[Stereotactic hypofractionated radiotherapy of non-hepatic abdominal tumors]

The clinical experiences of 12 patients with non-hepatic abdominal tumors who underwent stereotactic hypofractionated radiotherapy are presented.

Ten lesions were metastatic, one was a primary pancreatic cancer, and the remaining one was irradiated postoperatively for a positive margin of extrahepatic bile duct cancer. In one patient, single fractional stereotactic radiotherapy was employed, while the remaining 11 patients were treated with 3 fractions. Gross tumor volume of the 10 ranged from 2 cc to 32 cc (mean: 11 cc), and the minimal dose enclosing 95% of the planning target volume (D95) was between 28.6 Gy and 35 Gy. The minimal number of portals was 6. In 8 patients, radiotherapy was performed under respiratory gating. Mean follow-up time was 10 months (5-51 months).

Local regrowth was seen in 9 months in only 1 of the 12 tumors, and the patient died of the disease. Four patients died because of tumor growth in other sites. The remaining 7 patients are alive without disease. As for morbidity, NCI-CTC grade 3 gastritis was seen in one patient, grade 2 gastritis in 2 patients, and grade 2 duodenitis in one patient. These patients all improved with non-surgical therapy.

Stereotactic hypofractionated radiotherapy is effective for the treatment of selected non-hepatic abdominal tumors. However, the optimal radiation dose for tumor control and the tolerance dose of the gastrointestinal tract in hypofractionated irradiation must be studied further.