Gifu – Masayuki Kanematsu

Gifu – Masayuki Kanematsu

The Japanese way of managing HCC

Professor Masayuki Kanematsu, Gifu University Hospital, is one of the leading Japanese liver imaging specialists. He talks about HCC diagnosis and treatment and about the role of radiologists in Japan.

radiology.bayer.com: HCC numbers are on a plateau in Japan. How did Japan achieve this?

Masayuki Kanematsu: Actually, we even notice an HCC rate decrease in patients between 40 and 60 years. There are three main reasons: One is the successful prevention of hepatitis infections. Public and hospital hygiene has improved significantly over the decades – 40 years or more ago, surgeons did not use disposable plastic gloves and some unfortunately got infected with hepatitis B or C.
Treatment options for hepatitis are another reason for stable HCC numbers. The new anti-viral drugs are very advanced and work well. Another, very important point is diagnosis. When I became a doctor, patients used to have huge HCCs, their survival time being as low as six months. Nowadays, tumors are often very small, sometimes even less than 1.5 centimeters, and survival rates have increased. Early HCC detection is possible thanks to advanced imaging techniques – and Primovist-enhanced MRI has contributed much to that.

“We have a lot of experience with Primovist-MRI”

rbc: Can you tell us how monitoring for hepatitis patients works in Japan?

Kanematsu: Japan has implemented advanced screening programs for HCC risk patients. The Japanese health system covers most of the necessary examinations. One to two million people in Japan are infected with hepatitis C, and seven percent are inclined to develop HCC every year. Thanks to educational programs, hepatitis patients are quite aware of this. They are recommended to get their check-up on tumor markers every three to four months, along with an ultrasound. If findings are abnormal, a contrast-enhanced CT is, by and large, the next step. However, more hepatologists have come to ask for a Primovist-MRI.

rbc: How do Japanese HCC guidelines differ from others?

Kanematsu: We have a lot of experience with Primovist-MRI in Japan. Both the Japan Society of Hepatology and the Japan Radiological Society acknowledge Primovist-MRI as an important imaging technique in their most recent guidelines from 2013. For hypervascular HCCs, accuracy is comparable to that of contrast-enhanced CT, but for hypovascular lesions, Primovist-MRI is superior. I think no European or US-American guideline states this so clearly yet.

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Learning from each other is crucial

rbc: Then why does contrast-enhanced CT prevail over Primovist-enhanced MRI?

Kanematsu: Although many publications say that Primovist-enhanced MRI is the better option for detecting HCCs, especially for hypovascular lesions, contrast-enhanced CT is often the method of choice. There are several reasons: Access to a modern MRI scanner is one issue – not every hospital provides such a device. Patients would have to go to a different hospital and wait for an appointment. CT scanners, on the other hand, are widely used and accessible; there is no waiting period. Another reason is knowledge. Referring physicians may not know about the benefits of MRI. Even some hepatologists and surgeons can be quite oblivious to Primovist-MRI. MRI delivers many images that need to be interpreted – T1-weighted, T2-weighted, diffusion-weighted, extracellular- and hepatobiliary-phase images – some hepatologists and surgeons simply do not know what all these sequences are good for.
This is also one of the reasons why contrast-enhanced CT remains the first choice: It is far easier for most of physicians to interpret CT than MR images. And, more often than not, radiologists are not the ones who choose the imaging method.

rbc: What could shift the perspective of hepatologists and surgeons towards radiologists and their expertise?

Kanematsu: In my hospital in Gifu, we periodically host educational meetings. About 60-80 hepatologists and radiologists attend the meeting each time. We discuss several cases in order to learn from each other. Hepatologists in Gifu know quite a lot about the benefits of Primovist-MRI. I always suggest waiting some time before doing a post-treatment MRI exam. It is better to monitor the lesion for a while than to perform an MRI right after treatment.
If precise tumor staging is lacking, surgery may do more harm than good. I think that a good relationship between hepatologists, surgeons and radiologists is crucial for success in HCC diagnosis and treatment. The key is: meet and talk.

We need more radiologists

rbc: How are radiologists perceived in Japan? Radiological societies often complain about radiology’s invisibility...

Kanematsu: Recently, radiologists get more and more acknowledged for their work. Five or six years ago, the government increased the reimbursement for image interpretation if a board-certified radiologist does it. In my hospital, we get about extra 550,000 US$ every year because of this new program. It is not a lot of money, but it helps to spotlight radiologists. This way, hospitals begin to realize that radiologists are how important and needed for their expertise.
Moreover, medical law suits occur far more frequently nowadays. Doctors are sued for misinterpretation and malpractice. Hepatologists and surgeons begin to understand that they cannot interpret all images by themselves – they need our expertise. Additionally, the overall number of CT and MRI images is increasing. From one liver MRI protocol alone, I get around 750 images. Who is going to interpret all these images? Only radiologists can do that.

rbc: Do you have enough radiologists?

Kanematsu: Absolutely not – although the number of board-certified radiologists reached 5,057 in August 2013. It is not unusual in Japan that a hospital with more than 300 beds having CT and MRI scanners as well employs not a single radiologist working for it. We definitely need more radiologists.