Evaluation of a Novel Field-placement Algorithm for Locoregional Breast Cancer Radiotherapy Including the Internal Mammary Chain.

Ranger, A and Dunlop, A and Shah, P and Amin, K and Henderson, D and Bartlett, F R and Knowles, C and Brigden, B and Lacey, C and Donovan, E and Harris, E and Kirby, A M (2019) Evaluation of a Novel Field-placement Algorithm for Locoregional Breast Cancer Radiotherapy Including the Internal Mammary Chain. Clinical oncology (Royal College of Radiologists (Great Britain)), 31 (1). pp. 25-33. ISSN 1433-2981. This article is avalable to all UHB staff and students via ASK Discovery tool Http://tinyurl.comz795c8c by using their Athens login IDs

Full text not available from this repository.
Official URL: https://www.clinicaloncologyonline.net/article/S09...

Abstract

AIMS

Irradiation of the internal mammary chain (IMC) is increasing following recently published data, but the need for formal delineation of lymph node volumes is slowing implementation in some healthcare settings. A field-placement algorithm for irradiating locoregional lymph nodes including the IMC could reduce the resource impact of introducing irradiation of the IMC. This study describes the development and evaluation of such an algorithm.

MATERIALS AND METHODS

An algorithm was developed in which six points representing lymph node clinical target volume borders (based on European Society for Radiotherapy and Oncology consensus nodal contouring guidelines) were placed on computed tomography-defined anatomical landmarks and used to place tangential and nodal fields. Single-centre testing in 20 cases assessed the success of the algorithm in covering planning target volumes (PTVs) and adequately sparing organs at risk. Plans derived using the points algorithm were also compared with plans generated following formal delineation of nodal PTVs, using the Wilcoxon signed rank test. Timing data for point placement were collected. Multicentre testing using the same methods was then carried out to establish whether the technique was transferable to other centres.

RESULTS

Single-centre testing showed that 95% of cases met the nodal PTV coverage dose constraints (binomial probability confidence interval 75.1-99.9%) with no statistically significant reduction in mean heart dose or ipsilateral lung V associated with formal nodal delineation. In multicentre testing, 69% of cases met nodal PTV dose constraints and there was a statistically significant difference in IMC PTV coverage using the points algorithm when compared with formally delineated nodal volumes (P < 0.01). However, there was no difference in axillary level 1-4 PTV coverage (P = 0.11) with all cases meeting target volume constraints.

CONCLUSIONS

The optimal strategy for breast and locoregional lymph node radiotherapy is target volume delineation. However, use of this novel points-based field-placement algorithm results in dosimetrically acceptable plans without the need for formal lymph node contouring in a single-centre setting and for the breast and level 1-4 axilla in a multicentre setting. Further quality assurance measures are needed to enable implementation of the algorithm for irradiation of the IMC in a multicentre setting.

Item Type: Article
Additional Information: This article is avalable to all UHB staff and students via ASK Discovery tool Http://tinyurl.comz795c8c by using their Athens login IDs
Subjects: QZ Pathology. Oncology
WP Gynaecology. Women’s health
Divisions: Planned IP Care > Oncology and Clinical Haematology
Related URLs:
Depositing User: Jamie Edgar
Date Deposited: 20 Dec 2019 15:01
Last Modified: 20 Dec 2019 15:01
URI: http://www.repository.uhblibrary.co.uk/id/eprint/2706

Actions (login required)

View Item View Item