[Constraints of the dentist are consistent with the results of an optimal irradiation with modulated intensity in N0 oropharyngeal cancer].

PURPOSE

We compared intensity-modulated radiotherapy and 3D-conformal irradiation in oropharyngeal cancers according to the requirement of dentists.

MATERIAL AND METHODS

From the files of seven patients with cancer of the oropharynx, two dosimetry plannings for 3D-conformal radiotherapy and intensity-modulated radiotherapy with tomotherapy were performed. The dose distributions in the target volumes and organs at risk in relation to the dental sphere were compared.

RESULTS

For the planning target volume of the primitive tumour sites, average values of V95%, D2%, D98% and of the conformal index were statistically in favour of tomotherapy. For the planning target volume of node areas, averages values of V95%, D2%, D98% were statistically in favour of tomotherapy. For ipsi- and controlateral parotide glands, average values of V15Gy, V26Gy, V30Gy, V40Gy were significantly lower for tomotherapy. For the submaxillary glands, average values of mean doses and V40Gy were statistically in favour of tomotherapy. For the buccal cavity, the average values of V45Gy were statistically in favour of tomotherapy. For ipsi- and controlateral masseter muscles, the average values of mean doses were statistically in favour of tomotherapy. For the ipsi- and controlateral temporomandibular joints, average values of mean doses and V60Gy were statistically in favour of tomotherapy. For mandibular bone, average values of mean doses and V40Gy, V50Gy, V60Gy and V70Gy were statistically in favour of tomotherapy. For maxillary bone, average values of V40Gy, V50Gy and V60Gy were statistically in favour of tomotherapy.

CONCLUSION

The radiation oncologist can constrain the intensity-modulated radiotherapy dosimetry to the needs of dentists to prevent or improve dental care and quality of life.