Prospective study on the dose distribution to the acoustic structures during postoperative 3D conformal radiotherapy for parotid tumors

Abstract

Post-parotidectomy 3D-CRT is associated with relatively low doses to the ear and the surrounding structures. Post-RT audiometry did not show any permanent (neither conductive nor perceptive) hearing impairment. Only in 3 patients were there signs of transient unilateral dysfunction of the Eustachian tube observed during the first few months after RT. Longer follow-up and larger patient series are warranted to confirm these preliminary findings.

Radiotherapy for vestibular schwannoma: Review of recent literature results

“…A crucial issue remains the dose constraints for critical structures, first of all the inner ear that should be respected in order to limit long term side effects. [34][35][36][37][38] These constraints change by using different fractionation schedules and have to be taken carefully into account, especially when using a single shot radiation as in SRS (Table 3).…”

Effects of radiation on the temporal bone in patients with head and neck cancer

“…In that study, the mean radiation doses to the external auditory canal and middle ear cavity were 45.2 Gy and 37.4 Gy, respectively; the maximum doses were 64.5 Gy and 63.3 Gy, respectively . Jereczek–Fossa et al studied 17 patients who received postoperative 3D conformational radiotherapy for parotid gland neoplasms. The mean radiation doses were 44.8 Gy at the ipsilateral external auditory canal, 39.0 Gy within the mastoid cavity, 33.0 Gy within the external auditory canal, 19.6 Gy at the Eustachian tube, 19.6 Gy at the semicircular canals, and 19.2 Gy at the cochlea …”

“…Tumors of the nasopharynx and parotid gland have been classically associated with radiation injury to the temporal bone . Depending on the tumor location, target volumes, and technique used, doses as high as 70 Gy may be intentionally delivered to portions of the temporal bone (see Figure ).…”

“…Jereczek–Fossa et al studied 17 patients who received postoperative 3D conformational radiotherapy for parotid gland neoplasms. The mean radiation doses were 44.8 Gy at the ipsilateral external auditory canal, 39.0 Gy within the mastoid cavity, 33.0 Gy within the external auditory canal, 19.6 Gy at the Eustachian tube, 19.6 Gy at the semicircular canals, and 19.2 Gy at the cochlea …”

Proton versus conventional radiotherapy for pediatric salivary gland tumors: Acute toxicity and dosimetric characteristics.

“…Third, given the rarity of the tumor in the pediatric population, the X/E RT cohort included both EBT and IMRT plans. Although IMRT has largely become the mainstay of head and neck RT, its application to salivary tumors is still under investigation and has thus not entirely replaced EBT [36][37][38]. EBT may actually be particularly appropriate given the superficial location of the tumor.…”