Stereotactic body radiotherapy for moderately central and ultra-central oligometastatic disease: initial outcomes

Cooke, R., Camilleri, P., Chu, K.-Y., O'Cathail, S. M. , Robinson, M., Van Den Heuvel, F. and Hawkins, M. A. (2020) Stereotactic body radiotherapy for moderately central and ultra-central oligometastatic disease: initial outcomes. Technical Innovations and Patient Support in Radiation Oncology, 13, pp. 24-30. (doi: 10.1016/j.tipsro.2020.01.002) (PMID:32128460) (PMCID:PMC7042153)

Abstract

Background: Delivery of SBRT to central thoracic tumours within 2 cm of the proximal bronchial tree (PBT), and especially ultra-central tumours which directly abut the PBT, has been controversial due to concerns about high risk of toxicity and treatment-related death when delivering high doses close to critical mediastinal structures. We present dosimetric and clinical outcomes from a group of oligometastatic patients treated with a risk-adapted SBRT approach. Methods: Between September 2015 and October 2018, 27 patients with 28 central thoracic oligometastases (6 moderately central, 22 ultra-central) were treated with 60 Gy in 8 fractions under online CBCT guidance. PTV dose was compromised where necessary to meet mandatory OAR constraints. Patients were followed up for toxicity and disease status. Results: Mandatory OAR constraints were met in all cases; this required PTV coverage compromise in 23 cases, with V100% reduced to <70% in 11 cases. No acute or late toxicities of Grade ≥ 3 were reported. One and 2 year in-field control rates were 95.2% and 85.7% respectively, progression-free survival rates were 42.8% and 23.4% respectively, and overall survival rates were 82.7% and 69.5% respectively. No significant differences were seen in control or survival rates by extent of PTV underdosage or between moderately and ultra-central cases. Conclusion: It appears that compromising PTV coverage to meet OAR constraints allows safe and effective delivery of SBRT to moderately and ultra-central tumours, with low toxicity rates and high in-field control rates. This treatment can be delivered on standard linear accelerators with widely available imaging technology.

• Item Type: Articles
• Additional Information: We would like to acknowledge the funding support provided by Cancer Research UK and the Medical Research Council.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: O'Cathail, Dr Sean
• Authors: Cooke, R., Camilleri, P., Chu, K.-Y., O'Cathail, S. M., Robinson, M., Van Den Heuvel, F., and Hawkins, M. A.
• College/School: College of Medical Veterinary and Life Sciences > School of Cancer Sciences
• Journal Name: Technical Innovations and Patient Support in Radiation Oncology
• Publisher: Elsevier
• ISSN: 2405-6324
• ISSN (Online): 2405-6324
• Published Online: 17 February 2020
• Copyright Holders: Copyright © 2020 The Authors
• First Published: First published in Technical Innovations and Patient Support in Radiation Oncology 13: 24-30
• Publisher Policy: Reproduced under a Creative Commons License