Question

Type of medical service (radiation therapy): Conventional RT, interstitial and intracavitory brachytherapy, ortovoltage
radiotherapy.

1. What is the assessment of the economic aspect of the technical specification?
2. How much accuracy in the delivery of the prescribed dose and the effectiveness of radiation
therapy is improved based on this technical specification?
3. How will this technical specification affect the regulations for the Quality Assurance of radiation
therapy?
4. What impact will this technical task have on the qualifications and competence of each
employee?

Answer 1

1. Economic aspect: Conventional radiotherapy is done in sessions and treatment to normal cells is needed intermediately. Hence the cost for the entire treatment is comparatively lower than Brachytherapy and Orthovoltage

Orthovoltage device has mosfet tubes and beryllium windows which makes it partially expensive.

Brachytherapy device also come in varients based on the region of interest. There are seperate devices for skin, breast tissue, rectum and GI tumors. There are also much advanced varients in intrabeam and photoelectric therapy and they are effectively costly. Zeiss lens for intrabeam is much costlier. Voltage based varients also exist and they are based on the capacity and usage characteristics

2. Accuracy in delivery: Beam align verification in conventional radiotherapy are visualized through port films and electronic portal imaging. In Orthovoltage RT there is non uniform dose disribution and maximum dose is applied on the skin. Dose distribution is apparantly non-present in Conventional RT.

Delivery verificationa nd modification is adept and is done by pulse by pulse basis and hence there is much more accuracy in Brachyherapy RT devices.

3. Effect on the regulations on quality assurance:

Feasibility sub studies and toxic assessment is performed on more number of random patients in coventioanl RT. Example: A thoracic SABR safety sub study had minimum of 50 patients and unacceptable deviation is much higher

For Brachytherapy and Orthovoltage there is comparatively more number of acceptable variation and less deviation per protocol

4. Impact of the tech specifications on each employee:

For conventional radiography a radiophysist and a physician are compatible to work with the machine. Brachytherapy and Orthovoltage devices need a tomographist and a radiophysist for effective treatment, Adjustability of the volatages and the device handling should be professional and any error through deviation proves costly.