Role of PET scan in Stomach Cancer: Uses, Preparation, Procedure & Cost

What Is Stomach Cancer? Gastric cancer or stomach cancer is an abnormal cancerous growth that arises from the stomach. It can occur in any part of the stomach. Adenocarcinomas are the most common gastric malignancies that...

What Is Stomach Cancer?

Gastric cancer or stomach cancer is an abnormal cancerous growth that arises from the stomach. It can occur in any part of the stomach. Adenocarcinomas are the most common gastric malignancies that arises most frequently from the cardia of stomach.

In most cases (95%), gastric cancer begins from the lining of stomach and progresses slowly. It is often asymptomatic or produces non-specific symptoms and is usually diagnosed at an advanced stage when cancer have either invaded adjacent areas such as pancreas or the liver or have metastasizes to distant sites.

Incidence varies with geographical location. It is the 3^rd leading cause of cancer related death and 5^th leading cancer affecting worldwide.

What Are the Symptoms of Stomach Cancer?

Stomach cancer is often asymptomatic. However, depending upon the exact location, stage of tumor or its metastasis to distant sites, various symptoms or sign may be seen that includes:

Nausea and vomiting
Heartburn
Dysphagia
Indigestion
Diarrhea
Constipation
Anorexia
Weight loss
Fatigue
Weakness
Upper abdominal discomfort or pain
Bloating
Belching
Anemia
Hematemesis (Vomiting blood)
Melena (Blood in stool).

What Are the Uses of PET Scan in Stomach Cancer?

Malignant cells demonstrate altered growth and metabolism. PET scan is used for the assessment and evaluation of metabolic and biochemical properties of tissues or organ. It is indicated for the following purpose in stomach cancer:

Cancer staging: PET scan may be used for staging of stomach cancers.
Detection of metastases: Secondary malignant growths at distant site from primary tumours is known as metastases. PET scan plays a crucial role in identification and localization of metastases.
To monitor efficacy of treatment.
To evaluate the prognosis in cancer patients.
To check for cancer recurrence after treatment.

How to prepare for PET scan in stomach cancer?

Follow these steps if you are going for a PET scan:

Get an appointment: Fix an appointment in a diagnostic center having the facility of PET scan as it is available in limited centers. Prior appointment also saves your time by avoiding waiting at the time of scan.
Fasting: 6-7 hours fasting is required before PET test.
Caffeine: For 24-hours before the scan, avoid caffeinated products.
Medications: Certain drugs may alter test results. Inform your doctor about all medications and supplements that you are currently taking.
Clothing: Wear clothes as comfortable as possible and that are easy to put on and off.
Exercise: Don’t perform any strenuous exercise for 24-hours prior to your test.
Pregnancy and breastfeeding: Tell your doctor about pregnancy if you are pregnant or if you breastfed your baby so that your doctor can evaluate the risk vs benefit ratio.
Allergy: Inform your Clinician about prior history of allergy to any drug or medications.
Smoking and tobacco: On the day of your scan, don’t smoke or chew tobacco products as nicotine present in these substances causes vasoconstriction and may alter the test results.
Implants: Inform your doctor about any implant in your body such as cardiac implant, inner ear implants, metallic dentures, neurostimulators or any type of hearing aids etc.
Claustrophobia and anxiety: If you have claustrophobia or anxiety disorder then don’t hesitate to tell your doctor. He may give you sedative or some alternatives to help overcome this while performing test.
Medical reports: Don’t forget to carry all relevant medical reports along with you while going for PET scan. These reports may aid in better evaluation of your condition.
Take a company: Get accompanied by a friend or family member to have mental, emotional and physical support and to drive you home.

What is the procedure for PET scan in stomach cancer?

The procedure of PET scan includes the following steps:

Written consent is required before the procedure begins.
You will be then asked to change your clothes and wear a gown provided by the technician assisting the procedure.
You will be asked to remove all the metallic elements like jewellery, hearing aids, metallic hair clips, metallic underwired bras, wallets, keys, coins, cards containing metallic strips, belts, goggles etc.
An intravenous injection of radiopharmaceutical agent usually FDG (fluorodeoxyglucose) is given to you.
You will be then asked to sit quietly for about an hour to allow the radiotracer agent to get distributed to your body tissues and organs via bloodstream. The radioactive agent gets accumulated in areas of high metabolic activity such as cancerous tissues.
If PET-CT is being scheduled then you may get another intravenous injection of a contrast agent which yield high clarity images on CT scan.
You may be provided with head phones or ear plugs to make you feel more comfortable.
If you have Claustrophobia or anxiety disorder, then you may be given sedatives or some other alternatives to make you feel comfortable during the scan.
Before scan, your assisting Doctor will explain about all the possible adverse effects of using radiopharmaceutical or contrast material such as itching, rash, swelling etc. Your KFT report will be required to rule out any kidney disease/pathology and to check your GFR.
Then you will be asked to lie supine on the examination table which will slide and place you inside the scanner.
You need to lie still during the procedure as body movements may interfere with the quality of images produced.
Your Radiologist will take several images to evaluate the underlying pathology and at the end these images will be interpreted for making a definite diagnosis.

What happens after PET scan?

Once the imaging is over you may be allowed to exit the scanner room and asked to wait in the observation room for some time, to check for any possible side effect of radioactive or contrast agent being used. You should drink water to clear out the radiotracer or contrast agent from your body.Cost of PET scan for stomach cancer in Delhi?

Price of PET scan generally varies with city and location. Various diagnostic and imaging centers charges differently according to the quality of machines they provide and the offers currently availing in them. PET scan charges also vary with the body part which need to be examined and the type of PET scan.

PET scan test is an advanced diagnostic and monitoring tool that is available at limited diagnostic centers as it requires costly and modern equipments and skilled Radiologists to perform the scan.

To choose the best diagnostic center for PET scan in Delhi. Click here!

Ganesh Diagnostic and Imaging center (GDIC) is now offering 50% discount on all types of PET scan test.

Various PET scan prices at Ganesh Diagnostic and Imaging center (GDIC)are as following:

For more details, click here!

To avail free consultation with Pathologist. Click here!

To avail free consultation with Radiologist. Click here!

FAQs Related to Stomach Cancer & PET Scan:

What are the risk factors for stomach cancer?

There are several risk factors for the development of stomach or gastric cancer including:

H. pylori infection
Family history of gastric cancers
Pickled vegetables
Red meat
Processed meat
High salt intake
Salt rich foods
Brackens
Smoked foods
Smoking
Alcohol
Obesity
Male sexOlder age
Type A blood group
Iodine deficiency
Intestinal metaplasia in the stomach.
Diseases such as:
1. Peptic ulcers
2. Chronic atrophic gastritis
3. Pernicious Anemia
4. Menetrier’s disease
5. GERD (Gastro-esophageal reflux disease)
6. Diabetes
7. Epstein-Barr virus infection.
Genetic conditions:
1. Hereditary diffuse gastric cancer
2. Peutz-Jeghers syndrome
3. Familial adenomatous polyposis
4. HNPCC or Lynch syndrome
5. Foxp3 polymorphism.

Types of stomach tumors?

Histologically, there are several types of stomach cancer such as:

Adenocarcinoma: Most common (90%)
Gastric lymphoma: Less common (5%)
GIST (Gastrointestinal stromal tumors)
Carcinoid tumors.

How is screening done for stomach cancer?

Screening tests are used to screen or look for stomach cancer before the appearance of signs and symptoms. Screening is done through upper GI endoscopy in people belonging to the high-risk group for stomach cancer. It helps in early screening and determine the need for further testing if reports are abnormal.

Whereas, diagnostic tests are performed when you have sign or symptoms of stomach cancer or if the screening tests are found to be suspicious or abnormal.

How is stomach cancer diagnosed?

Diagnosis of stomach cancer is done using multiple tests that includes:

Blood examination:
- CBC (Complete blood count)
- Tumor markers such as CEA and CA 19-9.
Upper GI endoscopy
Histopathological examination:
- Tissue biopsy
Imaging tests:
- Barium swallow or barium meal
- X-rays
- Ultrasound
- MRI
- CT scan
- PET scan.
Stool examination:
- Fecal occult blood test.

What is the prognosis of stomach cancer?

Prognosis of stomach or gastric cancer is usually poor and depends upon many variables such as:

Involvement of Genes such as P2RX7 or ITGAV
Stage of tumor
Response to treatment
Patient age
Presence of Co-morbid conditions
Metastasis.

What is the survival rate of stomach cancer?

The 5-year survival rate of stomach cancer depending upon the patients’ age, type of tumor, stage of cancer, grade of cancer, extent of invasion or metastasis are as following:

Overall 5-year survival rate for all stages is 33%.
5-year survival rate in case of localized stomach cancer is 72%.
5-year survival rate in case of local metastasis to regional lymph nodes aur adjacent areas is 33%
In case of distant metastasis, the 5-year survival rate is 6%.

How to prevent stomach cancer?

Protective factors that may prevent the development of stomach cancers includes:

Avoid red meat
Avoid processed food
Intake of fruits and vegetables
Cessation of smoking
Limit alcohol intake
Maintain normal BMI
Exercise regularly
H. pylori eradication.

How is stomach cancer treated?

Treatment options available for the management of gastric carcinoma includes:

Surgery.
Chemotherapy.
Radiotherapy.
Targeted therapy with trastuzumab in case of HER2 gene overexpression.
Any combination of the above treatments.
H. pylori eradication in case of MALT lymphomas.

How much time taken during PET scan for stomach cancer?

The whole procedure of PET scan takes approximately 2 hours. Up to 60 minutes are required to begin the scanning procedure after giving an intravenous radioactive agent. However, the actual process of PET scan takes approx. 30-40 minutes.

Also, it may last longer depending upon the severity of your illness and associated co-morbid conditions.

How much time it takes for PET scan report of stomach cancer?

You will get reports on the next day. However, you can get the image films on the same day if required by your doctor.

Risks/Side effects of PET scan in stomach cancer?

PET scan is a safe procedure. The radioactivity in the radioactive drug is very low, also it doesn’t stay for longtime in your body. Drinking water can flush the radioactive agent faster from your body.

However, some risks/side effects about PET scan are as following:

Allergic reactions to the radiotracer or contrast agent, although rare but can happen in some individuals. However, these allergic reactions are usually mild.
Diabetic patients have low levels of insulin (help in transport of glucose across cells). Insulin deficiency may lead to low absorption of FDG (fluorodeoxyglucose) which may alter test results. So, inform your doctor before test.

Pregnant and breastfeeding mothers should avoid certain medications and test for the safety of baby. Ask your doctor before undergoing PET scan.