ABSTRACT
The present report describes, an easy fast and cheap technique to construct a device for brachytherapy in an edentulous patient. The device is positioned on the polished surface of the denture and it is removable. These unique features allow patients to use their own complete denture regularly after radiation therapy for masticatory function.

KEYWORDS
brachytherapy, maxillofacial device and radiotherapy

   

Figure 1 - Teflon tubes and stone cast of the existing denture necessary to fabricate the device.
Figure 2 - The device after resin polymerization, before delivery to the patient.

INTRODUCTION
Brachytherapy is a technique of radiation treatment in which radioactive sources are delivered into the tissues (direct insertion), intracavitary or surface application (i.e. molds). This method takes advantage of the rapid decrease in dose with distance from a radiation source (inverse square law). Thus, a high radiation dose can be delivered to the tumor while sparing surrounding normal tissues. ⁽¹⁾
Prosthetic removable devices can be indicated to allow the brachytherapy effect. ^(1) (2)
The main feature of such devices is to bring Iridium¹⁹² needles for brachytherapy close contact to tumor site. In an edentulous patient on the maxillary jaw it is possible to anchor Teflon tubes (radiation carriers) to the polished surface of the denture palate. But usually the presence of Teflon tubes does not allow masticatory function for the entire duration of radiation therapy cycle. ^(3) (6)
The objective of the short report is to describe an easy, fast and cheap procedure to fabricate a removable clear resin device anchored on a maxillary complete denture that overcome functional limitation of brachytherapy devices.

PROCEDURE
First an impression of the polished surface of the existing maxillary complete denture is made with irreversible hydrocolloids (Alginoplast; Heraeus Kulzer, Hanau, Holland) in a stock tray and a stone cast poured in type III dental stone (Dental Hydrocal White; Kerr Italia spa, Torino, Italy).
Multiple layers of separating fluid (Separating fluid, Ivoclar.Vivadent AG srl, Bolzano,Italy) are applied on the stone cast.
Resin posterior teeth and palate are coated with cold cured clear acrylic resin and Teflon tubes (radiation carriers) are positioned as prescribed by the radiation oncologist, to host Iridium¹⁹² needles, as close as possible to the tumor lesion.
Acrylic resin is polymerized in Hydromuffle (Ivomat IP3, Ivoclar-Vivadent AG, Schaan, Lichtenstein) under 6 bar pressure at 40°C for 10 minutes. The device is then removed from the plaster cast, finished and polished.
During the radiotherapy session the patient will apply the device on his own denture. Usually the undercuts of artificial teeth guarantee sufficient retention to the device. However in case of absence of undercuts, retentive clasps can be used.
At the end of every therapeutic session the patient can remove the device with Teflon carriers and use the denture for regular function.

CONCLUSION
It is described an easy fast and cheap technique to construct a device for brachytherapy in edentulous patient that is retained by the denture itself and it is removable. These unique features allow patients to use their own complete denture daily after radiation therapy.

BIBLIOGRAPHY
1. Beumer J 3rd, Curtis TA, Marunick MT. Maxillofacial Rehabilitation: Prosthodontic and Surgical Considerations. 1st ed. St. Louis: Ishiyaku EuroAmerica, Inc; 1996. p. 55-61.

2. Branchi R, Fancelli V, De Salvador A, Giovannoni A. Cancer of the head and neck: general principles of radiobiology, radiotherapy and chemotherapy. Radiation damage. Minerva Stomatol. 2003;52:411-25.

3. Sela M, Taicher S. Intraoral carrier for edentulous patients. J Prosthet Dent 1983;50:815-7.

4. Herring HW Jr, Greene PE. Use of a complete denture as a radiation carrier. J Prosthet Dent 1983;49:803-4.

5. Minsley GE, Rothenberg S. Use of the afterloading technique for intraoral radiation carriers. J Prosthet Dent 1985;53:676-8.

6. Randall ME, Salisbury PL 3rd, Schmidtke M. Afterloaded radiation carrier for carcinoma of the palate. A clinical report. J Prosthet Dent 1988;60:655-9.