Friday, April 25, 2014

Nuclear Medicine

In one of my previous post, I wrote that my class (consisting of 28 students) will have a trip to the National Cancer Institute (IKN) & Putrajaya Hospital (HPj). Alhamdulillah, the trip was a success. It was tiring but fun and I learned a lot.

We arrived at IKN at around 9:15AM and were lead to the cafeteria for our breakfast.

IKN from side view. On our way to the decay tank.
A bit of background about IKN

It is a relatively new institute and only started to fully operate early this year. Costing about RM709 million ($215 million) and were located nearby the Putrajaya Hospital in Precinct 7.
Unlike normal hospital, IKN not only treat and manage cancer patients but would also act as a reference and research centre on cancer in Malaysia and regionally. Thus, giving its the status of an institute.

Because of its relatively new operations, we are the first set of students to ever have a tour at IKN.

It has 252 beds, is equipped with six radiotherapy bunkers, four surgery theatres, 28 rooms for iodine radiotherapy for thyroid cancer and also a a unit for day chemotherapy treatment. (source)

The 28 rooms for iodine radiotheraphy makes it the largest thyroid cancer theraphy center in the world. Some hospital in europe only have 16 rooms. Two of those rooms is equipped with dialysis facility for patients that might have kidney problems.

Lectures by IKN & HPj representatives
Briefing & lectures

Before we start touring the facilities, we were given a brief lecture about the history of IKN, its facilities and also the physics concept for the treatment and machines.

Some of the departments in IKN
  • Department of Oncology (this is the general cancer treatment using Chemotheaphy) 
  • Nuclear medicine (this is what I'm going to explain). 
  • Radiology. [External Beam Theraphy using Linear accelerator (Linacs)]
  • Diagnostic imaging. (MRI, Ultrasound etc)
  • Clinical pharmacy. 
  • Palliative care. (this is for patients that have no hope to survive, the treatment is only to lessen his/her pains)

Roles of Nuclear Medicine (NM) physicist in IKN 
  • 70% is radiation protection.  
  • Radionuclide theraphy using unsealed sources (Iodine-131).
  • Quality control (QC) for radiation equipments.
  • Research & development.

*A very important point to readers.
In nuclear medicine, there are two main components. Namely diagnosis and theraphy. Diagnosis is for the detection/identification of cancer while theraphy is for curing the cancer (by killing the cancerous cell with radiation).

Differences of Nuclear Medicine & Radiology

Nuclear medicine uses unsealed and sealed sources for diagnosis & theraphy while in radiology department only use sealed sources. What is this sealed and unsealed sources? Sealed radioactive sources is where there is no direct exposure with the sources to the patients.

Example of sealed sources
  • Computed Tomography (CT-scan). This is for diagnosis using x-ray.
  • Linear Accelerator (Linacs). This is for theraphy using high energy x-ray.
  • Co-60 theraphy. 

Example of unsealed sources
  • The consumption  of radio-iodine (I-131) for thyroid cancer treatment.
  • The injection of Technetium-99m (Tc-99m) into the body, detection using gamma camera (SPECT). This is for diagnosis.
  • The injection of Fludeoxyglucose (FDG) into the body, detection using Positron Emission Tomography (PET). Diagnosis purposes.
An open Isolation chamber. Normally it is closed.
Iodine radiotheraphy unit in NM IKN

Back to the tour. We were broken into four groups. 
The first place that my group get to visit is the iodine radiotheraphy unit. Consists of 28 rooms. Each two rooms is inside an isolation chamber. (see left)

Inside each room there is a CCTV for monitoring the patients. Radiation detectors (it is conceled inside the ceilings) for radiation monitoring. An intercom for contacting the nurses and of course toilet. The waste from the toilet will flow to the decay tank.

Before the patients drank the Iodine-131 (it has half-life of 8 days), they will be consulted by the doctor in consultation room. There they will be briefed with what they can and can't do inside the room. For example, the patients are advised to change clothes only in the toilet and if they feel like vomitting do not do it in the sink rather in the toilet bowl. This consultation is very important because once they went into the room inside the insolation chamber there will be 100% isolated. No visitors, even the nurses can't enter the room. The nurses can only enter the isolation chamber to supply food. 

Iodine radiotheraphy is a secondary treatment for thyroid cancer. Usually the thyroid gland of the patient that have been infected with cancer is removed surgically first. Only after that will the doctor prescribe them with Iodine-131 to kill all the remaining cancer cell.

The Iodine-131 is prepared by the pharmacists in that unit. Either 80mCi (read as 80 millicurie), 120mCi... I don't remember.

The average duration the patient need to stay in the room is 5 days but it all depends on the radiation activity.

Diagnostic unit in NM IKN
Next, we went to the diagnostic unit in NM.
The concept of SPECT is the patients are injected with a radiotracer (Technetium-99m) that emits gamma radiation, the radiation is then detected by detector on the machine.

Gamma ray is used because it have high penetrating power and low ionisation energy.

Technetium-99m have a half-life of 6 hours making it very suitable to be injected into the body.

A machine to see the iodine uptake by thyroid

A radioactive iodine uptake (RAIU) test uses a radioactive tracer and a special probe to measure how much tracer the thyroid gland camera.gif absorbs from the blood. The test can show how much tracer is absorbed by the thyroid gland and if it is evenly spread in the gland. This helps your doctor know if the thyroid gland is working properly. The radioactive tracer commonly used in this test is iodine. A radioactive iodine uptake test is done to find problems with how the thyroid gland works, such as hyperthyroidism. An RAIU test may be done at the same time as a thyroid scan. (source)

1:30PM we have our lunch and prayer break.

Radioactive feces are inside that tank bro

After the break we went to the 'bunker' to see the decay tank outside of the main building.
There is a vacuum systems, grinder (to grind feces), four large tanks, a lot of pipes and other uninteresting stuff.

Uninteresting but very important parts of the facilities.

NM department in HPj

Putrajaya Hospital (HPj)

Nuclear Medicine Department in HPj

There are two facilities in NM department at HPj. The radiophamacieutical preparation facility (Cyclotron) and the PET-CT services.

Cyclotron by Hitachi GE.
This is the only cyclotron that is owed by the government of Malaysia
It cost RM9 million ($2.75 million)
See that small bottle? It is enriched H2O.
 The oxygen is oxygen-18 (O-18).
 That small bottle cost RM4000 ($1223)
Cyclotron is a particle accelerator, to produce new nuclides. For this cyclotron, the radionuclide Fluorine-18 (F-18) is produced. This F-18 will be tagged with glucose to produce the radiophamacieutical product, Fludeoxyglucose (FDG).

At the center of cyclotron there is an ion-source (Hydrogen gas). The hydrogen ion, either H- or H+ (depends on the type of cyclotron) will be accelerated in spiral direction. And will hit a target, in this case enriched water.

Still remember F = qvB sin θ ?

I don't quite sure but I think 1ml of enriched water (O-18) will yield around 5000mCi of F-18.
One process takes roughly two hours. 1mCi of F-18 is RM22. So one process will yield roughly RM110000 ($33654) worth of F-18. If you want to get rich fast, buy a cyclotron and start a F-18 bussiness. Haha.

The F-18 produce here will usually be used at HPj or supplied to other goverment hospitals. But sometimes private hospitals also ordered their F-18 here.

Private hospitals that have their own cyclotron includes Beacon Hospital and the very expensive Prince Court Hospital.

Watch this very simple video about cyclotron


At the front is CT

At the back is PET

You can read about PET yourself right?


PS : The trip was fun mainly because the staff/guiders of the tour was very friendly. Some of the staff are ex-nuclear science students.