Title
Weakly Supervised Tumor Detection in PET Using Class Response for Treatment Outcome Prediction
Abstract
It is proven that radiomic characteristics extracted from the tumor region are predictive. The first step in radiomic analysis is the segmentation of the lesion. However, this task is time consuming and requires a highly trained physician. This process could be automated using computer-aided detection (CAD) tools. Current state-of-the-art methods are trained in a supervised learning setting, which requires a lot of data that are usually not available in the medical imaging field. The challenge is to train one model to segment different types of tumors with only a weak segmentation ground truth. In this work, we propose a prediction framework including a 3D tumor segmentation in positron emission tomography (PET) images, based on a weakly supervised deep learning method, and an outcome prediction based on a 3D-CNN classifier applied to the segmented tumor regions. The key step is to locate the tumor in 3D. We propose to (1) calculate two maximum intensity projection (MIP) images from 3D PET images in two directions, (2) classify the MIP images into different types of cancers, (3) generate the class activation maps through a multitask learning approach with a weak prior knowledge, and (4) segment the 3D tumor region from the two 2D activation maps with a proposed new loss function for the multitask. The proposed approach achieves state-of-the-art prediction results with a small data set and with a weak segmentation ground truth. Our model was tested and validated for treatment response and survival in lung and esophageal cancers on 195 patients, with an area under the receiver operating characteristic curve (AUC) of 67% and 59%, respectively, and a dice coefficient of 73% and 0.77% for tumor segmentation.
Year
DOI
Venue
2022
10.3390/jimaging8050130
JOURNAL OF IMAGING
Keywords
DocType
Volume
weakly supervised learning, class activation maps, tumor detection, radiomics, image classification, image segmentation
Journal
8
Issue
ISSN
Citations 
5
2313-433X
0
PageRank 
References 
Authors
0.34
0
5
Name
Order
Citations
PageRank
Amine Amyar100.34
Romain Modzelewski200.34
Pierre Vera300.34
Vincent Morard400.34
Ruan Su555953.00