11 Lip and buccal mucosa

Lip and buccal mucosa

3

THE GEC ESTROHANDBOOKOF BRACHYTHERAPY | Part II Clinical Practice Version 1 - 10/05/2019

11 Lip and buccal mucosa

Jose Luis Guinot, Vratislav Strnad, Erik Van Limbergen

1. Summary 2. Introduction

3 3 3 4 4 4 5 5

9. Treatment planning

7 7 8 8

10. Dose, Dose Rate, Fractionation

3. Anatomical topography

11. Monitoring

4. Pathology 5. Work up

12. Results

13. Adverse side effects 14. Key messages

11 13 14

6. Indications, contra-indications 7. Tumour and Target Volume

15. References

8. Technique

1. SUMMARY

Lip and buccal mucosa cancers can be managed with surgery, but at the high cost of impaired functional or cosmetic outcomes in some cases. Radiation therapy can be a good alternative. These tumours are well localized and have been treated with low dose rate (LDR) brachytherapy with excellent results for decades. Pulsed and high dose rate brachytherapy (PDR and HDR) are the current standard, but few papers have been published on results in these tumour locations. An optimal treatment scheme has not been agreed upon, but the results show that local control is at least as high as expected with LDR and the incidence of complications is probably lower than with the old techniques. Functional outcome and cosmesis is better than with surgery, especially for lip cancer. Therefore brachytherapy should be considered in most of these cancers.

2. INTRODUCTION

contributes to one third of cases and alcohol to 20% of them, but these aetiological factors are often underestimated.The proportion of females is higher than in other head-and-neck cancers: the sex ratio is 3 : 1 (males : females). Involvement of the buccal mucosa or lateral commissure is difficult to treat with surgery due to the great alteration of function. Radiation is a good alternative, and brachytherapy allows an increase in the local dose leading to higher rates of local control. There are a lot of references of cases treated with low-dose rate (LDR) techniques, with high rates of success [3], but nowadays LDR 192-Iridiumwires are no longer available in Europe. Therefore we have to use PDR or HDR stepping sources to treat these tumours. The fear of adverse effects when using high doses per fraction has led to HDR-BT less frequently being used to treat carcinoma of the lip, compared to other head and neck locations, but the published results show that functional, cosmetic and control outcomes are similar to the LDR experience, with fewer complications [4].

The vermilion of the lip forms a transition zone between skin and oral mucosa and therefore the risk for cancer is related both to sun exposure and classical etiological factors for oral cancer such as tobacco, alcohol and bad oral hygiene [1]. Farm labourers and fishermen have a higher risk of lip cancer, as they are likely to be exposed to these risk factors. The involvement of the outer lower lip is 40 times more prevalent than the upper lip [2]. Early detection is usually possible because of location and slow growth. The incidence is higher in men (ratio, 6:1). It is the most common cancer of the oral cavity, approximately 30%, as well as being the one with the highest survival. Cases will increase with aging population and increasing life span. Patients are often old (the mean age of a patient suffering from lip cancer is over 65 years) or have poor general condition, contraindicating major surgical excision and flap reconstruction. Surgery as well as external radiotherapy, and interstitial implants with radioactive sources are very successful in treating these lesions. Modern brachytherapy (BT) is a simple and effective treatment modality leading to excellent local control rates and cosmetic and functional results. Nevertheless, in some countries, few patients are considered for treatment with brachytherapy. Buccal mucosa carcinoma represents 3 to 5% of oral-cavity cancers in Europe and North America; it is much more frequent in South Asia and LatinAmerica.These differences are due to people chewing areca and betel nuts, tobacco leaves and coca leaves mixed with lime, since these are carcinogenic. In developed countries, tobacco

3. ANATOMICAL TOPOGRAPHY

Anatomically the lip can be divided in three different parts. The cutaneous lip goes over to the vermilion or dry mucosa of the lip, which forms a transition zone between the skin and the wet oral mucosa. Its lateral limits are about 1cm from the lip commissures: