Teacher: In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.
Teacher: Now, understand the problem? If you are still confused, see the following example:
The Inheritance Cycle is a series of fantasy books written by Christopher Paolini.
Solution: The Inheritance Cycle is a tetralogy of young adult high fantasy novels written by American author Christopher Paolini.
Reason: The output sentence elaborates on the input sentence without changing its general meaning e.g. "tetralogy of young adult high fantasy novels".

Now, solve this instance: Besides the tumor itself , the target for the radiation may also include the lymph nodes that drain the area .
Student:
Besides the tumour itself , the radiation fields may also include the draining lymph nodes if they are clinically or radiologically involved with tumor , or if there is thought to be a risk of subclinical malignant spread .