Table 1 Literature Review.

From: XcepFusion for brain tumor detection using a hybrid transfer learning framework with layer pruning and freezing

Ref

Model Type

Method / Model Used

Dataset

Innovation

Strength

Research Gap

12

Hybrid DL + ML

CNN + SVM/RF with multimodal data

BRATS

Combined multimodal MRI features with robust selection

High precision and reduced overfitting

Limited to small dataset; lacks real-time validation

13

CNN (Explainable)

CNN-TumorNet + XAI

Custom MRI

Integrates explainability into CNN

Enhances trust and interpretability

Requires clinical deployment and scalability testing

14

CNN

Optimized CNN

BRATS 2020

Automated hyperparameter tuning

High consistency across folds

Needs comparison with TL models

15

CNN + ML

AlexNet + SVM/KNN/RF

BRATS MRI

Combines DL features with ML classifiers

Better feature generalization

Feature fusion can be further optimized

16

Transfer Learning

ResNet, VGG16

BRATS, Kaggle

Uses TL for MRI with fine-tuning

High accuracy with low training cost

Dataset imbalance not addressed

17

Hybrid DL + ML

CNN + XAI + ML

BRATS, TCIA

Introduces explainability with hybrid fusion

Very high accuracy and interpretability

High computational cost

18

ML (Unsupervised + SVM)

K-means + SVM

Custom MRI

Combines segmentation and ML classification

Improved edge detection

Not end-to-end DL; lacks automation

19

CNN + Attention

CNN + Soft Attention

Kaggle MRI

Attention mechanism for ROI focus

Better tumor localization

High model complexity

20

CNN

CNN

BRATS, Harvard Dataverse

Improved CNN architecture

Robust detection accuracy

Limited explainability

21

ML

SVM + Novel Feature Extraction

BRATS 2021

Unique handcrafted features

Simple and interpretable

Lower performance than CNN

22

Hybrid

CNN + Random Forest

Kaggle MRI

Combines CNN and ML

Balanced accuracy and efficiency

Needs end-to-end optimization

23

CNN

CNN

BRATS 2020

End-to-end automated CNN pipeline

Robust classification

No interpretability layer

24

Hybrid DL + ML

CNN + SVM + Genetic Algorithm

BRATS 2020

Genetic feature selection

High efficiency

Computationally heavy

25

Ensemble DL + ML

CNN Ensemble + SVM/RF

BRATS 2018

Feature-level ensemble

Improved robustness

Needs real-time evaluation

26

CNN + Segmentation

ResNet50 + U-Net

TCGA-LGG, TCIA

Combines classification & segmentation

Superior localization & accuracy

High GPU requirements

27

Hybrid DL + ML

CNN + ML

BRATS 2021

Fuses ML with DL for optimization

Reduced complexity

Limited transferability

28

CNN (Explainable)

Explainable CNN + Grad-CAM

BRATS 2020

Visual interpretability integration

High clinical potential

Lower accuracy vs. non-XAI models

29

Hybrid

CNN-SVM + PSO

Kaggle MRI

PSO optimization for feature weights

Improved hybrid performance

Limited generalization

30

Ensemble DL

VGG + ResNet + DenseNet

BRATS

Multi-architecture ensemble

Exceptional classification accuracy

High computational cost

31

CNN

EfficientNet

Custom MRI

EfficientNet optimization

Lightweight and accurate

Needs more diverse data

32

Ensemble DL + ML

CNN + Ensemble ML

BRATS 2019

Combined multiple feature sources

Enhanced model stability

Lacks real-time validation

33

Transfer Learning

DenseNet121

BRATS, TCGA

Transfer learning with DenseNet

Accurate on small data

Model explainability missing

34

CNN

CNN + Optimized Parameters

BRATS

Classifier optimization

Improved efficiency

Dataset generalization needed

35

Hybrid DL + ML

CNN + SVM/KNN/RF

BRATS 2021

CNN feature extraction + ML classification

Easy to interpret

Lower accuracy than TL models

36

Transfer Learning

CNN + TL + SVM

BRATS

Combined TL and ML techniques

Improved adaptability

Limited dataset variation

37

CNN + GDD

Deep Learning + GDD

Kaggle MRI

Introduces GDD feature approximation

Accurate classification & survival prediction

Complex preprocessing stage