Radiotherapy course

All patients were operated in the same institution by two experienced surgeons working in close collaboration with one of the radiotherapists. The SST was resected by means of a high extended posterolateral approach. In three patients with an anterior-mediastinal localization, a hemi-clamshell incision was carried out. The goal was a radical resection (R0) of at least the upper lobe en bloc with the chest wall. Only in the anterior chest wall resection, an artificial layer was used for reconstruction. For the posterior localization, the scapula was considered to be sufficient as a firm chest wall coverage. Postoperative mortality was defined as death within 4 weeks after surgery.

Radiotherapy course

Radiotherapy course

Instead of using catheters (which have to be fixed separately), a so-called flexible intraoperative template (FIT) was used to deliver a homogenous dose to a surface to which the shape of the mold is adjusted. This is a flexible 5-mm-thick silicone mold in which afterloader catheters are inserted parallel to each other at a fixed distance of 1 cm. The tumor bed was clipped by the surgeon, and the FIT was shaped and fixed to the target area. After inserting dummy catheters, orthogonal x-rays are made of the implant and loaded into the planning system. The treatment plan is generated with the indicated active dwell positions of the catheters. The radiation is delivered during remote-controlled anesthesia. A single radiation fraction of 10 Gy was administered, specified in a plane parallel to the surface of the FIT at 1-cm distance (1.25 cm from the catheters) with the MicroSelectron high-dose rate Ir afterloader.

After the external beam radiotherapy course, three patients dropped out of the protocol because of progressive disease resulting in an nonresectable tumor. We planned for the thoracic inlet resection in combination with intraoperative radiotherapy in 23 patients. Thoracotomy revealed that two patients had no chest wall invasion; these patients only had adhesions to the chest wall not requiring a chest wall resection, and therefore intraoperative radiation was considered not beneficial and thus not performed.

Finally, 21 patients (12 women and 9 men) underwent the entire planned treatment schedule, including resection and intraoperative radiotherapy. Their mean age was 58 years (range, 38 to 78 years). The preoperative clinical staging was stage IIB (all T3N0M0) in 18 patients, and stage IIIB (all T4N0M0) in 3 patients.