MANAGEMENT OF A PATIENT UNDER CERVICOFACIAL RADIOTHERAPY
1-Radiotherapy
Therapeutic modality used in cancerology, intended to destroy tumor cells.
It allows a precise dose of ionizing radiation to be delivered to the tumor and its extensions.
2-Indication
- Curative radiotherapy: (to cure)
- Small tumors, radiosensitive or inoperable tumors.
- Local recurrence, lymph node metastases.
- Palliative radiotherapy: (to provide relief when there is hope of recovery)
- Large tumors.
- Inoperable patients (general problem).
3-The different types of radiotherapy
Radiotherapy is constantly progressing, it is impossible to describe all the techniques in our course. They all aim to focus the rays as precisely as possible on the tumor and to spare healthy tissue as much as possible.
Standard conformal radiotherapy
This is “classic” radiotherapy. Anything outside the irradiation zone is not irradiated. Side effects cannot appear outside the irradiated zone.
Intensity-modulated radiotherapy (IMRT)
Is a highly technical procedure. It consists of varying the shape of the irradiation beam during the same session to adapt to the constraints of shape and volume of the organ to be treated.
Stereotaxic radiotherapy
This technique can only be used for the treatment of small volume cancer. It consists of using few radiotherapy sessions but delivering large doses at each of these sessions.
4-Fundamental notions
- Dosimetry
Study of the doses received by the different points of the irradiated volumes. Expressed in Grays (Gy).
- Target volume
Corresponds to the tumor volume to be reached by the rays in the same position in order to control the regression of the tumor and limit the after-effects on the surrounding tissues.
- Irradiation fields
In the case of VADS tumors, these include:
The salivary glands.
The jaws.
Teeth.
The lymph node areas.
MANAGEMENT OF A PATIENT UNDER CERVICOFACIAL RADIOTHERAPY
5-Complications and after-effects
5-1-acute complications
5-1-1-Complications involving the skin covering
– From the third week, at 20Gys.
– Pigmentation, epidermatitis, pruritus of the irradiated area.
– Hair loss.
– Repair 6 weeks after stopping TRT.
5-1-2-Complications involving the oral mucosa.
- The radio is silent:
- Iatrogenic, painful stomatitis induced by ionizing radiation.
- Functional signs: pain, dysphagia, speech disorder.
- Time to onset: 10 to 15 days after the start of TRT.
- Duration: Persists 2-3 weeks after TRT ends.
- Physiopathology: Mucositis is a complex biological process
We describe 4 phases:
– inflammatory phase (vascular)
– epithelial phase
– ulcerative phase
– remission phase
- Risk factors:
- Dose and duration of irradiation
- Hyposialia
- The bad HBD
- Smoking
- Mucous candidiasis:
Quantitative and qualitative changes in saliva
↓
Decrease in PH
↓
Development of acidogenic flora
↓
Bacterial and candidal infections
5-1-3-Taste disorders “Ageusia”:
- Disturbance of taste function.
- Settles in from the second or third week.
- From 30 Gys.
- Irradiation of sensory receptors of the mucosa.
- Metallic taste sensation.
- Regression 4 to 6 weeks after the end of treatment.
5-1-4-Salivary complications “Hyposialy”:
- Consequence of irradiation of the salivary glands
- From 50 to 70 Gys → viscous saliva, acidic pH
- Dry mouth → functional difficulties
- Hyposialia can be transient or permanent (xerostomia).
5-2-Late effects
5-2-1-Muscular complications: limitation of mouth opening
- It is due to two causes:
- Fibrosis of the masticatory muscles
- ATM irradiation
- Occurs after 3 to 6 months.
- Disruption of feeding, brushing and prosthetic realization.
5-2-2-Consequences on the dental organ:
- Brownish or black discoloration of the enamel-dentin surfaces
- Speed of evolution.
5-2-3-Xerostomia
- Consequence of salivary gland atrophy
- Definitive from 65 Gys.
- Dry mouth.
- Speech and swallowing problems.
- Oral infections and cavities.
5-2-4-Bone complications: ORN (osteoradionecrosis)
- Definition
This is an iatrogenic osteitis which appears at doses of ionizing radiation = or > 40 Gys; observed especially at the level of the mandible.
-Etiological factors
• Determining factors: radiotherapy (> 60Gys)
• Triggering factors: trauma.
• Favoring factors: large tumor volume, bone proximity.
-Clinical aspects:
- Aseptic ORN: asymptomatic.
- Septic ORN: superinfection of the bone.
-Radiological aspects:
- Bone rarefaction, osteolysis.
- Sequestration image
-Evolution :
Extension, superinfection, fistulas, pathological fractures.
MANAGEMENT OF A PATIENT UNDER CERVICOFACIAL RADIOTHERAPY
6-Precautions to take when undergoing radiotherapy
6-1-Before radiotherapy:
ROLE OF THE DENTIST :
– Carry out an initial assessment of the oral health.
– Assess the patient’s level of motivation.
– Carry out a restoration of the oral cavity.
– Implement certain prophylactic acts.
RESTORATION OF THE ORAL CAVITY:
– Motivation for hygiene.
– Tooth extractions.
– Evaluation in conservative dentistry.
– Preventive laser therapy.
– Production of fluorinated gel holder gutter.
6-2-During radiotherapy :
ROLE OF THE ODONTOSTOMATOLOGIST :
– Relieve the patient.
– Intercept or control bacterial or candidal infection.
– Maintain good oral health.
– Manage the emergency.
6-3 -After radiotherapy :
CONTROLLING SALIVARY DEFICIT:
– Use of saliva substitutes:
– Artificial saliva.
– Salivary prosthesis .
– Others: oil, butter, chewing gum.
– Prescription of sialagogues.
FIGHT AGAINST RESTRICTION OF MOUTH OPENING:
– Massages.
– Mandibular mobilization.
EXTRACTIONS:
In the irradiation field:
- Extraction after 6 months.
- Radiotherapist’s agreement.
- ATB coverage 2 days before → healing.
- Anesthesia without vasoconstrictor.
- Sutures.
Outside the irradiation field: The patient is considered healthy.
PROSTHESIS :
– Carried out after the disappearance of any reaction phenomenon of the mucosa .
– Joint prosthesis: motivated patient, widely dented.
– Adjunct prosthesis:
– Non-compressive imprint.
– Occlusion of convenience.
– Resin teeth.
– Periodic checks.
SURGICAL TRT FOR OSTEORADIONECROSE :
– Intended for severe forms.
– Limited surgery: sequestration.
– Large surgery: hemi mandibulectomy.
NON-SURGICAL TRT
- Hyperbaric oxygen therapy: Stimulation of collagen synthesis at bone level.
- Laser therapy
IRRADIATED CHILD:
– Monitoring and evaluation of HBD.
– Extractions and care are carried out with the same precautions as for adults.
Conclusion :
The role of the dentist is important from the therapeutic decision-making stage and throughout the TRT. Restoring the oral cavity before treatment allows for a reduction in complications, greater patient comfort and improved therapeutic results.
Good oral hygiene Regular scaling at the dentist Dental implant placement Dental x-rays Teeth whitening A visit to the dentist The dentist uses local anesthesia to minimize pain