A PET-CT scan may be recommended in the following cases:

1. Detection and staging of cancer
2. Check for suspected relapse, recurrent, or malignant lesion
3. Check for the effectiveness of cancer treatment 
4. Check if cancer has spread in the body
5. Evaluation of the prognosis
6. Assessment of tissue metabolism and viability
7. Map the normal human brain and heart function
8. Check the effects of heart attack or myocardial infarction on the heart areas
9. Identification of the areas of the heart that could benefit from procedures like angioplasty or coronary artery bypass surgery
10. Evaluation of brain abnormalities like tumors, seizures, memory disorders, and other disorders of the central nervous system 

1. Physical examination: The doctor will evaluate the physical health of the patient. The patient’s medical history and symptoms will be noted.
2. Blood tests: Certain underlying medical conditions like diabetes can be diagnosed using blood tests. Serum creatinine blood test helps in evaluating the function of the kidneys.
3. X-rays: They can help in obtaining images of the different organs of the body.
4. Imaging tests: Other imaging tests like MRI scans, CT scans, PET scans, and ultrasounds may be used before or in conjunction with PET-CT scans to obtain a clear image of the internal organs of the body.

• The doctor may give you a sedative before the procedure to help you relax.
• You need to change into a hospital gown. 
• You need to remove all types of jewelry and metal objects from your body as the metal will interfere with the images produced by the scanner.
• A small plastic tube, known as a cannula, is placed in your arm intravenously (IV) and the doctor will inject a radioactive liquid, known as a radiotracer, through the cannula approximately one hour before the scan.
• You should avoid moving too much during this hour and test in one place to allow the radiotracer to spread through the body and into the tissues.
• You will then be taken to the scanning room.
• Most scans are taken with you lying down on the PET-CT scan machine couch on your back.
• The radiologist will leave the room once you are in the right position. They can see you through a window from the control room or on a TV screen. You can communicate with the doctor through an intercom.
• The PET-CT scan machine appears like a large donut. The couch will slowly slide backward and forwards through the scanning machine.
• The machine will take pictures as you move through it.
• Although the scan is painless, it could be uncomfortable as you need to stay still during the procedure. Tell the doctor if you are feeling stiff and need to move.
• Once the procedure is completed, the doctor will come back in the room and lower the couch for you so that you can get up. 
• The scan itself takes approximately 30 minutes. The whole procedure including the waiting period after the injection of the radioactive liquid may take about one to three hours.

PET-CT scans are usually safe and non-invasive. In certain conditions, PET-CT scans may, however, cause the following side effects:

1. Increased risk of abortion or mutation in pregnancy
2. Allergic reaction to the radioactive tracer used
3. Breastfeeding women need to stop breastfeeding one day before and after the scan
4. Bruising in the area of needle insertion
5. Pain and swelling in the arm due to the leakage of radioactive tracer outside the vein
6. Slightly increased risk of cancer development due to radiation exposure 

• The cannula will be removed from your arm.
• You can go home immediately after the procedure.
• You can eat and drink normally after the procedure.
• Drink lots of fluids after the scan to aid in flushing the radioactive tracer out of the system.
• If you have been given a sedative before the procedure, you will need someone to drive you home after the procedure. You will not be able to drive for the remaining part of the day as you may feel drowsy.
• For about six hours after the procedure, stay at an arm’s distance from pregnant women and young children as the radioactive tracer may give off small amounts of radiation for some time after the procedure.
• Take your doctor’s letter with you if you are planning to travel abroad within one week of your scan as some airports may have sensitive radiation monitors that could pick up any trace of radiation left in your body after the test.
• You will get the results of your scan within one or two weeks.

Benefits:

The advantages of PET-CT scan are:

• Early diagnosis
• Helps in precise treatment planning
• Quick procedure
• High levels of accuracy and detail

Cost of PET-CT scan in India- 

The cost of a PET-CT scan in Mumbai is between INR 10,000 to INR 25,000.
The cost of a PET-CT scan in Delhi is between INR 8,000 to INR 22,000.
The cost of a PET-CT scan in Bangalore is between INR 8,000 to INR 22,000.
The cost of a PET-CT scan in Chennai is between INR 7,500 to INR 20,000.