| Author: | Chan, Shing-chi |
| Title: | Swallowing function of head and neck cancer patients after concomitant radiotherapy : a comparative study between IMRT and conformal technique |
| Degree: | M.Sc. |
| Year: | 2009 |
| Subject: | Hong Kong Polytechnic University -- Dissertations. Radiotherapy. Deglutition. Head -- Cancer -- Radiotherapy. Neck -- Cancer -- Radiotherapy. |
| Department: | Department of Health Technology and Informatics |
| Pages: | vii, 75 leaves : col. ill. ; 30 cm. |
| Language: | English |
| Abstract: | In Prince of Wales Hospital, Hong Kong, advanced head and neck cancer is commonly treated by concomitant radiotherapy with concurrent chemotherapy in order to achieve better local control as well as disease free survival. Two techniques, conventional-conformal concomitant boost (3DCRTB) and IMRT-IMRT concomitant boost (IMRTB) had been used. A retrospective study was conducted to exam whether the IMRTB has any advantages in preserving swallowing function over 3DCRTB. The objectives were to study the relationship among radiation dose received by the dysphagia / aspiration related structures (DARS), dose-volume effect of DARS and swallowing function. It also compares the treatment out come (swallowing function) by using these two techniques. Form April 2006 to December 2007, the medical records and radiotherapy planning films and computer plans of sixty patients with advanced head and neck cancer treated by either 3DCRTB or IMRTB were reviewed. Two DARS were delineated on their planning computer tomography. The superior, middle and inferior pharyngeal constrictors was delineated as a single DARS, Pharyngeal Constrictors (PC) and the glottic larynx and supraglottic larynx were delineated as GSL. The radiation dose to DARS and volume of DARS was calculated according to their treatment history. The swallowing function score at four different observation time points, pre-treatment, one month, three months and six months after treatment completed were retrieved. Dose-volume data from dose volume histogram and swallowing function score were compared. Results show that, in both techniques, the swallowing function is the poorest at one month after treatment completed. The swallowing function deteriorated as the radiation dose to DARS increased. The percentage volume of DARS receiving specified dose level is significantly lower in IMRTB especially when the dose level is over 50 Gy (20% less at 50 Gy, 40 % less at 70 Gy, p < 0.05). IMRTB delivered significantly less dose to DARS (14 Gy, 7.1 Gy and 19.3 Gy for whole DARS, PC and GSL respectively, p < 0.05) when compared with 3DCRTB. Though IMRTB can reduce the volume of BARS receiving radiation dose and reduce the mean dose, it cannot show any advantage in improving swallowing function. Further reduction of radiation dose to BARS and improve the swallowing function after IMRTB is possible by changing the daily practice. Swallowing exercises are highly recommended for patients who undergo concomitant radiotherapy. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b23154275.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 2.15 MB | Adobe PDF | View/Open |
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