Home About us Editorial board Ahead of print Current issue Search Archives Submit article Instructions Subscribe Contacts Login 


 
 Table of Contents  
SHORT COMMUNICATION
Year : 2016  |  Volume : 12  |  Issue : 2  |  Page : 1102-1103

Cerrobend shielding stents for buccal carcinoma patients


Department of Prosthodontics, Faculty of Dental Sciences, King George's Medical University, Lucknow, Uttar Pradesh, India

Date of Web Publication25-Jul-2016

Correspondence Address:
Himanshi Aggarwal
Department of Prosthodontics, Room No. 404 E, Gautam Buddha Hostel, Chowk, Lucknow - 226 003, Uttar Pradesh
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0973-1482.144688

Rights and Permissions
 > Abstract 


Buccal carcinoma is one of the most common oral malignant neoplasms, especially in the South Asian region. Radiotherapy, which plays a significant role in the treatment of this carcinoma, has severe adverse effects. Different types of prosthesis may be constructed to protect healthy tissues from the adverse effects of treatment and concentrate radiation in the region of the tumor mass. However, the technique for fabrication of shielding stent with Lipowitz's alloy (cerrobend/Wood's alloy) has not been well documented. This article describes detailed technique for fabrication of such a stent for unilateral buccal carcinoma patients to spare the unaffected oral cavity from potential harmful effects associated with radiotherapy.

Keywords: Buccal carcinoma, radiotherapy, stent


How to cite this article:
Yangchen K, Singh SV, Aggarwal H, Singh RD, Siddharth R, Mishra N, Tripathi S. Cerrobend shielding stents for buccal carcinoma patients. J Can Res Ther 2016;12:1102-3

How to cite this URL:
Yangchen K, Singh SV, Aggarwal H, Singh RD, Siddharth R, Mishra N, Tripathi S. Cerrobend shielding stents for buccal carcinoma patients. J Can Res Ther [serial online] 2016 [cited 2019 Dec 12];12:1102-3. Available from: http://www.cancerjournal.net/text.asp?2016/12/2/1102/144688


 > Introduction Top


The high-frequency of oral cancer in Asian countries has been known since the last century, buccal mucosa being the most common site.[1] Radiation therapy is being used with increasing frequency in the management of such head and neck tumors. The adverse effects of radiotherapy manifest themselves in varying degree, depending upon factors such as volume of tissue irradiated, site and size of the tumor, type of radiotherapy technique used, etc., Stents may be constructed to protect healthy tissues from adverse effects of treatment and concentrate radiation in the region of the tumor mass.[2] Lipowitz's alloy or Wood's metal (eutectic alloy of 50% bismuth, 26.7% lead, 13.3% tin, and 10% cadmium by weight), popularly known as cerrobend, is commonly used to shield uninvolved tissues from electron beams used in therapeutic radiation treatment of head and neck cancers.[3] However, the technique for fabrication of such stents has not been documented properly. This article details such a technique.


 > Technique Top


  • Maxillary and mandibular impressions were made with irreversible hydrocolloid impression material and poured with type III gypsum
  • After facebow transfer, interocclusal records were made with aluwax (Aluwax Dental Products Co., Michigan, United States) at maximum comfortable mouth opening of the patient
  • After mounting on a semi-adjustable articulator, a 2 mm thickness of base plate wax (Maarc Goregoan, Mumbai, India) was adapted over the unaffected side of the maxillary cast extending to the mid-palatine raphe and facial sulcus, till the midline [Figure 1]
  • A similar baseplate was adapted over the mandibular unaffected half up to the alveolo-lingual and facial sulcus till the midline [Figure 1]
  • Occlusal rims of approximately similar height were then fabricated on these bases at the height decided by the interocclusal record [Figure 1]. It was ensured that the combined facio-lingual thickness of wax was at least 10 mm to provide adequate shielding of unaffected oral tissues from adverse effects of radiotherapy
  • Nicks and notches were made on the occlusal surface of the maxillary and mandibular wax rims, so that the upper and lower separate parts interlock and maintain the desired position of the stent in the mouth
  • The trial stents were then tried in the patient's mouth and adjusted
  • The maxillary and mandibular trial stents were flasked and dewaxed identical to processing of heat cured acrylic dentures. Lipowitz's alloy (available commercially by the names of cerrobend, bendalloy, pewtalloy and MCP 158) is a low temperature casting eutectic alloy with a melting point of approximately 70°C (158°F)
  • The cerrobend was liquefied in a casting crucible on a Bunsen burner and poured in the molds, followed by the flask closure. Care should be taken to use personnel protection devices such as gloves and mouth mask while melting and pouring the alloy
  • Immediately after pouring the molten cerrobend alloy into the mold, the flask assembly was cooled evenly by immersing in water, to prevent flaws such as holes, dents, cracks and/or crystallization in the castings [4]
  • The castings were recovered and finished and polished [Figure 2] in a similar fashion to other metal restorations. The stent was adjusted intraorally [Figure 3].



 > Discussion Top


Radiotherapy has been used in the management of carcinomas of head and neck region for many years. External beam radiotherapy is generally used postoperatively or rarely as a primary treatment in advanced lesions.[5] Radiation stents assist in the delivery of radiotherapy for carcinomas. These prostheses are used to protect or displace vital structures from the radiation field, locate diseased tissues in a repeatable position during radiation treatment, position the radiation beam, carry radioactive material or dosimetric devices to the tumor site, recontour tissues to simplify the therapy, or shield tissues from radiation. The use of shielding stent for buccal carcinoma besides protecting tissues of the contralateral side, simplifies dosimetry by flattening the affected cheek due to stretching action of the stent.[1]
Figure 1: Trial denture bases with indented wax occlusal rims

Click here to view
Figure 2: Finished and polished shielding stent with indexed maxillary and mandibular components

Click here to view
Figure 3: View of radiation stent in situ

Click here to view


Using gloves and mouth mask are of utmost importance during processing as wood's metal contains lead and cadmium. Contact with bare skin may be harmful, especially in the molten state as vapors from this alloy carry the risk of cancer, anosmia and damage to the liver, kidneys, nerves, bones, and respiratory system.[6]


 > Conclusion Top


It is essential to be familiar with fabrication method of shielding stents for dental personnel, who should be an integral part of a multidisciplinary team treating an oral carcinoma patient by radiation therapy. This will aid predictable and fast service for such patients.

 
 > References Top

1.
Beumer J, Curtis TA, Nishimura R. Radiation therapy of head and neck tumors: Oral effects, dental manifestations and dental treatment. In: Beumer J, Curtis TA, Marunick MT, editors. Maxillofacial Rehabilitation, Prosthodontics and Surgical Considerations. St. Louis: Ishiyaku Euroamerica Inc.; 1996. p. 43-112.  Back to cited text no. 1
    
2.
Toljanic JA, Saunders VW Jr. Radiation therapy and management of the irradiated patient. J Prosthet Dent 1984;52:852-8.  Back to cited text no. 2
    
3.
Walker C, Wadd NJ, Lucraft HH. Novel solutions to the problems encountered in electron irradiation to the surface of the head. Br J Radiol 1999;72:787-91.  Back to cited text no. 3
    
4.
Dea D, San Luis E. Casting of electron field defining apertures: Casting with the metal mold kits. Med Dosim 1988;13:149-51.  Back to cited text no. 4
    
5.
Million RR, Cassisi NJ, Mancuso M. Oral cavity. In: Million RR, Cassisi NJ, editors. Management of Head and Neck Cancer: A Multidisciplinary Approach. 2nd ed. Philadelphia: JB Lippincott; 1994. p. 321-400.  Back to cited text no. 5
    
6.
Fernández MA, Sanz P, Palomar M, Serra J, Gadea E. Fatal chemical pneumonitis due to cadmium fumes. Occup Med (Lond) 1996;46:372-4.  Back to cited text no. 6
    


    Figures

  [Figure 1], [Figure 2], [Figure 3]



 

Top
 
 
  Search
 
Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
Access Statistics
Email Alert *
Add to My List *
* Registration required (free)

  >Abstract>Introduction>Technique>Discussion>Conclusion>Article Figures
  In this article
>References

 Article Access Statistics
    Viewed1634    
    Printed22    
    Emailed0    
    PDF Downloaded125    
    Comments [Add]    

Recommend this journal


[TAG2]
[TAG3]
[TAG4]