CFIMRT is Intensity Modulation for the OARs (Organ at Risk) !


Concepts of CFIMRT

CFIMRT is not a sort of IMRT which combined a number of small segments to make plans, whereas several conventional-sized parts are combined in CFIMRT. If there's any extensive high-dose area, the corresponding portion is to be cut with MLC (multi-leaf collimator), which shows the resemble the distribution of IMRT. That's why we call this method 'Cutting Field IMRT'.

The dose distribution almost equivalent to IMRT can be achieved easily by combining one or two rectangular rotation irradiations and approximately four fixed multi-port irradiation. All the examples given here are planned only through high energy-X-rays and neither various filters nor cauch movement is used. I strongly recommend you try a conventional method first, including CFIMRT, before choosing complexed irradiation represented by IMRT and 3DCRT.

If you are interested in CFIMRT, please contact me with e-mail.


I usually spare only 30 minutes for planning of CFIMRT including caluculating time using superposition algorythm.

This method is combined conventional techniques, composed of about 7 ports simple irradiation, and need no subsegments. A single therapy session is within 5 minutes by SIMTEC.

<Sample Case>

CFIMRT is such a simple and easy method that even an employee, a lay individual, from Toshiba Medical Co. was able to complete the plan (the image shown above) in only 30 min all by himself for the first try. This plan is made of 6 irradiation ports of the conventional field without any subsegments.


Why we can treat one patient within 5 min at one session?

Because we use autosequence by SIMTEC (SIEMENS).

Gantry angle : IEC (International Electrotechnical Commission)

1) First we treat the right side (of patient) by fixed ports.

The 270degs port is used for treatment, EPI, and Linacgraphy (treatment and QA).

2) Then we use rotational port(s).

 3) Next, we treat left side ports.

 4) At last, we treat 0 deg. port. This port is also used EPI, linacgraphy.

  This is sample, but almost all cases will be treated within 5 min.

But even if you don't use autosequence, you can treat within 10 min.

Comparison with IMRT and CFIMRT

Small segment                                                             

                               IMRT: yes                                                      

                           CFIMRT: no                                                

Total MU                                                      

IMRT: high                       

                     CFIMRT: almost equal with prescribed dose


                                                IMRT: inverse planning (correction by human's power is difficult.)
                          CFIMRT: forward planning (easy to correct plan)

Delivery time                                                            

IMRT: relatively long time     

CFIMRT: short (within 5 min)

QA procedures                                                            
IMRT: difficult                    

                       CFIMRT: same with conventional methodology


<And near future>


PTV is covered perfectly, and rectal dose is very very little!! Off course this plan was made by conventional fields. Its methodology will be announced later. It is called CF-Technology.

<Although I wrote the above-mentioned text in 2006, changing until it continues up to now twists it, and it is true.>

last modification date: 2014/08/15