Trial Information

Evaluating The Response to Pre-Operative Chemotherapy and/or Radiation Therapy For Rectal Cancer Using Three-Dimension Transrectal Ultrasound (3-D TRUS) - A Pilot Project

Transrectal ultrasound (TRUS) is widely accepted as an accurate and effective technique for
staging of rectal cancer. The decision to administer pre-operative chemotherapy/radiation
therapy is often made based on the results of the TRUS. The greatest limitation of TRUS is
its operator-dependence. Three-dimensional TRUS (3-D TRUS) is a new modality that provides
all of the information of traditional TRUS as well as the ability to provide three
dimensional views of the tumor. This provides greater detail regarding the configuration of
the tumor as well as the ability to calculate tumor volume. The results of 3-D TRUS are
interpreted after the study and thus, operator-dependence is reduced. There are no currently
accepted techniques that allow for objective and accurate assessment of a rectal tumor's
response to pre-operative treatment short of post-operative pathologic evaluation. Our
objectives are to evaluate the ability of 3-D TRUS to quantify the tumor's response to
pre-operative radiation therapy and/or chemotherapy and to correlate these findings with
post-operative pathologic examination of the specimen. These objectives can be accomplished
with 2 ultrasounds, one before treatment and one before surgery. All patients with
biopsy-proven (with pathology confirmed at MSKCC) rectal cancer are eligible for the study.
The size, volume and depth of penetration and lymph node involvement will all be assessed
during both ultrasound examinations. Our findings will then be compared to those found at
post-operative pathologic examination. These data will then be analyzed to determine if 3-D
TRUS was accurate in predicting the tumor's response to preoperative treatment.