Pleurectomy/decortication (P/D) is becoming the preferred surgery for malignant mesothelioma. This has pushed postoperative radiation therapy to the wayside.
The reason is potential damage to lung tissue. Some specialists and surgeons believe it’s premature to not consider radiotherapy with this type of surgery.
Memorial Sloan Kettering Cancer Center hosts a new clinical trial for P/D surgery. The true test is how IMPRINT radiation therapy helps, or hurts, after the resection.
It’s a phase 3 study at multiple U.S. hospitals, with 16 patients already part of the study and another 46 in consideration. This trial follows a phase 2 study with success in both safety and survival outcomes. Up to 150 patients can enroll, and the quickest way to get your name to the recruiters is by contacting a patient advocate.
Our patient advocate, Karen Ritter, is the best resource for enrolling in this trial or similar ones for mesothelioma. Email her at email@example.com for her assistance applying to clinical studies at cancer centers.
Protocol for the Phase 3 Study
Patients begin with either intravenous chemotherapy or pleurectomy/decortication surgery. Some patients receive cisplatin and pemetrexed before P/D surgery. Others go immediately to surgery with chemotherapy in the weeks following.
After these two lines of treatment, half of patients receive hemithoracic IMPRINT radiation. Hemithoracic means the treatment goes just to one side of the chest, usually where tumors formed.
The other half of patients in the trial don’t receive radiation therapy. The purpose is to compare the survival of each segment — notably whether radiation for mesothelioma helps prolong survival without causing pneumonitis or other complications.
The data will be split into different categories to help determine how to utilize radiation after P/D surgery:
- Epithelioid cell type versus biphasic cell type
- Completed resection versus incomplete resection
- High-volume centers (more than 10 P/D surgeries per year) versus low-volume centers (10 or fewer P/D surgeries per year)
Protecting the Lung: Why Radiation After P/D Is Debated
Can radiotherapy control microscopic tumors and avoid damage to lung tissue? This is a question that has lingered for years, if not decades.
Radiation therapy can spray onto healthy tissue in the lung cavity. Inflammation of lung tissue, called pneumonitis, is a common issue for radiation treatment. This can lead to lung scarring, called pulmonary fibrosis.
This complication is why many doctors don’t use radiation after pleurectomy/decortication surgery. This operation avoids removing either lung, unlike lung-resection surgery counterpart extrapleural pneumonectomy (EPP).
Leaving both lungs is preferred by many surgeons, as it improves quality of life and lowers the recovery time. Survival is also comparable, with many cancer centers reporting P/D has equal or better average survival than EPP.
With the rise of P/D surgery, radiation therapy seems to be in the past. If both lungs remain, this puts the organs at risk since there’s no target area not close to one of them.
IMPRINT is the acronym for intensity-modulated pleural radiation therapy. It’s a hyper-focused type of radiotherapy keeping the beam contained. This causes little spray and less tissue damage in other areas.
The development of IMPRINT may allow for radiation therapy after P/D surgery. This clinical trial might be a barometer for the future of radiation therapy in mesothelioma treatment.
Sources & Author
- A Phase III Randomized Trial of Pleurectomy/Decortication Plus Chemotherapy With or Without Adjuvant Hemithoracic Intensity-Modulated Pleural Radiation Therapy (IMPRINT) for Malignant Pleural Mesothelioma (MPM) (NRG LU-006). International Journal of Radiation Oncology. Retrieved from: https://www.redjournal.org/article/S0360-3016(21)02168-4/fulltext#relatedArticles. Accessed: 10/31/2021.