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Updated: Jun 16, 2026
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Stereotactic Radiosurgery for Gynecologic Cancer
Published on: April 17, 2012
Dynamic Radiologic Changes and Predictors of Pseudoprogression After Lung Stereotactic Ablative Radiotherapy (SABR)
Xue Song1, Qicen Xu1, Yu Chen1
1Department of Radiation Oncology, Affiliated Cancer Hospital of Nanjing Medical University, Baiziting 42#, Xuanwu district, Nanjing, PR China (X.S., Q.X., Y.C., L.Z., Z.Z., D.Z., N.J., J.W., X.H., X.Z.).
Academic Radiology
|March 3, 2026
Summary
Post-SABR lung imaging shows dynamic changes that can mimic local failure. Planning target volume (PTV) predicts pseudoprogression, requiring careful interpretation of radiographic enlargement during follow-up.
Area of Science:
- Radiology
- Oncology
- Pulmonary Medicine
Background:
- Radiologic appearances after stereotactic ablative radiotherapy (SABR) for lung tumors are dynamic.
- These changes can mimic local tumor recurrence, complicating post-treatment monitoring.
- The evolution and predictors of pseudoprogression after SABR remain unclear.
Purpose of the Study:
- To characterize the serial computed tomography (CT) evolution of post-SABR lung lesions.
- To identify predictors of pseudoprogression following SABR.
- To differentiate true local failure from benign post-treatment changes.
Main Methods:
- Retrospective analysis of 109 lesions from 104 patients with ≥24 months follow-up post-SABR.
- Defined pseudoprogression as >20% increase in lesion diameter followed by stabilization, without recurrence evidence.
- Assessed CT evolution phases and identified predictors, including planning target volume (PTV).
Main Results:
- Mass-like consolidation developed in 86% of lesions.
- CT evolution occurred in three phases: initiation, development, and mass-like consolidation.
- Pseudoprogression (>20% diameter increase) occurred in 68% of lesions, with PTV being an independent predictor (aOR 0.98).
Conclusions:
- Dynamic CT evolution after SABR frequently results in mass-like consolidation.
- High rates of pseudoprogression are observed, influenced by PTV.
- Radiographic enlargement post-SABR necessitates cautious interpretation due to the potential for pseudoprogression.
