CT Evaluation Correlates with Actual Mesothelioma Tumor Volume, Subtype, and Survival

Two new studies highlight the value of CT evaluation for patients with either peritoneal or pleural mesothelioma. 

CT stands for computed tomography. The technology uses X-rays to create three dimensional images of internal structures. 

The studies show CT evaluation can give doctors an accurate idea of the size and extent of mesothelioma tumors. These scans can also help predict which patients have the best odds of survival. This helps doctors plan better, more effective treatment strategies. 

What is Malignant Mesothelioma?

Malignant mesothelioma is a type of cancer that grows on the membranes around internal organs. The most common type of mesothelioma is pleural mesothelioma. This kind of tumor starts on the pleural membrane around the lungs. 

Peritoneal mesothelioma accounts for about a fifth of mesothelioma cases. Peritoneal mesothelioma tumors grow on the peritoneum. This membrane surrounds the abdominal organs.

It is common for patients with mesothelioma to undergo CT evaluation. But how well do these images depict what is really going on inside? And how does that relate to mesothelioma survival? These are the questions researchers in Switzerland and the US wanted to answer. 

CT Evaluation and Real World Mesothelioma Outcomes

Doctors classify mesothelioma into three subtypes. Some subtypes are more aggressive than others. A patient’s subtype impacts what kind of treatments will work best. Right now, the only way to determine mesothelioma subtype is to look at tumor cells under a microscope.

But researchers at Boston’s Massachusetts General Hospital wanted to know how much CT evaluation could help. They compared the subtypes of 51 peritoneal mesothelioma patients with their CT images.

Eighty percent of patients had epithelioid mesothelioma. The other 20 percent had a sarcomatoid subtype (either pure sarcomatoid or biphasic, which is a mix of epithelioid and sarcomatoid cells). How aggressive the cancer was on CT evaluation correlated closely with subtype. 

“Sarcomatoid type of MPM showed significant correlation with more aggressive imaging features of metastases and visceral [deep in the membrane] infiltration as compared to epithelioid type,” writes study author Isha Atre. 

Higher CT Tumor Volume = Shorter Mesothelioma Survival

The second study compared CT measurements of the volume and thickness of pleural mesothelioma tumors with their actual measurements after surgery. The goal of the Swiss researchers was to see a) how accurate the measurements were and b) how they related to mesothelioma survival.

“Preoperatively assessed CT tumor volume and actual tumor volume showed a significant correlation,” writes author Olivia Lauk of University Hospital Zurich.

The team also determined that CT evaluation of tumor volume correlated with overall survival. CT measurements of tumor thickness did not. 

“CT tumor volume may predict pathological tumor volume as a reflection of tumor burden, which supports the integration of CT tumor volume into future staging systems,” Lauk concludes. 

Source:

Atre, I, et al, “Malignant peritoneal mesothelioma: correlation between CT imaging features and histologic subtypes”, August 3, 2021, Abdominal Radiology, Online ahead of print, https://link.springer.com/article/10.1007%2Fs00261-021-03231-4

Lauk, O, et al, “Implementing CT tumor volume and CT pleural thickness into future staging systems for malignant pleural mesothelioma”, August 3, 2021, Cancer Imaging, https://cancerimagingjournal.biomedcentral.com/articles/10.1186/s40644-021-00415-5