Abstract
Post-treatment MRI in patients with glioma provides serial observations for updating patient-specific tumor-state proxy estimates, but variable appearances and trajectories complicate forecasting. We formulate forecasting as an observation-aware digital-twin update in which an intermediate observation anchors the patient-specific state. Among 203 patients and 594 follow-up time points, a predefined no-new-treatment criterion retained 120 of 236 candidate triplets, split into 81/24/15 training/validation/test triplets at the patient level. Each time point was represented by a continuous voxel-wise tumor-state proxy map in[0,1]derived from MRI lesion labels. A SegMamba-based singlestep forecaster predicted update proposals from multimodal source-state tensors. Observation-Anchored Selective Assimilation (OASA) retained the observed intermediate proxy as the state anchor and selectively applied updates through a validation-selected tiered case-level rule and voxel-wise soft gate. We compared initial-scan forecasting, rollout without assimilation, latest-observation persistence, direct prediction, OASA, OASA + calibration, and morphological dilation. Checkpoints, OASA rules, and calibration thresholds were selected using validation data only. Across three seeds on 15 held-out test triplets, OASA maintained Dice atτ= 0.2comparable to persistence (0.6071±0.0025vs.0.6070) while yielding numerically higher Dice atτ= 0.5(0.4269±0.0079vs.0.3981), with a small RMSE increase. Calibration increased Dice atτ= 0.2to 0.6178±0.0025, increased false-positive (FP) support (11,836→18,663), and reduced false-negative (FN) support (22,107→17,536). This reflects near-threshold support calibration rather than improved biological predictive capability. Code is publicly available athttps://github.com/ jsudg436/longitudinal-proxy-forecasting.
Links to Paper and Supplementary Materials
Main Paper (Open Access Version): https://papers.miccai.org/miccai-2026-sat/paper/DT4H_021.pdf
SharedIt Link: Not yet available
SpringerLink (DOI): Not yet available
Supplementary Material: Not Submitted
Link to Open Review
Open Review Page: https://openreview.net/forum?id=YOnLQV0qdN
BibTex
@InProceedings{JunYeo_ObservationAnchored_MICCAISAT2026,
author = { Jung, Yeonjae AND Shin, Minwoo},
title = { { Observation-Anchored Selective Assimilation for Longitudinal Tumor-State Proxy Forecasting in Post-Treatment Glioma } },
booktitle = {Medical Image Computing and Computer Assisted Intervention -- MICCAI 2026 Workshops and Challenges},
year = {2026},
publisher = {Springer Nature Switzerland},
volume = {LNCS 17275},
month = {pending},
page = {pending}
}