Journal of Clinical Oncology, Vol 6, 18-25, Copyright © 1988 by American Society of Clinical Oncology
Preliminary results of a randomized study of adjuvant radiation therapy in resectable adult retroperitoneal soft tissue sarcomas
TJ Kinsella, WF Sindelar, E Lack, E Glatstein and SA Rosenberg
Radiation Oncology Branch, National Cancer Institute, Bethesda, MD 20892.
Between January 1980 and September 1985, 35 adult patients with resectable
retroperitoneal soft tissue sarcomas were entered on a randomized trial
comparing two forms of adjuvant radiation therapy. Fifteen patients
received the experimental therapy consisting of intraoperative radiotherapy
(IORT) to 20 Gy using high-energy electrons followed by low-dose (35 to 40
Gy) postoperative external beam irradiation. Twenty patients received
standard therapy consisting of high-dose (50 to 55 Gy) postoperative
external beam irradiation. With a minimum follow-up of 15 months, there is
no significant difference in the actuarial disease-free survival (DFS) and
overall survival (OS) comparing the two groups (median DFS, 34 months;
median OS, 38 months). At 5 years follow-up, approximately 40% of patients
are alive and 20% of patients remain disease-free. Although there is a
trend towards an improvement in in-field local control in the experimental
arm, the predominant pattern of failure in both groups was locoregional
within the retroperitoneum and/or peritoneal cavity. Acute and late
radiation enteritis were significantly reduced in the experimental group.
However, four experimental patients developed late (greater than 6 months
following treatment) peripheral neuropathy believed related to the use of
IORT; all four recovered. We conclude that there is no difference in the
therapeutic effectiveness of the combination of IORT and low-dose external
beam radiation compared with conventional high- dose radiation as adjuvant
treatment in retroperitoneal sarcomas, although the former appears to be
less toxic. Newer combined modality treatment strategies are discussed to
improve the prognosis in these patients.