European Radiology: a nomogram of CT imaging that predicts the prognosis of patients with intrahepatic mass cholangiocarcinoma

Intrahepatic cholangiocarcinoma (ICC) accounts for about 10% to 15% of all primary liver malignancies and is the second most common malignancy after hepatocellular carcinoma
.
Over the past three decades, the incidence of ICC has been increasing
worldwide.
According to the macroscopic growth pattern of the tumor, ICC can be divided into three types: periductal invasive, intraductal growth, and mass formation
.
Intrahepatic mass-forming cholangiocarcinoma (IMCC) accounts for about 80%
of all ICC cases.

To the best of our knowledge, surgical resection remains the mainstay of curative treatment for
IMCC.
Despite advances in surgical techniques and perioperative care, the prognosis for IMCC patients remains relatively poor, with 5-year overall survival (OS) after liver resection ranging from
25-40%.
It is worth noting that most patients who undergo surgery relapse
within 2 years.
Therefore, there is an urgent clinical need for effective risk stratification methods to optimize patient selection and determine who is a suitable candidate
for surgical resection.
By far, the AJCC staging system is the most commonly used method
.
However, most commonly used prognostic tools are based on clinicopathological parameters that are often not available
prior to surgery.

Imaging can play an important role in the diagnosis and staging of IMCC, and the correlation between imaging features and specific histopathological features of IMCC has been well established
by several studies.
The presence of varying degrees of fibrous matrix in IMCC is one of
the most characteristic histological findings.
There is growing evidence that the fibrous matrix in IMCC continuously supports cancer cells and promotes tumor invasion and metastasis
.
Recent studies have confirmed the correlation
between imaging features and fibrous matrix in IMCC patients.
Among them, the arterial strengthening pattern was significantly correlated
with the content of fibrous matrix in the tumor.
Previous studies have shown that arterial strengthening patterns are an important risk predictor for
survival in patients with IMCC.
Therefore, imaging features, as non-invasive tumor features, can assist clinicians in predicting prognosis
before surgery.

Recently, a study published in the journal European Radiology has developed and validated a nomogram based on computed tomography (CT) imaging features to predict the prognosis of IMCC patients, creating a better risk stratification of IMCC patients for the clinic, thereby improving personalized treatment
.

Two models for predicting overall survival (OS) were established in the training set (179 IMCC patients who underwent surgical treatment at Institution No.
1 from 2009 to 2019): imaging-based nomograms included imaging features and clinical features obtained preoperatively; Postoperative nomination plots include imaging-based scoring, linear predictors equal to imaging-based nomograms, and pathological parameters
.
Both prognostic nomograms were validated
in a separate external dataset (103 IMCC patients who underwent surgery at two separate institutions from 2009 to 2019).
Predictive performance and differentiation were evaluated and compared
with common prognostic models.

The imaging-based nomination map was established based on preoperative serum carbohydrate antigen 19-9 and four imaging features (multiple nodules, arterial enhancement pattern, CT-reported lymph node (LN) metastasis, and capsular retraction); Postoperative nomograms are based on imaging-based scoring and three pathological parameters, including tumor differentiation grade, capsular invasion, and LN status
.
Both nomograms showed better prognostic performance and differential diagnostic performance than ordinary prognostic models in training and external validation datasets (Consistency Index, 0.
770-0.
812; Composite Brier Score, 0.
120-0.
138).

In addition, the nomogram divides the OS of IMCC patients into two risk tiers
.

Imaging features of intrahepatic mass-forming cholangiocarcinoma on CT images: (a) multiple nodules; (b) lymph node metastases, marked by white arrows; (c) Capsular retraction, marked by a white arrow; (D-F) Arterial enhancement pattern, diffuse high enhancement (D), peripheral margin enhancement (E), diffuse low enhancement (F).

Imaging features including multiple nodules, arterial strengthening patterns, CT-reported LN metastases, and capsular retraction are independent predictors of poor prognosis in patients with IMCC
.
The nomogram based on CT imaging features can provide accurate individual survival predictions for IMCC patients before and after surgery, thereby guiding the selection of
surgical or treatment strategies.

Original source:

Chen Yu Jiao,Hui Zhang,Gu Wei Ji,et al.
CT-based clinico-radiological nomograms for prognosis prediction in patients with intrahepatic mass-forming cholangiocarcinoma: a multi-institutional study.
DOI:10.
1007/s00330-022-08914-0