Whole neck irradiation ( prescribe dose 50Gy )

 Whole neck irradiation (Level II - V )

 ( This plan was made with 4MV photon, but almost same plan can be made with 10MV photon )

Isocenter is just posterior of A hyoid bone. (rotational center)

MLC margin was set CTV + 1.0cm

port 1: 290-70 CW rotation (140deg arc, rectangular shape), dose indication point is isocenter.

port 2: spinal cord is cut, dose indication point is lt additional point.

port 3: spinal cord is cut, dose indication point is rt additional point.

The dose indication points of other ports are isocenter.

Parotid glands are cut just near side of CTV.

Caution! Please be cautious in esophageal dose enough.

Intensity-modulated radiotherapy for nasopharyngeal carcinoma: Clinical correlation of dose to the pharyngo-esophageal axis and dysphagia.

Fua TF, Corry J, Milner AD,et.al. Int J Radiat Oncol Biol Phys.

In this article, they said 95% (19/20) patients developed Grade 3 dysphagia and the mean dose of pharyngo-esophageal axis was 55.2 Gy. If you try to arrange this template, please be cautious in esophageal dose enough.

Nasopharyngeal treatment plan ( application of this template )

whole neck 50Gy GTV 70Gy

whole neck 50Gy GTV 70Gy (same template)

Whole neck 60Gy GTV 75Gy

Caution!  Whole neck->60Gy maybe overdosage

Dr. N. Lee said that she treats metastatic neck lymphnodes with 60Gy IMRT previously.

Nancy Lee M.D. and Ping Xia Ph.D. In response to Drs. Clark et al. Int J Radiat Oncol Biol Phys. 2003 Mar 15;55(4):1150

 So I planed imaginary this plan. But I think that whole neck irradiation for 60Gy may cause sever complaints. Indeed, in MSKCC, nasopharyngeal cancer patiens were treated for 54Gy (1.8Gy/fr) recentry. Its resulut is very good. Again, I think whole neck irradiation for 60Gy will be overdosage.

Wolden SL, Chen WC, Pfister DG et.al. Intensity-modulated radiation therapy (IMRT) for nasopharynx cancer: Update of the Memorial Sloan-Kettering experience. Int J Radiat Oncol Biol Phys. 2006 Jan 1;64(1):57-62.

Whole neck ( Level I-V ) using same template

Application for non-MLC machine

 

Center Splitting by CFIMRT

It comparable so called 'Split-Field IMRT'

last modification date: 2008/1/1