A Feasibility Study Evaluating Surgery for Mesothelioma After Radiation Therapy Using Extensive Pleural Resection

Not Applicable

Active, not recruiting

Brief Summary: This study aims to find the maximum tolerated dose level for malignant pleural mesothelioma patients receiving background radiation + boost radiation, and surgery. Boost radiation is an experimental form of radiation that involves targeting non-uniform high doses of radiation to bulky pleural masses. We hypothesize the immunologic abscopal effect is an important component in controlling disease, and may be stimulated with highly hypofractionated doses. Doses will increase with every three patients who will be enrolled in the study until the background radiation reaches 1800 cGy or the maximum tolerated dose, whichever is lower.

Detailed Description: This study aims to find the maximum tolerated dose level for mesothelioma patients receiving background radiation + boost radiation, and surgery. 3 patients will start with a background radiation therapy (RT) dose of 0 cGy, and boost RT of at least 2100 cGy. If the radiation is manageable (radiation related AEs grade \< 4), the next set of 3 patients will be enrolled, and the background radiation dose will be increased by 600 cGy. This will continue until the background radiation dose reaches 1800 cGy. If 1 patient exhibits dose limiting toxicities (AEs grade 4 \& 5), the dose level will repeat with the next 3 patients. If 2 or more patients exhibit DLTs, the previous dose level will be determined as the maximum tolerated dose level. Surgery will be scheduled to occur approximately 1-2 weeks after completing radiation therapy, and will subsequently be followed up as per study schedule.

Recruitment & Eligibility

Inclusion Criteria

Age ≥ 18 years
Eastern Cooperative Oncology Group (ECOG) performance status of 0-2
Good pulmonary function precluding radiation therapy (FEV1>1 L or >40% predicted or DLCO >45% predicted)
Any patient with a new histological diagnosis of malignant pleural mesothelioma (MPM). Sarcomatoid or biphasic histologies can be included but will be analyzed separately due to their poor prognosis.
Stage T1-3 N0-1 M0 according to the 8th edition of the tumor, node, and metastases (TNM) staging system based on conventional investigations and tests (Appendix 1). Note that the updated TNM staging system now categorizes ipsilateral mediastinal nodes as N1 disease.
Suitable for combined modality therapy
Informed consent.

Exclusion Criteria

Age < 18 years.
Contralateral mediastinal nodal disease (N2)
Distant metastatic disease (M1).
Poor performance status ECOG 3-4.
Poor pulmonary function precluding radiation therapy (FEV1<1 L or <40% predicted or diffusion lung capacity for carbon monoxide (DLCO) <45% predicted)
Failure to provide informed consent.
Previous thoracic irradiation.
Serious non-malignant disease (e.g. cardiovascular, pulmonary, systemic lupus erythematosus (SLE), scleroderma) which would preclude definitive radiation treatment.
Previous chemotherapy for this or concurrent malignancy.
Previous or concomitant malignancies except for patients with non-melanoma skin cancer, contralateral non-invasive breast cancer, prostate cancer treated with curative intent or carcinoma in situ of any other site. In addition, patients with invasive cancers treated more than 3 years previously and without evidence of recurrence will be eligible.
Women who are currently pregnant or lactating.

Arm && Interventions

Group	Intervention	Description
Radiation	Varying Doses of Background and Boost RT	This study involves a 3+3 design. The starting cohort (n=3) will receive a neoadjuvant Background dose to the affected hemithorax (starting at 0 cGy) as well as concomitant Boost dose (of at least 2100 cGy) to a part of the gross tumour volume (GTV). The radiation will be delivered over 3 alternate days over 5-7 calendar days followed by macroscopically complete extensive pleural resection (either extra-pleural pneumonectomy or extended pleurectomy decortication, at the surgeon's discretion) after 7 to 14 days. If no dose limiting toxicities (DLTs) seen, then the Background RT dose will be increased by 600 cGy (up to 1800 cGy) and the cohort (n=3) for the next dose level will be accrued. If only 1 DLT seen, then an additional 3 patients will be treated on this dose level. If 2 or more DLTs seen at any given dose level, then the previous dose level will be defined as the maximum tolerated dose (MTD). Patients will be stratified by type of resection.

Primary Outcome Measures

Name	Time	Method
Maximum Tolerated Dose for Background Radiation	Up to five years	AEs will be graded by CTCAE. Maximum tolerated dose is the dose level that do not result in fatal lung injury (grade 5 lung toxicity) or life-threatening or fatal treatment related toxicity (grade 4+).

Secondary Outcome Measures

Name	Time	Method
Patient Morbidity	Up to five years	NCI common toxicity scale
Local recurrence	Up to five years	Documented radiographically
Evaluating patients' pain	Up to five years	Assess by using a variety of standard instruments including the Injustice Experience Questionnaire (IEQ).
Patients' quality of life	Up to five years	Short Form Health Survey-36 (SF-36) Form

Locations (1): Princess Margaret Hospital, University Health Network
🇨🇦
Toronto, Ontario, Canada