Background: The treatment of stage IV thymoma with pleural dissemination and recurrence remains challenging, with complete surgical resection regarded as the best approach to achieve prolonged survival. Drawing from the principles of surgical management for malignant pleural mesothelioma, we employed extensive thymothymectomy along with cytoreductive, lung-sparing pleurectomy/decortication and intraoperative photodynamic therapy to optimize local control and extend survival.
Methods: This retrospective study reviewed patients who underwent extensive thymothymectomy along with cytoreductive, lung-sparing pleurectomy/decortication surgery with intraoperative adjuvant photodynamic therapy for malignant pleural thymoma between April 2006 and December 2010.
Results: A total of 15 patients (4 males, 11 females; mean age 43.9 years) with primary stage IVa thymoma (n=6) or thymoma with pleural relapse (n=9) were included after successful transsternal thymoma resection. There were 14 cases of thymoma and one case of thymic carcinoma. Eleven patients had concomitant myasthenia gravis, while four did not. Six patients proceeded directly to surgery without prior chemoradiotherapy, while the remaining nine received chemotherapy and radiotherapy before surgery. Patients with myasthenia gravis underwent preoperative management including plasmapheresis by neurologists to ensure adequate control of their condition prior to surgery. The surgical approach was tailored to the tumor’s location. One patient underwent surgery via video-assisted thoracic surgery (VATS) due to isolated pleural wall recurrence; nine patients had thoracotomy, four had sternotomy, and one underwent clamshell thoracotomy. Radical pleurodectomy/decortication (P/D) (4/15; 26.7%) was extended with resection of the pericardium and diaphragm in 11/15 (73.3%) patients. After complete macroscopic resection (R0/R1), intraoperative photodynamic therapy was performed (2 mg/kg sodium porfimer administered intravenously 48 hours prior to surgery, followed by 30 J/cm2 of 630 nm light intraoperatively). Two patients developed chylothorax, which was successfully managed conservatively without further surgery, and there was one case of 30-day surgical mortality due to uncontrolled intraoperative bleeding. One patient was lost to follow-up six months postoperatively. Thirteen patients were followed up after surgery, all of whom received postoperative radiotherapy targeting the surgical chest wall wound site, as well as chemotherapy for systemic control. Six patients experienced local and pleural recurrence, which was managed with repeat surgery and/or chemoradiotherapy. One patient died from complications of repeat surgery, and one patient with thymic carcinoma developed distant metastasis. After a mean follow-up of 106.8±65.4 months, the median recurrence-free survival was 75±34.4 months [5-year recurrence-free survival (RFS): 61.5 months, 10-year RFS: 36.9 months], and the median overall survival (OS) was 104±23.4 months (5-year OS: 69.2 months, 10-year OS: 38.5 months). To date, three patients remain alive: one patient without myasthenia gravis has survived without disease recurrence (205 months of follow-up), and two patients with myasthenia gravis and thymoma have survived despite tumor recurrence; they remain alive following repeat surgery and chemoradiotherapy (172 and 186 months of follow-up, respectively).
Conclusions: Thorough surgical resection of thymoma and all pleural metastases, combined with intraoperative photodynamic therapy, can improve local tumor control and prolong survival.
