Pulmonary imaging after stereotactic radiotherapy-does RECIST still apply?

Area of Science:

• Oncology
• Radiology
• Medical Imaging

Background:

• Stereotactic ablative radiotherapy (SABR) use for lung cancer is increasing.
• Benign fibrotic changes post-SABR mimic tumor recurrence on CT scans.
• Misclassification leads to unnecessary interventions.

Purpose of the Study:

• To evaluate challenges in assessing treatment response after SABR for lung cancer.
• To compare the efficacy of RECIST criteria, PET, and radiomic analysis in distinguishing fibrosis from recurrence.
• To identify advanced methods for accurate early response assessment.

Main Methods:

• Review of current response assessment methods including CT imaging, RECIST criteria, and PET.
• Exploration of limitations of RECIST for irregular post-SABR changes.
• Investigation of advanced quantitative radiomic analysis on CT imaging.

Main Results:

• Fibrotic changes on CT imaging pose a challenge for response assessment post-SABR.
• RECIST criteria have limitations with irregular post-SABR fibrotic changes.
• Radiomic analysis demonstrates potential for earlier and more accurate differentiation of fibrosis from recurrence compared to physician assessment.

Conclusions:

• Current methods like RECIST and PET have limitations in accurately assessing treatment response post-SABR.
• Advanced quantitative radiomic analysis shows promise for improved early detection and differentiation of recurrence from benign changes.
• Novel metrics may outperform RECIST alone for response assessment.