Statistics is scary!

So as I promised, I will be discussing the controversies around lung cancer screening trial lead at NYP and now many other places around the world by Dr. Henschke. So Traditionally to evaluate the merits of a treatment/screening trial (I will be focusing on screening here), clinicians set up what is called a Randomized Control Trial (RCT). In an RCT people are divided randomly into two groups: one which will be screened and one which will receieve either no screening or another form of screening. Clinicians design a regimen of screening for both groups, then screen them for a specified period of time and later on perform a follow up. The efficiency of the screening will be evaluated by what is called the rate of mortality reduction due to screening, which is the number of people who will die of a particular disease of interest over the total number of deaths (in the period of screening).
RCTs have a lot of merit in clinical treatment trials, however, they do not seem to be very informative and efficient as far as screening is concerned. I am simplifying so much here but what I just said seems to be the matter of controversy in the medical community. In the 1970's three RCTs, Mayo Lung Project (MLP), Memorial Sloan-Kettering Lung Project (MSKLP), and Johns Hopkins Lung Project (JHLP) looked at the effect of screening people with a high risk of developing lung cancer with chest radiograph (CXR) and sputum cytology. The MLP (the largest of all three and funded by NCI) after 6 years of screening and about 14 years of follow up, concluded that screening with CXR does improve the survival but does not reduce mortality rate compared to the controled groups. In other words, CXR may be detecting a lot of biologically cancerous, but clinically benign cases that will improve the survival but it is not actually saving lives and that's why the difference in mortality between the two groups did not turn out significant. This result was followed by same results from MSKLP and JHLP. As a result mass screening for lung cancer, at least for individuals with high risk of developing it did not turn into public policy (as opposed to other cancers screenings such as breast cancer or cervical cancer).
So here is the question: it makes intuitive sense that the sooner you catch cancer, the better your chances of treating it. So why the the above RCTs prove the opposite? It's also worth mentioning that a few years ago the same controversy was involved in questioning the merits of annual mamography for women to screen for breast cancer. In this case again a few RCTs disprove the value of mamography screening while a lot of clinicians disagreed with the results. So where's the mystery? What seems to be inconsistent here? stay tuned.......:)

Catheterization Lab

This week I want to take a break from looking at my mentor clicking images, so I went to the catheterization lab in the cardiology department. I observed an angiography procedure. This procedure is used to visualize the blood vessels near the heart. The doctor first threaded a catheter into an artery of the groin region and pushes the tip of the catheter up to the major coronary arteries. Then a contrast agent is released from the tip to light up the blood vessels. Typical images from angiography are as showed below.

The patient has a stenosis in one of his arteries; therefore, an angioplasty procedure is followed. A typical stenosis region is as shown in the left image above (red arrow). It appears as a sudden narrowing of the blood vessels. After looking at the stenosis or blockage area, the physician asked one of his assistant to get a stent and balloon. Then, he uses a guidewire (basically a very thin wire that fits inside the catheter) to guide the stent through the catheter to the area of blockage and placed the stent there. Next, he uses the guidewire again to direct the balloon in place. Then the physician inflated the balloon, so it crushed the plaque and expand the vessels. Finally, he checks the x-ray to make sure the stenosis is no longer there.

Interestingly, a woman who is not a medical staff always walks back and forth between different catheter labs. After talking with a fellow student in the lab, I found out that she is actually from Boston scientific, a company making medical equipments. She is in the hospital most of the time, making sure the doctors know how to use their products, and introduces the doctors to their new products.

This week I also met with Thanh, a research scientist in the MRI imaging lab. He will be working with me on the T1 mapping project. After talking with him, I found out that my project is to develop an image analysis tool for the researchers and clinicians to perform t1 mapping analysis on a sequence of images. So basically I use Matlab to create a graphical user interface (GUI) for them. Well I guess the “good” thing is that I don’t need to kno what t1 mapping is after all.

The Emergency Room On A Saturday Night-Sunday Morning

NYC is a great place, lots of people to talk to, great food to eat, way to many ways to spend money. However, great educational-entertainment is easily obtained if you have access to the back-rooms of the ER at Cornell-Medical Center.....I DO!

Now I have seen many great things~Open Brain Surgery~Busted Aneurysms~Open Heart Surgery~Tendon/rotator cuff reconstruction. But nothing has compared to my 2 am visit to the ER after going out to a nice dinner!

The ER was cluttered with Manhattans elite; drunk CEO's with broken bones, as well as the not so fortunate stab wounded victims from a large street brawl. I was lucky that I went with my scrubs on, since it was hard to distinguish hospital-people in hustle and bustle.

It's hot and humid outside, but so cool in the OR

For the last two weeks I have been shadowing Dr. Schwartz, a neurosurgeon and research scientist at the hospital. So far it has been quite an experience. The first day was extremely hectic. None of us had any idea where anything was. I was nervous about meeting my clinician, mainly becuase I had no idea what to expect. I was given a yellow post-it note telling me to meet him at "Greenburg OR 3." It took me a while, but being a graduate student, I was able to find my way. I showed up at the check-in counter confused and lost in a dress shirt, tie and slacks, receiving just as confused looks from the staff. I told them I was supposed to meet Dr. Schwartz where they then proceeded to tell me that I would not be able to get into the OR with the attire I was currently wearing. After scrambling around, I was able to get some scrubs and head into the OR Room 19. When I first entered, I again received some of the same confused looks from the nurses and residents. The resident came up to me and told me my face mask was put on incorrectly. I felt pretty dumb, but he was nice about it and proceeded to show my how put it on correctly. Dr. Schwartz finally arrived and before I knew it, I was experiencing my first surgery: a muscle biopsy. The first day were relatively simple surgeries. The next two surgeries, were similar ones in that they placed a chemotherapeutic reservoir between the skull and the skin. From there, a catheter was connected and implanted into the brain to help release the drug deep into the brain.

The next day, I observed an endoscopic removal of a tumor through the nasal cavity. The operation consisted of the entire removal of the pituitary gland, which the tumor had infiltrated. The entire surgery took about 7 hours. It was amazing to see how much the doctors were capable of doing despite the size of the tools and how little degrees of freedom they had. Later that week, I saw a removal of the lesion (possible tumor) in the temporal lobe in one patient and the removal of the amygdala and hippocampus in another. I observed a clinical experience in which electrodes were used to stimulate and record electrical activity of the epileptic tissue. As a part of my project, I wll be analyzing some of the clinical data, which should be very interesting.

This week has been just as interesting. Monday there was a case in which the patient had to be kept awake while the brain tumor (near the motor cortex) was being removed. The doctors had to make sure they did not commit any collateral damage to the brain. I also observed a patient that had surface and depth electrodes implanted into the brain. I believe they will be used to monitor his brain activity to hopefully map the focal point of the seizures.

It has been a great two weeks so far, and I expect it to get even better.

Plastics Make It Possible

Every Monday morning at 7 am the Department of Plastic Surgery has their Divisional Academic Conference to discuss cases of interest from the previous week. Each fellow chooses one case that is of particular interest and guides the group through all of the intricate details. It was at this conference that I was scheduled to meet my clinician, Dr. Robert Grant, along with the rest of the plastics crew. I am very grateful that Dr. Grant chose to introduce me in this manner, as I was able to meet just about the entire team all at once and immediately begin to recognize the considerations involved in a plastics case. The meeting was brief, but educational…I was truly amazed at how knowledgeable every one of these surgeons are…they were not only freely tossing around language I couldn’t follow, but were also quoting coded procedures and classifications off the top of their heads.

After the conference, I followed Dr. Grant to his satellite ambulatory clinic where he holds office hours. This was a casual environment and a nice way to start my summer immersion. We saw patients together, followed by debriefing periods in which Dr. Grant would explain his thought process involved in the diagnosis and allowed me to ask questions on just about everything.

As Dr. Grant’s research lab is currently in flux for a few weeks, the remainder of the week was predominantly spent doing rounds with the plastics team and observing lots of procedures in the OR. While both of these experiences were very exciting, rounds were also very nerve-wracking. There are so many patients to see before we hit the OR that we were essentially running from room to room.

On the other hand, the OR is surprisingly much less stressful, yet still very entertaining. I essentially have the freedom to roam around the different rooms and observe the most interesting of the plastics cases...which is very cool. Some of the more interesting ones were a bilateral mastectomy with breast and nipple reconstruction, a ventral hernia repair via surgical endoscopy (using a tubular probe with light and camera apparatus to view internal organs on a monitor) with circumferential abdominoplasty, and an abdominal wall reconstruction after excision of a sarcoma …however, I will save the details for a later post.

Babies and Stuff

My clinician mentor is Dr. Frayer from the department of pediatric neonatology, a field that focuses mainly on the treatment of premature infants. Dr. Frayer will not be on service until July 1, so during the first week I made rounds with Dr. Schulman in the Neonatal Intensive Care Unit (NICU). The unit consists of two teams in which the residents of each are responsible for different patients, but each team is led by a primary physician. Despite the fast pace and the seriousness of some of the patients' conditions, the environment felt quite laid back, with many people cracking jokes (mostly by Dr. Schulman) during the rounds. I even found YouTube to be quite popular among the residents, much to my delight.

The conditions of the patients range from serious to stable. Two of the more serious patients in particular were of interest to me. Baby X (can't use the real name, or I will be fired), for example, was undergoing treatment using an experimental head cooling device called the CoolCap. It allows the baby's head temperature to be regulated by circulating cold water inside plastic tubes in contact with the head. It has been shown to prevent brain damage in newborns who have been oxygen deprived supposedly by reducing brain metabolism, although the mechanism is not totally understood. What is understood, however, is that the CoolCap is far from cool looking. I suggested putting some type of design or insignia on it. If it was my kid, I'd probably write "mofo" on it, just so the other babies would recognize.

Baby Y (again, I'll get fired) was experiencing obstruction in the bowels, though the exact cause was unknown. It was decided last week to schedule him for exploratory surgery with Dr. Spigland (Nathan's clinician) on Monday. Having visited this patient each day last week, I felt compelled to see his operation. So I went yesterday, and it was pretty messy. Dr. Spigland started by first pulling out his intestines and examining them. There were many perforations, and several parts of the bowel were necrotic (it was literally falling apart). At the end, the small intestines were separated between the duodenum and jejunum (which are close to the stomach in the intestinal tract), and a tube was inserted. He was closed up, but will need additional surgery in the future. All of that surgery gave me a hankering for some German blood sausages.

My goal while I am here is to do rounds in the pediatric and adult ICUs as well to see how patients of various age groups are treated. In addition, I am working on a project involving the modeling of infant lungs, but I will have to write about that at a later point.

Radiology in NYPH

When I walked in to meet the physician I would be shadowing, Dr. Yankelevitz in Radiology, I was bit nervous. I interacted with him often in the past, mainly through working with my advisor Dr. Anthony Reeves and their many collaborations with one another. That was always with me in the place of an engineer, and the generic conversations basically going,

Drs.: "We need to measure this from XYZ data"
Engineers: "Sure, we can do that."

Followed by literature searches and then design/implementation of some algorithm to accomplish. In general though, we as engineers are usually never concerned with the finer points of patient care (unless you work in industry and then, understandably, you are concerned with anything that can help turn a profit), just how to get Y measure from X data. On the flip side, most doctors tend to treat the output from engineer designs as blackboxes. As long as the result is correct, their happy. Its just a fundamental difference in mindset. I think it will take a special set of people (like biomedical engineers) that take a step back from the super-specialized form of education that modern society praises and back into the realm of inter-disciplinary, generic, "I know some of a lot of subjects" education, so that no matter who you're discussing a project with, you can follow along, and possibly even translate from "Doctor-ish" to "Engineer-ese" and back. At any rate, I digress.

This would be the first time though that I would get to see things from a clinical perspective. The first time I would have to be more than an engineer in a sense, and that was a bit unnerving. Luckily, since I have collaborated with my doctor in the past, a part of me gets to stay an engineer, and that's probably a good thing. So I met with my doctor and since I have a seen alot more than just the images most people think of when they hear the word 'Radiology'.

So in my time here I have been able to see a many things. Lung biopsy's that were border-line absurd in difficulty (and therefore took far longer than normal), and which made me understand why Dr. Yankelevitz is world renowned for performing them. I've seen the histology and cytology that is done as part of the biopsy (i.e. something other than the black and white images that I'm used to seeing). I've been in the reading room where dozens of ICU X-ray images are read multiple times a day at rapid speed. I definitely have been busy this past week.

I know that soon I'm going to shadowing several more groups of people before my time is out, so we'll see how that goes.

Peace,
-Brad