Oral Cancer Flashcards
what therapies are utilized in oral cancer
- surgery
- radiation
- chemotherapy
what are the types of surgery used in oral cancer
- biopsy/radical neck dissection
- mandibular resection/graft
- maxillectomy/oro-antral communication
- glossectomy
where would radiation be targeted at in oral cancer
- base of tongue
- nasopharynx
what are the two ways radiation can be delivered in oral cancer and which is more common
- fixed beam radiation
- intensity modulated radiation therapy (IMRT): more common
what is fixed beam radiation therapy
all the tissue between the portals receive the same dose
- more like a PA xray
what is intensity modulated radiation therapy
- a constantly moving beam administers different amounts of radiation to the tissues
- the tumor receives the highest amount of radiation
- minimal amounts of radiation are applied to vital structures - spinal cord, salivary glands
- more like a pano
what is fractionation
the application of radiation therapy in smaller consecutive doses to minimize the lethal effects and limit the side effects of the therapy
what is the dose used in fractionation
5 times a week for 5 to 7 consecutive weeks
what are the 5 Rs of fractionation
- repair
- redistribution
- repopulation
- reoxygenation
- radiosensitivity
radiation causes _____ damage to normal and malignant cells
sub-lethal
the repair pathways are often blocked or impaired by:
the malignant cells resulting in death
describe redistribution
- DNA is more sensitive during G2 and M phases
- most stable is S phase
- fractionation provides multiple opportunities to affect the cells when they are in the sensitive phase
describe repopulation
- rapid repopulation of the malignant cells can occur approximately 4-5 weeks after the initial radiation dose
- fractionation over 5-7 weeks prevents the rapid repopulation of these cells
describe reoxygenation
- tumor cells are more resistance to radiation in hypoxic environments
- fractionaction increases the odds that the tumor cells will be in a nutrient field during radiation
- the outermost tumor cells are destroyed exposing the hypoxic inner layers of tumor cells
describe radiosensitivity
- involves the recognition of certain proteins, receptors and kinases that may make cells less sensitive to radiation
- recognizing the presence of the components may help predict the success of radiation therapy in certain cases
what should be done prior to radiation
- complete dental/perio evaluation
- establish a baseline
- previous dental experience/frequency
- extract suspect teeth in the radiation field
- complete prophy and restorative tx
- fabricate custom fluoride trays
what are the indications for extractions prior to radiation therapy
- non restorable caries or high caries rate
- periodontal pocketing greater than 5mm
- furcation involvement
- impacted teeth
what are the complications of radiation
- xerostomia/dental caries
- mucositis
- osteoradionecrosis
- trismus
- hypoguesia/dysgeusia
- nutritional deficiency
what salivary glands are most affected by radiation
serous glands such as parotid and submandibular
what types of glands are each of the major salivary glands
- parotid: seroud
- submandibular: serous/mucous
- sublingual: primarily mucous
salivary hypofunction can occur when exposed to radiation doses as low as:
25 Gy
the rapid formation and progression of dental caries is mainly attributed to the:
reduced quality and quantity of the saliva
what are the treatments for xerostomia
- water
- salivary substitutes
- minimize carbohydrate and alcohol intake
- alcohol free mouth rinses: peridex and crest pro health
- listerine
- sugar free gum
what is xylitol from and why is it effective
- sugar alcohol originally derived from birch trees
- commercially produced from corn cobs
- caries causing bacteria are unable to metabolize it
what is the therapeutic amount of xylitol
- ingesting 6-8g daily can decrease aries
- frequency of use more important that quantity
how is xylitol packaged
as sweetener in gums, mints, candies or oral rinses
how much xylitol per piece of ice breaker cubes, epic gum, epic mints, spry gum, and xylimelts
- ice breakers ice cubes: 1g/piece
- epic gum: 1g/piece
- epic mints: 0.5/piece
- spry gum: 0.72/piece
-xylimelts: 0.5/piece
what are the issues with xylitol
- can cause gastric issues with some patients: primarily when over 50g ingested daily
- extremely toxic to dogs
what are the sialogogues and the dosage
- cholinergic agonist
- pilocarpine hydrochloride: 5-10mg tid. max dose 30mg/day. may take 12 weeks to see results
how is fluoride therapy used
- rinse, brush, floss, fluoride trays
- 10 minutes a day
- no food or drink for 30 minutes
- best results when used prior to bedtime
what are the types of fluoride
1.1% sodium fluoride
- 0.4% stannous fluoride
what is 0.4% stannous fluoride better for and what is its downside
- better for root caries
- may stain the teeth brown
what is mucositis
- oral mucosa exposed to radiation becomes edematous, erythematous and ulcerated
- the condition can be extremely painful and cause issues with mastication and swallowingw
when do the signs and symptoms of mucositis often arise
after the second week of therapy and may last a few weeks after the completion of treatment
what should you recommend to patients with mild pain with mucositis
- maintain OH
- bland oral rinses
- baking soda/water with or without salt
what should you recommend for topical oral pain management with mucositis
- caphosol
- magic mouthwash: viscous lidocaine, maaloc, diphenhydramine with or without nystatin
- mild analgesics
what is the magic mouthwash made of
- 1 part (120mL) diphenhydramine 12.5mg/5mL
- 1 part (120mL) maalox
- 1 part (120mL) viscous lidocaine 2%
- 1 part (120mL) nystatin susp. 100,000 U/mL (optional)
what is caphsol used for
mucositis to soothe the gums- its a rinse
what do you recommend for patients with moderate pain with mucositis
- addition of moderate strength opiods
- hydrocodone and oxycodone
- altered diet (soft)
what do you recommend for patients with severe pain with mucositis
- addition of strong opiods- oxycodone, morphine, oxymorphone
- may need nasogastric or PEG tube
what is osteoradionecrosis
radiation results in vascular changes in the bone limiting the blood supply and the ability to heal after trauma or extractions
ORN is associated with radiation doses above _____
50Gy
ORN is more common in the _____ because
mandible because of less vascularity
how can you prevent ORN
- extraction of questionable teeth prior to radiation therapy
- complete RCT if it is an option
- if a post radiation TE is necessary hyperbaric oxygen therapy may be necessary:20 dives prior to TE/10 dives after TE
how many times is HBO needed
once a lifetime
what is stage 0 of ONJ
- no exposed bone but pt is sympotmatic
- radiographic changes may be present
what is the tx for stage 0 ONJ
- periodic monitoring
- systemic management - antibiotics and pain meds
what is stage 1 of ONJ and the tx
- bone is exposed, asymptomatic, no infection present
- ts: monitor closely for 8 weeks, if no changes monitor quarterly. meticulous home care. antimicrobial oral rinses. remove loose sequestra if present
what is stage 2 ONJ and the tx
- exposed bone with associated pain
- purulent exudate may be present
- tx: same as stage 1. addition of systemic antibiotics (penicillin, clindamycin, doxycycline). superficial debridement to relieve soft tissue irritation. possible HBO therapy
what is stage 3 ONJ and the tx
- exposed bone with pain and one of the following:
- pathologic fracture
- extra oral fistula
- necrotic lesion extends to the inferior border
- tx: surgical debridement or resection. antibiotic therapy. possible HBO