"Doctor, my tumor marker levels have been rising since May last year, and theyre now over 300. Despite multiple tests, no issues have been found. Whats going on?"
Mr. Zhao, a 68-year-old lung cancer patient, came to the Thoracic Tumor Multidisciplinary Clinic of Hainan Cancer Hospital with doubts. The expert team quickly found "clues" and arranged a PET/CT precise investigation, revealing the hidden truth of his condition. Subsequently, under the guidance of experts, Mr. Zhao adjusted his treatment plan in a timely manner, and his condition is currently stable.
Puzzlement: Why is the CT examination normal when the tumor marker continues to soar
Two years ago, Mr. Zhao underwent surgery at another hospital due to advanced lung cancer. After the surgery, he followed the doctors advice and took targeted medication to control his condition, and his body did not show any significant discomfort.
However, since May last year, the follow-up examination revealed that the originally stable tumor marker levels had continued to rise like a kite that had lost its string, with CA125 consistently increasing to 300 U/ml, nearly 10 times higher than the normal range (0-35 U/ml).
"The indicators keep rising, there must be a problem!" Mr. Zhao was filled with doubts. But what puzzled him was that every time he had a chest CT scan for follow-up, the results always showed no signs of recurrent lesions or metastasis. Faced with the situation of "abnormal indicators but normal imaging", the clinician suggested "continuing observation and follow-up".
On one hand, the tumor markers kept "alarming", while on the other hand, the CT report showed "normal". The contradictory examination results were like a puzzle lingering in Mr. Zhaos mind. To solve the puzzle, he made a special trip to the Thoracic Tumor Multidisciplinary Clinic of Hainan Cancer Hospital.
Multidisciplinary Thoracic Oncology Clinic Expert Team
Transition: PET/CT scan reveals all systemic metastases
Professor Wang Changli, a multidisciplinary outpatient specialist in thoracic oncology and a renowned expert in lung cancer diagnosis and treatment in China, as well as Professor Yu Lijuan, a well-known imaging diagnosis expert, combined their years of experience to determine that conventional CT scans may have missed small lesions. They recommended using a more precise examination device, PET/CT, to thoroughly understand the "true situation" of the tumor.
Soon, Mr. Zhao successfully completed the PET/CT examination. As expected, the report showed multiple small metastatic lesions in the right hilar region, supraclavicular lymph nodes, pleura, and both lungs. More seriously, the originally dense bones had become like a "sieve", filled with tiny metastatic lesions - multiple bone metastases were found in the ribs, thoracic vertebrae, and lumbar vertebrae.
PET/CT
Professor Yu Lijuan, Director of the Nuclear Medicine Department at Hainan Cancer Hospital, stated that PET/CT can detect small metastatic lesions that are difficult to find through conventional examinations. The patient had developed multiple metastases throughout the body, but fortunately, the liver and brain had not been invaded (once these two sites are metastasized, the difficulty of treatment will increase significantly). Subsequently, the expert team from the Thoracic Tumor Center promptly adjusted Mr. Zhaos treatment plan. After a period of standardized treatment, when Mr. Zhao underwent a follow-up examination, his tumor marker levels had significantly decreased, and his condition had stabilized.
Reveal: Why can PET/CT detect problems that CT cannot?
Professor Yu Lijuan explained, "Although the patients recurrent and metastatic lesions are numerous, they are relatively small. Coupled with the fact that the density of postoperative scars and tumor recurrent lesions is very close, it is difficult to distinguish them using conventional CT images. In addition, bone metastatic lesions usually do not cause bone destruction in the early stage, so there is no abnormal bone density on CT, naturally making it impossible to display the lesions.".
However, the imaging principle of PET/CT is completely different from that of CT - it does not rely on lesion size and density for visualization, but rather judges by capturing the metabolic activity of cells. Tumor cells have a much higher metabolism than normal cells, which will show a clear highlighted signal on the image. Even if it is only a millimeter-sized small metastatic lesion, it cannot escape its golden eye."
The Department of Nuclear Medicine at Hainan Cancer Hospital is a Class I key clinical specialty in our province, boasting a top-tier and leading expert team in the country. The PET/CT equipment introduced is a cutting-edge molecular imaging diagnostic device in nuclear medicine, providing powerful support for early screening, accurate diagnosis, precise localization, and clinical staging of various malignant tumors such as lung cancer.
Expert Reminder
If a cancer patient experiences the following four situations, they must be vigilant about "occult metastasis" and undergo PET/CT examination under the guidance of a doctor to avoid delaying the treatment:
1. During or after treatment, tumor patients may experience a gradual increase in tumor markers, yet routine imaging examinations fail to detect recurrent or metastatic lesions;
2. Patients with tumors who experience pain or other discomforts during or after treatment, where no abnormalities are found in routine imaging or various examination results are contradictory;
After a tumor is diagnosed, it is necessary to accurately determine the extent of tumor involvement and systemic metastasis (i.e., precise staging) to decide on subsequent treatment options;
4. Patients with suspected metastatic tumors in the neck or other parts, who require the identification of the primary lesion.
Expert Introduction
Yu Lijuan
Director of Nuclear Medicine Department, Medical Imaging Department
Chief Physician
Professor Postdoctoral Fellow
Graduate supervisor Doctoral supervisor
Top-notch talent in Hainan Province
Provincial Outstanding Science and Technology Worker
Medical expertise
Multimodal imaging diagnosis of tumors includes X-ray, CT, MR, SPECT/CT, and PET/CT, etc. Special expertise lies in the differential diagnosis of small nodular lung cancer and the PET/CT diagnosis of malignant tumors across various systems.
Clinic Hours
Multidisciplinary Clinic for Thoracic Tumors:
Friday morning
Pulmonary nodule clinic:
Monday morning, Tuesday morning, Wednesday morning
Nuclear medicine outpatient clinic:
Monday to Friday
Written by | Chen Lin