The Radiation Physics Section (RPS) focuses on the therapeutic applications of radiation in medicine. The primary activities are devoted to clinical physics and quality assurance services for cancer patients receiving radiation therapy. The RPS aims to provide the best clinical physics and quality assurance services to radiation oncology and also to maintain a continuous quality improvement program.
The RPS is the largest section in the department. Its responsibilities include: quality control for the therapeutic linear accelerators, simulators, CT scanners, treatment planning systems and brachytherapy equipment. The section also plays a vital role in selecting suitable radiation therapy equipment, designing facilities’ shielding and obtaining accurate data from equipment used for clinical services. The section supports the treatment of more than 1,500 cancer patients per year by providing more than 3,000 medical physics procedures annually.
In 2006, the RPS, in collaboration with the Oncology Center, launched a state-of-the-art intensity modulated radiation therapy (IMRT) service, which became the de facto cancer treatment technique at KFSH&RC covering more than 24 tumor sites. In 2009, RPS spearheaded the program for the procurement of the advanced modes of high-precision and innovative radiotherapy techniques, TomoTherapy, CyberKnife and RapidArc, as well as for the acquisition of a new large-bore CT scanner. Future plans for expanding the treatment services include Image Guided Radiation Therapy (IGRT), Intra-Operative Radiation Therapy (IORT) and Hadron therapy. Our principle aim is to operate a centre of excellence in clinical medical physics and radiation oncology. Specific duties of the RPS include:
CLINICAL DOSIMETRY & TREATMENT PLANNING UNIT
The Clinical Dosimetry and Treatment Planning Unit (CDTPU) is a sub-section of the RPS. It comprises of medical dosimetrists and physicists. The group works closely in collaboration with radiation oncologists, radiation therapists, imaging physicists, radiologists, surgeons and radiation biologists. It is charged with conducting radiation treatment plans and dosimetric calculations for a wide variety of malignant cancers and benign diseases.
The aim of radiation treatment planning is to design plans that optimize the dose to tumor volumes while minimizing the dose that vital organs and normal tissues receive. This is achieved with sophisticated computer algorithms and state-of-the-art planning techniques using various radiation energies, beam modifiers, intensity modulation, etc. The latest image fusion techniques are used to fuse CT with MR and PET images to assist the radiation oncologists in delineating tumors accurately. Extensive QA is performed regularly to ensure that actual treatment is delivered as planned.
Every plan and calculation performed by dosimetrist or physicist also has an independent check by another physics staff member. Also Intensity Modulated Radiation Therapy (IMRT) plans are further checked with sophisticated QA software before the patients are treated.
IMRT was implemented in July 2006 for the first time to treat a patient with nasopharyngeal cancer. KFSH&RC was the first institution to employ this state of the art technique in the Kingdom. Currently in the Kingdom only IMRT is able to conform to complex tumor volumes while better sparing adjacent critical organs. However KFSH&RC will soon again be at the fore-front by introducing new modalities that will possibly even improve on what IMRT offers. Clinical consultation is provided to radiation oncologists to assist in offering the best possible individual treatment plans for their patients.