The radiation therapy patient- treatment planning and post treatment care, dental care

1. The radiation therapy patient:
treatment planning and post
treatment care
Ashwini Narayankar
Reader, Department of Prosthodontics
S B Patil Dental college, Bidar

2. Radiation
therapy
Dental
management
during
radiotherapy
Pre-
radiation
dental
treatment
Post
radiation
prosthodon
tic care
Radiation
induced
changes in the
oral cavity
Dental
manageme
nt post -
radiation

3. • Role of the dentist
• Prior to the early 1960s
• In the 1970s

4. • Where is radiation therapy used ?

5. Radiation therapy of head
and neck tumors
• Radiation therapy is defined as the
therapeutic use of ionizing radiation.
Electromagnetic Particulate

6. • Ionization occurs when these rays give up
energy by colliding with and exciting
electrons from atomic orbits

7. Primary effects of radiation
• Nucleus (100 to 1000 times more sensitive)
• Mostly confined to DNA and mitotic
apparatus, G1 phase
• Causes cell death

8. External beam radiotherapy
• Daily divided doses of 180 rad to 250 rad,
5 times / week
• Total treatment dose administered for oral
cancer generally ranges from 4500 rad to 7500
rad (45Gy-75Gy)

9. Brachytherapy
• Sealed radioactive sources are used to deliver
the dose a short distance by interstitial - direct
insertion into tissue, intracavitary placement
within a cavity or surface application - molds

10. Advantage
• Rapid decrease in dose
with distance from the
radiation source -
inverse square law.
• I α 1/ D2
• High radiation to
tumor sparing normal
tissues
• Small tumors on or
close to surface

11. Radiation induced changes
in the oral cavity
• Fibrosis of the musculature
• Fibrosis of connective tissues
• Trismus
• Capillary fragility and friability
• Decreased vascular elasticity
• Decreased vascular permeability
• Telangiectasia

12. • Tissue fragility and friability
• Decreased repair potential
• Susceptibility to soft tissue necrosis
• Susceptibility to osteoradio necrosis
• Increased susceptibility to caries

13. • Mucositis (200 cGy/day)
• Susceptibility to infection
• Salivary changes

14. • Erythema extensive ulceration
desquamation
• severe radiation mucositis

16. • Pain
• Spicy food
• Dysphagia
• Resultant weight loss

17. Mucositis
2 - 3 weeks after
Healing – rapid, complete in 2-3weeks
soft palate >mucosa of hypophaynx > floor of
mouth > buccal mucosa > base of tongue
>dorsum of tongue
Acute candidiasis , diabetes
Chemotherapy

18. Treatment
Supportive and symptomatic
Saline and soda rinses,
Viscous xylocaine,
Systemic analgesics

19. Taste and olfaction
Degeneration and atrophy
at 1000 cGy
Starts at 2 – 4 Gy
Cancericidal levels of
radiation - architecture of
buds almost completely
obliterated (55 Gy)

20. • Alterations in taste – during
second week and continue
throughout course of treatment
• Bitter and acid flavors more
susceptible to impairment than
salt and sweet

21. • Taste gradually returns to near normal levels
• Reduction in saliva decreases number of taste
buds

22. Edema and trismus
Most prominent in submental areas, tongue,
buccal mucosa - irradiation of lateral tongue
or floor of mouth carcinoma
Compromise tongue mobility, impair salivary
control and make denture utilization and
speech articulation more difficult

23. • Recurrent tongue and cheek biting
• Occlusal alterations
• Removal of dentures

24. Trismus
• Nasopharyngeal, palatal, parotid and
nasal sinus tumors
• Opening may be reduced to 10 to
15 mm

25. • Treatment
• Exercise and use of dynamic bite openers
most effective in dentulous patients
• 5 – 10 times each session for 2 – 5 min
• Edentulous patient
• Tongue blades
• Chewing gum

26. Diet
 Loss of taste acuity
 Reduced salivary output
 Pain upon swallowing
 Loss of appetite
 Nausea and malaise - weight loss

27.  Enriched dietary supplements
 Soft and semisoft food
 Avoiding coarser, acidic and citric foods.

28. Salivary Glands
• Changes in volume
• Viscosity, pH
• Inorganic and organic
constituents of saliva
• Caries, and periodontal
disease

29.  Increased viscosity and
reduced flow of saliva -
impairment of taste acuity
and poor tolerance of
prosthetic restorations
 Swallowing becomes difficult
 Appetite is affected

30. Histologically
 Infiltration of interlobular
connective tissue,
predominantly with lymphocytes
and plasma cells
 Progressive degeneration of
acinar epithelium with a
progressive increase in
interlobular and intralobular
fibrosis

31. Serous acinar cells more easily affected than
mucous acinar cells - more profusely
vascularated
Saliva becomes more viscous
Glands reduce in size, become more adherent
When all major salivary glands within radiation
beam, mean salivary output can be reduced
from 93% to 88%

32. • Reduced bicarbonate levels – reduced
buffering capacity of saliva – caries
• Less saliva – friction between the mucosa
and prosthesis

33. • Pilocarpine –
• Mouth rinse -1 mg/cc 4 times per
day
• Tablet form - 5mg 3times per day.
• Carboxymethylcellulose, glycerine
and mucin

34. • Ideally saliva substitutes –
• Provide a protective coating for oral
mucosa
• Maintain normal flora
• Capable of remineralising decalcified
enamel and long lasting

35. Bone
• 1.8 times as dense as soft tissue
• Mandible absorbs more radiation than
maxilla

36. • Loss of osteocytes from lacunae, atrophy
of endosteum
• Loss of osteoblasts and osteoclasts
Periosteum - fibrosis
• Loss of remodeling

37. Periodontium
– Fibres become disoriented
– Periodontal ligament thickens
– Decreased cellularity and vascularity
– Repair and regeneration capacity of
cementum is severely compromised
– 5500 cGy – loss of attachment

38. Teeth
 Secretory metabolism of
odontoblasts affected at 4200-
6900 cGy
 Pulp – decrease in vascular
elements with fibrosis and
atrophy

39.  Affect tooth development at as low as
2500cGy
 Exposure before calcification – tooth is
damaged
 Exposure after – irregularities in enamel and
dentin – full coverage restoration

40. Composition of oral flora
• Aerobic and anaerobic
organisms increase
• Streptococcus mutans ,
lactobacillus – caries
• Actinomyces – lowers pH

41. • Fungal growth – candida albicans
• Erythema and burning sensation
• Nystatin 435mg lozenge
• OHI and topical fluoride
• Secondary to xerostomia

42. Treatment rationale
• Early intervention
• Explain the outcome to the patient
– Mucositis
– Xerostomia
– Change in oral microflora
– Loss of taste
– Increased sensitivity to spicy food

43. • Long term problems – reduced bone
healing, ORN, permanent loss of salivary
function, dental caries, susceptibility of
oral infection, trismus

44. Dental examination and
treatment plan
• Restorative procedures and dental
extractions
• Full mouth radiographs
• Oral hygiene
• Dental caries
• Restorations

45. • Extractions – healing period (10 days to 3
weeks)
• Antibiotic coverage
• Periodontally compromised
• Denture experience
• Lack of saliva affects retention
• Save healthy teeth
• Partially erupted and impacted teeth

46. Preradiation prosthodontic care
• Weight loss
• Relining ill – fitting dentures
• Soft temporary reline
• Advised not to wear denture
• Metallic crowns or fixed partial denture
• Custom made soft plastic stent
• Implants need to be removed

47. Dental management during
radiation therapy
• Mucositis
• Severe soft tissue irritation
• 1 or 2 weeks
• Desquamation and ulceration
• Pain, dysphagia
• Difficulty in eating
• Acute mucositis – 2 or 3 weeks and
subsides within 8 to 10 weeks

48. • Oral hygiene
• Salt and sodium bicarbonate in water or
dilute solutions of hydrogen peroxide
• Benedryl elixirs, sucrafate solutions,
topical anesthetics

49. Loss of taste
• 1st or 2 weeks
• Taste buds and microvilli, disrupted
innervation
• Lack of saliva
• Lack of desire for food

50. Xerostomia and dental caries
• Quantity and quality of saliva
• Decreased salivary flow rate
• Increase in acidogenic and cariogenic
microorganisms and decrease in
noncariogenic microorganisms resulting in
severe dental caries
• Topical fluoride
• S mutans count

51. • Major initiators for dental necrosis
• Pre-existing dental disease not identified prior
to RT
• Poor dental compliance
• Breakdown of pre-radiation extraction wounds
– surgical trauma, inadequate healing time
• Breakdown of post-radiation extraction
wounds – impaired vasculature of mucosa,
periosteum, bone

52. • Periodontally compromised teeth
• Furcation involvement
• Healthy abutment teeth for RPD,
overdentures

53. • Extraction of third molars
• Impacted and partially erupted

54. Preradiation Prosthodontic care
• Mucositis will limit wearing of
prosthesis during therapy
• Weight loss – tissue changes – new
dentures

55. • Soft temporary reline materials – surface
porosity, abrasiveness, fungal growth,
mucosal irritation
• Metallic crowns or FPD – custom made,
soft plastic stent
• Dental implants (2000 cGy)

56. Dental management during
radiotherapy
• Mucositis:
After a week or 2- a moderate
amount of erythema
Desquamation and frank
ulceration
Pain and dysphagia
Subsides within 8 to 10 weeks
Smokers , alcohol abuse

57. Good oral hygiene
Frequent oral rinses with a combination
of salt and sodium bicarbonate in water
or dilute solutions of hydrogen peroxide
Rinsing with Benadryl elixirs, sucralfate
solutions and topical anesthetics

59. • Loss of taste
Radiation to tongue and palate
Rapidly during first or second
week
Damage to taste buds,
microvilli and innervation
Returns to normal
Alteration and loss of taste
may begin with the first 200-
400 cGy

60. After three weeks of therapy, it takes 500-
8,000 times normal concentrations of taste
stimulant to elicit a normal taste response
Taste acuity levels return to normal 2-4
months following completion of therapy, if
adequate saliva is available

61. Xerostomia and dental caries
Brown 1978
Salivary flow rate
decreased
Acidogenic and cariogenic
Caries activity increased
Dreizen et al 1997
Topical application of
fluoride

62. Saliva substitutes and sialogouges
– 1st week of therapy and worsens over time
– Food debris accumulates – no self cleansing
– Fox 1986
– Pilocarpine
– Antholethrithone

63. –Carboxymethylcellulose with various
salts and flavoring agents
–Mixture of glycerin and fruit juices or
mouth rinse
–Oral Balance
–Excess mucous-type secretions -
Organidin NR as a liquid or tablet may
help as a mucolytic agent (200-400 mg,
3 to 4 times daily)

64. Trismus and fibrosis
Eating difficulty
Exacerbated by surgery
Exercise – bite openers or devices /
tongue blades

65. Shielding and positioning stents
• Kaanders et al 1992
• Positioning stents
• Shielding stents

66. Dental management post -radiation
• Mucositis and loss of taste –
–Subside gradually over 6-8 weeks
–Heavy smokers or drinkers – delayed
–Good oral hygiene

67. Xerostomia and dental caries
–Meticulous oral hygiene
–Frequent daily rinsing
–Saliva substitutes
–Dental visits
–Topical Fluoride / Calcium
phosphate mouth rinse

68. Candidiasis
Xerostomia and changes in
oral flora
Burning mouth
Troches or rinses containing
clotrimazole or nystatin
Soaking prosthesis in an
antifungal or dilute
hypochlorite

69. Trismus and Fibrosis
Increases with time – 10 to 15mm
Difficulty in placing dentures or
obturators
Exercises

70. Dental Extractions
 Diminished ability to heal
 Osteoradionecrosis
 Extremely mobile, periodontally
compromised teeth
 Localised periodontal or periapical
infection – antibiotics
 RCT to avoid extractions

71.  In areas not under radiation -
extractions
 Hyperbaric oxygen – expensive and
time consuming.
 Extraction following initial 20 minutes
dive

72. Osteoradionecrosis
 Trauma,
 Exposure of radiated
bone
 Infection
 Hypovascular
 Hypocellular and
 Hypoxic conditions
 More in mandible

73. • Soft tissue ulcer and varying degrees
of discomfort
• Conservative – sequestered bone
removed
• Rinse with dilute hydrogen peroxide /
salt and soda solution
• Dentures relieved
• Soft plastic mouth guards
• Topical packing with zinc oxide or
antibiotics

74. • Systemic antibiotics
• Pathologic fracture – hyperbaric oxygen
• Mandibular reconstruction using
microvascular surgery

75. • Osteoradionecrosis is a wound healing
defect caused by high dosage radiation
treatments
• 20 preoperative treatments at 2.4 ATA for
90 minutes
• Surgery
• 10 postoperative treatments at 2.4 ATA for
90 minutes

76. Therapeutic recommendations
• Beumer categorized patients based on
amount of radiation dose received as:
 High dose patients - >6500cGy
 Intermediate dose – between 5500 and
6500 cGy
 Low dose - < 5500cGy

77.  For high dose –
 Multiple extractions – hyperbaric oxygen therapy
 RCT
 Intermediate dose –
RCT, hyperbaric oxygen
 For low dose – atraumatic extraction

79. Post radiation Prosthodontic care
• Adequate healing
• Wait atleast 6 months to 1 years before dentures
• Social status – young and socially active
• Gentle soft tissue manipulation
• Denture retention may be compromised –
xerostomia

80. • Less VD – less force on alveolar ridge
• Monoplane teeth
• Well balanced, non interfering occlusion
• Soft denture base – fungal growth
• Denture remounting
• Pressure indicating paste

81. • Rounded denture borders
• Remove dentures if irritation
• Maintain oral hygiene
• Twice a week after denture delivery

82. References
• Thomas T Taylor , Clinical Maxillofacial
Prosthetics, First edition,2000, Quintessence
publications, Illionis, pp 37 – 52
• Beumer J, Curtis TA, Marunick
MT, Maxillofacial Rehabilitation, Prosthodontic
and Surgical Considerations, 1996 Ishiyaku
EuroAmerica, St. Louis and Tokyo, pp 43-
105

83. • Hancock P J , Epstein J B, Sadler Oral and
Dental Management Related to Radiation
Therapy for Head and Neck Cancer, J Can
Dent Assoc 2003; 69(9):585-90
• Garg Arun, Mago Maurico, Manifestations
and treatment of xerostomia and
associated oral effects secondary to head
and neck radiation therapy , JADA, 1997;
128,:1128 -1133

84. • David L et al, Hyperbaric Oxygen Therapy
and Mandibular Osteoradionecrosis: A
retrospective Study and Analysis of
Treatment Outcomes; J Can Dent Assoc
2001; 67:384-390
• Radiation Therapy - Evaluation and
Treatment Plan BC Cancer agency.htm