Tomotherapy after pleurectomy/decortication or biopsy for malignant pleural mesothelioma allows the delivery of high dose of radiation in patients with intact lung

Our plain-English summary of Tomotherapy after pleurectomy/decortication or biopsy for malignant pleural mesothelioma allows the delivery of high dose of radiation in patients with intact lung, by E. Minatel, M. Trovo, J. Polesel, et al (Journal of Thoracic Oncology, 2012).

The study

• Authors: E. Minatel, M. Trovo, J. Polesel, I.A. Rumeileh, T. Baresic, A. Bearz, A. Del Conte, G. Franchin, C. Gobitti, A. Drigo, A. Dassie, V. Pagan, M.G. Trovo
• Journal: Journal of Thoracic Oncology
• Published: 2012;7(12):1862-1866
• Cited by: 36 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Introduction: This study aimed to assess the safety of high doses of radiation delivered with tomotherapy to the intact lung after radical pleurectomy/decortication or biopsy for malignant pleural mesothelioma (MPM).

Methods: Twenty-eight patients were enrolled in this prospective study and underwent adjuvant or definitive tomotherapy after radical pleurectomy/decortication (n = 20) or pleural biopsy (n = 8) for MPM. The dose prescribed to the planning target volume, defined as the entire hemithorax, including chest-wall incisions and drain sites and excluding the intact lung, was 50 Gy delivered in 25 fractions. All patients underwent fluorodeoxyglucose-positron emission tomography for staging after surgery. Any fluorodeoxyglucose-avid areas or regions of particular concern for residual disease were given a simultaneous boost of radiotherapy to 60 Gy. Specific lung dosimetric parameters were reported. Toxicity was graded using the modified Common Toxicity Criteria version 3.0.

Results: The median follow-up was of 19 months (range, 6-29 months). Five patients (17.8%) experienced severe respiratory symptoms corresponding to grade 2 pneumonitis in three cases, and grade 3 pneumonitis in two cases. No fatal respiratory toxicity was reported. Controlateral lung V5 was strongly correlated with the risk of pneumonitis. Patients who developed grade 2 and 3 pneumonitis had a higher controlateral lung V5 (mean V5=32%) than those without pneumonitis (mean V5=17%) (p=0.002). Other two grade 3 toxicities were registered: one severe pain to the chest wall, and one severe thrombocytopenia.

Conclusions: Tomotherapy allows the safe delivery of high dose of radiation to the hemithorax of MPM patients with intact lung.

In plain English

This prospective study from Aviano, Italy, followed 28 patients with malignant pleural mesothelioma treated between January 2009 and June 2011. Twenty had radical pleurectomy/decortication, which leaves the lung in place, and eight only a pleural biopsy. All then received helical tomotherapy, 50 Gy in 25 fractions, to the affected side of the chest excluding the lung itself; in 25 of the 28, areas of possible remaining disease were boosted at the same time to a total of 60 Gy. Median follow-up was 19 months; every patient completed the planned treatment. Five of the 28 (17.8%) developed radiation pneumonitis (lung inflammation) within 5 months. Three cases were grade 2 and two were grade 3, and none was fatal. Patients with pneumonitis had a larger share of the opposite lung receiving more than 5 Gy (mean 32% versus 17%, p = 0.02). One patient had severe chest wall pain and one severe thrombocytopenia (low platelets). The authors concluded that tomotherapy allows safe delivery of high radiation doses with the lung intact. They noted that most patients had good performance status and the sample was small.

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: Prospective study (single-institution case series) of radiation dose and toxicity
• Who was studied: 28 patients with malignant pleural mesothelioma treated at Centro di Riferimento Oncologico of Aviano, Italy, between January 2009 and June 2011. Twenty had radical pleurectomy/decortication and eight had pleural biopsy only. There were 25 men and 3 women, with a median age of 68 years (range 44 to 83). Of 35 patients initially treated, 7 were excluded because they received palliative radiation doses.
• Exposure: Hemithoracic radiation by helical tomotherapy, 50 Gy in 25 fractions (2 Gy per fraction). The planning target was the entire hemithorax, including chest-wall incisions and drain sites, but excluding the intact lung. Areas that lit up on PET scans or were of concern for residual disease received a simultaneous boost, given in the same sessions at 2.4 Gy per fraction, bringing those areas to 60 Gy. Twenty-five patients received this boost. The patients' asbestos exposure was not reported.
• Main results:
  • Five of the 28 patients (17.8%) had severe respiratory symptoms within 5 months after radiotherapy: grade 2 pneumonitis in three and grade 3 pneumonitis in two. No fatal respiratory toxicity occurred.
  • Patients who developed grade 2 or 3 pneumonitis had a higher contralateral lung V5 (mean 32%) than those without pneumonitis (mean 17%), p = 0.02. V5 is the share of the opposite lung receiving more than 5 Gy. Table 2 gives 33% for the pneumonitis group (n=5) and 17% for the group without pneumonitis (n=23).
  • Two other grade 3 toxicities occurred: one patient had severe chest wall pain requiring narcotics, and one developed severe thrombocytopenia. There was no grade 3 esophagitis and there were no rib fractures.
  • No treatment was interrupted because of toxicity, and all patients received the planned dose. All patients had grade 1 or 2 nausea or vomiting, and 12 (43%) had grade 1 or 2 fatigue.
• The authors' conclusion: The authors concluded that helical tomotherapy allows the safe delivery of high radiation doses to the hemithorax of mesothelioma patients with an intact lung. They said its effect on prognosis remains to be answered.
• Limitations the authors state:
  • Most treated patients had a good performance status, which could explain why the treatment was well tolerated.
  • The small sample size might have underestimated the rate of other severe complications.
  • Local control and survival were not reported; the authors said these will be reported with longer follow-up.

Topics

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

Medical terms in this study, explained in our Lexicon: Pleurectomy/Decortication (P/D), Biopsy, Pleural Mesothelioma, Pleural Biopsy, Hemithorax, Staging, Pneumonitis.

Related studies

• Tomotherapy after pleurectomy or decortication or biopsy for malignant pleural mesothelioma — M. Trovo, E. Minatel (2013)
• Tomotherapy after pleurectomy or decortication or biopsy for malignant pleural mesothelioma — S. Bölükbas, J. Schirren, et al. (2013)
• High dose irradiation after pleurectomy/decortication or biopsy for pleural mesothelioma treatment — E. Parisi, A. Romeo, et al. (2017)
• Geometric dose prediction model for hemithoracic intensity-modulated radiation therapy in mesothelioma patients with two intact lungs — L. Kuo, E.D. Yorke, et al. (2016)
• A feasibility study evaluating Surgery for Mesothelioma After Radiation Therapy: the "SMART" approach for resectable malignant pleural mesothelioma — B.C. Cho, R. Feld, et al. (2014)
• Dosimetric Correlates of Pulmonary Toxicity in Patients with Malignant Pleural Mesothelioma Receiving Radiation Therapy to the Intact Lungs — M.R. Thompson, V.A. Dumane, et al. (2019)

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