A simple manual method of repositioning small bowel during pelvic irradiation

Systematic review of the role of a belly board device in radiotherapy delivery in patients with pelvic malignancies

PURPOSE

This review analyses the literature concerning the influence of the patient position (supine, prone and prone on a belly board device (BB) on the irradiated small-bowel-volume (SB-V)) and the resulting morbidity of radiation therapy (RT) in pelvic malignancies.

METHODS

A literature search was performed in MEDLINE, web of science and Scopus.

RESULTS

Forty-six full papers were found, of which 33 met the eligibility criteria. Fifteen articles focussed on the irradiated SB-V using dose volume histograms (DVHs). Twenty-seven articles studied the patient setup in different patient positions. This review showed that a prone treatment position can result in a lower irradiated SB-V as compared to a supine position, but a more significant reduction of the SB-V can be reached by the additional use of a BB in prone position, for both 3D-CRT and IMRT treatment plans. This reduction of the irradiated SB-V might result in a reduced GI-morbidity. The patient position did not influence the required PTV margins for prostate and rectum.

CONCLUSIONS

The irradiated SB-V can be maximally reduced by the use of a prone treatment position combined with a BB for both 3D-CRT and IMRT, which might individually result in a reduction of GI-morbidity.

Feasibility and morbidity of using saline filled tissue expanders to reduce radiation-induced bowel injury in patients with gynecologic malignancies

OBJECTIVES

To evaluate the feasibility and morbidity of using saline filled tissue expanders (TE) to displace the small bowel during radiation therapy in patients with gynecologic malignancies.

STUDY DESIGN

Ten patients undergoing surgical exploration for a gynecologic malignancy and deemed to be at high risk for the late effects of radiation therapy were consented for the possible placement of a TE. Indication for placement was need for post-operative radiation. Small bowel exclusion was reported in terms of the lowest loop identified on treatment planning film using orally ingested barium.

RESULTS

Small bowel loops were excluded from the pelvis to varying degrees in all patients. Lowest identifiable bowel was marked at the L4-L5 interspace in one patient, L5-S1 interspace in three patients, at or near the sacral promontory in three patients, and to the middle of S2 in one patient. In two patients the TE was removed prior to simulation. Early complications included migration of the TE during treatment, development of a vesicovaginal fistula requiring immediate removal of the TE, and enterocutaneous fistula formation in a patient who developed an abscess following treatment completion. Another patient experienced a rectovaginal fistula 18 months after removal of the TE.

CONCLUSIONS

TE placement can successfully isolate small bowel from the pelvis. Usage should be individualized to minimize the likelihood of short and long-term complications, particularly in patients at higher risk of morbidity.

Radiation proctopathy in the treatment of prostate cancer

PURPOSE

To compile and review data on radiation proctopathy in the treatment of prostate cancer with respect to epidemiology, clinical manifestations, pathogenesis, risk factors, and treatment.

METHODS

Medical literature databases including PubMed and Medline were screened for pertinent reports, and critically analyzed for relevance in the scope of our purpose.

RESULTS

Rectal toxicity as a complication of radiotherapy has received attention over the past decade, especially with the advent of dose-escalation in prostate cancer treatment. A number of clinical criteria help to define acute and chronic radiation proctopathy, but lack of a unified grading scale makes comparing studies difficult. A variety of risk factors, related to either radiation delivery or patient, are the subject of intense study. Also, a variety of treatment options, including medical therapy, endoscopic treatments, and surgery have shown varied results, but a lack of large randomized trials evaluating their efficacy prevents forming concrete recommendations.

CONCLUSION

Radiation proctopathy should be an important consideration for the clinician in the treatment of prostate cancer especially with dose escalation. With further study of possible risk factors, the advent of a standardized grading scale, and more randomized trials to evaluate treatments, patients and physicians will be better armed to make appropriate management decisions.

Treatment with a belly-board device significantly reduces the volume of small bowel irradiated and results in low acute toxicity in adjuvant radiotherapy for gynecologic cancer: results of a prospective study

BACKGROUND AND PURPOSE

To determine whether treatment prone on a belly-board significantly reduces the volume of small bowel irradiated in women receiving adjuvant radiotherapy for gynecologic cancer, and to prospectively study acute small bowel toxicity using an accepted recording instrument.

MATERIAL AND METHODS

Thirty-two gynecologic patients underwent simulation with CT scanning supine and prone. Small bowel was delineated on every CT slice, and treatment was prone on the belly-board using 3-5 fields-typically Anterior, Right and Left Lateral, plus or minus Lateral Boosts. Median prescribed dose was 50.4 Gy and all treatments were delivered in 1.8 Gy fractions. Concomitant Cisplatin was administered in 13 patients with cervical carcinoma. Comparison of small bowel dose-volumes was made between supine and prone, with each subject acting as their own matched pair. Acute small bowel toxicity was prospectively measured using the Common Toxicity Criteria: Version 2.0.

RESULTS

Treatment prone on the belly-board significantly reduced the volume of small bowel receiving > or = 100; > or = 95; > or = 90; and > or = 80% of the prescribed dose, but not > or = 50%. This was found whether volume was defined in cubic centimeters or % of total small bowel volume. Of 29 evaluable subjects, 2 (7%) experienced 1 episode each of grade 3 diarrhoea. All other toxicity events were grade 2 or less and comprised diarrhoea (59%), abdominal pain or cramping (48%), nausea (38%), anorexia (17%), vomiting (10%). There were no Grade 4 events and no treatment days were lost due to toxicity.

CONCLUSIONS

Treatment prone on a belly-board device results in significant small bowel sparing, during adjuvant radiotherapy for gynecologic cancer. The absence of Grade 4 events or Treatment Days Lost compares favorably with the published literature.

Small-bowel displacement system for the sparing of Small bowel in three-dimensional conformal radiotherapy for cervical cancer

AIMS

The efficacy of the small-bowel displacement system (SBDS) in three-dimensional conformal radiotherapy (3-D CRT) planning for sparing the volume of small bowel is presented for cervical cancer.

MATERIALS AND METHODS

Ten consecutive patients, who received pelvic radiation therapy for uterine cervical cancer with the SBDS from January to March 2003, were included in this study. The SBDS consists of a customised Styrofoam compression device, which can displace the small bowel out of the radiation fields, and an individualised immobilisation board. With oral contrast before scanning, computed tomography was taken in the prone position with and without the SBDS. 3-D conformal planning was carried out, and dose distribution was compared in the target volumes and in the organs-at-risk with and without the SBDS.

RESULTS

In all patients, the SBDS significantly reduced the small-bowel volume within radiation fields. The median small-bowel volume with SBDS was reduced by 56.4% compared with the small-bowel volume without SBDS (from 491 to 214 cm3; P = 0.004). Among the 10 patients, the highest small-bowel volume reduction was 70.2% (from 544 to 62 cm3). At the prescription dose, the median volume of small bowel irradiated was reduced significantly with SBDS (9.8% vs 1.2%; P = 0.005). Differences in the dose-volume histogram for the rectum and the bladder between the 3-D CRT plans with and without SBDS were not statistically significant (P > 0.1). All patients completed radiotherapy without a break in treatment.

CONCLUSION

The SBDS is a novel method that can be used to displace the small bowel away from the 3-D CRT fields effectively, and reduce radiation therapy morbidity.

Reduction of irradiated small bowel volume and accurate patient positioning by use of a bellyboard device in pelvic radiotherapy of gynecological cancer patients

PURPOSE

To reduce the volume of small bowel within pelvic treatment fields for gynecological cancer using a bellyboard device and to determine the accuracy of the prone treatment position.

MATERIALS AND METHODS

Fifteen consecutive patients with a gynecologic malignancy who were treated with postoperative pelvic radiotherapy were selected for this study. The volume of small bowel within the treatment fields was calculated for both the supine and prone treatment positions. The patients were treated in the prone position in a so-called bellyboard device. During treatment sessions electronic portal images were obtained. An off-line setup verification and correction protocol was used and the setup accuracy of the positioning in the bellyboard was determined.

RESULTS

The average volume of small bowel within the treatment fields was 229 cm(3) and 66 cm(3) in the supine and prone treatment, respectively, which means an average volume reduction in the prone position of 64% (95% CI 56-72%), as compared with the supine position. For the position of the patient in the field, the systematic error defined by the standard deviation (SD) of the mean difference per patient between simulation and treatment images was 1.7 mm in the lateral direction, 2.1 mm in the craniocaudal direction and 1.7 mm in the ventrodorsal direction. On average, only 0.4 setup correction per patient was required to achieve this accuracy. The random day-to-day variations were 1.9 (1SD), 2.6 and 2.3 mm, respectively. Standard deviations of the systematic differences between patient positioning relative to the bellyboard were 6.2 mm in lateral direction and 9.1 mm in craniocaudal direction.

CONCLUSIONS

Treatment of gynecological cancer patients in the prone position using a bellyboard reduces the volume of irradiated small bowel. An off-line verification and correction protocol ensures accurate patient positioning. Daily setup variations using the bellyboard were small (1 SD<3 mm). Therefore for pelvic radiotherapy in patients with a gynecological malignancy, the use of a bellyboard is recommended.

Effect of customized small bowel displacement system in pelvic irradiation

PURPOSE

Authors designed a customized small bowel displacement system (SBDS) to displace the small bowel out of the pelvic radiation fields and to minimize treatment related bowel morbidity.

METHODS AND MATERIALS

From August 1995 to May 1996, 55 consecutive patients who received pelvic radiation therapy with the SBDS were included in this study. The SBDS consists of a customized Styrofoam compression device that can displace the small bowel out of the radiation fields and an individualized immobilization abdominal board for easy daily setup of the patient in prone position. After opacifying the small bowel with barium, the patients were laid prone and posterior-anterior (PA) and lateral (LAT) simulation films were taken with and without the SBDS. The volume of the small bowel included in the radiation fields with and without the SBDS were compared.

RESULTS

Using the SBDS, the mean small bowel volume was reduced by 59% on PA and 51% on LAT films (p = 0.0001). In six patients (6 of 55, 11%), it was possible that no small bowel was included within the treatment fields. The mean upward displacement of the most caudal small bowel was 4.8 cm using the SBDS. Patients treated with the SBDS manifested a significantly lower incidence of diarrhea requiring medication (8 of 55, 15%) vs. those without the SBDS (24 of 39, 62%) (p < 0.05).

CONCLUSION

The SBDS is a novel method that can be used to displace the small bowel away from the treatment portal effectively and to reduce the radiation therapy morbidity. Compliance with setup is excellent.

Efficacy of a belly board device with CT-simulation in reducing small bowel volume within pelvic irradiation fields

PURPOSE/OBJECTIVE

Acute and chronic small bowel toxicity associated with pelvic irradiation limits dose escalation for both chemotherapy and radiotherapy for rectal cancer. Various surgical and technical maneuvers including compression and belly board devices (BBD) have been used to reduce small bowel volume in treatment fields. However, quantitative dose volume advantages of such methods have not been reported. In this study, the efficacy of BBD with CT-simulation is presented with dose-volume histogram (DVH) analyses for rectal cancer.

METHODS AND MATERIALS

Twelve consecutive patients referred to our department with rectal cancer were included in this study. Patients were given oral contrast 1.5 h prior to scanning and instructed not to empty their bladder during the procedure. The initial CT scan without BBD was taken in the prone position with an immobilization cast. A second CT study was performed with a commercially available BBD consisting of an 18-cm thick hard sponge with an adjustable opening (maximum 42 x 42 cm2). All patients were positioned prone over the BBD so that the opening was above the treatment volume and usually extended from the diaphragm to the bottom of the fourth lumbar spine. Image fusion between both sets of CT scans (with and without BBD) was performed using common bony landmarks to maintain the same target volume. The critical structures including small bowel and bladder were delineated on each slice for DVH analysis. On each study, a three-field optimized plan with conformal blocks in beams-eye-view was generated for volumetric analysis. The DVHs with and without BBD were evaluated for each patient.

RESULTS

The median age and body weight of 12 patients (4 females and 8 males) were 57.5 years and 82.7 kg, respectively. The changes in posterior-anterior (PA) and lateral separation with and without BBD at central axis slices were analyzed. The changes in lateral separation were minimal (<0.8 cm); however, the PA separation was reduced by 11.3 +/- 3.3% when BBD was used. The reduction in PA separation was directly related to the reduction in small bowel volume. The small bowel volume was significantly reduced with a median reduction of 70% (range 10-100%) compared to the small bowel volume without BBD. The small bowel volume reduction did not correlate either with body weight, age, gender, or sequence of radiation treatment with surgery (pre-op vs. post-op). The DVH analysis of small bowel with BBD showed significant volume reduction at each dose level. For 50% patients, the DVH analysis demonstrated an increase in bladder volume with BBD. All patients treated with the BBD completed their treatment without any break and without significant acute gastrointestinal or genitourinary toxicity.

CONCLUSIONS

For rectal cancers, small bowel is the dose-limiting structure for acute and chronic toxicity. The use of the BBD should improve the tolerance of aggressive combined modality treatment by reducing the small bowel volume within the pelvis compared to the prone position alone. The BBD provides an easy, economical, comfortable, and noninvasive technique to displace small bowel from pelvic treatment fields. The small bowel volume is dramatically reduced at each dose level. The volume reduction does not correlate with gender, age, weight, pelvic separation, and sequence of radiation treatment vs. surgery.