Traditional transrectal ultrasound (TRUS) is a technique used to help determine the stage of
rectal cancer. All patients at Memorial Sloan-Kettering Cancer Center with rectal cancer
have an ultrasound at the beginning of their treatment to accurately determine the depth of
penetration (how deep into the rectal wall the tumor goes) and lymph node involvement of
their tumor. This information helps determine the best way to treat the patient's disease.
Three-dimensional TRUS (3-D TRUS) is a new form of ultrasound that gives us all of the
information of traditional ultrasound in addition to being able to view the tumor in
3-dimensions. This image can be stored and analyzed to evaluate the tumor size and volume as
well as determine the unique shape of the tumor. Chemoradiotherapy before surgery is
considered standard of care for most rectal cancers.
Currently, there is no accurate way to determine whether or not the tumor has responded to
the pre-operative radiation therapy. The purpose of this study is to evaluate the response
of rectal cancer to pre-operative chemotherapy and/or radiation therapy using 3-D TRUS to
measure the volume of the tumor before and after chemoradiotherapy.
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.
- biopsy proven rectal cancer (path confirmed at MSKCC)
- able to provide consent for 3-D TRUS
- eligible for pre-operative chemotherapy and/or radiation therapy
- unable to provide informed consent
- unable to tolerate 3-D TRUS either pre- or post-chemo/RT
- unable to tolerate full course of chemotherapy and/or radiation therapy