Esophageal cancer cells with PET/CT scan overlay

Esophageal Cancer Treatment: Why Initial PET/CT Scans Might Not Tell the Whole Story

Elliot Brynn in Health & Wellness November 2025 • 4 min read.

"New research reveals the limitations of pre-treatment PET/CT scans in predicting the success of esophageal cancer therapies, emphasizing the need for adaptive strategies."

Esophageal cancer is a formidable disease, demanding innovative approaches to improve treatment outcomes. While combination therapies like chemoradiation (CRT) followed by surgery have become standard, local failures remain a significant challenge. Improving local control is crucial, leading researchers to explore ways to intensify treatment for high-risk areas within tumors.

One promising strategy is simultaneous integrated boost (SIB), where specific tumor subvolumes receive higher radiation doses. Identifying these 'high-risk' subvolumes, potentially characterized by higher metabolic activity, could allow for more targeted and effective treatment. This is where 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) comes into play, a widely used imaging technique in cancer management.

A recent study delved into whether pre-CRT FDG-PET/CT scans can reliably identify residual metabolically-active volumes (MAVs) post-CRT within individual esophageal tumors. The findings challenge the assumption that initial scans can accurately predict treatment response, suggesting the need for more dynamic and adaptive strategies.

Challenging the Status Quo: What the Research Reveals About Esophageal Tumors?

Esophageal cancer cells with PET/CT scan overlay

Researchers at the University of Maryland School of Medicine conducted a study involving twenty patients with esophageal cancer undergoing CRT plus surgery. These patients had FDG-PET/CT scans both before and after CRT, which were then meticulously analyzed to assess the correlation between pre- and post-treatment metabolic activity within the tumors.

The goal was to determine if subvolumes with high FDG uptake before CRT could pinpoint the locations of metabolically active tumor cells that persist after treatment. To quantify the relationship between pre- and post-CRT metabolic activity, the team used several metrics, including:

Fraction of post-CRT MAV included in pre-CRT MAV: This measures the extent to which the metabolically active tumor volume after treatment is contained within the area identified as metabolically active before treatment.
Volume overlap: A measure of how much the pre- and post-CRT metabolically active volumes coincide.
Centroid distance: The distance between the centers of the pre- and post-CRT metabolically active volumes.

The study revealed that pre-CRT PET/CT scans could not reliably identify the residual metabolically-active volumes within individual esophageal tumors. Less than 65% of any post-CRT MAV was included in any pre-CRT MAVs, with a low volume overlap <45%, and large centroid distance >8.6 mm. These findings indicate a significant shift in the location and metabolic activity of tumor cells following CRT.

A Call for Adaptive Strategies in Esophageal Cancer Treatment

This research underscores the limitations of relying solely on pre-treatment imaging to guide esophageal cancer therapy. The disconnect between pre- and post-CRT metabolic activity highlights the need for adaptive strategies that incorporate real-time monitoring of treatment response. This may involve re-imaging during treatment to identify persistent areas of high metabolic activity, allowing for adjustments to the radiation plan to target these resistant tumor cells more effectively. The future of esophageal cancer treatment lies in personalized approaches that consider the dynamic changes occurring within the tumor during therapy.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.4172/2155-9619.1000226, Alternate LINK

Title: Pre-Chemoradiotherapy Fdg Pet/Ct Cannot Identify Residual Metabolically-Active Volumes Within Individual Esophageal Tumors

Subject: General Earth and Planetary Sciences

Journal: Journal of Nuclear Medicine and Radiation Therapy

Publisher: OMICS Publishing Group

Authors: Lu W Tan S

Published: 2015-01-01

Everything You Need To Know

Why might initial PET/CT scans not tell the whole story in esophageal cancer treatment?

Researchers have found that pre-chemoradiation (CRT) FDG-PET/CT scans may not accurately identify the residual metabolically-active volumes (MAVs) within esophageal tumors after treatment. The initial scans don't reliably predict where the metabolically active tumor cells will persist, challenging the assumption that treatment response can be accurately predicted from initial imaging. Less than 65% of any post-CRT MAV was included in any pre-CRT MAVs, with a low volume overlap <45%, and large centroid distance >8.6 mm. This suggests the need for adaptive treatment strategies.

How did researchers at the University of Maryland School of Medicine study the correlation between pre- and post-CRT metabolic activity in esophageal tumors?

The University of Maryland School of Medicine study utilized FDG-PET/CT scans taken before and after chemoradiation (CRT) on twenty esophageal cancer patients. They then measured the Fraction of post-CRT MAV included in pre-CRT MAV, Volume overlap, and Centroid distance to evaluate the relationship between the pre- and post-CRT metabolic activity within the tumors. The aim was to see if areas showing high FDG uptake before CRT could indicate where metabolically active tumor cells would persist after treatment. The conclusion was that the intial imaging was not predictive.

What is simultaneous integrated boost (SIB) and how could it improve esophageal cancer treatment?

Simultaneous integrated boost (SIB) involves delivering higher doses of radiation to specific subvolumes within a tumor. The goal is to intensify treatment to 'high-risk' areas, potentially characterized by higher metabolic activity. By identifying these subvolumes with FDG-PET, treatment could be more targeted and effective, improving local control of the cancer. The concept of SIB is to improve current approaches to improve treatment outcomes for a formidable disease.

What are adaptive strategies in the context of esophageal cancer treatment, and why are they needed?

Adaptive strategies in esophageal cancer treatment involve real-time monitoring of a tumor's response to therapy. This may include re-imaging during treatment to identify persistent areas of high metabolic activity. By adapting the radiation plan to target these resistant tumor cells more effectively, personalized approaches can be used to consider the dynamic changes occurring within the tumor during therapy. The idea is that initial treatment planning can be updated to give the patient better outcomes.

What is the significance of local failures in esophageal cancer treatment, and how is it related to metabolic activity?

Local failures after chemoradiation (CRT) and surgery remain a significant challenge in esophageal cancer treatment. While combination therapies have become standard, improving local control is crucial. This has led researchers to explore ways to intensify treatment for high-risk areas within tumors, such as through simultaneous integrated boost (SIB), to improve patient outcomes.