open access

Vol 12, No 4 (2007)
Untitled
Published online: 2007-07-01
Submitted: 2006-12-07
Get Citation

Estimation of the α/β ratio for lower lip cancer treated with interstitial HDR brachytherapy

Andrzej Lebioda, Roman Makarewicz, Agata Rembielak, Brygida Bialas, Renata Kabacinska
DOI: 10.1016/S1507-1367(10)60058-2
·
Rep Pract Oncol Radiother 2007;12(4):207-210.

open access

Vol 12, No 4 (2007)
Untitled
Published online: 2007-07-01
Submitted: 2006-12-07

Abstract

Background

A standard linear-quadratic (LQ) model is now routinely used for clinical data analysis and the prediction of the clinical effect of radiotherapy. The typical α/β values suggested in the literature range from 10 to 20Gy for most tumours and early responding normal tissues, and from 2 to 5Gy for late responding tissues.

Aim

The estimation of α/β ratio values for planoepithelial lower lip cancer.

Materials/Methods

The clinical material is based on the records of 25 patients undergoing radical treatment with interstitial brachytherapy: 19 patients were administered brachytherapy exclusively and 6 patients were treated postoperatively. The following stage arrangement was applied: T1 in 15 pts, T2 in 9 pts, N0 in 24 pts and N1 only in one T2 patient. Radiotherapy was based on HDR brachytherapy using the interstitial technique. Patients with positive margins after surgery were qualified for postoperative brachytherapy. The dose was either specified at the reference 80% isodose according to the Paris System or points calculated 3-5 mm from the macroscopic tumour. The average total dose was 38.3Gy, the number of fractions being 7 and the fraction dose 5.3Gy. The overall treatment time was 12 days. The average follow-up period was 30 months. A standard probit regression in conjunction with a linear-quadratic model was used.

Results

The estimated value of the α/β ratio for lip cancer was 12Gy (±3.72*10−10 95% CI).

Conclusions

The estimated α/β ratio is consistent with α/β ratios published for squamous cell head and neck cancers.

Abstract

Background

A standard linear-quadratic (LQ) model is now routinely used for clinical data analysis and the prediction of the clinical effect of radiotherapy. The typical α/β values suggested in the literature range from 10 to 20Gy for most tumours and early responding normal tissues, and from 2 to 5Gy for late responding tissues.

Aim

The estimation of α/β ratio values for planoepithelial lower lip cancer.

Materials/Methods

The clinical material is based on the records of 25 patients undergoing radical treatment with interstitial brachytherapy: 19 patients were administered brachytherapy exclusively and 6 patients were treated postoperatively. The following stage arrangement was applied: T1 in 15 pts, T2 in 9 pts, N0 in 24 pts and N1 only in one T2 patient. Radiotherapy was based on HDR brachytherapy using the interstitial technique. Patients with positive margins after surgery were qualified for postoperative brachytherapy. The dose was either specified at the reference 80% isodose according to the Paris System or points calculated 3-5 mm from the macroscopic tumour. The average total dose was 38.3Gy, the number of fractions being 7 and the fraction dose 5.3Gy. The overall treatment time was 12 days. The average follow-up period was 30 months. A standard probit regression in conjunction with a linear-quadratic model was used.

Results

The estimated value of the α/β ratio for lip cancer was 12Gy (±3.72*10−10 95% CI).

Conclusions

The estimated α/β ratio is consistent with α/β ratios published for squamous cell head and neck cancers.

Get Citation

Keywords

lower lip cancer; LQ model; α/β ratio; brachytherapy

About this article
Title

Estimation of the α/β ratio for lower lip cancer treated with interstitial HDR brachytherapy

Journal

Reports of Practical Oncology and Radiotherapy

Issue

Vol 12, No 4 (2007)

Pages

207-210

Published online

2007-07-01

DOI

10.1016/S1507-1367(10)60058-2

Bibliographic record

Rep Pract Oncol Radiother 2007;12(4):207-210.

Keywords

lower lip cancer
LQ model
α/β ratio
brachytherapy

Authors

Andrzej Lebioda
Roman Makarewicz
Agata Rembielak
Brygida Bialas
Renata Kabacinska

Important: This website uses cookies. More >>

The cookies allow us to identify your computer and find out details about your last visit. They remembering whether you've visited the site before, so that you remain logged in - or to help us work out how many new website visitors we get each month. Most internet browsers accept cookies automatically, but you can change the settings of your browser to erase cookies or prevent automatic acceptance if you prefer.

By "Via Medica sp. z o.o." sp.k., ul. Świętokrzyska 73, 80–180 Gdańsk, Poland
tel.:+48 58 320 94 94, fax:+48 58 320 94 60, e-mail: journals@viamedica.pl