PET Scan Results and Cancer Risks: Key Questions Answered

Positron Emission Tomography (PET) Report Issue 2

Dr.
Chen, thank you for your response.
Although I am still unsure about how to decide, I appreciate your analytical suggestions.
I have a few questions that I would like to clarify:
1.
The PET scan report indicates a suspected lesion in the epiglottic area, and the doctor mentioned that it is not just a small point or part, but the entire epiglottic region.
Previously, I asked you if a biopsy would help in identifying the lesion (you replied that it would be helpful).
However, I did not explain in detail that the doctor said if the biopsy only samples the brightest area, rather than the entire region, would this still be helpful in distinguishing the nature of the entire epiglottic area?
2.
The internet states that an SUV value greater than 2.5 significantly increases the likelihood of cancer cells.
Is this true?
3.
You mentioned that we could wait 3 to 6 months for another PET scan to observe any changes.
Is there a risk that during this waiting period, the condition could progress from having no obvious symptoms to late-stage disease? Should I continue to follow up with an ENT specialist during this waiting period? If I have another PET scan in March, would having two PET scans within about six months increase the risk of cancer due to radiation exposure? Would this also pose an increased risk to my children, who are 3 and 9 years old? I apologize for not being clear earlier, and I would appreciate your assistance in answering these questions.
Thank you very much.

Miss Lin, 40~49 year old female. Ask Date: 2021/11/09

Dr. Chen Sirong reply Oncology

Ms.
Lin / 45 years old / Female
1.
The doctor mentioned that the biopsy only examines the brightest areas and not the entire specimen.
Does this approach help in identifying the overall nature of the epiglottis?
A: The biopsy does not involve the complete excision of the specimen, so it is indeed focused on the brightest areas.
2.
There is information online stating that an SUV (Standardized Uptake Value) greater than 2.5 indicates a high likelihood of cancer cells.
Is this true?
A: This is a matter of probability; the higher the value, the greater the likelihood, which is a natural principle.
3.
You mentioned that a follow-up PET scan can be done in 3 to 6 months to observe any changes.
Is there a risk that the condition could progress from no obvious symptoms to late-stage during this waiting period?
A: While there is a possibility of this happening, the diagnosis of diseases varies in difficulty, and more complex cases naturally take longer to evaluate.
You cannot rush this process.
4.
Should I continue to follow up with an Ear, Nose, and Throat (ENT) specialist during the waiting period?
A: The National Health Insurance Administration does not prohibit this; you can still receive coverage for ENT consultations.
However, for PET scans, if cancer is not confirmed, it will be out-of-pocket.
5.
If I undergo another PET scan in March, will having two scans within about six months increase my cancer risk due to radiation exposure?
A: This is also a matter of probability, but it typically takes 5 to 10 years for radiation exposure to potentially cause cancer.
6.
Will this increase the risk for my children at home?
A: No, you are the one undergoing the examination and receiving radiation, not your children.

Wishing you a speedy recovery,
Taoyuan Hospital
Dr.
Chen Sih-Rong

Reply Date: 2021/11/09

More Info

Understanding PET Scan Results and Cancer Risks: Key Questions Answered
Thank you for your thoughtful questions regarding the interpretation of PET scan results and the associated risks of cancer. It’s understandable to have concerns, especially when it comes to the health of loved ones. Let’s address your questions one by one.

1. Biopsy and the Affected Area: You mentioned that the PET report indicates a suspicious area in the epiglottis region, and your doctor suggested that the entire area is of concern, not just a specific point. When it comes to biopsies, it’s crucial to sample the most suspicious areas, as these are likely to yield the most informative results. However, if the biopsy only examines the brightest spot (the area with the highest uptake of the radioactive tracer), it may not provide a complete picture of the entire region's pathology. In some cases, cancer can be heterogeneous, meaning that different areas may have different characteristics. Therefore, if the biopsy is limited to just one part, it might miss other areas that could be malignant. A more comprehensive approach, such as sampling multiple areas or using imaging to guide the biopsy, can enhance diagnostic accuracy.

2. SUV Values and Cancer Probability: The Standardized Uptake Value (SUV) is a quantitative measure used in PET scans to assess how much of the radioactive tracer (FDG) is taken up by tissues. Generally, an SUV greater than 2.5 is often considered indicative of potential malignancy, but it is not definitive. Many benign conditions can also present with elevated SUV values. Therefore, while a higher SUV can suggest the presence of cancer, it should be interpreted in conjunction with clinical findings, histopathological results, and other imaging studies.

3. Monitoring and Risks of Delayed Diagnosis: You asked about the risks of waiting 3 to 6 months for a follow-up PET scan. While it’s essential to monitor any changes, there is always a concern that a delay could allow a potential malignancy to progress. However, if your doctor believes that the current findings do not warrant immediate intervention, it may be reasonable to wait for further evaluation. During this waiting period, it is advisable to continue regular follow-ups with your ENT specialist to monitor any symptoms or changes in your condition.

4. Radiation Exposure and Risks: Regarding your concerns about radiation exposure from PET scans, it’s true that repeated imaging can increase the cumulative dose of radiation. However, the risk associated with a single PET scan is generally considered low, especially when weighed against the benefits of obtaining critical diagnostic information. For children, the sensitivity to radiation is higher, so minimizing unnecessary scans is prudent. If your children are not directly involved in the imaging process, their risk from your scans is negligible. However, if they require imaging in the future, it’s essential to discuss the necessity and potential risks with their healthcare provider.

In conclusion, while PET scans are valuable tools in cancer diagnosis and management, they are just one part of a comprehensive evaluation. It’s essential to maintain open communication with your healthcare team, ask questions, and express any concerns you may have. They can provide personalized guidance based on your specific situation and help you navigate the complexities of cancer diagnosis and treatment. Remember, early detection and intervention are key factors in improving outcomes, so staying vigilant and proactive about follow-ups is crucial. Thank you for your questions, and I hope this information helps clarify your concerns.

Similar Q&A

Understanding PET Scan Results: Distinguishing Between Benign and Malignant Findings

Hello Doctor, I recently had a PET scan, and the doctor mentioned that the results were quite clean, except for one area of uptake in both my nose and neck. When I heard there was uptake, I felt worried, but the doctor said it was faint and should be benign. I would like to ask i...

Dr. Zheng Xiaoyi reply Nuclear Medicine
The principle of positron emission tomography (PET) imaging involves injecting a glucose-like radiotracer into the body. Cancer cells have a higher metabolic rate and therefore utilize more glucose, allowing for the identification of cancer cells based on this characteristic. How...

Understanding PET Scans for Lymph Node Concerns: Accuracy and Insights

Hello Doctor, I am a patient who is very concerned about lymphadenopathy and I am afraid that I might have lymphoma. I feel like I have many swollen lymph nodes all over my body, and I also have splenomegaly. To ease my mind, I have scheduled a PET scan, but I am unsure whether a...

Dr. Zheng Xiaoyi reply Nuclear Medicine
Hello, Mr. Chen. Positron Emission Tomography (PET) primarily utilizes radioactive tracers similar to glucose to detect tissues with high glucose metabolism rates, a characteristic commonly found in cancers. Therefore, PET can be used to detect cancer by identifying lymph nodes w...

Understanding PET Scan Results for Colon Cancer: A Patient's Guide

I underwent a colonoscopy for a health check-up, during which a 1 cm polyp was removed. I was then referred to the oncology department for a PET scan, with the report as follows: According to the NCCN guidelines, I have been diagnosed with pT1 colon cancer as of October 2023. The...

Dr. Zheng Xiaoyi reply Nuclear Medicine
Hello Mr. Li, based on your positron emission tomography (PET) report, there are three main conclusions: 1. There is no significant residual tumor or metastatic lesions observed in the imaging following treatment for your sigmoid colon cancer. 2. There is a lesion in the right ...

Understanding Radiation Risks in Nuclear Medicine: Patient Concerns Addressed

My female patient had an MRI of the lungs in December and is scheduled for a nuclear medicine thyroid scan in May. Will this pose any harm to her body? Is there a risk of cellular mutation?

Dr. Zheng Xiaoyi reply Nuclear Medicine
Hello, Miss Peng. According to the literature, low-dose radiation exposure below 100 millisieverts does not increase the risk of cancer, and most nuclear medicine examinations involve radiation exposure below this threshold, so they do not significantly impact human health. If yo...