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Doctor insights on: Can A Pet Scan Miss Cancer

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Dr. Barry Rosen
4,341 Doctors shared insights

Cancer (Definition)

Cancer is a group of diseases that is characterized by uncontrolled cell growth leading to invasion of surrounding tissues that spread to other parts of the body. Cancer can begin anywhere in the body and is usually related to one or more genetic mutations that allow normal cells to become malignant by interfering with internal cellular control mechanisms, such as programmed cell death or by preventing ...Read more


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Radiology Does a PET scan have a much better chance of picking up a central lung cancer if it was missed at LDCT? Thank You

Radiology Does a PET scan have a much better chance of picking up a central lung cancer if it was missed at LDCT? Thank You

LDCT is a: Noncontrast lung nodule screening study, and it is possible that small central lesions may not be visualized due to proximity to normal blood vessels or other structures. PET is extremely sensitive, but if a diagnostic contrast enhanced CT scan with thinner collimation and higher resolution is negative, probably unnecessary. ...Read more

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Should a pet scan show any cancer?

Should a pet scan show any cancer?

Glucose: Pet scan relies on the theory that tumors utilize a significant amount of glucose. Many different types of cancer can show up on pet scan but certain types of cancer are much more FDG avid. Low grade tumors usually have much less uptake than high grade tumors. In addition, mucinous neoplasms often do not have much FDG uptake. Small size tumors or micrometastases also may not show up on pet. ...Read more

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On a pet scan, are the dark areas cancer?

On a pet scan, are the dark areas cancer?

Yes and no: Areas with cancer are usually hypermetabolic in a pet scan due to the increased uptake of the radioactive glucose by cancerous cells. Looking at an FDG pet scan alone, you can grossly see "dark" areas in the brain, heart, kidneys and bladder and these are due to physiologic distribution/excretion of fdg. Not all "dark" is cancer and cancer is often but not always "dark". ...Read more

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Should pet scans continue to be part of cancer surveillance?

Should pet scans continue to be part of cancer surveillance?

Yes: Not every cancer should be followed with pet/ct. But when the cancer is visible by this technology, it is often helpful in treatment planning and follow up. Here is link: http://www. Petscaninfo. Com/zportal/portals/pat/cancer. ...Read more

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Why do some cancers have a high uptake on pet scan and some low?

Why do some cancers have a high uptake on pet scan and some low?

Uptake on PET: The uptake of 18F-FDG by tissues is a marker for the tissue uptake of glucose, which in turn is closely correlated with certain types of tissue metabolism. Tumors in general are more metabolically active than normal tissues and this difference in uptake is what makes PET scans possible. Tumors that have a higher metabolic rate will have more FDG uptake. Tumors that are less active havel less. ...Read more

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If a pet scan indicates cancer but biopsy is normal, could I still have cancer?

If a pet scan indicates cancer but biopsy is normal, could I still have cancer?

PET is not 100%: The distribution and intensity of hyper-metabolic activity appearance on a pet/ct scan could be abnormal and may represent malignancy but is not pathognomonic and may also represent inflammation, infection or granulomatous disease. If biopsy is correctly done, results of direct tissue are usually more certain. However, short interval follow-up with pet/ct is often recommended. ...Read more

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On a pet scan does a lower SUV uptake meAn less aggressive cancer? The SUV uptake was 5.2,

On a pet scan does a lower SUV uptake meAn less aggressive cancer? The SUV uptake was 5.2,

No: SUV has no bearing on the aggressiveness of the cancer. It is a relative measure of the glucose metabolism. In fact, some very aggressive tumors have no FDG uptake at all. Some benign conditions like infection can have high uptake. The standard uptake value depends on many factors like patient body size and serum glucose level and the normal uptake in the tissue surrounding the target lesion. ...Read more

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Not long ago I had a pet scan done, one lympnode lit up, it was light. I want to know if that still means cancer.?

Not long ago I had a pet scan done, one lympnode lit up, it was light. I want to know if that still means cancer.?

Possibly: The purpose of a PET scan is to evaluate the extent of a cancerous process and see if before treatment there are several sites to be concerned about. After treatment to see if there is residual disease that may not have responded properly. If a node lights up it may suggest that there is still remaining disease. ...Read more

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Is it better that the SUV Max on a pet scan is lower than higher? Does this mean the cancer Is less aggressive and less active What is the highest it can be!

Is it better that the SUV Max on a pet scan is lower than higher? Does this mean the cancer Is less aggressive and less active What is the highest it can be!

SUV: SUV refers to amount of metabolic activity (glucose uptake) and often corresponds to tumor grade. Lower is usually better. A higher tumor grade usually has higher SUV. SUVs can be very high. There is no exact cutoff. ...Read more

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What does a cancer free pet scan show? When a pet scan shows that a person is cancer free, does that really mean they're done with cancer? Is it cured? Are there any general statistics for a person who had cancer, but a pet scan later showed that the canc

What does a cancer free pet scan show? When a pet scan shows that a person is cancer free, does that really mean they're done with cancer? Is it cured? Are there any general statistics for a person who had cancer, but a pet scan later showed that the canc

PET: Pet scans are used for diagnosis, staging, and restaging of certain kinds of cancers such as lung, colorectal, esophageal, and head and neck cancers, and for monitoring response to therapy in breast cancer. Different kinds of cancers behave differently, and there is no guarantee that a given cancer is completely "cured, " even following complete remission. In general, evidence of a complete remission on a pet scan is a very favorable prognostic sign, and indicates that treatment was successful. Followup pet scans are still performed at regular intervals, often for the patient's lifetime, in order to monitor for any possible recurrence that might require new treatment. In general, if follow-up pet scans continue to show no evidence of disease over a period of many years, the likelihood of recurrence is low. ...Read more

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Are pet scans used for ovarian cancer?

Are pet scans used for ovarian cancer?

Not to diagnose: Pet/ct is not typically used to diagnose ovarian cancer, but may play a role in surgical planning or treatment followup. ...Read more

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What does a pet scan with cancer look like?

What does a pet scan with cancer look like?

Hypermetobolic: A pet scan will show increased metabolic activity or a area of locality that is different from surrounding tissue indicating area concerning for cancer. ...Read more

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Could a pet scan detect ovarian cancer?

Could a pet scan detect ovarian cancer?

Possibly: If tumor metabolically active will pick up isotope f18 FDG, analog of glucose. Imaging with pet ct will detect abnormality. Most malignant tumors are active, but not all. ...Read more

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Are bright orange spots on pet scan cancer?

Are bright orange spots on pet scan cancer?

Tricky: Not all cancers are bright on pet scans and not all bright activity in a pet scan is cancer. Inflammation/infection can also show bright activity. Pet scans are performed in conjugation with ct (pet/ct) and though pet is great for detecting metabolism, its specificity is not as great. Reading a pet requires care/skill. Normal activity is seen in the brain, heart, liver, spleen, kidneys, bladder. ...Read more

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Can you tell me how pet scan reveal information about cancer spread?

Can you tell me how pet scan reveal information about cancer spread?

Radioactive sugar: A PET scan looks for areas in the body that are using more sugar than other areas. The only way to "see" the sugar is to label it with a short-lived radioactive tag. Areas that are much brighter on the scan than others can indicate areas of tumor, though inflammation and infection can also light up (sometimes to a lesser degree). Details of the clinical scenario should be provided when ordered ...Read more

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What to do if I had a pet scan yesterday. I have cervical cancer right after the scan?

What to do if I had a pet scan yesterday. I have cervical cancer right after the scan?

Follow drs. Protocol: If metabolically active and of significant size tumor of cervix and metastases would likely be recognized on pet scan. Tumor does not arise in one day. Microscopic small lesions detected by pap smear are not likely recognized on pet scan. Treatment is determined by physician taking care of you. ...Read more

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After cancer surgery I had 2 clear pet scans. Nw after 5 yrs the pet scan is abnormal. Possible causes?

Not enough info...: It is possible to have an abnormal scan at 5 years but I do not know enough about your history and what was abnormal in this scan. There are many sources of false positive on pet scan but without seeing your images or reports and without your exact history it is difficult to determine what the status is. ...Read more

Dr. Guido Davidzon
291 Doctors shared insights

Pet Scan (Definition)

Pet scans most often use a radioactive form of glucose, the energy source for most of the cells in our bodies. The pet scanner can detect and measure how much of the radioactive glucose analog, f-18 fdg, is in a particular organ or region. The areas using more glucose are hyper metabolic and generally more worrisome. Our brains and sometimes hearts prefer glucose as food, making ...Read more