4A01b-LINAC MLC Acceptance and QA for IMRT

Ching-Chong Jack Yang, PhD

Radiation Oncology Dept.

Monmouth Medical Center

300 2nd Ave

Long Branch, NJ 07740

Modern LINAC has many features which can automate and improve the radiation treatment delivery efficiency. Multi-Leaf Collimator (MLC) is one of the items which improves the delivery efficiency dramatically. MLC was implemented in early 90’s to replace the customized blocks, automatically shaping treatment portals and sequencing delivery can reduce the overhead of staff time and increase patient daily treatment numbers. When MLC based IMRT was introduced in mid 90’s, the MLC punctualities were extensively tested and the QA procedures were implemented to maintain the delivery efficiency. Using MLC for IMRT delivery, it went through lots of wear and tear of the machine mechanical and electronic components, QA procedures for MLC becomes very important for LINAC. Routine and annual QA as well as acceptance tests will be introduced in this lecture, preset accepting criteria are also addressed in details. Based on the different delivery methods (dMLC, sMLC and IMAT), the requirements for MLC are different. We will introduce the daily, weekly, monthly, and annual QA process for MLC performance evaluation, which are the key success for IMRT treatment delivery.