Safety and efficacy of helical tomotherapy following lung-sparing surgery in locally advanced malignant pleural mesothelioma

Our plain-English summary of Safety and efficacy of helical tomotherapy following lung-sparing surgery in locally advanced malignant pleural mesothelioma, by J.P. Layer, P. Fischer, C.S. Dejonckheere, et al (Strahlentherapie und Onkologie, 2024).

The study

• Authors: J.P. Layer, P. Fischer, C.S. Dejonckheere, G.R. Sarria, R. Mispelbaum, T. Hattenhauer, S. Wiegreffe, A.R. Glasmacher, K. Layer, Y. Nour, L. Caglayan, F. Grau, T. Müdder, M. Köksal, D. Scafa, F.A. Giordano, A. Lopez-Pastorini, E. Stoelben, L.C. Schmeel, C. Leitzen
• Journal: Strahlentherapie und Onkologie
• Published: 2024;200(7):605-613
• Cited by: 3 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Purpose: To assess the value of radiation therapy (RT) with helical tomotherapy (HT) in the management of locally advanced malignant pleural mesothelioma (MPM) receiving no or lung-sparing surgery.

Methods: Consecutive MPM cases not undergoing extrapleural pneumonectomy and receiving intensity-modulated (IM) HT were retrospectively evaluated for local control, distant control, progression-free survival (PFS), and overall survival (OS). Impact of age, systemic treatment, RT dose, and recurrence patterns was analyzed by univariate and multivariate analysis. As a secondary endpoint, reported toxicity was assessed.

Results: A total of 34 localized MPM cases undergoing IMHT were identified, of which follow-up data were available for 31 patients. Grade 3 side effects were experienced by 26.7% of patients and there were no grade 4 or 5 events observed. Median PFS was 19 months. Median OS was 20 months and the rates for 1‑ and 2‑year OS were 86.2 and 41.4%, respectively. OS was significantly superior for patients receiving adjuvant chemotherapy (p = 0.008).

Conclusion: IMHT of locally advanced MPM after lung-sparing surgery is safe and feasible, resulting in satisfactory local control and survival. Adjuvant chemotherapy significantly improves OS. Randomized clinical trials incorporating modern RT techniques as a component of trimodal treatment are warranted to establish an evidence-based standard of care pattern for locally advanced MPM.

© 2023. The Author(s).

In plain English

This was a retrospective, single-centre study at the University Hospital Bonn, Germany. The authors reviewed patients with malignant pleural mesothelioma treated between January 2009 and September 2020 with helical tomotherapy, a form of intensity-modulated radiotherapy. All patients had had lung-sparing surgery (pleurectomy) or a biopsy only, and none had extrapleural pneumonectomy. Of 34 patients identified, 31 had follow-up data. Radiation totalled 45 to 60 Gy. Grade 3 side effects, most often difficulty swallowing, occurred in 26.7% of patients, and no grade 4 or 5 events were seen. Over a median follow-up of 20 months, local control was 92.6% at 1 year. Median progression-free survival was 19 months and median overall survival was 20 months, with 86.2% alive at 1 year and 41.4% at 2 years. Chemotherapy given after surgery was associated with significantly better overall survival. The authors concluded the treatment was safe and tolerable and called for randomized trials. They named the small sample and long study period as limitations. Asbestos exposure was not studied.

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 single-centre study of consecutive patients (case series) treated with helical tomotherapy
• Who was studied: Patients with histologically confirmed malignant pleural mesothelioma referred to the Department of Radiation Oncology, University Hospital Bonn, Germany, January 2009 to September 2020, after lung-sparing surgery (biopsy only or pleurectomy/decortication). Of 50 MPM cases, 34 were identified and 31 had follow-up data. Median age was 65 (range 46 to 77); 24 were male and 7 female; 27 had epithelioid and 4 had biphasic histology; 18 had total pleurectomy, 3 partial pleurectomy, and 10 biopsy only; none had extrapleural pneumonectomy.
• Exposure: The study examined a treatment, not asbestos exposure. Patients received intensity-modulated, image-guided helical tomotherapy covering the whole pleura, at 1.8 to 2 Gy per session to a total of 45 to 60 Gy (median 50.4 Gy). Patients also received neoadjuvant (18) or adjuvant (13) platinum-based chemotherapy; 2 received no perioperative systemic therapy.
• Main results:
  • Grade 3 side effects occurred in 26.7% of patients (dysphagia 16.7%, dyspnea 6.7%, pain 3.3%).
  • No grade 4 or 5 side effects were observed.
  • Local control lasted a median of 23 months; local control was 92.6% at 1 year, 47.3% at 2 years and 40.6% at 3 years.
  • Median distant control time was 23 months; distant control rates were 69.0%, 37.9% and 20.7% at 1, 2 and 3 years.
  • Median progression-free survival was 19 months; the 1-year rate was 72.4% and the 2-year rate was 24.1%.
  • Median overall survival was 20 months; 1-year and 2-year overall survival were 86.2% and 41.4%.
  • Overall survival was significantly better for patients who received adjuvant chemotherapy (p = 0.008 in the abstract; the results section reports p = 0.001 in multivariate analysis, confirmed in univariate analysis).
  • In multivariate analysis, no factor was significantly associated with improved progression-free survival.
• The authors' conclusion: The authors concluded that helical tomotherapy after lung-sparing surgery is safe and tolerable, with satisfactory local control and overall survival, and that adjuvant chemotherapy can further improve outcome. They stated that careful patient selection is crucial and that randomized trials are needed to confirm the findings.
• Limitations the authors state:
  • The small sample size prevented more detailed analysis of prognostic factors or comparison of treatment groups.
  • The long period between the first and last patients may have introduced bias from changing care patterns.

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, Extrapleural Pneumonectomy (EPP), Progression-Free Survival, Overall Survival, Multivariate Analysis, Chemotherapy, Clinical Trial.

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• Mesothelioma at era of helical tomotherapy: results of two institutions in combining chemotherapy, surgery and radiotherapy — A. Sylvestre, M.A. Mahé, et al. (2011)
• Dosimetric Comparison Between Helical Tomotherapy and Volumetric Modulated Arc Therapy in Patients With Malignant Pleural Mesothelioma — T. Müdder, G.R. Sarria, et al. (2022)
• Dosimetric Comparison of Lung-Sparing Radiation Therapy between Volumetric Arc Therapy and Helical Tomotherapy for Unresectable Malignant Pleural Mesothelioma — B. Pehlivan, K. Sengul, et al. (2019)
• Optimal gross tumor volume definition in lung-sparing intensity modulated radiotherapy for pleural mesothelioma: an in silico study — A. Botticella, G. Defraene, et al. (2016)
• Long-term survival after lung-sparing total pleurectomy for locally advanced (International Mesothelioma Interest Group Stage T3-T4) non-sarcomatoid malignant pleural mesothelioma — A. Nakas, E. von Meyenfeldt, et al. (2012)

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