High dose irradiation after pleurectomy/decortication or biopsy for pleural mesothelioma treatment

Our plain-English summary of High dose irradiation after pleurectomy/decortication or biopsy for pleural mesothelioma treatment, by E. Parisi, A. Romeo, A. Sarnelli, et al (Cancer Radiothérapie, 2017).

The study

• Authors: E. Parisi, A. Romeo, A. Sarnelli, G. Ghigi, S.R. Bellia, E. Neri, S. Micheletti, B. Dipalma, D. Arpa, G. Furini, M.A. Burgio, G. Genestreti, C. Gurioli, S. Sanna, P. Bovolato, F. Rea, G. Storme, E. Scarpi, C. Arienti, A. Tesei, R. Polico
• Journal: Cancer Radiothérapie
• Published: 2017;21(8):766-773
• Cited by: 11 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Purpose: The role played by radiation therapy after pleurectomy/decortication or surgical biopsy in malignant pleural mesothelioma is uncertain. We treated patients with accelerated hypofractionated radiotherapy using helical tomotherapy and intensity-modulated arc therapy in an attempt to keep lung toxicity to a minimum. The present study reports the feasibility and toxicity of this approach.

Material And Methods: Between 2008 and 2012, 36 patients with malignant pleural mesothelioma underwent accelerated hypofractionated radiotherapy to the hemithorax after pleurectomy/decortication (19 patients) or biopsy (17 patients). The prescription dose was 25Gy in five fractions over 5 consecutive days.

Results: We observed three patients with G3 pneumonitis, five cases of grade 2 dyspnea and six cases of grade 2 cough. The median follow-up was 37 months (range: 3-54 months). The median overall survival for patients who underwent pleurectomy/decortication followed by radiotherapy was 21.6 months [95% confidence interval (95% CI): 15.5-24.1] compared to 19.4 months for patients not submitted to surgery.

Conclusion: Treatment of intact lung with pleural intensity-modulated arc irradiation in malignant pleural mesothelioma patients with malignant pleural mesothelioma proved safe and feasible, with an acceptable rate of pneumonitis. Survival rates were encouraging for both biopsy-only and pleurectomy/decortication groups. We are currently conducting a phase II dose escalation trial in a similar patient setting to prospectively evaluate the impact of radiotherapy on toxicity, disease-free survival and overall survival.

Copyright © 2017 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

In plain English

This retrospective study from Meldola, Italy, described 36 patients with malignant pleural mesothelioma given radiotherapy to one side of the chest between 2008 and 2012. They received a median of 25 Gy (range 25 to 30 Gy) in five daily fractions by helical tomotherapy, and 26 patients also received up to 37.5 Gy to visible or remaining tumour. Nineteen had first had lung-sparing surgery (pleurectomy/decortication), and 17 had only a biopsy. Fifteen had occupational asbestos exposure and were ex-smokers, and six others had asbestos exposure. Afterwards, 11% had grade 2 breathlessness and 14% grade 2 cough. Three patients (8%) developed grade 3 pneumonitis (lung inflammation), and no deaths were linked to it. Toxicity did not differ between the surgery and biopsy groups. Median overall survival for all patients was 21.6 months (95% confidence interval 15.5 to 24.1). The surgery group's median was also 21.6 months, printed with the same interval, versus 19.4 months after biopsy only. The difference was not statistically significant (P = 0.376). The authors concluded the treatment was safe and feasible with acceptable lung toxicity. They noted the surgery group was mixed and follow-up took place at different centres.

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: Retrospective analysis of patients treated at one institute (case series of a radiotherapy technique)
• Who was studied: 36 patients with biopsy-proven malignant pleural mesothelioma treated at the IRST institute, Meldola, Italy, between January 2008 and August 2012. 19 had radiotherapy after pleurectomy/decortication and 17 after biopsy only. Median age was 70 (range 44 to 85); 29 were male and 7 female; 34 had epithelial histology.
• Exposure: The study examined a treatment: accelerated hypofractionated radiotherapy to the hemithorax, median 25 Gy (range 25 to 30 Gy) in five daily fractions. In 26 patients (biopsy or partial pleurectomy/decortication), the dose was escalated heterogeneously up to 37.5 Gy inside gross tumour or residual disease. On asbestos history, 15 patients had occupational asbestos exposure and were ex-smokers, 6 had asbestos exposure, and 4 were ex-smokers. No fiber types were reported for these patients. 80% also received chemotherapy.
• Main results:
  • The gross tumour volume was contoured, with heterogeneous dose escalation to 37.5 Gy, in 26 patients who had biopsy or partial pleurectomy/decortication.
  • Acute toxicity in all patients: 11% had grade 2 dyspnea, 14% had grade 2 cough and 8% had grade 3 pneumonitis.
  • Of the three grade 3 pneumonitis cases, one occurred 4 months after radiotherapy and two occurred 6 months after the end of radiotherapy. No deaths were correlated with radiation-induced pneumonitis.
  • No differences in toxicity were seen between the pleurectomy/decortication group and the biopsy group.
  • Late toxicity among the 32 assessable patients: 22% had grade 1 dyspnea and 3% had grade 2 dyspnea.
  • Mean FEV1 was 77% (range 56 to 91%) before radiotherapy and 70% (range 50 to 86%) six months after.
  • All patients: median follow-up 37 months (range 3 to 54) in surviving patients; median overall survival 21.6 months (95% CI 15.5 to 24.1); 1- and 2-year survival around 80% and 30%.
  • Pleurectomy/decortication plus radiotherapy group: 1- and 2-year survival around 85% and 40%; median survival 21.6 months, given with a range of 13.3 to 29.5 months in the results and with a 95% CI of 15.5 to 24.1 in the discussion.
  • Biopsy plus radiotherapy group: 1- and 2-year survival 75% and 20%; median survival 19.4 months (range 12.6 to 24.1 months).
  • The survival difference between the surgery and biopsy groups was not statistically significant (P = 0.376).
  • Thoracic progression was recorded in 17 patients during follow-up: 10 in the pleurectomy/decortication group and 7 in the biopsy group.
• The authors' conclusion: The authors concluded that treating the intact lung with pleural intensity-modulated arc therapy using helical tomotherapy was a safe and feasible option with acceptable lung toxicity. They also described survival as encouraging in both groups.
• Limitations the authors state:
  • The study was retrospective, and the cohort was not uniform in the type and extent of surgery.
  • Patients were followed up at different cancer centres, which sometimes made detailed follow-up information hard to obtain.

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: Pleurectomy/Decortication (P/D), Biopsy, Pleural Mesothelioma, Hemithorax, Pneumonitis, Dyspnea, Median Overall Survival, confidence interval.

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• Pleurectomy decortication in the treatment of the "trapped lung" in benign and malignant pleural effusions — S. Rathinam, D.A. Waller (2013)

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