Friday, July 25, 2008

Chemotherapy

My initial 3 posts on Cancer Centers focused on radiation therapy. The linear accelerator, brachytherapy and a few of the more unique radiation treatment systems (The Gamma Knife and The Cyber Knife). These devices require rooms that are equipment intensive and require shielding to contain the radiation.

By contrast, chemotherapy allows a very open room design concept. The terms infusion therapy, chemo, and oncology are used interchangeably. They refer to an additional form of cancer treatment. Sometimes used as the primary treatment, but typically used in concert with radiation therapy. Chemotherapy or "Chemo" is normally delivered as an IV fluid. The chemicals are harsh on the patients system, but they are not radioactive. However, just as in radiation treatment, the treatment attacks healthy cells in addition to the cancer cells. Hair loss, weakness, vomiting and a host of other adverse side-effects are created for the patient.

The chemo treatment typically involves being hooked to an IV for 90 minutes. (There are also some inhaled treatments, but this delivery method is rare.) Depending upon the patient, this duration may be longer or shorter. The patient population is varied. Age, sex, weight, health, etc. cover all extremes. Improved cancer screening and detection means otherwise healthy patients are being treated along side very weak and frail patients. The very sick inpatients may receive a chemo treatment in their hospital room. Typically both inpatient and outpatients are intermingled in the chemo area.

Patients normally sit in a recliner chair.

When planning for a chemotherapy area, there are several factors the design team should keep in mind:

1) Patient comfort
Most IV therapy areas are "communal" in nature. The patients are able to see each other and interact. A warming cabinet to provide a warm blanket to patients who are cold will allow the room temperature to be kept at a more moderate temperature. With weight loss and frailty, the ability to maintain body heat is marginalized. A comfortable seat, comfortable temperature and a choice on their individual level of privacy are important.




2) Patient Sensitivities
There are many adverse side-effects to chemo therapy. Among them are sensitivities to certain smells and reduced immune function. As best as possible the space should remain free of odors and fragrances. That means no microwave for popping popcorn or coffee pots for making coffee. The environmental services crew (Housekeeping) will sometimes use different cleaning solvents in the area to minimize any lingering smell. It is a good idea to plan the room air changes beyond the code minimum. I believe the recommended room air change rate is 12 per hour. This also helps to avoid cross infection of patients who might otherwise come in contact with an airborne virus or bacteria.


3) Patient Entertainment
In this age of ipods and video games, a 90 minute chemo session can be passed more easily with a personal entertainment device. A common area TV is difficult to view when cubicle curtains are in the way. An individual TV with pillow speaker is the ideal. Patients should also have the option of bringing their own headphones and media players.



4) Materials
In a new facility, that new carpet smell can be nauseating for some patients. Take care in selecting your flooring, paint and fabrics to minimize passive emissions. With the green movement in full-swing, talking to your vendors should reveal some products to meet these requirements.


Creating an environment that is comfortable and accommodating to varying patient needs is the goal.

Samples:

Here is a chemo infusion area looking rather clinical:





Here is another one with a more pleasing aesthetic feel.





Here is a virtual walk-thru of a very nice infusion area. I doubt very many projects could afford this.

No matter your budget or patient population, if you are planning an oncology area and do not have hands-on clinical experience it is a good idea to spend some time on a site tour to get a feel for the space.

Saturday, July 12, 2008

Cyber Knife, Gamma Knife and others

In addition to the more typical linear accelerator and brachytherapy unit designs, there are also radiation treatment units offering a unique design approach. Two of these are:

The Cyber Knife (Manufactured by Accuray) which uses a robotic arm and highly sophisticated 3D planning software to offer full body treatment. Here is a video overview of the system. You can see that the robot arm and patient gantry move to achieve the best access to the tumor.




Gamma Knife (Manufactured by Elekta), specializing in brain tumors. The system uses about 200 low-dose beams of energy to focus on the brain tumor. This allows the healthy brain surrounding the tumor to receive a low-dose of radiation and the tumor to receive the combined energy of all the beams.

Here is the manufacturers video about one of their 3 current models:




The design of all these systems are unique because their inventors have taken different approaches to building their mouse-trap. The ultimate goal is the same: Deliver a lethal dose of radiation to the tumor, while minimizing damage to the surrounding healthy tissue.

For each of these devices, the room shielding requirements are similar to conventional Linear accellerators. Please view the previous Linac post for details.

Tuesday, July 1, 2008

Brachytherapy

Brachytherapy is an umbrella term used to describe three forms of radiation delivery: High Dose Rate, Low Dose Rate and Pulsed Dose Rate. These are all delivered via a machine frequently referred to as an "afterloader". So the terms brachytherapy and afterloader therapy are interchangeable.

The three deliver methods are simply variations in the strength and frequency of the dose. HDR (High Dose), LDR (Low Dose) and PDR (Pulsed Dose).







In brachytherapy, the patient and afterloader are placed into a lead shielded room. The afterloader contains a radiation source that is safely contained within an integral lead container. Tubes are connected between the patient and the afterloader to allow wires to feed the radiation source from the afterloader to the cancerous area in the patient. Brachytherapy is common in brain, prostate, cervical and many other types of other cancers.


The planning criteria for the room includes the following:
1. The room must be shielded to prevent radiation exposure to the adjacent areas. (Walls, floor and ceiling).

2. Both audio and video communication are used to maintain surveillance and communication between the patient and the technician. A CCTV camera and an intercom are used.

3. The afterloader is typically housed in a lead lined room in the oncology department or cancer center and transported to the patient.

Brachytherapy can occur in a lead-lined patient room or within a specialized room designed specifically for brachytherapy. If available, a linac vault can also be used. The ability to contain the radiation within the room, allow the staff to maintain visual and audio communication, and allow the transport of the afterloader from its "home" to the treatment space are the key design criteria.