Soft-tissue sarcomas arising from the retroperitoneum are rare
tumors, and their successful treatment is problematic. This group
of tumors tends to be large at presentation, and they exist in
a body cavity with few fascial planes to contain them. They frequently
abut vital organs or major blood vessels, which further complicates
their complete removal.
Surgical resection with clear margins is the only curative treatment
for retroperitoneal sarcomas. Although complete gross tumor excision
can be performed in up to 79% to 96% of patients, as noted in
two recent series, clear margins can be obtained in only 63% of
patients who have all gross tumor removed.[1,2] Local failure
rates are quite high, varying between 50% and 70% at 5-year follow-up.
These high local recurrence rates are inclusive of all tumor grades.
Furthermore, overall 5-year survival rates in various series range
from 20% to 60%. In most series, survival has been correlated
with tumor grade and the ability to perform a resection with clear
The high local failure rate coupled with the poor overall survival
for retroperitoneal sarcomas has led clinicians, over the last
20 years, to search for effective adjuvant treatment regimens.
Much has been written about adjuvant therapy for soft-tissue sarcoma
of the retroperitoneum, but the literature on this subject is
difficult to interpret. This is due primarily to the rarity of
the tumor, the difficulty in collecting prospective data, and
the inability to account for multiple variables in a particular
Most of the studies that have been reported in the literature
are small, from single institutions, and are retrospective. The
patients receiving adjuvant therapies in these studies are a mixed
group, with varying amounts of residual microscopic or macroscopic
disease. Some patients had primary tumors, while others had recurrent
disease. Many series included patients who were treated with combinations
of surgery, external-beam radiation, intraoperative radiation,
brachytherapy, and various chemotherapy regimens.
Adjuvant Radiation Therapy
The article by Drs. Clark and Tepper presents a concise overview
of the rationale for neoadjuvant radiation therapy in the treatment
of retroperitoneal sarcomas. Their basis for advocating combined
therapy is derived from the literature on extremity sarcomas.
However, extrapolating from extremity sarcomas to retroperitoneal
sarcomas may not be valid for several reasons: (1) Sarcomas of
the extremity are often more amenable to complete surgical extirpation;
and (2) adjuvant radiation doses to the involved extremity (which
can exceed 6,000 cGy with shrinking fields) are not limited by
the radiation tolerance of the small intestine. To date, no prospective
randomized trial has confirmed the benefit of surgery plus radiation
therapy over surgery alone in the treatment of retroperitoneal
At this time, the role of radiation therapy in the treatment of
soft-tissue sarcoma arising from the retroperitoneum has yet to
be defined. There is evidence to suggest that individual patients
with less than ideal surgical margins will experience less local
recurrence if they are treated with radiation therapy. This
effect is thought to be dose-dependent, with the best local control
rates reported from institutions that employ intraoperative boost
radiation in the form of intraoperative radiation therapy or brachytherapy.
However, any benefit afforded by radiation therapy has to be weighed
against the potential significant morbidity that can follow a
course of radiation to the retroperitoneum, especially if doses
more than 5,500 cGy are to be employed, as suggested by Fein et
al. Kinsella et al showed a more than 60% incidence of enteritis
using external-beam radiation and a similar incidence of peripheral
neuropathy using intraoperative radiation therapy.
Strategies to Reduce the Complications of Radiation
In their article, Drs. Clark and Tepper address these potential
complications by advocating the use of preoperative radiation
in the treatment of retroperitoneal sarcoma. The potential benefits
of preoperative therapy, as they correctly indicate, include smaller
treatment fields, protection of adjacent organs that are displaced
by in-situ tumor acting as a "tissue expander," and,
perhaps, a better chance of achieving clear surgical margins due
to tumor shrinkage.
Other strategies can be used to prevent postoperative radiation-associated
complications. These include the use of tissue expanders to displace
bowel out of the radiation field at the time of resection; the
use of a new adhesion prevention film (Seprafilm), coupled with
careful positioning of patients during radiation therapy; and
the use of an absorbable small bowel sling to exclude the intestine
from the radiation field. The advantage of postoperative treatment
is that it delivers radiation to limited fields, ie, it treats
only those areas thought to be at high risk for recurrence. These
high-risk areas can be marked with titanium clips at the time
Approach to Radiation Therapy at Fox Chase Cancer Center
Realizing the lack of data confirming the efficacy of combined
surgery and radiation in the local control of soft-tissue sarcoma,
it is our policy at Fox Chase Cancer Center to treat patients
with minimal residual gross disease or positive postoperative
margins with radiation therapy. In general, this is postoperative
management employing some method to exclude the small intestine
from the radiation field. Preoperative radiation is utilized in
patients with large (more than 15 cm) or marginally resectable
tumors. However, it has been our experience that because of the
symptoms created by these patients' bulky tumors (poor appetite,
partial small bowel obstruction, and so on), it is difficult for
them to complete a 4- to 6-week course of preoperative radiation
1. Karakousis CP, Gerstenbluth R, Kontzoglou K, et al: Retroperitoneal
sarcomas and their management. Arch Surg 130:1104-1109, 1995.
2. Kilkenny JW, Bland KI, Copeland EM: Retroperitoneal sarcoma:
The University of Florida experience. J Am Coll Surg 182:329-339,
3. Jaques DP, Coit DG, Brennan MF: Soft tissue sarcoma of the
retroperitoneum, in Shui MH, Brennan MF: Management of Soft Tissue
Sarcoma, pp 157-159. Philadelphia, Lea & Febiger, 1994.
4. Tepper JE, Suit HD, Wood WC, et al: Radiation therapy of retroperitoneal
soft tissue sarcomas. Int J Radiat Oncol Biol Phys 10:825-830,
5. Sindelar WF, Kinsella TJ, Chen PW, et al: Intraoperative radiotherapy
in retroperitoneal sarcomas. Arch Surg 128:402-410, 1993.
6. Fein DA, Corn BW, Lanciano RM, et al: Management of retroperitoneal
sarcomas: Does dose escalation impact on locoregional control?
Int J Radiat Oncol Biol Phys 31:129-134, 1995.
7. Kinsella TJ, Sindelar WF, Lack E, et al: Preliminary results
of a randomized study of adjuvant radiation therapy in resectable
adult retroperitoneal soft tissue sarcomas. J Clin Oncol 6:18-25,