: 93.8, 94.5, 95.3% (normal, benign, malignant)
[62]

Gastric*67 (238 total tissue sites)Ant colony optimization integrated with linear discriminant analysis (ACO-LDA)Sensitivity: 94.6%, 89.3%
Specificity: 94.6%, 97.8%
Accuracy: 94.6%, 96.7% (diagnostic, predictive)
[63]

Esophgeal27 (75 total tissue sites)Nonnegative constrained least squares minimization (NNCLSM) and linear discriminate analysis (LDA)Sensitivity: 97.0%
Specificity: 95.2%
Accuracy: 96.0%
[65]

Upper GI tract107 (1189 spectra acquired)Nonnegative constrained least squares minimization (NNCLSM) with reference database for biomolecular modelingSensitivities: 92.6%, 90.9%
Specificities: 88.6%, 93.9%
Accuracy: 89.3%, 94.7% (gastric, esophagus)
[66]

Cervical66* (172 tissue sites) (11 patients excluded)Logistic regression discrimination algorithmsSensitivity: 89%
Specificity: 81%
[82]

Cervical (effect of hormonal
variation on
cervical disease)
122Nonlinear maximum representation and discrimination (MRDF) and Sparse linear multinomial logistic regression (SMLR)Incorporation of the hormonal variation information into a previous model improved model accuracy from 74% to 97% for diagnosis of LGSIL[83]

Lung26 (129 spectra acquired)Principal component analysis and linear discriminant analysis with a databased biomolecular modelSensitivity: 96%
Specificity: 91%
[110]

*Denotes that these three studies involved the same group of patients.