Thursday, February 25, 2010

Diagnosis of Recurrent Brain Tumor.


The advantages of positron imaging in diagnosis of various malignancies have been touted by proponents of positron emission tomography (PET) technology. While PET lacks the anatomic resolution of CT and MR imaging, it is quite sensitive to small foci of increased metabolic activity, such as small tumors.ECRI conducted a short-form technology assessment of PET for diagnosis of recurrent brain tumor, comparing it to single photon emission CT (SPECT) and to CT and MRI.A total of 22 published journal articles with PET clinical trial results were examined. Eight of these met our criteria for analysis:$#183; Study was reported in the English-language peer-reviewed literature, as a full article rather than an abstract only$#183; Study compared results of the positron imaging modality to results of a reference test (surgical pathology or clinical follow-up) in patients with recurrent brain tumor and in patients with radionecrosis or other treatment-related changes.$#183; Interpretation of the positron results was blinded to the reference standard$#183; Study reported sufficient data to permit calculation of sensitivity and specificity.$#183; Study did not include any pre-treatment patients, or reported them separately.$#183; At least ten patients total in recurrent tumor and control groups.Studies were included irrespective of their prospective or retrospective design, and irrespective of the role of MR or CT in acquiring or analyzing PET results.Meta-analysis of these trials yielded a summary ROC with a very broad confidence interval. The summary ROC derived from five clinical trials of thallium-201 SPECT also had a very broad confidence interval.14 of the 22 PET studies reported that CT and/or MRI was used in a complementary role to PET: CT and MR images were used to identify lesions to be analyzed with PET. 10 of the 17 SPECT trials also used CT and/or MRI for localization purposes.We concluded that PET appears to have some capability for differential diagnosis between brain tumor recurrence, but there is insufficient evidence for proving this hypothesis or for estimating the sensitivity and specificity of PET. We were unable to draw any conclusions about whether PET is more effective than SPECT for this particular diagnostic task.

Thursday, January 7, 2010

Best Treatment for Prostate Cancer?

Prostate cancer treatment is complex. Knowing which treatment will give the greatest life expectancy is a difficult decisions. Doctors and patients much choose among prostatectomy, radiotherapy, watchful waiting, hormone therapy and other treatments. Looking over past data, researchers have learned the survival rates for each of these treatments in a Swiss population.

Prostate Cancer Treatment, Longevity and LIfe Expectancy
Which Prostate Cancer Treatment Gives The Best Life Expectancy?

Prostate cancer treatments cover a wide range of approaches that impact life expectancy differently. Believe it or not, no formal clinical studies have been done to determine how best to treat localized prostate cancer. These studies would be extremely difficult to do -- they would take up to 10 years to complete, people would have to be randomly assigned to different treatment groups and the cost would be quite high. So instead, researchers have taken data from the past to compare treatments. This is called a retrospective (or historical) study. Keep in mind that there may be factors unknown to the researchers reviewing medical charts that impact the outcome.
Life Expectancy and Localized Prostate Cancer.
Swiss researchers examined the treatment and outcomes of 844 patients diagnosed with localized prostate cancer sometime between 1989 and 1998.

Five different types of treatment were applied (the "n" indicates the number of participants):prostatectomy (surgical removal of the prostate) n=158
radiotherapy (radiation treatment) n=205
watchful waiting (monitoring the cancer) n=378
hormone therapy n=72
other treatments n=31
prostatectomy (surgical removal of the prostate) n=158
radiotherapy (radiation treatment) n=205
watchful waiting (monitoring the cancer) n=378
hormone therapy n=72
other treatments n=31
Survival and Lie Expectancy in Localized Prostate Cancer.
The researchers looked at the survival rates for each group and found that at five years from diagnosis, the type of treatment made little difference to survival. When the researchers went to 10 years from diagnosis, they did find a difference in survival based on treatment. Overall, 10-year survival was:83% for prostatectomy
75% for radiotherapy
72% for watchful waiting
83% for prostatectomy
75% for radiotherapy
72% for watchful waiting
Those who had hormone risk had decreased survival rates at 5 years, but this is almost certainly because their cancer was a much more aggressive type when they were diagnosed.
Is Prostatectomy the Best Treatment for Prostate Cancer Then?
You cannot conclude that from this study. What we don't know is why certain people were given the treatment they received. It could be the Swiss doctors have a preference. For example, they might prefer a prosatectomy when the cancer presents a certain way and radiotherapy when it "looks" different. In other words, this study tells us that prostectomy is the most effective OR that doctors tend to send patients with less threatening tumors for prostectomies OR (more likely) a complex combination of both (and throw in some other factors too). Confused yet? Sorry about that. But it is important that you understand the limitations of these studies. Ask your doctor what factors he or she uses to decide on treatment and engage with that discussion.

What Are Prostate Cancer Basics?

Prostate Cancer Basics

Whether you or someone you know has been recently diagnosed with prostate cancer or you are simply interested in learning more about this important disease, there are three key questions that need to be answered.

What Is the Prostate?

The prostate is a small, walnut-sized gland that exists only in men. It is situated just below the bladder and just in front of the rectum in the lower pelvis.

The bladder acts as a storage area for urine. When the bladder is emptied, the urine travels through a thin tube called the urethra to the penis and then out. The very beginning of the urethra as it leaves the bladder passes directly through the prostate. This fact accounts for why so many men with either prostate cancer or BPH (benign prostatic hyperplasia) develop trouble urinating. As the prostate enlarges, the urethra is pinched off, leaving a smaller tube to carry urine from the bladder to outside the body.

The prostate’s primary function is to produce much of the fluid that makes up semen. Semen acts to protect sperm as it makes its way out of the body.

The prostate is present from before birth and grows in response to male hormones such as testosterone. Blocking the production or effects of these hormones is one of the primary treatment options for prostate cancer.
What Is Cancer?

Cancer is most simply explained as cells in a certain part of the body that have started to grow in an out-of-control and unregulated fashion.

The human body is made up of billions of tiny units called cells. These are the smallest structures in the body that can be considered to be living. They can only be seen under high-powered microscopes. Cells normally go through a life cycle of growth, division, and death. When this occurs in an orderly fashion, cells are created and die in roughly equal numbers. They also normally stay confined to the area of the body in which they were meant to be.

Unfortunately, certain cells sometimes begin to multiply much faster than they die. When this happens, these abnormal cells squeeze out nearby normal cells. These abnormal cancerous cells can also spread outside of their original site in the body and spread to other areas. When cancer from one body site has spread to other areas of the body, the cancer can be said to have “metastasized". This is always an unfortunate occurrence as cancer that has spread is much harder to treat in general.

A cancer is named after its original site in the body. For example, prostate cancer, even if it were to spread to the bones or to the colon would still be called prostate cancer and not bone or colon cancer. This would more appropriately be called “prostate cancer with metastasis to the bone.”

All types of cancer are different. For example, prostate cancer is very different from lung cancer. The two are caused by different factors, diagnosed in different ways, and treated differently. Regardless of the type of cancer, the underlying problem is the unregulated and abnormal growth of the cells in that part of the body.
What Is Prostate Cancer?

Since cancer is the uncontrolled and abnormal growth of cells in a certain area of the body, prostate cancer is simply the uncontrolled and abnormal growth of cells in the prostate.

Some men have BPH (benign prostatic hyperplasia). This is often confused with prostate cancer. With BPH, prostate cells multiply faster than they should. This causes the prostate to enlarge and the patient to develop difficulty urinating. With prostate cancer, the cells not only multiply faster, but also behave abnormally by spreading outside of the prostate if not caught in time. BPH is not cancer, but can show some of the same symptoms.

The prostate is made up of many different types of cells. The gland cells (those cells that actually work to produce the fluid that is released into the semen) however, are nearly always the cells that become cancerous. The technical medical term for cancer that arises from gland cells is adenocarcinoma. Thus, the technical term for prostate cancer is prostate (or prostatic) adenocarcinoma.

Early detection, prompt diagnosis, and effective treatment are the mainstays of good prostate cancer care.