What is the role of radiotherapy in malignant pleural mesothelioma?

Our plain-English summary of What is the role of radiotherapy in malignant pleural mesothelioma?, by A. Price (The Oncologist, 2011).

The study

• Author: A. Price
• Journal: The Oncologist
• Published: 2011;16(3):359-65
• Type of article: Review
• Cited by: 27 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Objective: A review of the evidence supporting the use of radiotherapy in patients with mesothelioma was performed.

Methods: Relevant publications were searched for on Medline.

Results: In a Medline search on radiotherapy and mesothelioma, 611 hits were obtained. A limited number of prospective phase II trials of radiotherapy as part of trimodality protocols for early disease and in the palliation of pain were found, along with three small randomized controlled trials of port-site prophylaxis.

Conclusion: No randomized data exist to support the use of radiotherapy after radical surgery, although there are a large number of publications describing its use as an integral part of therapy, including seven phase II studies. One ongoing trial is randomizing patients to radiotherapy or not after extrapleural pneumonectomy. None of these studies provided any assessment of radiotherapy independent of the other modalities investigated, nor did any formally assess intensity-modulated radiotherapy. There have been several reports of excessive toxicity with this technique, and its use should be limited to phase I studies until the basis of this toxicity is better understood. Three trials have looked at port-site prophylaxis, one supporting its use and two showing no evidence of benefit. Two studies addressed pain control prospectively, one showing definite but short-lived benefits. Implications. Radiotherapy is widely used in treating mesothelioma with little supporting evidence. More randomized trials are required to justify this use in all three common settings for its use.

In plain English

This single-author review looked at the published evidence for radiotherapy in malignant pleural mesothelioma. A Medline search for radiotherapy and mesothelioma found 611 hits. English-language publications on clinical practice formed the basis of the review, which covered three uses: radiotherapy after radical surgery, prevention of tumor regrowth at chest-wall entry sites (port sites), and pain relief. The author found no randomized data on radiotherapy after extrapleural pneumonectomy. Seven prospective studies of combined chemotherapy, surgery and radiotherapy, involving 313 patients, mostly reported median survival of 16 to 20 months, and almost half of patients did not complete all planned treatment. For intensity-modulated radiotherapy after this surgery, the author found no evidence of benefit and cited deaths from radiation pneumonitis, including 6 of 13 patients in one Boston series. Of three port-site trials, one supported radiotherapy and two found no benefit. Of two prospective pain studies, one found short-lived benefit. The author concluded there was no evidence supporting routine radiotherapy in mesothelioma and called for randomized trials. The review did not study asbestos exposure.

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: Narrative literature review by a single author, based on a Medline search
• Who was studied: Published studies on radiotherapy in mesothelioma found by a Medline search (611 hits); English-language publications referring to clinical practice were used. Patients in the reviewed studies had malignant pleural mesothelioma.
• Exposure: Not asbestos exposure. The review covers radiotherapy for mesothelioma in three settings: as part of trimodality therapy for early-stage disease (after extrapleural pneumonectomy or pleurectomy/decortication, including intensity-modulated radiotherapy), prophylaxis of port-site recurrence, and palliation of pain.
• Main results:
  • The review found no randomized data on radiotherapy after extrapleural pneumonectomy (EPP). It noted that a Swiss trial was expected to finish in 2011.
  • Seven prospective studies of trimodality therapy with conventional radiotherapy, involving 313 patients, were identified.
  • In those prospective trimodality studies, median survival was between 16 and 20 months in all but one study. Almost half of patients did not complete all planned therapies.
  • For intensity-modulated radiotherapy (IMRT) after EPP, reviewed reports included a Boston series in which 6 of 13 patients died from radiation pneumonitis.
  • The author found no evidence of benefit from IMRT after EPP and said its use should be experimental, limited to carefully monitored phase I studies.
  • Port-site prophylaxis: a French trial reported 0 recurrences in 20 irradiated sites versus 8 in 20 unirradiated sites. Two more recent randomized trials found no benefit of radiotherapy.
  • Pain palliation: in a Glasgow prospective study of 22 patients, 13 had less pain at 1 month. This fell to 3 patients by 3 months and 1 by 5 months.
  • In a second prospective study, from Sweden (47 patients), only 1 of 31 (3%) had a partial response. No favorable effect on chest pain, weight loss or performance status was reported.
• The authors' conclusion: The author concluded that there is currently no evidence to support routine radiotherapy in patients with mesothelioma. The author called for more randomized trials in all three settings and suggested a possible role in poorly controlled pain that needs prospective evidence.
• Limitations the authors state:
  • The review did not attempt a detailed analysis of the literature on technical aspects of radiotherapy.
  • The author questioned whether the available prospective pain data apply to modern palliative care.

Topics

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

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Mesothelioma, Extrapleural Pneumonectomy (EPP), Intensity-Modulated Radiation Therapy (IMRT).

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• Survival after trimodality therapy for malignant pleural mesothelioma: Radical Pleurectomy, chemotherapy with Cisplatin/Pemetrexed and radiotherapy — S. Bölükbas, C. Manegold, et al. (2011)
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• Adjuvant radiotherapy after extrapleural pneumonectomy for mesothelioma. Prospective analysis of a multi-institutional series — S. Tonoli, P. Vitali, et al. (2011)
• Induction chemotherapy, extrapleural pneumonectomy, and adjuvant radiotherapy for malignant pleural mesothelioma: experience of Guy's and St Thomas' hospitals — A. Bille, E. Belcher, et al. (2012)

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