IMPROVED TREATMENT PLANNING FOR THE SYED-NEBLETT TEMPLATE USING ENDORECTAL-COLI MAGNETIC-RESONANCE AND INTRAOPERATIVE (LAPAROTOMY LAPAROSCOPY) GUIDANCE - A NEW INTEGRATED TECHNIQUE FOR HYSTERECTOMIZED WOMEN WITH VAGINAL TUMORS
Bw. Corn et al., IMPROVED TREATMENT PLANNING FOR THE SYED-NEBLETT TEMPLATE USING ENDORECTAL-COLI MAGNETIC-RESONANCE AND INTRAOPERATIVE (LAPAROTOMY LAPAROSCOPY) GUIDANCE - A NEW INTEGRATED TECHNIQUE FOR HYSTERECTOMIZED WOMEN WITH VAGINAL TUMORS, Gynecologic oncology, 56(2), 1995, pp. 255-261
The Syed template (Alpha-Omega Services, Bellflower, CA) represents an
advance in interstitial gynecologic brachytherapy; however, its appea
l is diminished by inaccuracies in target definition secondary to subo
ptimal imaging of gynecologic tumors and the risk of viscus perforatio
n during a ''blind'' procedure. Magnetic resonance (MR) scanning with
an endorectal coil and computed tomography were studied as a possible
tool to improve target definition and maximize treatment planning with
Syed templates. Abdominopelvic contents could be visualized directly
through a laparotomy incision or indirectly with a laparoscopic video
display to allow further target definition and minimize complications
associated with blind procedures after hysterectomy. The synthesis of
these techniques with Syed template applications was attempted to pote
ntiate the utility of this brachytherapy system. Five patients with ap
ical vaginal tumors which arose after previous hysterectomies (two end
ometrial cancer recurrences, one recurrent uterine sarcoma, two primar
y vaginal cancers) were referred for radiotherapy. In three cases, ext
ernal beam pelvic radiotherapy (median dose, 45 Gy; range, 45-50.4 Gy)
was delivered initially. In all cases, the Syed applicator was used f
or the brachytherapy component of the treatment. In two cases, high-re
solution MR images (400 x 400 mu m) of the vaginal apex were obtained
after insertion of an endorectal surface coil. The images defined the
relationships between the template, target volume, bladder, rectum, an
d intestine. The other three cases were planned with computerized tomo
graphy (CT). In all cases, intraoperative examination of the abdominop
elvic contents was provided when laparotomy and/or laparoscopy was per
formed by the surgical team. The median brachytherapy dose prescribed
to the isodose envelope covering the target volume was 40 Gy (range, 3
1-50 Gy). In all cases,the target volumes could be encompassed by the
60 cGy/hr isodose line. Tumor volume estimation was better with MR tha
n CT. Procedure time was shorter with laparoscopy than with laparotomy
. In two cases, bowel displacement was performed (one tissue expander,
one omental sling) to prevent viscus perforation by interstitial need
les. Four of five patients responded completely to the treatment. In t
hree cases, local control was maintained at a median follow-up of 11 m
onths. In conclusion, endorectal coil MRI may be advantageous to CT of
the pelvis in that it allows preplanning to be achieved with greater
precision and with less planning time. Major intraoperative complicati
ons (i.e., perforation of hollow viscus organs) can be avoided when th
e course of interstitial catheters is visualized from above by the sur
gical team. The integration of these innovative techniques with an eff
ective brachytherapy system has the potential of improving control and
reducing complications when treating challenging gynecologic tumors.
(C) 1995 Academic Press, Inc.