Cancer is one of the most complex diseases, and its diagnosis and treatment require high precision. To ensure accuracy, doctors often recommend a PET CT Scan. Many patients wonder, “Why is PET CT suggested in cancer when other scans like MRI or CT are available?”
The answer lies in the unique ability of PET CT to show both structure and function of tissues in the body. Let’s explore in detail why PET CT is so important in cancer diagnosis and treatment.
What is a PET CT Scan?
A PET CT Scan (Positron Emission Tomography – Computed Tomography) combines two imaging techniques:
- PET (Positron Emission Tomography): Uses a small amount of radioactive tracer (usually a sugar-like substance) to highlight areas of high metabolic activity. Cancer cells, which grow and consume sugar rapidly, absorb more tracer and appear brighter on the scan.
- CT (Computed Tomography): Provides detailed anatomical images of the body.
When combined, PET CT shows not only where a tumour is located but also how active it is.
Why Do Doctors Recommend PET CT in Cancer?
1. Early Detection of Cancer
Cancer cells behave differently from normal cells — they grow faster and consume more energy. PET CT detects this abnormal activity at a very early stage, sometimes even before structural changes appear on MRI or CT.
2. Accurate Staging of Cancer
Staging tells doctors how advanced the cancer is and whether it has spread. PET CT helps in:
- Detecting the primary tumour
- Finding if cancer has spread to lymph nodes
- Checking for metastasis (spread to distant organs)
This is crucial for planning the right treatment.
3. Treatment Planning
Doctors use PET CT results to design a personalised treatment plan. For example:
- Deciding if surgery is possible
- Planning radiation therapy by mapping exact tumour sites
- Choosing between chemotherapy, targeted therapy, or immunotherapy
4. Monitoring Treatment Response
Not all treatments work the same for every patient. PET CT allows doctors to see if the cancer is responding to treatment.
- If the tumour is shrinking or showing less activity, the treatment is working.
- If cancer is still active, doctors can change the treatment plan quickly.
5. Detecting Recurrence
Even after successful treatment, there is always a risk of cancer coming back. PET CT can detect recurrence early, often before symptoms appear. This ensures timely intervention.
PET CT vs. Other Scans in Cancer
- CT or MRI: Show detailed structure (size, shape, location) but cannot always tell if a tumour is active or dead tissue.
- PET CT: Shows both structure and function, helping differentiate between scar tissue and active cancer.
Is PET CT Safe for Cancer Patients?
Yes, PET CT is considered safe. The radioactive tracer used is in very small amounts and usually leaves the body within 24 hours through urine. However, it may not be recommended for pregnant or breastfeeding women.
Cost of PET CT in Cancer
In India, PET CT scan costs usually range between ₹15,000 to ₹30,000, depending on the city, hospital, and type of tracer used. While it is more expensive than MRI or CT, the comprehensive information it provides makes it highly valuable in cancer care.
Final Thoughts
Doctors recommend PET CT scans in cancer because they provide the most accurate and complete picture of the disease. From early detection to staging, treatment planning, monitoring, and recurrence detection, PET CT plays a vital role in saving lives.
If your doctor has suggested a PET CT scan, it is not just another test — it is an essential step to ensure you receive the best possible cancer treatment.
FAQs on PET CT in Cancer
Q1. Can PET CT detect all types of cancer?
Not all cancers are easily visible on PET CT, but it is highly effective for lung, lymphoma, head & neck, breast, colorectal, and other cancers.
Q2. Is PET CT painful?
No. The scan is painless. The only discomfort may be the injection of the tracer.
Q3. How long does a PET CT scan take?
The procedure usually takes about 2–3 hours, including preparation and scan time.
Q4. Can PET CT replace biopsy?
No. PET CT shows abnormal activity, but a biopsy is still required to confirm cancer diagnosis.
Q5. How often should a cancer patient undergo PET CT?
This depends on the treatment plan. Some patients may need scans before, during, and after treatment, as advised by their doctor.
