Multi-centric, one arm phase II study. The first phase of the study will consist of an evaluation of the initial dental state of each subject based on a stomatological examination, an orthopantomogram, two bitewing radiographs (right and left sides) and an evaluation of all potential risks of caries and fractures. For all of subjects, a dental decalcification, dental care and/or avulsion if necessary, and afterwards, a dental splint will be performed before the start of RT treatment. Our previously developed predictive model for dental dose in function of the localisation of tumour and suspect lymph nodes based on the stomatological examination and on the pre-treatment imaging. An estimation of the intensity-modulated radiotherapy (IMRT) teeth dose will be made and translated into a colour based form of the pre-RT dental status. A contouring of the teeth will be performed and the planned dose for each tooth of each subject will be recorded by a dose volume histogram (DVH) curve based on the pre-treatment imaging. In the same way the mean dose and the V25 (the volume receiving 25 Gy) of the homo- and the heterolateral parotid gland will be calculated. Based on our predictive model, every tooth which potentially will receive more than 40 Gy and for which long term survival is compromised will be avulsed at least 2 weeks before the start of RT. After RT, the subject will have clinical follow-up with dental evaluation every 6 months for 36 months in order to identify possible dental events. At each consultation, a stomatological examination will be performed as well as two bitewing radiographs. An orthopantomogram will be done once a year. Furthermore, periapical X-rays will be performed if there is a dental complain or to refine a lesion visible on orthopantomogram.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
PREVENTION
Masking
NONE
Enrollment
40
Before radiotherapy, each subject undergoes a dental evaluation and if it is necessary, dental avulsions if their long-term survival is compromised (see in section 6.1.2) and if they are located in an area at risk to receive more than 40 Gy, so to develop osteoradionecrosis of the jaw. The avulsions should be performed as far as possible from the start of radiotherapy (RT) namely at least 2 weeks before irradiation to allow mucosal healing.
Radiotherapy: All Subjects will be treated by simultaneous integrated boost (SIB) intensity modulated radiotherapy (IMRT) / volumetric modulated arc therapy (VMAT).
CHU saint Pierre
Brussels, Belgium
Hôpital Erasme
Brussels, Belgium
Institut Jules Bordet
Brussels, Belgium
Risk of dental complication
Frequency of dental fractures according to the teeth radiotherapy delivered dose
Time frame: At 36 months after end of radiotherapy
Risk of dental complication
Frequency of dental caries according to the parotid radiotherapy delivered dose
Time frame: At 36 months after end of radiotherapy
Validation of a "predictive dose model" of radiotherapy
Predictive dose of radiotherapy according to the location of the tumour
Time frame: At 36 months after end of radiotherapy
Validation of a "predictive dose model" of radiotherapy
Predictive dose of radiotherapy according to the TNM stage
Time frame: At 36 months after end of radiotherapy
Validation of a "predictive dose model" of radiotherapy
Predictive dose of radiotherapy with the real dose of radiotherapy received
Time frame: At 36 months after end of radiotherapy
Comparison of the predictive dose of radiotherapy with the dental complication probability
Number of dental caries per patient
Time frame: At 36 months after end of radiotherapy
Comparison of the predictive dose of radiotherapy with the dental complication probability
Number of dental fractures per patient
Time frame: At 36 months after end of radiotherapy
Comparison of the predictive dose of radiotherapy with the dental complication probability
Number of dental avulsions per patient
Time frame: At 36 months after end of radiotherapy
Assessment of Quality of life
Avulsion-free
Time frame: At 36 months after end of radiotherapy
Assessment of Quality of life
Number of patients who developp an osteoradionecrosis of the jaw
Time frame: At 36 months after end of radiotherapy
Assessment of Quality of life
Outcome measure: completion of xerostomia questionnaire
Time frame: At 36 months after end of radiotherapy
Assessment of Quality of life
Outcome measure: completion of EORTC: QLQ-C30 questionnaire
Time frame: At 36 months after end of radiotherapy
Assessment of Quality of life
Outcome measure: completion of EORTC: QLQ-H\&N43 questionnaire
Time frame: At 36 months after end of radiotherapy
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