Cancer is a dreadful disease characterized by out-of-control cell growth. The cancer harms the human body when damaged cells divide uncontrollably to form lumps or masses of tissue called tumors. Radiotherapy (RT) is one of the major modalities of cancer treatment and every alternate cancer patient will require radiation during the course of treatment. Over the years, RT has progressed considerably towards this goal by the development of three dimensional (3D) conformal radiation therapy techniques such as IMRT, Stereotactic Radiosurgery and Radiotherapy (SRS/SRT), Brachytherapy and etc. These techniques are becoming standards of practice benefiting a significant proportion of patients. Therefore the verification of the actual dose delivery is vital to the effective delivery of conformal RT. Conventional dosimeters such as, ion chambers, thermoluminescent dosimeters (TLDs) and radiographic film are only 1 and 2-D dosimeters, and therefore are limited in their ability to integrate radiation dose over 3-D volumes. Gel dosimetry is the only 3-D dosimetric technique which is capable of recording and integrating complex 3-D dose distributions and offers comprehensive verification.

Gopishankar Natanasabapathi is working as Medical Physicist for the past 17 years at AIIMS, New Delhi, India. His main area of expertise are Radiosurgery, 3D dosimetry, film dosimetry. At present he is actively involved in several research projects and guiding research scholars.