- Email: [email protected]
Dental management of the pediatric post radiation therapy—rhabdomyosarcoma patient: Case reports and review of literature
Oral Oncology EXTRA (2005) 41, 242–248
http://intl.elsevierhealth.com/journal/ooex
CASE REPORT
Dental management of the pediatric post radiation therapy—rhabdomyosarcoma patient: Case reports and review of literature Kishore Shetty *, Heber Tuft LSU Health Sciences Center, Oral and Maxillofacial Surgery, 1100 Florida Avenue, #127, New Orleans, Louisiana 70119, USA Received 18 June 2005; accepted 21 June 2005
KEYWORDS
Summary This article describes the dental management in two patients aged 8 and 5 with rhabdomyosarcoma (RMS) post-radiation therapy. The report discusses some of the common problems faced such as osteoradionecrosis, xerostomia, mucositis, candidiasis, trismus, loss of taste, soft tissue necrosis, and scar tissue formation and the need for the oral healthcare provider to understand these sequelae in order to best treat patients. c 2005 Elsevier Ltd. All rights reserved.
Rhabdomyosarcoma; Radiation therapy; Pediatric; Osteoradionecrosis; Hyperbaric oxygen
Introduction Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma of childhood and adolescence involving the head and neck and is the third most common extracranial solid tumor of childhood after Wilm’s tumor and neuroblastoma.1–3 A malignant tumor composed of neoplastic mesenchymal cells, RMS has varying degrees of striated musclecell differentiation.4 Adolescents younger than 20 years of age are mostly diagnosed with this sarcoma.5 About 65% of these cases are diagnosed in children under 6 years of age.5 RMS occurs in males
* Corresponding author. Tel.: +1 504 619 8524. E-mail address: [email protected] (K. Shetty).
more than females. In females RMS has a higher incidence in the Caucasian race.6,7 Common sites of primary disease include the head and neck, genitourinary tract, and extremities.1,2 The head and neck is the most common site for RMS with about 40% of the cases.5,8,9 This region can be divided into 3 subsites: the orbit, non-parameningealnnon-orbitregion, and parameningeal.5 The most common site of occurrence in the head and neck is the orbit, followed by the nasal cavity and the nasopharynx.10 RMS is uncommon in the oral cavity, and jaw involvement is extremely rare.8,11 The most common site in the oral cavity is the tongue, followed by the soft palate, hard palate, and buccal mucosa.8,9 RMS can be described by three basic types: embryonal, alveolar, and pleomorphic.10 Embryonal RMS, occurring in
1741-9409/$ - see front matter c 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.ooe.2005.06.010
Dental management of the pediatric postradiation therapy—rhabdomyosarcoma patient about 60% of the cases, is the most common of the three types and appears within the first 10 years of life. Alveolar RMS occurs in 20–30% of the cases and appears between ten to twenty-five years of age. Pleomorphic RMS is found in less than 5% of the cases and shows peak prevalence in patients over forty years of age. Commonly found in the extremities, pleomorphic RMS cells are loosely arranged, haphazardly oriented, and exist with variable morphology.10 As the name implies, the cells of embryonal RMS resemble that of the developing muscle cells of a six-to-eight-week-old fetus. Common sites for this cancer are the head and neck, bladder, the vagina, the prostate, and the testes. Its prognosis is relatively good to intermediate. Alveolar RMS receives its name because its cells form hollow spaces. These cells look like normal muscle cells of a 10-week-old fetus and are typically found in the large muscles of the trunk, arms, and legs. Its prognosis is poor, and it tends to be more aggressive than the embryonal RMS.12 The alveolar variant is relatively rare compared to the embryonal form.8,11 Rhabdomyosarcomas are aggressive, frequently recur, and metastasize via blood and lymph routes.3,13,14 Lesions involving the posterior mandible, especially the alveolar variant, have the worst prognosis.13,14 Combined modality therapy can cure 60–70% of newly diagnosed patients with non-metastatic disease. The 5-year survival rate is 71%. Despite aggressive multimodality treatment, less than 20% of patients with the metastatic disease are currently cured; the 5-year survival rate is 27%.4,15 Treatment approaches to RMS incorporate surgery, radiation therapy, and chemotherapy. In sites such as the head and neck or pelvis, tumors often cannot be completely removed with surgery; radiation therapy (RT) can eradicate residual tumor cells in such instances. Early guidelines for RT recommend doses as high as 5500 to 6000 cGy for control of the primary tumor site.15 No clear etiologic factors can account for these malignant neoplastic growths. However, increasing evidence indicates that gene abnormalities may play a role in the development of some childhood malignancies, especially RMS.16 RMS has been associated with familial syndromes, such as neurofibromatosis, and the Li–Fraumeni syndrome.17 Differential diagnoses of RMS include Ewing sarcoma, Wilms’ tumor, lymphoma, neuroblastoma, alveolar soft-part sarcoma, fibrosarcoma, and leiomyosarcoma. These case reports demonstrate some effective post-radiation therapies for RMS patients.
243
Patient #1 An 8-year-old white male patient presented to the Childrens’ Hospital Dental Clinic with a lower left facial swelling and pain in lower left first molar (Fig. 1). The panorex revealed periapical radiolucencies on both root tips and an irregular trabecular pattern with rarefactions (Fig. 2). The diagnosis was irreversible pulpitis leading to chronic periapical abscess and buccal-infected cyst. The patient’s medical history was significant for embryonal auricular RMS diagnosed six years ago (Fig. 3). The surgery took out most of the tumor and the middle ear. As a result he had limited opening of his jaw and no hearing in his right ear. Six weeks of maximum RT of 5900 cGy was followed by fourteen months of chemotherapy followed the radiation therapy (RT). The patient was scheduled to have an extraction on #19 subsequent to hyperbaric oxygen therapy using Mark protocol, which entailed 20 dives prior
Figure 1 Initial presentation with pain and abscess in lower left first molar.
Figure 2 Radiolucencies and irregular trabecular pattern with rarefactions on the tip of both roots on lower left first molar.
244
K. Shetty, H. Tuft
Figure 3 On the frontal (coronal) CT an expansile radiolucent lesion is apparent in the ramus area and appears to extend into the condylar/coronoid regions.
to extraction and 10 dives postextraction.18 Post extraction healing was uneventful with no complications. Future treatment included frequent recalls to watch the progression of his premolars and second molars.
Patient #2 A 5-year-old Caucasian female presented to the Dental Clinic accompanied by her mother with a chief complaint of ‘‘jaw is swollen and cannot open mouth wide enough to clean inside’’ (Fig. 4). Her medical history was significant for alveolar RMS stage III, diagnosed 5 years ago and surgically
Figure 4 Gross facial asymmetry and large swelling of the right posterior mandible.
Figure 5 On the horizontal CT the medial extension of the lesion can be better appreciated with obvious lateral expansion and probable violation of the cortical bone as well.
removed 3 months later (Fig. 5). A coronoidectomy on the right mandible was performed and metal plates were placed in the infratemporal fossa and zygoma regions. Her right mandibular area was irradiated with 4500 cGy for 6 weeks subsequent to surgical healing to destroy any remaining parts of the tumor. She had a history of trismus which developed after tumor removal, and was presently practicing postoral muscle stretching. She has no history of dental restorations or of trauma to the orofacial region (Fig. 6). The extraoral exam showed gross facial asymmetry and a large swelling of the right posterior mandible. This swelling was firm and tender on palpation. There was a mild lymphadenopathy of the right submandibular and cervical nodes. Intraoral exam showed swelling that extended from the right mandibular canine to right mandibular second primary molar. Trismus was present with a constricted oral opening of approximately 7 mm vertically (Fig. 7). She had generalized radiation caries with an increased occurrence on the side irradiated, poor oral hygiene, and xerostomia. Appropriate Medical consults obtained prior to dental treatment under general anesthesia did not prescribe any hyperbaric oxygen therapy. The patient had extensive dental treatment done involving extractions of unrestorable primary teeth, multiple stainless steel crowns and resin restorations (Fig. 8). All of her teeth were prophylaxed with application of topical fluoride varnish.
Dental management of the pediatric postradiation therapy—rhabdomyosarcoma patient
Figure 6
245
Initial presentation showing no history of dental restorations or of trauma to the oral facial region.
Discussion
Figure 7
Constricted oral opening of 7 mm vertically.
The mother was counseled on home care and stretching exercises. A follow-up appointment showed that the extraction sites were healing well and that the restorations were successful.
Figure 8
Radiation therapy (RT) is a major defense against RMS and other such diseases. One of the top challenges in pediatric oncology today is to develop a cure for the disease and to restrict the development of RT late toxicity.17 RT is primarily responsible for the dental sequelae in patients receiving treatment for these diseases.19 The special care dentist needs a strong understanding of these sequelae in order to best treat patients. Radiation reduces or eliminates the reproduction of neoplastic cells in general and can be used in conjunction with other therapy, such as surgery or chemotherapy. It can cure the patient’s disease, or, as palliative care, it may simply prolong and improve the quality of life. Head and neck radiation is measured in Megavolts. Generally, the more penetration needed for deeper tissues, the more megavoltage radiation is chosen. Some of the side effects of post-radiation include delayed eruption of teeth, retarded tooth
Panorex post dental treatment involving multiple stainless steel crowns and resin restorations.
246 and bone development, dwarfed teeth, partial anodontia, erosive caries (radiation caries), discoloration of teeth due to dentinal changes, poor enamel and cervical fracture, osteoradionecrosis, xerostomia (salivary-gland dysfunction), mucositis (dose related), candidiasis (moniliasis, thrush), trismus, loss of taste due to damage to the papillae of the tongue, soft-tissue necrosis, and scar-tissue formation. Osteoradionecrosis (ORN) is one of the most serious complications of radiation therapy. It occurs in the mandible more frequently than in the maxilla, probably because of the greater vascularity in the maxilla. ORN is defined as ‘‘a sequence of radiation, hypovascular–hypocellular–hypoxic tissue formation, and trauma-induced or spontaneous mucosa breakdown leading to a nonhealing wound.’’20 In ORN, ionizing radiation leads to obliterative endarteritis with atrophy of skin and supportive tissues that is progressive over time. Injured tissues become atrophic, often ‘‘dry’’ and woody, and tolerate wounding very poorly. Effected tissues lose most or all of their capillary microcirculation.21 Irradiation affects both bone matrix and marrow elements. Osteoblast numbers are decreased, which leads to decreased collagen production.22 Etiology of ORN depends on the mode of radiation therapy, daily-dose rate, and radiation fields. ORN is found in both children and adults.20 Clinical signs and symptoms of ORN are often associated with the development of cutaneous fistulas, trismus, pain, and masticatory difficulties. The patient may have a foul odor due to the accumulation of debris in the defect and exposure of the bone to oral fluids. Exposed bone is usually covered by grayish-yellow surface coagulum that easily scrapes off, leaving an avascular bed with a brownish-yellow color. The mucosa overlying the bony lesion will frequently have an ulcerated, rolled border that may bleed when probed. Radiographically, ORN will present as an erosion of the cortical surface with an underlying, poorly circumscribed, radiolucency with nonsclerotic borders. Interspersed radiopacities, which represent sequestrum formation, may be seen. Pathological fractures may also occur in the affected bone.18 Some of the risk factors for the development of ORN are: the anatomic location of the lesion (the tongue,floor of the mouth, retromolar region have a higher incidence of ORN), the dental status prior to patient pretreatment, dental and gingival trauma after RT, and the area of bone exposure (attached gingival mucosa is better than vestibular area).18 To help prevent the occurrence of post-radiation ORN, the following should be performed prior to radiation. The non-restorable teeth should be
K. Shetty, H. Tuft extracted, the salvageable teeth restored, and periodontal therapy should be completed. The patient should begin a home-care program, which would include the use of a topical fluoride, antimicrobial mouth rinses, and proper brushing and flossing techniques. Salivary stimulants should be used to replace and enhance salivary flow. If removal of teeth is indicated before radiation treatment, extractions should be completed with flap elevation, alveoloplasty, and primary closure of the flap without tension. Radiation should be delayed a minimum of 10–14 days after extraction.18 To help prevent the occurrence of postradiation ORN, after radiation, the patient should begin treatment for mucositis, oral dryness, and hyposalivation. The patient should learn to use range of motion exercises to prevent trismus and should recieve nutritional counseling.18 Hyperbaric oxygen therapy (HBO) in most cases is needed to help healing.16 HBO is the therapeutic administration of oxygen at greater than atmospheric pressure for therapeutic purposes. Delivery of the oxygen must be systemic. It combats osteoradionecrosis because it helps revascularize radiated or infected tissue and improves fibroblastic density. It creates a capillary ingrowth, which spawns healing of infected tissues.22 The target tissue is not necrotic bone, but the soft tissue and bone still undamaged and viable. Necrotic bone must be surgically removed. Therefore, HBO is used to limit surgical bone removal of nonviable bone, to enhance healing of the surgical wound, and to prepare the tissue for reconstruction. Most pediatric patients adapt to HBO therapy easily once middle ear pressure is equalized. Dental caries typically occur during the first year after RT. To help prevent and treat radiation caries, the patient can floss and brush with 0.4% stannous fluoride toothpaste or use 1.1% sodium fluoride in a disposable or freshly cleansed flexible custom fluoride tray over the teeth for 5 min daily. Extractions should be avoided from portions of the jaws receiving over 5000 rads; less than 5000 is acceptable. If extractions are unavoidable for portions receiving over 5000 rads, consider HBO prior to and after extractions. The effects of radiation on the salivary glands can cause xerostomia. Of the serous and mucous components of saliva, only the mucous components remain after a second week of radiation treatment, especially if the major salivary glands are in the radiation field. Xerostomia treatment may include frequent sips of water or lemon water, pilocarpine 5–10 mg twice a day, a glycerine swab before meals, special food preparation, sugarless candy and gum, and artificial saliva solutions. The patient
Dental management of the pediatric postradiation therapy—rhabdomyosarcoma patient should avoid high-sugar-content foods, alcoholbased mouth washes or mouth rinses and alcohol intake. Also a mouthwash of 1/2 teaspoon of salt and 1/2 teaspoon of baking soda to a quart of warm water will remove the viscous component of saliva from the oral cavity. Mucositis may start the second week of RT and is characterized by sloughing of the mucosa and a denuded burning surface which is due to of the rapidly dividing epithelial cells. Mucosa may take one to three months after radiation to return to normal. Most cases of mucositis are reversed with the cessation of therapy. Mucositis can usually be anesthetized with a gentle mixture of benadryl elixir and kaopectate 1:1 volumetric constituent. This mixture can be used often to control pain. Its treatment is palliative and includes mixtures of maalox, benadryl, and xylocaine formed into a viscous rinse. Carafate liquid can act as an oral bandage and can prevent secondary infection of these lesions. A good prevention for candidiasis is chlorhexidine 0.12% TID. Treatment of pain associated with candidiasis includes alkaline mouth rinses (salt + bicarbonate) and 0.5% povidone–iodine mouth rinses q2h. Treatments of infection associated with scandidiasis may include clotrimaxole troches; fluconazole or nystatin. Loss of taste usually persists up to 4 months after the end of therapy. Zinc sulfate 220 mg BID can increase taste perception and may increase salivation. Active jaw opening exercises can prevent or reduce scar-tissue formation and can reduce trismus during and after radiation therapy. Trismus can occur progressively after radiation therapy and is most common when the elevator muscles are in the field of radiation therapy. A sudden incidence of trismus may indicate recurrent disease. Tongue blades inserted between the teeth several times each day can prevent trismus. This insertion is a passive stretching exercise to maintain inter-incisal opening. Moist heat on the muscle experiencing trismus may make the exercise easier and less painful. Chemotherapy, often used with RT to treat RMS, consists of antineoplastic medications that suppress the autoimmune system and/or directly kill cells. Most antineoplastic agents affect normal cells, as well as tumor cells.23 Antineoplastic agents such as vincristine, actinomycin, and cyclophosphamide can interfere with odontogenesis, causing root shortening, tapering, and blunting, and can also interfere with amelogenesis, resulting in hypomineralized enamel defects.8 Chemotherapy can cause xerostomia, gingival hemorrhage, oral infections, bacterial overgrowth, herpetic
247
overgrowth, candida overgrowth, mucosal ulcerations, and teeth sensitivity.23 Professional follow-up supervision is a key element of successful long-term dental health maintenance after RT.24 An identification of late sequelae due to RT is vital to afford the long-term survivor an excellent quality of life.8
References 1. Kramer S, Meadows AT, Jarrett P, Evans AE. Incidence of childhood cancer: experience of a decade in a populationbased registry. J Natl Cancer Inst 1983;70:49–55. 2. Young Jr JL, Ries LG, Silverberg E, Horm JW, Miller RW. Cancer incidence, survival, and mortality for children younger than age 15 years. Cancer 1986;58(suppl 2): 598–602. 3. Carl W, Sako K, Schaaf NG. Dental complications in the treatment of rhabdomyosarcoma of the oral cavity. Oral Surg Oral Med Oral Pathol 1974;38:367–71. 4. Moller P, Perrier M. Dento-maxillofacial sequelae in a child treated for a rhabdomyosarcoma in the head and neck: a case report. Oral Surg Oral Med Oral Pathol 1998;86:297–303. 5. Estilo CL, Huryn JM, Kraus DH, et al. Effects of therapy on dentofacial development in long-term survivors of head and neck rhabdomyosarcoma: the Memorial Sloan–Kettering Cancer Center experience. J Pediatr Hematol Oncol 2003;25:215–22. 6. Wexler L, Helman L. Rhabdomyosarcoma and the undifferentiated sarcomas. In: Pizzo PA, Poplack DG, editors. Principles and practice of pediatric oncology. 3rd ed. Philadelphia: Lippincott-Raven; 1997. p. 799–829. 7. Crist W, Gehan EA, Ragab AH, et al. The third intergroup rhabdomyosarcoma study. J Clin Oncol 1995;13:610–30. 8. Bras J, Batsakis JG, Luna MA. Rhabdomyosarcoma of the oral soft tissues. Oral Surg Oral Med Oral Pathol 1987;64:585–96. 9. Pap GS. Rhabdomyosarcoma: Report of a case with involvement of the angle of the mandible. Int J Oral Surg 1980;9:491–3. 10. Neville BW, Damm DD, Allen CM, Bouquot JE. Oral and maxillofacial pathology. second ed. Philadelphia: Saunders; 2002., pp. 486–88. 11. Yamamoto H, Kozawa Y, Takagi M, Otake S. Rhabdomosarcoma of the left mandible. J Oral Maxillofac Surg 1984;42:613–8. 12. Vapiwala N. Rhabdomyosarcoma. web page on the Internet Oncolink. Abramson Cancer Center, University of Pennsylvania. Apr. 27, 2004 [Cited 2005, June 6. Available from:. 13. Albin RE, O’Donnell RS, Hendee Jr RW, Heideman R, Bailey JA, Majure JA. Rhabdomyosarcoma of pterygoid fossa. Resection for cure utilizing an innervated facial flap and craniofacial reconstruction. Cancer 1986;58:163–8. 14. Peters E, Cohen M, Altini M, Murray J. Rhabdomyosarcoma of the oral and paraoral region. Cancer 1989;63:963–6. 15. Dagher R, Helman L. Rhabdomyosarcoma: an overview. Oncologist 1999;4:34–44. 16. Chen SY, Thakur A, Miller AS, Harwick RD. Rhabdomyosarcoma of the oral cavity. Report of four cases. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1995;80:192–201.
248 17. Malkin D, Li FP, Strong LC, et al. Germ line p53 mutations in a familial syndrome of breast cancer, and other neoplasms. Science 1990;250:1233–8. 18. American Association of Oral and Maxillofacial Surgeons, Radiation therapy, 15(2), AAOMS surgical update, 2000. 19. Paulino AC, Simon JH, Zhen W, Wen BC. Long-term effects in children treated with radiotherapy for head and neck rhabdomyosarcoma. Int J Radiat Oncol Biol Phys 2000;48:1489–95. 20. Curi MM, Dib LL. Osteoradionecrosis of the jaws: a retrospective study of the background factors and treatment in 104 cases. J Oral Maxillofac Surg 1997;55:540–4.
K. Shetty, H. Tuft 21. Santamaria JP, Williams 3rd ET, Desautels DA. Hyperbaric oxygen therapy in pediatrics. Adv Pediatr 1995;42:335–66. 22. Aitasalo K, Niinikowski J, Grenman R, Virolainen E. A modified protocol for early treatment of osteomyelitis and osteoradionecrosis of the mandible. Head Neck 1998;20:411–7. 23. Rothstein JP. Oral care of cancer patients. 6th ed. American Cancer Society; 1996., pp. 15–16. 24. Toljanic JA, Heshmati RH, Bedard JF. Dental follow-up compliance in a population of irradiated head and neck cancer patients. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002;93:35–8.
http://intl.elsevierhealth.com/journal/ooex
CASE REPORT
Dental management of the pediatric post radiation therapy—rhabdomyosarcoma patient: Case reports and review of literature Kishore Shetty *, Heber Tuft LSU Health Sciences Center, Oral and Maxillofacial Surgery, 1100 Florida Avenue, #127, New Orleans, Louisiana 70119, USA Received 18 June 2005; accepted 21 June 2005
KEYWORDS
Summary This article describes the dental management in two patients aged 8 and 5 with rhabdomyosarcoma (RMS) post-radiation therapy. The report discusses some of the common problems faced such as osteoradionecrosis, xerostomia, mucositis, candidiasis, trismus, loss of taste, soft tissue necrosis, and scar tissue formation and the need for the oral healthcare provider to understand these sequelae in order to best treat patients. c 2005 Elsevier Ltd. All rights reserved.
Rhabdomyosarcoma; Radiation therapy; Pediatric; Osteoradionecrosis; Hyperbaric oxygen
Introduction Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma of childhood and adolescence involving the head and neck and is the third most common extracranial solid tumor of childhood after Wilm’s tumor and neuroblastoma.1–3 A malignant tumor composed of neoplastic mesenchymal cells, RMS has varying degrees of striated musclecell differentiation.4 Adolescents younger than 20 years of age are mostly diagnosed with this sarcoma.5 About 65% of these cases are diagnosed in children under 6 years of age.5 RMS occurs in males
* Corresponding author. Tel.: +1 504 619 8524. E-mail address: [email protected] (K. Shetty).
more than females. In females RMS has a higher incidence in the Caucasian race.6,7 Common sites of primary disease include the head and neck, genitourinary tract, and extremities.1,2 The head and neck is the most common site for RMS with about 40% of the cases.5,8,9 This region can be divided into 3 subsites: the orbit, non-parameningealnnon-orbitregion, and parameningeal.5 The most common site of occurrence in the head and neck is the orbit, followed by the nasal cavity and the nasopharynx.10 RMS is uncommon in the oral cavity, and jaw involvement is extremely rare.8,11 The most common site in the oral cavity is the tongue, followed by the soft palate, hard palate, and buccal mucosa.8,9 RMS can be described by three basic types: embryonal, alveolar, and pleomorphic.10 Embryonal RMS, occurring in
1741-9409/$ - see front matter c 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.ooe.2005.06.010
Dental management of the pediatric postradiation therapy—rhabdomyosarcoma patient about 60% of the cases, is the most common of the three types and appears within the first 10 years of life. Alveolar RMS occurs in 20–30% of the cases and appears between ten to twenty-five years of age. Pleomorphic RMS is found in less than 5% of the cases and shows peak prevalence in patients over forty years of age. Commonly found in the extremities, pleomorphic RMS cells are loosely arranged, haphazardly oriented, and exist with variable morphology.10 As the name implies, the cells of embryonal RMS resemble that of the developing muscle cells of a six-to-eight-week-old fetus. Common sites for this cancer are the head and neck, bladder, the vagina, the prostate, and the testes. Its prognosis is relatively good to intermediate. Alveolar RMS receives its name because its cells form hollow spaces. These cells look like normal muscle cells of a 10-week-old fetus and are typically found in the large muscles of the trunk, arms, and legs. Its prognosis is poor, and it tends to be more aggressive than the embryonal RMS.12 The alveolar variant is relatively rare compared to the embryonal form.8,11 Rhabdomyosarcomas are aggressive, frequently recur, and metastasize via blood and lymph routes.3,13,14 Lesions involving the posterior mandible, especially the alveolar variant, have the worst prognosis.13,14 Combined modality therapy can cure 60–70% of newly diagnosed patients with non-metastatic disease. The 5-year survival rate is 71%. Despite aggressive multimodality treatment, less than 20% of patients with the metastatic disease are currently cured; the 5-year survival rate is 27%.4,15 Treatment approaches to RMS incorporate surgery, radiation therapy, and chemotherapy. In sites such as the head and neck or pelvis, tumors often cannot be completely removed with surgery; radiation therapy (RT) can eradicate residual tumor cells in such instances. Early guidelines for RT recommend doses as high as 5500 to 6000 cGy for control of the primary tumor site.15 No clear etiologic factors can account for these malignant neoplastic growths. However, increasing evidence indicates that gene abnormalities may play a role in the development of some childhood malignancies, especially RMS.16 RMS has been associated with familial syndromes, such as neurofibromatosis, and the Li–Fraumeni syndrome.17 Differential diagnoses of RMS include Ewing sarcoma, Wilms’ tumor, lymphoma, neuroblastoma, alveolar soft-part sarcoma, fibrosarcoma, and leiomyosarcoma. These case reports demonstrate some effective post-radiation therapies for RMS patients.
243
Patient #1 An 8-year-old white male patient presented to the Childrens’ Hospital Dental Clinic with a lower left facial swelling and pain in lower left first molar (Fig. 1). The panorex revealed periapical radiolucencies on both root tips and an irregular trabecular pattern with rarefactions (Fig. 2). The diagnosis was irreversible pulpitis leading to chronic periapical abscess and buccal-infected cyst. The patient’s medical history was significant for embryonal auricular RMS diagnosed six years ago (Fig. 3). The surgery took out most of the tumor and the middle ear. As a result he had limited opening of his jaw and no hearing in his right ear. Six weeks of maximum RT of 5900 cGy was followed by fourteen months of chemotherapy followed the radiation therapy (RT). The patient was scheduled to have an extraction on #19 subsequent to hyperbaric oxygen therapy using Mark protocol, which entailed 20 dives prior
Figure 1 Initial presentation with pain and abscess in lower left first molar.
Figure 2 Radiolucencies and irregular trabecular pattern with rarefactions on the tip of both roots on lower left first molar.
244
K. Shetty, H. Tuft
Figure 3 On the frontal (coronal) CT an expansile radiolucent lesion is apparent in the ramus area and appears to extend into the condylar/coronoid regions.
to extraction and 10 dives postextraction.18 Post extraction healing was uneventful with no complications. Future treatment included frequent recalls to watch the progression of his premolars and second molars.
Patient #2 A 5-year-old Caucasian female presented to the Dental Clinic accompanied by her mother with a chief complaint of ‘‘jaw is swollen and cannot open mouth wide enough to clean inside’’ (Fig. 4). Her medical history was significant for alveolar RMS stage III, diagnosed 5 years ago and surgically
Figure 4 Gross facial asymmetry and large swelling of the right posterior mandible.
Figure 5 On the horizontal CT the medial extension of the lesion can be better appreciated with obvious lateral expansion and probable violation of the cortical bone as well.
removed 3 months later (Fig. 5). A coronoidectomy on the right mandible was performed and metal plates were placed in the infratemporal fossa and zygoma regions. Her right mandibular area was irradiated with 4500 cGy for 6 weeks subsequent to surgical healing to destroy any remaining parts of the tumor. She had a history of trismus which developed after tumor removal, and was presently practicing postoral muscle stretching. She has no history of dental restorations or of trauma to the orofacial region (Fig. 6). The extraoral exam showed gross facial asymmetry and a large swelling of the right posterior mandible. This swelling was firm and tender on palpation. There was a mild lymphadenopathy of the right submandibular and cervical nodes. Intraoral exam showed swelling that extended from the right mandibular canine to right mandibular second primary molar. Trismus was present with a constricted oral opening of approximately 7 mm vertically (Fig. 7). She had generalized radiation caries with an increased occurrence on the side irradiated, poor oral hygiene, and xerostomia. Appropriate Medical consults obtained prior to dental treatment under general anesthesia did not prescribe any hyperbaric oxygen therapy. The patient had extensive dental treatment done involving extractions of unrestorable primary teeth, multiple stainless steel crowns and resin restorations (Fig. 8). All of her teeth were prophylaxed with application of topical fluoride varnish.
Dental management of the pediatric postradiation therapy—rhabdomyosarcoma patient
Figure 6
245
Initial presentation showing no history of dental restorations or of trauma to the oral facial region.
Discussion
Figure 7
Constricted oral opening of 7 mm vertically.
The mother was counseled on home care and stretching exercises. A follow-up appointment showed that the extraction sites were healing well and that the restorations were successful.
Figure 8
Radiation therapy (RT) is a major defense against RMS and other such diseases. One of the top challenges in pediatric oncology today is to develop a cure for the disease and to restrict the development of RT late toxicity.17 RT is primarily responsible for the dental sequelae in patients receiving treatment for these diseases.19 The special care dentist needs a strong understanding of these sequelae in order to best treat patients. Radiation reduces or eliminates the reproduction of neoplastic cells in general and can be used in conjunction with other therapy, such as surgery or chemotherapy. It can cure the patient’s disease, or, as palliative care, it may simply prolong and improve the quality of life. Head and neck radiation is measured in Megavolts. Generally, the more penetration needed for deeper tissues, the more megavoltage radiation is chosen. Some of the side effects of post-radiation include delayed eruption of teeth, retarded tooth
Panorex post dental treatment involving multiple stainless steel crowns and resin restorations.
246 and bone development, dwarfed teeth, partial anodontia, erosive caries (radiation caries), discoloration of teeth due to dentinal changes, poor enamel and cervical fracture, osteoradionecrosis, xerostomia (salivary-gland dysfunction), mucositis (dose related), candidiasis (moniliasis, thrush), trismus, loss of taste due to damage to the papillae of the tongue, soft-tissue necrosis, and scar-tissue formation. Osteoradionecrosis (ORN) is one of the most serious complications of radiation therapy. It occurs in the mandible more frequently than in the maxilla, probably because of the greater vascularity in the maxilla. ORN is defined as ‘‘a sequence of radiation, hypovascular–hypocellular–hypoxic tissue formation, and trauma-induced or spontaneous mucosa breakdown leading to a nonhealing wound.’’20 In ORN, ionizing radiation leads to obliterative endarteritis with atrophy of skin and supportive tissues that is progressive over time. Injured tissues become atrophic, often ‘‘dry’’ and woody, and tolerate wounding very poorly. Effected tissues lose most or all of their capillary microcirculation.21 Irradiation affects both bone matrix and marrow elements. Osteoblast numbers are decreased, which leads to decreased collagen production.22 Etiology of ORN depends on the mode of radiation therapy, daily-dose rate, and radiation fields. ORN is found in both children and adults.20 Clinical signs and symptoms of ORN are often associated with the development of cutaneous fistulas, trismus, pain, and masticatory difficulties. The patient may have a foul odor due to the accumulation of debris in the defect and exposure of the bone to oral fluids. Exposed bone is usually covered by grayish-yellow surface coagulum that easily scrapes off, leaving an avascular bed with a brownish-yellow color. The mucosa overlying the bony lesion will frequently have an ulcerated, rolled border that may bleed when probed. Radiographically, ORN will present as an erosion of the cortical surface with an underlying, poorly circumscribed, radiolucency with nonsclerotic borders. Interspersed radiopacities, which represent sequestrum formation, may be seen. Pathological fractures may also occur in the affected bone.18 Some of the risk factors for the development of ORN are: the anatomic location of the lesion (the tongue,floor of the mouth, retromolar region have a higher incidence of ORN), the dental status prior to patient pretreatment, dental and gingival trauma after RT, and the area of bone exposure (attached gingival mucosa is better than vestibular area).18 To help prevent the occurrence of post-radiation ORN, the following should be performed prior to radiation. The non-restorable teeth should be
K. Shetty, H. Tuft extracted, the salvageable teeth restored, and periodontal therapy should be completed. The patient should begin a home-care program, which would include the use of a topical fluoride, antimicrobial mouth rinses, and proper brushing and flossing techniques. Salivary stimulants should be used to replace and enhance salivary flow. If removal of teeth is indicated before radiation treatment, extractions should be completed with flap elevation, alveoloplasty, and primary closure of the flap without tension. Radiation should be delayed a minimum of 10–14 days after extraction.18 To help prevent the occurrence of postradiation ORN, after radiation, the patient should begin treatment for mucositis, oral dryness, and hyposalivation. The patient should learn to use range of motion exercises to prevent trismus and should recieve nutritional counseling.18 Hyperbaric oxygen therapy (HBO) in most cases is needed to help healing.16 HBO is the therapeutic administration of oxygen at greater than atmospheric pressure for therapeutic purposes. Delivery of the oxygen must be systemic. It combats osteoradionecrosis because it helps revascularize radiated or infected tissue and improves fibroblastic density. It creates a capillary ingrowth, which spawns healing of infected tissues.22 The target tissue is not necrotic bone, but the soft tissue and bone still undamaged and viable. Necrotic bone must be surgically removed. Therefore, HBO is used to limit surgical bone removal of nonviable bone, to enhance healing of the surgical wound, and to prepare the tissue for reconstruction. Most pediatric patients adapt to HBO therapy easily once middle ear pressure is equalized. Dental caries typically occur during the first year after RT. To help prevent and treat radiation caries, the patient can floss and brush with 0.4% stannous fluoride toothpaste or use 1.1% sodium fluoride in a disposable or freshly cleansed flexible custom fluoride tray over the teeth for 5 min daily. Extractions should be avoided from portions of the jaws receiving over 5000 rads; less than 5000 is acceptable. If extractions are unavoidable for portions receiving over 5000 rads, consider HBO prior to and after extractions. The effects of radiation on the salivary glands can cause xerostomia. Of the serous and mucous components of saliva, only the mucous components remain after a second week of radiation treatment, especially if the major salivary glands are in the radiation field. Xerostomia treatment may include frequent sips of water or lemon water, pilocarpine 5–10 mg twice a day, a glycerine swab before meals, special food preparation, sugarless candy and gum, and artificial saliva solutions. The patient
Dental management of the pediatric postradiation therapy—rhabdomyosarcoma patient should avoid high-sugar-content foods, alcoholbased mouth washes or mouth rinses and alcohol intake. Also a mouthwash of 1/2 teaspoon of salt and 1/2 teaspoon of baking soda to a quart of warm water will remove the viscous component of saliva from the oral cavity. Mucositis may start the second week of RT and is characterized by sloughing of the mucosa and a denuded burning surface which is due to of the rapidly dividing epithelial cells. Mucosa may take one to three months after radiation to return to normal. Most cases of mucositis are reversed with the cessation of therapy. Mucositis can usually be anesthetized with a gentle mixture of benadryl elixir and kaopectate 1:1 volumetric constituent. This mixture can be used often to control pain. Its treatment is palliative and includes mixtures of maalox, benadryl, and xylocaine formed into a viscous rinse. Carafate liquid can act as an oral bandage and can prevent secondary infection of these lesions. A good prevention for candidiasis is chlorhexidine 0.12% TID. Treatment of pain associated with candidiasis includes alkaline mouth rinses (salt + bicarbonate) and 0.5% povidone–iodine mouth rinses q2h. Treatments of infection associated with scandidiasis may include clotrimaxole troches; fluconazole or nystatin. Loss of taste usually persists up to 4 months after the end of therapy. Zinc sulfate 220 mg BID can increase taste perception and may increase salivation. Active jaw opening exercises can prevent or reduce scar-tissue formation and can reduce trismus during and after radiation therapy. Trismus can occur progressively after radiation therapy and is most common when the elevator muscles are in the field of radiation therapy. A sudden incidence of trismus may indicate recurrent disease. Tongue blades inserted between the teeth several times each day can prevent trismus. This insertion is a passive stretching exercise to maintain inter-incisal opening. Moist heat on the muscle experiencing trismus may make the exercise easier and less painful. Chemotherapy, often used with RT to treat RMS, consists of antineoplastic medications that suppress the autoimmune system and/or directly kill cells. Most antineoplastic agents affect normal cells, as well as tumor cells.23 Antineoplastic agents such as vincristine, actinomycin, and cyclophosphamide can interfere with odontogenesis, causing root shortening, tapering, and blunting, and can also interfere with amelogenesis, resulting in hypomineralized enamel defects.8 Chemotherapy can cause xerostomia, gingival hemorrhage, oral infections, bacterial overgrowth, herpetic
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overgrowth, candida overgrowth, mucosal ulcerations, and teeth sensitivity.23 Professional follow-up supervision is a key element of successful long-term dental health maintenance after RT.24 An identification of late sequelae due to RT is vital to afford the long-term survivor an excellent quality of life.8
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248 17. Malkin D, Li FP, Strong LC, et al. Germ line p53 mutations in a familial syndrome of breast cancer, and other neoplasms. Science 1990;250:1233–8. 18. American Association of Oral and Maxillofacial Surgeons, Radiation therapy, 15(2), AAOMS surgical update, 2000. 19. Paulino AC, Simon JH, Zhen W, Wen BC. Long-term effects in children treated with radiotherapy for head and neck rhabdomyosarcoma. Int J Radiat Oncol Biol Phys 2000;48:1489–95. 20. Curi MM, Dib LL. Osteoradionecrosis of the jaws: a retrospective study of the background factors and treatment in 104 cases. J Oral Maxillofac Surg 1997;55:540–4.
K. Shetty, H. Tuft 21. Santamaria JP, Williams 3rd ET, Desautels DA. Hyperbaric oxygen therapy in pediatrics. Adv Pediatr 1995;42:335–66. 22. Aitasalo K, Niinikowski J, Grenman R, Virolainen E. A modified protocol for early treatment of osteomyelitis and osteoradionecrosis of the mandible. Head Neck 1998;20:411–7. 23. Rothstein JP. Oral care of cancer patients. 6th ed. American Cancer Society; 1996., pp. 15–16. 24. Toljanic JA, Heshmati RH, Bedard JF. Dental follow-up compliance in a population of irradiated head and neck cancer patients. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002;93:35–8.