MEDIACAL PROBABILITY

   In past I have stated that in medicine we treat patients many a times based on probability. But at the same time the probability is based on science  and so we know based on education and studies and experience that certain diseases are likely to be present and certain are not likely. But that is never 100%. So, in medicine we talked of 2 words one is Probability and other is Possibility. To understand this I will say that everything is possible but not probable. The word probability means that that the chance is more than 50 %. So it is possible that I will be President of US but it is not probable that I will be President. That brings me to a story for today. 

   I saw this patient who happen to be spouse of my other patient. She was 70 years old and has never smoked , but was exposed to second hand smoke from her husband. Sh started with cough and the PCP gave her some antibiotics and some cough syrup and then the cough continued and so he did chest x- ray and that showed some abnormality and so more antibiotics were given . She had o fever and she has no chest pain and she has stable weight . She had no shortness of breath, She saw me and we did the work up ..I though she may have mild asthma and so did some work up like Pulmonary Functions studies and also allergy blood tests called IGE and RAST. I also gave her some inhalers and steroids - prednisone . She felt better but still had cough . The steroids did help the cough  and when they were stopped she had cough . So I decided to do CT scan and I was surprised. She had a mass like density in upper part of the lung. So we decided to do Bronchoscopy . That was done and no obstructing cancer was seen and the biopsy showed inflammation and there was no bacteria or TB or mold. I decided to allow the body ti=o heal and so did follow up CT  scan in 6 weeks or 8 weeks . The CT scan did not change much . Now I was stuck. She had what looks like pneumonia but that was not getting better and so I did PET scan . The PET scan tends to pick up metabolic activity of the cells  and when there is cancer or infection, there will be cells which are more metabolically active than normal cells, and so they show more glucose uptake.The test is 80 % accurate . In case of my patient it did not show much pick up. I was stuck . I had suggested her to se thoracic surgery to do OPEN BIOPSY. .She came to my office for the follow up. I though that based on the low pick up we could wait and do new Ct scan .The size of the 'mass like density ' was also smaller. So I decided that we will do new CT scann in future  amy be 2-3 months . She had seen the surgeon same day that I saw her  and he felt the same thing, that based on PET SCAN findings , we should wait  and not do surgery now. OUR DECISION IS BASED ON PROBAILITY of cancer being low with low pick up on PET scan. The possibility of cancer is still there but it is less probable based on low pick up on PET  SCAN  and also on smaller size of the mass. 

   Let us see what happens . By the way her cough is gone with inhalers alone.