ccessful at first due to the damage caused to surrounding tissues. Then the analogy drawn from a simple story gave insight on how to focus the rays on the cancer and not harm the surrounding tissues and organs. The story goes like this.A small country was ruled from a strong fortress by a dictator. The fortress was situated in the middle of the country, surrounded by farms and villages. Many roads led to the fortress through the countryside. A rebel general vowed to capture the fortress. The general knew that an attack by his entire army would capture the fortress. He gathered his army at the head of one of the roads, ready to launch a full-scale direct attack. However, the general then learned that the dictator had planted mines on each of the roads. The mines were set so that small bodies of men could pass over them safely, since the dictator needed to move his troops and workers to and from the fortress. However, any large force would detonate the mines. Not only would this blow up the road, but it would also destroy many neighboring villages. It therefore seemed impossible to capture the fortress. However, the general devised a simple plan. He divided his army into small groups and dispatched each group to the head of a different road. When all were ready he gave the signal and each group marched down a different road. Each group continued down its road to the fortress so that the entire army arrived together at the fortress at the same time. In this way, the general was able to capture the fortress and overthrow the dictator.This simple story was the basis for intensity modulated radiotherapy (IMRT). This is a technique used to treat cancerous tumors on which a removal operation could not be performed. Interesting dose distributions generated by IMRT allow a better sparing of normal tissues with decreased acute and late toxicity, and offer a window for further dose escalations. (De Neve W; Claus F; Van Houtte P...
