Chang Jee-Suk, Professor of Radiation Oncology, Yonsei University Cancer Center
Normal Organ Compartmentalization During Radiation Therapy - Bringing AI to the Treatment Planning Stage
Participated in the development of OncoStudio,an AI software for radiation therapy
Terminal cancer patients with distant metastases also improve survival - keeping hope alive for a cure
“The diagnosis of biliary tract cancer was embarrassing enough, but when I found out it had metastasized to my lungs,I was blindsided. I never thought I would be able to attend my son's graduation ceremony. He is a lifesaver for me and my family.”
Seo Ji-hyeok (65, pseudonym)was diagnosed with stage 4 biliary tract cancer in July 2019 after visiting a hospital with unexplained indigestion and jaundice.
At the time, the doctors said, “The biliary tract cancer has metastasized to the lungs and he has six months to live at most,” but he is still alive with chemotherapy for nearly five years. He also sent his regards to Chang Jee-Suk, a professor of radiation oncology at Yonsei Cancer Hospital, who has been a clinical instructor at BC Cancer Centre in Vancouver, Canada, since August 2022, along with a photo from his son's graduation ceremony. How is it possible for a patient with terminal cancer, the worst form of cancer with a survival rate of only 3%, to survive for such along period of time?
◇ Biliarytract cancer, which is difficult to diagnose early... 'only 3% survival rate'if it metastasizes remotely
Biliary tract cancer is cancer of the biliary tract (biliary tree), the passageway that drains bile (gallbladder bile) that helps digest fats. In general, malignancies in the biliary tract, which is the pathway for bile made by the liver to flow into the duodenum, as well as in the gallbladder, the primary storage site for bile, are collectively referred to as biliary cancers.
According to the National Cancer Registry, there were 7,619 newly diagnosed cases of gallbladder and other biliary tract cancers in 2021, accounting for 3.9% of all cancer cases (247,952 cases). It is the ninth most common cancer in Korea, but it is considered a cancer with a poor prognosis due to difficulty in early detection. In the early stages, there are no symptoms such as jaundice, and as it progresses, it is often diagnosed accidentally through medical examinations because it is accompanied by uncharacteristic symptoms such as indigestion, abdominal pain, and weight loss.
The prognosis is also poor due to late detection. According to the National Cancer Registry, the five-year survival rate, which refers to the probability of surviving five years compared to the general population, was 50.0% for patients with gallbladder and other biliary tract cancers from 2017 to 2021. The five-year survival rate is only half as good when the cancer is localized, meaning it hasn't spread beyond the organ where it started. The five-year survival rate drops to 34.2% for locally advanced stage, which means the cancer has invaded nearby organs, adjacent tissues, or lymph nodes, and to 3.2% for distant metastatic stage, which means the cancer has spread to other parts of the body.
◇ Improving radiotherapy precision...a new treatment alternative for inoperable terminal cancer patients
Surgery is currently the most reliable treatment to improve survival rates for biliary tract cancer patients. However, only about 40 to 50 percent of all patients are able to undergo radical resection (removal of the entire compartment along with the tumor), and those who cannot under go surgery, like Mr. Seo, are treated with chemotherapy or radiation to relieve symptoms. Seo first met Prof. Chang when he came to Yonsei Cancer Hospital for radiation therapy after being diagnosed with terminal cancer.
It wasn't always a pleasant encounter.After six to seven weeks of chemotherapy and radiation treatments once a day,Monday through Friday, the cancer cells had spread to every nook and cranny of her body. For Seo, the hardest part was hearing the results of the imaging tests after the planned treatment.
“You don't know how fast radiation therapy is advancing these days, it's almost as good as surgery for some cancers. You should be in your son's graduation picture.”
Whenever Professor Chang would report that a metastatic lesion had enlarged or that a new metastasis had appeared, he would introduce the non-medical scientist to the breakthroughs in radiotherapy.
◇ AI algorithm applied...“Reduced 3D long-term contouring time by 90%”
The process of using images from computed tomography (CT) and magnetic resonance imaging (MRI) scans to outline organs and plan radiation treatments, combined with cutting-edge technologies such as artificial intelligence (AI), has led to faster and more effective treatments.
For so-called “oligometastasis,” where the cancer is confined to a small number of metastases, even if it's stage 4,there's hope that stereotactic body radiation therapy (SBRT), a highly precise treatment that delivers high doses of radiation over three to five treatments,could lead to long-term survival and even a cure.
After trusting Professor Chang and continuing to undergo radiation therapy, Seo was told that in less than two years, “all the metastatic lesions had disappeared.” More than three years later, she continues to receive the same treatment with no new metastases.
OncoStudio, which OncoSoft began developing shortly after its launch and obtained a Class 2 medical device license from the Ministry of Food and Drug Safety, is an AI-based automatic contouring software.
It automates the contouring work that was done manually by medical staff, reducing the work time by 90%.
It's like a medical version of the image-generating AI Midjourney.
By utilizing OncoStudio's algorithm, it is possible to reduce the work time from 1-2 days to a few minutes, and it is highly accurate.
Prior to his overseas training, Prof. Chang was directly involved in the development of OncoStudio's AI-based contouring(compartmentalization) software for radiotherapy. Radiotherapy, which uses high doses of radiation to kill cancer cells, is all about protecting surrounding normal tissue and minimizing side effects. Precise radiotherapy planning requires technology that can contour normal organs on images such as CT-MRI and predict the radiation dose to each cancerous tissue and organ.
OncoStudio automates this process, which was previously done manually by medical staff, with AI. OncoStudio's AI algorithm reduces the time it takes to contour (segment) normal organs in three-dimensional (3D) images by 90%. This reduces the time from three to four hours to one to two days to a matter of minutes, while increasing accuracy. This effect is expected to be maximized as AI technology is applied to various stages of radiation therapy.
OncoStudio was approved as a Class 2medical device by the Ministry of Food and Drug Safety in February 2022 and is used in more than 50 radiation oncology departments in Korea, including Severance Hospital and Samsung Medical Center. Several overseas institutions are also showing interest, including a hospital in Canada where Prof. Chang is currently working.
“BC Cancer Center is testing several products to implement an AI contouring program,” said Prof. Chang. ”When we demonstrated OncoStudio to local doctors, they praised it for being faster and more accurate than other products.”
He will be returning to Yonsei Cancer Hospital in August this year and is working with OncoStudio and local researchers on a collaborative research project. The ultimate goal is to use AI technology to automatically locate the location of metastasized cancer and calculate the speed of the disease to identify when and under what indications body stereotactic radiotherapy can help.
He emphasized, “AI algorithms can help reduce variation between hospitals and improve care efficiency” and “I want to contribute to conquering incurable cancer as well as improving the overall quality of treatment by allowing cancer patients and doctors to communicate closely.”
