EVALUATING INTRAOPERATIVE RADIATION-THERAPY (IORT) AND EXTERNAL-BEAM RADIATION-THERAPY (EBRT) IN NONSMALL CELL LUNG-CANCER (NSCLC) - 5 YEARS EXPERIENCE

A pilot study on intraoperative radiation therapy (IORT) combined with external beam radiation therapy (EBRT) in nonresectable non-small cel l lung cancer (NSCLC) was performed in 31 patients (mean age: 66.2 yea rs, range: 51-80; 10 anatomically and functionally, 21 functionally, n onresectable; 20 squamous-cell, 11 adenocarcinoma). The tumor was expo sed by lateral thoracotomy and a staging lymph node dissection was per formed (final staging 7 T1, 16 T2, 8 T3; 11 nodal positive). Ten to 20 Gy IORT (energy: 7-20 MeV electrons) were delivered to the tumor. Uni lateral continuous positive airway pressure ventilation of the disease d lung was used to reduce the amount of healthy lung tissue in the IOR T port and to minimize the ventilatory movement. Secondary collimation and direct shielding of radio-sensitive structures within the IORT po rt by aluminium sheets were used to further reduce collateral damage. Four weeks after IORT, 46 Gy EBRT (2 Gy/day 5 times a week; 8-23 MeV p hotons) were administered to the mediastinum and to the tumor-bearing area on an outpatient basis. In nodal positive cases the mediastinal d ose was increased to 56 Gy. Twenty-three patients were evaluable. In 1 3 complete, in 8 partial (50-97% regression) and in 2 minor response h as been achieved. Five patients experienced a recurrence (local only: 2; local and distant: 1, distant only: 2). Twelve patients died of und erlying cardio-respiratory disorders within 6 to 25 months after IORT; 7 died of cancer. The overall 5-year survival rate including the inci dental deaths is 14.7%. The recurrence-free survival rate is 53.2%.