European Radiology: Quantitative CT to assess the value of predicting prognosis in patients with locally advanced esophageal cancer

According to statistics, esophageal cancer is the eighth most common cancer in the world and the seventh leading cause
of cancer-related death.
At present, radical surgical resection after preoperative neoadjuvant chemotherapy is the first-line treatment strategy
for locally advanced esophageal squamous cell carcinoma (ESCC).
One study showed that 13% of patients failed to achieve R0 resection
even after preoperative neoadjuvant chemotherapy.
For patients who do not benefit from resection or who cannot tolerate surgery due to poor clinical condition, definitive chemoradiotherapy/radiotherapy (CRT/RT) is clinically recommended as an alternative
.
However, more than 50% of patients do not respond well
to CRT/RT.
Concurrent use of molecularly targeted agents and immune checkpoint inhibitors (ICIs) can be complementary therapies to control tumor progression
in these patients.
Therefore, timely diagnosis of patients who do not respond well to CRT/RT can help clinicians better adjust treatment strategies to achieve individualized and patient-specific treatment
.

Changes in ESCC after induction therapy reflect the biological behavior
of the tumor.
Imaging modalities that evaluate these changes are of great value in predicting the response and prognosis of CRT/RT.

Computed tomography (CT) is one of the common tools used to assess the response and prognosis of patients with ESCC.

During cancer treatment, CT-based assessment of changes in tumor burden is often performed
through the Response Evaluation Criteria for Solid Tumors (RECIST, version 1.
1) guidelines.
However, ESCC does not meet the definition of target lesion in the RECIST (version 1.
1) guidelines, and the evaluation of ESCC is primarily based on metastatic lymph nodes
.
However, more than 88% of ESCC metastatic lymph nodes are less than 10 mm and are therefore often underestimated
by RECIST (ver.
1.
1) guidelines.

Some studies focused on CT measurements of primary tumours, and they found that changes after neoadjuvant therapy or during neoadjuvant therapy were strongly
associated with tumor retraction grade in ESCC patients treated with neoadjuvant therapy and radical resection.
Other studies on lymph node status have shown that lymph node shrinkage after neoadjuvant therapy predicts the histologic response of tumors and can be an independent prognostic factor
for long-term survival after surgery.
To our knowledge, few studies have focused on survival analysis
using CT scans for changes in primary tumour and lymph node status in patients treated with CRT/RT.

A study published today in the journal European Radiology evaluated the performance of CT scans in predicting survival in patients with locally advanced ESCC treated with CRT/RT, based on changes after two cycles of induction chemotherapy, and contributed to
the development of further effective locally advanced ESCC treatment strategies.

A retrospective analysis of 110 patients with locally advanced ESCC included baseline chest CT and CT images
after two cycles of induction chemotherapy.
A multivariate Cox proportional-risk regression model was used to determine independent prognostic markers for survival analysis, and then a CT scoring system
was established.
Time-dependent receiver operating characteristic (ROC) curve analysis and Kaplan-Meier method were used to analyze the prognostic value
of CT scoring system.

Body mass index, treatment strategy, thickness change ratio (ΔTHmax), CT value (ΔCTVaxial) and short diameter (ΔSD-LN) of the primary tumor, and enlarged small lymph nodes (ESLN) after two cycles of chemotherapy were identified as independent factors
predicting overall survival (OS).
The presence of ESLN is up to 100%
specific for death after 12 months.
The CT scoring system predicts OS and progression-free survival (PFS) with higher subcurve values than RECIST (P < 0.
05).

OS and PFS in reactors are significantly longer than in non-responders
.

Figure Region of Interest (ROI).

The ROI (white circle) of the tumor on the baseline CT and second CT axial images (a) and sagittal images (b) were manually plotted, avoiding necrosis, blood vessels, bleeding, and esophageal lumen
。 Baseline CT showed a small lymph node with a short diameter of 4.
4 mm in the right paraesophageal region (white arrow), and after two cycles of induction chemotherapy, CT showed an enlarged lymph node with a short diameter of 9.
5 mm in the right paraesophageal area (white arrow).

This study demonstrated that quantitative analysis of CT after 2 cycles of induction chemotherapy can predict the long-term prognosis
of patients with locally advanced ESCC who receive CRT/RT.
CT scoring systems can provide valuable imaging support for prognostic indications in the early stages of treatment, and can assist clinicians in developing personalized treatment plans
.

Original source:

Shuo Yan,Yan-Jie Shi,Chang Liu,et al.
Quantitative CT evaluation after two cycles of induction chemotherapy to predict prognosis of patients with locally advanced oesophageal squamous cell carcinoma before undergoing definitive chemoradiotherapy/radiotherapy.
DOI:10.
1007/s00330-022-08994-y