Oral Complications Associated with Radiation, Chemo, and Antiresorptive Meds Flashcards by Michael McMahan

How many Grays of radiation causes ORN in an area?

Greater than 50 Grays

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What are the 2 ways radiation is delivered?

 Fixed Beam Radiation

 Intensity Modulated Radiation Therapy (IMRT)

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 All the tissue between the portals receives the same

dose

Fixed Beam Radiation Therapy

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 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)

Intensity Modulated Radiation

Therapy

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 The application of radiation therapy in smaller
consecutive doses to minimize the lethal effects and limit
the side effects of the therapy.
 The dose is usually administered 5 times a week for 5 to
7 consecutive weeks.

Fractionation

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What are the 5 R’s of fractionation?

 Repair
 Redistribution
 Repopulation
 Reoxygenation 
 Radiosensitivity

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(5 R’s of fractionation)
 Radiation causes sub-lethal damage to normal and
malignant cells
 The repair pathways are often blocked or impaired in the
malignant cells resulting in cell death.

Repair

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(5 R’s of fractionation)

 DNA is more sensitive during certain stages of cell
replication. (G2 and M phases)
 Most stable (S phase)
 Fractionation provides multiple opportunities to affect
the cells when they are in the sensitive phase.

Redistribution

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(5 R’s of fractionation)

 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

Repopulation

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(5 R’s of fractionation)

 Tumor cells are more resistant to radiation in hypoxic
environments
 Fractionation increases the odds that that tumor cells will
be in a nutrient field during radiation
 The outermost tumor cells are destroyed exposing the
“hypoxic”inner layers of tumor cells

Reoxygenation

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(5 R’s of fractionation)

 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

Radiosensitivity

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Indications for _____ Prior to Radiation Therapy
 Non-restorable caries or high caries rate
 Periodontal pocketing > 5mm
 Furcation involvement
 Impacted teeth

Extractions

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Which salivary gland is spared the most in radiation therapy? What type of saliva does it produce?

Sublingual; mucous saliva

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 Hypofunction can occur when exposed radiation
doses as low as 25 Gy
 Serous glands are more sensitive to radiation than
mucous glands

Xerostomia

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Are serous or mucous salivary glands more sensitive to radiation?

Serous glands

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The rapid formation and
progression of dental caries is
mainly attributed to the reduced
quality and quantity of the _____

saliva.

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 Sugar alcohol originally derived from birch trees
 Commercially produced from corn cobs (xylan)
 Caries causing bacteria are unable to metabolize it

Xylitol

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 Ingesting 6-8 grams daily can decreased caries
 Frequency of use more important than quantity
 Available as a packaged sweetener or in gums, mints,
candies and oral rinses

Xylitol

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How. many grams of xylitol need to be ingested each day to get anti-caries effect?

6-8 g

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 Can cause gastric issues with some pts
 Primarily when over 50g ingested/day
 Extremely toxic to dogs (pancreas issues)

Xylitol

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 Cholinergic agonist 
 Pilocarpine hydrochloride
 5-10mg tid
 Max dose 30mg/day
 May take 12 weeks to see results
-Side effect of med is salivary effects not primary effect

Sialogues

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 5-10mg tid
 Max dose 30mg/day
 May take 12 weeks to see results
-Side effect of med is salivary effects not primary effect

 Pilocarpine hydrochloride

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 Rinse, brush, floss, fluoride trays
 10 minutes/day
 No food or drink for 30 minutes
 Best results when used prior to bedtime

Fluoride Therapy

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What type of fluoride is better for root caries but can stain the teeth brown?

Stanous fluoride

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 Oral mucosa exposed to radiation becomes edematous, erythematous, and ulcerated.  The condition can be extremely painful and cause issues with mastication and swallowing.  The signs and symptoms often arise after the second week of therapy and may last a few weeks after the completion of treatment

Mucositis

```  Mild Pain  Maintain oral hygiene  Use bland oral rinses  Baking soda/water  With/without salt  Use topical oral pain management  Caphosol  Magic Mouthwash  Viscous lidocaine, Maalox, diphenhydramine  With/without nystatin  Mild analgesics (OTC) ```

Mucositis tx

 Diphenhydramine 12.5mg/5mL 1 part (120mL)  Maalox 1 part (120mL)  Viscous Lidocaine 2% 1 part (120mL)  Nystatin Susp. 100,000 U/mL 1 part (120mL)  (Optional)

Magic mouthwash used for mucositis

```  Moderate pain  Addition of moderate strength opioids  Hydrocodone and oxycodone  Altered diet (soft)  Severe pain  Addition of strong opioids  Oxycodone, morphine, oxymorphone  May need nasogastric or PEG tube ```

Mucositis tx

 Radiation results in vascular changes in the bone limiting the blood supply and the ability to heal after trauma or extractions  Associated with radiation doses above 50 Gy  More common with the mandible

Osteoradionecrosis (ORN)

Is Osteoradionecrosis (ORN) more common in max or mand?

Mand

 Prevention is the key  Extraction of questionable teeth prior to radiation therapy  Complete root canal therapy if it is an option  If a post radiation TE is necessary, hyperbaric oxygen (HBO) therapy may be necessary  20 dives prior to TE/10 dives after TE  HBO is only needed once in a lifetime, not for each procedure

Osteoradionecrosis

 Stage ___ ORN  No exposed bone, but pt. is symptomatic  Radiographic changes may be present  Treatment  Periodic monitoring  Systemic management (antibiotics and pain meds)

Stage 0

 Stage ___ ORN  Bone is exposed, asymptomatic, no infection present  Treatment:  Monitor closely for 8 weeks  If no changes, continue to monitor quarterly  Meticulous home care  Antimicrobial oral rinses  Remove loose sequestra if present

 Stage 1:

 Stage ___ ORN ```  Exposed bone with associated pain  Purulent exudate may be present  Treatment:  Same treatment as Stage 1  Addition of systemic antibiotics(Penicillin, Clindamycin, Doxycycline)  Superficial debridement to relieve soft tissue irritation  Possible hyperbaric oxygen therapy? ```

 Stage 2:

 Stage ___ ORN ```  Exposed bone with pain and one of the following:  Pathologic fracture  Extra-oral fistula  Necrotic lesion extends to the inferior border  Treatment:  Surgical debridement or resection  Antibiotic therapy  Possible hyperbaric oxygen? ```

 Stage 3:

 Primarily occurs when the pterygoid region is irradiated  Usually noticed near the completion of radiation therapy  Radiation may cause spasms or fibrosis of the TMJ and muscles of mastication resulting in a limited range of motion  The effects usually are not permanent, but may last for several months after the completion of radiation therapy

Trismus

```  Treatment of _____:  Warm, moist heat  Massage  Physical therapy  Tongue depressors  TheraBite  Dynasplint ```

Trismus

 Permanent taste loss may occur with a cumulative dose | of ___ Gy.

 Permanent taste loss may occur with a cumulative dose of 60 Gy.  At lesser dosages, the taste may return.  Xerostomia and mucositis may also contribute to the alterations in taste.  May or may not improve depending of the site and amount of radiation  Treatment:  Water/salivary substitutes  Constantly monitor for bacterial or fungal infections

Hypogeusia/Dysgeusia

``` Radiation indications for ____  Wait 6-9 months after the completion of radiation to fabricate dentures and RPDs  Educate the patient  Limit the amount of use  Place silicone liners (GC Reline)  Set a 3 month recall ```

Removable appliances

a form of cancer treatment that involves taking one or more of a type of drug that interferes with the DNA (genes) of fast-growing cells. These drugs are further subdivided into specific classes such as alkylating agents, antimetabolites, anthracyclines, and topoisomerase inhibitors.

Chemotherapy

Tx indication for ____ pts  Avoid any dental treatment if possible during chemotherapy  Pts usually reach their “nadir”(lowest blood counts) 7-14 days after a course of chemo  If treatment is needed, blood counts are usually best just prior to their next course of chemo

Chemo pts

When should you tx a pt in relation to chemo doses?

20-21 days post chemo bc of high blood counts

What should the ANC be for an invasive procedure for chemo pt?

>1000

What should the platelet count be for an invasive procedure for chemo pt?

>75,000

What are the 2 indication for ABX prophy pre dental treatment?

 Presence of a Port-A-Cath |  Neutrophils between 1,000 and 2,000/mm3

```  Prevention is key  Brush and floss  Chlorhexidine rinse (non-alcohol)  Neutral rinse (baking soda and water)  Treat opportunistic infections  Fungal (Candida)  Nystatin, Fluconazole  Viral (Herpetic)  Acyclovir, Famciclovir ```

Immunosuppression

Does xerostomia persist or resolve in chemo pts

Usually resolves

Are the effects of taste loss/change permanent or temporary in chemo pts?

Temporary

 Chemotherapy is used to destroy the bone marrow  Hematopoietic stem cells are then transplanted to repopulate the bone marrow

Bone marrow transplant

 The pts own bone marrow or stem cells are removed | and preserved for transplantation.

 Autologous

 Bone marrow or stem cells from a HLA (Human leukocyte antigen) matched individual are used for transplantation.

 Allogeneic

 Bone marrow or stem cells from an identical twin are | used for transplantation.

 Syngeneic

No elective treatment for bone. marrow transplant until how long after bone. marrow transplant?

1 year after

 Occurs primarily with allogeneic transplants  Treatment involves severe immunosuppression  Oral manifestations:  Mucositis  Infections (bacterial, fungal, viral)  Mucosal atrophy  Xerostomia

Graft-Versus-Host-Disease

What are the 2 forms of antiresorptive meds?

Bisphosphonates | RANK ligand inhibitors

 Initially used for the treatment of osteoporosis, Paget’s disease, and osteogenesis imperfecta  More recently, they have been used as an adjunctive treatment of cancer  Decrease osteoclastic activity

Bisphosphonates

 Oral only  Etidronate –Didronel  Clodronate –Bonefos, Clasteon, Loron  Primarily used for the treatment of Paget’s disease  Low potency  Prevents osteoclast proliferation by inhibiting ATP (adenine triphosphate) dependent enzymes

Non-nitrogen bisphosphonates

 Oral or IV  Mechanism of action  Prevents binding of essential proteins to the cell membrane leading to apoptosis  Prevents adhesion of the osteoclasts to the hydroxyapatite crystals by altering the cell cytoskeleton

Nitrogen containing bisphosphonates

```  Approved for use in the treatment of Paget’s disease and osteoporosis  Alendronate (Fosamax)  Risedronate (Actonel)  Ibandronate (Boniva) ```

Oral Nitrogen Containing | Bisphosphonates

```  Used in the treatment of osteoporosis  Zolendronate (Reclast) –5mg/year  Used in the treatment of bone metastases  Zolendronate (Zometa) –4mg/3 weeks  Pamidronate (Aredia) –90mg/3 weeks ```

IV Nitrogen Containing | Bisphosphonates

Are oral bisphosphonates used for treatment of metastatic cancers?

No never

 Osteoporosis –Prolia –60mg/6 months  Bone Metastases –Xgeva –120mg/4 weeks  Mechanism of action  Tumor cell promote the release of RANK Ligand from the osteoblast with in turn promote the production of osteoclasts  Denosumab binds to the RANK Ligand an prevents osteoclast proliferation

 Denosumab (Monoclonal antibody)

``` _____ meds  Tyrosine kinase inhibitor  Sunitinib (Sutent)  Sorafenib (Nexavar)  Humanized monoclonal antibody  Bevacizumab (Avastin) ```

Antiangiogenic meds

_____ meds  Mechanism of action  Recognizes and blocks vascular endothelial growth factor (VEGF), a protein necessary for angiogenesis  Used in the treatment of gastrointestinal tumors, renal cell carcinomas, and neuroendocrine tumors

Antiangiogenic meds

What primary cancer has the greatest risk for MRONJ?

Multiple myeloma

____% of the bisphosphonate is excreted by the kidneys | within hours of ingestion or infusion

50%

___% of bisphosphonates are deposited in the skeleton

 Make up 85% of resting bone  Have a long life span  Have a low affinity for bisphosphonates  Bisphosphonates loosely bind to the surface and are removed within days

Osteocytes

 Make up 2-4% of resting bone  Have a life span of 2 weeks  8x the affinity for bisphosphonates  Upon death of osteoclasts, bisphosphonates are reabsorbed by the skeleton or excreted by the kidneys

Osteoclasts

```  Make up 10-12% of resting bone  Have a life span of 2 months  4x the affinity for bisphosphonates  Bisphosphonates are incorporated into the bone instead of being released ```

Osteoblasts

``` __ month presurgical holiday  Osteoclasts are the only reservoir for the bisphosphonates  Allows for 4 life cycles  Minimal remaining bisphosphonate ```

2 months

 Average __ month postsurgical holiday (ideally 8 months)  Necessary time needed for bones to return to “resting” state  No needed alteration in bisphosphonate therapy if planned correctly

4 month

``` ______ and the Body  Osteoclasts decreased by 85% in 3 days  ½ life is 25 days  80% degraded in 2 months  only affects the RANK ligand  Not incorporated in the bone ```

Denosumab

What is the Denosumab drug vacation timeline?

2 months before | 4 months after (8 is better)

 Measures serum levels of C-terminal telopeptide  Metabolite of bone matrix degradation  Marker for osteoclastic activity  Normal is >300 (average 400-550)  150 or less is at risk for MRONJ -Does not denote location of breakdown of osteoclasts

CTX testing

 Recombinant parathyroid hormone teriparatide  Binds to osteoblasts and promotes proliferation  Daily injections for up to 2 years  > 2 years of use may lead to osteogenic sarcoma  Expensive ($560/month)

Forteo

Oral Complications Associated with Radiation, Chemo, and Antiresorptive Meds Flashcards

(77 cards)