Electrical and Mechanical hazards are important factor in the hazards evaluation. Mainly hazard evaluation can be divided into two types one is External and another one is internal hazard. Out of these we are going to see the external hazards (electrical and mechanical hazards).
Electrical hazards are the one which arises due to electrical failure or component failure or malfunction of the equipment during the treatment.
1. The first and foremost thing is mishandling of the machine leads to malfunction as well as severe effect. So that, trained personnel should be handled the machine is a good practice.
2. In linear accelerators the output of the machine will change day by day due to some power fluctuations and other reasons. It might be increase or decrease, so that we need to check the output of the machine daily. If it’s not it leads to under or over dosage to the patient.
3. Improper accessory mounting is also leads to wrong treatment as well as potential damage to the patient.
4. Delivering the incorrect wedge value during the treatment is also a one of the electrical hazard. (Suppose if, the patient is planned for 30 degree wedge in a particular field but, the machine is delivering the 60 degree wedge distribution)
5. Software malfunction of the machine leads to the selection of the different energies other than the prescribed one automatically during the time of execution.
6. Due to the high voltage, the electric shock will also be possible sometimes.
7. The treatment room monitors or control console monitor will show one reading but, in the machine other sets of reading could be there. It is due to the malfunction of the software.
1. The main mechanical hazard usually happen all the treatment units is that the optical field and radiation field of the treatment machine congruence will not be there. This has to be checked as weekly or periodically.
2. Treating the patient in the physics mode of the linear accelerator will leads to potential hazards.
3. The external accessory latching will failure during the treatment and fell down on the patient it leads to severe injury.
4. The opening of the collimator or MLC’s other than the prescribed one will also leads to potential hazards.
5. The failure or malfunction of the dose monitoring chambers leads to potential hazard to the patient. Because it will give always false reading until or unless detected.
6. The tip of the SSD scale is not sharp edged means it will show the some variation in the SSD when compared to the digital.
1. The mechanical and electrical hazards of the machine can be reduce by,
a) Periodic servicing and checking of the machine by service engineer
b) Should not ignore the minute problems in the machine
c) Periodic quality assurance should be done to check it
1. Lecture notes on Radiation Hazards Evaluation and Control by R.K. Yadav, BARC, Mumbai, India