Protocol for the surgical and large bore procedures in malignant pleural mesothelioma and radiotherapy trial (SMART Trial): an RCT evaluating whether prophylactic radiotherapy reduces the incidence of procedure tract metastases

Our plain-English summary of Protocol for the surgical and large bore procedures in malignant pleural mesothelioma and radiotherapy trial (SMART Trial): an RCT evaluating whether prophylactic radiotherapy reduces the incidence of procedure tract metastases, by A.O. Clive, P. Wilson, H. Taylor, et al (BMJ Open, 2015).

The study

• Authors: A.O. Clive, P. Wilson, H. Taylor, A.J. Morley, E. de Winton, N. Panakis, N. Rahman, J. Pepperell, T. Howell, T.J. Batchelor, N. Jordan, Y.C. Lee, L. Dobson, N.A. Maskell
• Journal: BMJ Open
• Published: 2015;5(1):e006673
• Type of article: Randomized trial
• Cited by: 11 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Introduction: Patients with malignant pleural mesothelioma (MPM) may develop painful 'procedure tract metastasis' (PTM) at the site of previous pleural interventions. Prophylactic radiotherapy has been used to minimise this complication; however, three small randomised trials have shown conflicting results regarding its effectiveness. The surgical and large bore procedures in malignant pleural mesothelioma and radiotherapy trial (SMART Trial) is a suitably powered, multicentre, randomised controlled trial, designed to evaluate the efficacy of prophylactic radiotherapy within 42 days of pleural instrumentation in preventing the development of PTM in MPM.

Methods And Analysis: 203 patients with a histocytologically proven diagnosis of MPM, who have undergone a large bore pleural intervention (thoracic surgery, large bore chest drain, indwelling pleural catheter or local anaesthetic thoracoscopy) in the previous 35 days, will be recruited from UK hospitals. Patients will be randomised (1:1) to receive immediate radiotherapy (21 Gy in 3 fractions over 3 working days within 42 days of the pleural intervention) or deferred radiotherapy (21 Gy in 3 fractions over 3 working days given if a PTM develops). Patients will be followed up for 12 months. The primary outcome measure is the rate of PTM until death or 12 months (whichever is sooner), as defined by the presence of a clinically palpable nodule of at least 1 cm diameter felt within 7 cm of the margins of the procedure site as confirmed by two assessors. Secondary outcome measures include chest pain, quality of life, analgaesic requirements, healthcare utilisation and safety (including radiotherapy toxicity).

Ethics And Dissemination: The trial has received ethical approval from the Southampton B Research Ethics Committee (11/SC/0408). There is a Trial Steering Committee, including independent members and a patient and public representative. The trial results will be published in a peer-reviewed journal and presented at international conferences.

Trial Registration Number: ISRCTN72767336.

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In plain English

This article was a protocol: it described how the SMART Trial would be run and reported no results. The SMART Trial was planned as a multicentre randomised controlled trial in UK hospitals. It would enrol 203 patients with malignant pleural mesothelioma (MPM) who had had a large bore pleural procedure, such as thoracic surgery, a large bore chest drain, an indwelling pleural catheter or local anaesthetic thoracoscopy, in the previous 35 days. Patients would be randomly assigned to one of two groups. One group would get immediate radiotherapy (21 Gy in 3 fractions over 3 working days, within 42 days of the procedure). The other would get the same radiotherapy only if a procedure tract metastasis (PTM, a tumour growing at the procedure site) developed. The trial aimed to test whether early radiotherapy prevents PTM. The authors explained that three small earlier randomised trials had given conflicting results. They named the exclusion of small bore chest tubes as a limitation. At the time of writing, recruitment had run from December 2011 to August 2014 and the trial was in follow-up.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Protocol for a multicentre randomised controlled trial; no results reported
• Who was studied: Planned 203 patients with a histocytologically proven diagnosis of malignant pleural mesothelioma who had a large bore pleural intervention in the preceding 35 days, recruited from UK hospitals
• Exposure: Not an asbestos exposure study. The intervention was immediate prophylactic radiotherapy (21 Gy in 3 fractions over 3 working days within 42 days of the pleural intervention) compared with deferred radiotherapy of the same dose given only if a PTM developed
• Main results:
  • No outcome results were reported. At the time of writing the trial was in follow-up, with recruitment from December 2011 to August 2014
• The authors' conclusion: The article drew no conclusions about effectiveness. The authors gave as the reason for the trial that earlier small randomised trials had conflicting results
• Limitations the authors state:
  • Small bore chest tubes were excluded from the trial

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma.

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Tract Metastasis, Thoracic Surgery, Indwelling Pleural Catheter, Thoracoscopy, Quality of Life.

Related studies

• Prophylactic radiotherapy for the prevention of procedure-tract metastases after surgical and large-bore pleural procedures in malignant pleural mesothelioma (SMART): a multicentre, open-label, phase 3, randomised controlled trial — A.O. Clive, H. Taylor, et al. (2016)
• Prophylactic radiotherapy for procedure tract metastases in mesothelioma: a review — D.T. Arnold, A.O. Clive (2017)
• Protocol for PIT: a phase III trial of prophylactic irradiation of tracts in patients with malignant pleural mesothelioma following invasive chest wall intervention — N. Bayman, D. Ardron, et al. (2016)
• Evaluating quality of life and cost implications of prophylactic radiotherapy in mesothelioma: Health economic analysis of the SMART trial — S.A. Stewart, A.O. Clive, et al. (2018)
• Prophylactic radiotherapy to prevent procedure-tract metastases — G. Zalcman, S. Brosseau, et al. (2016)
• Prophylactic radiotherapy to prevent procedure-tract metastases — D. Landau, E. Lim (2016)

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