Belly Board Research Articles

Using kV-kV and CBCT imaging to evaluate rectal cancer patient position when treated prone on a newly available belly board

The goal of this work was to use daily kV-kV imaging and weekly cone-beam CT (CBCT) to evaluate rectal cancer patient position when treated on a new couch top belly board (BB). Quality assurance (QA) of the imaging system was conducted weekly to ensure proper performance. The positional uncertainty of the combined kV-kV image match and subsequent couch move was found to be no more than ± 1.0 mm. The average (1 SD) CBCT QA phantom match was anterior-posterior (AP) = −0.8 ± 0.2 mm, superior-inferior (SI) = 0.9 ± 0.2 mm, and left-right (LR) = −0.1 ± 0.1 mm. For treatment, a set of orthogonal kV-kV images were taken and a bony anatomy match performed online. Moves were made along each axis (AP, SI, and LR) and recorded for analysis. CBCT data were acquired once every 5 fractions for a total of 5 images per patient. The images were all taken after the couch move but before treatment. A 3-dimensional (3D-3D) bony anatomy auto-match was performed offline and the residual difference in position recorded for analysis. The average (± 1 SD) move required from skin marks, calculated over all 375 fractions (15 patients × 25 fractions/patient), were AP = −2.6 ± 3.7 mm, SI = −0.3 ± 4.9 mm, and LR = 1.8 ± 4.5 mm. The average residual difference in patient position calculated from the weekly CBCT data (75 total) were AP = −1.7 ± 0.4 mm, SI = 1.1 ± 0.6 mm, and LR = −0.5 ± 0.2 mm. These results show that the BB does provide simple patient positioning that is accurate to within ± 2.0 mm when using online orthogonal kV-kV image matching of the pelvic bony anatomy.

The Efficacy of the Change in Belly Board Aperture Location by the Addition of Bladder Compression Device for Radiotherapy of Rectal Cancer

The Efficacy of the Change in Belly Board Aperture Location by the Addition of Bladder Compression Device for Radiotherapy of Rectal Cancer

Radiothérapie à visée curative du carcinome du canal anal : impact défavorable d’une résection préalable. Étude rétrospective de 57 patients traités en intention curative

Purpose To describe retrospectively the overall survival, the cancer specific survival and the tumor control in an homogeneous series of patients with epidermoid carcinoma of the anal canal treated with definitive radiotherapy; to assess the impact of brachytherapy, chemotherapy and pre-radiotherapy resection on the risk of recurrence. Patients and methods From 1997 to 2007, 57 patients (pts) presenting with an epidermoid carcinoma of the anal canal (T1: 14, T2: 33, T3-4: 10, N0: 31, N1: 19, N2: 3, N3: 4, M0: 57) were treated with definitive radiotherapy by the same radiation oncologist. The treatment included an external beam irradiation (EBRT) given to the posterior pelvis (45 Gy/25 fractions) and, six weeks later, a boost delivered with interstitial brachytherapy (37/57) or external beam irradiation (20/57). Twelve pts had undergone a surgical resection of the tumour before radiotherapy. A belly board was used for EBRT in 13 pts. A concurrent platinum based chemotherapy was done in 42 pts. The mean follow-up was 57 months. Results The overall survival rate at 5 years was 89% with a cause specific survival of 96%. Five patients recurred (5-year rate: 12%: four had local relapse (5-year rate: 8%), four had groin recurrence, and distant metastases were seen in two. In univariate analysis, the risk of relapse was higher in patients who had undergone a pre-radiation excision ( p = 0.018), in those who did not receive chemotherapy ( p = 0.076) and in those who were irradiated on a belly board ( p = 0.049). In multivariate analysis, a pre-radiotherapy resection ( p = 0.084) had an inverse impact on the tumour control reaching the level of statistical significance and the use of a belly board was of marginal influence ( p = 0.13). Conclusion Radiotherapy and chemoradiation with cisplatine-based chemotherapy cure a vast majority of patients with epidermoid carcinoma of the anal canal. Therapeutic factors that may interfere with the definition of the target volume and the patients’ repositioning may decrease the efficacy of radiotherapy. Pre-radiotherapy surgical resection should be avoided.

Favorable IMRT Experience Treating Obese Prostate Cancer Patients in the Prone Position using Electromagnetic Tracking and a “Belly Board”

We sought to extend the use of electromagnetic localization and tracking technology (Calypso Medical Technologies, Seattle, WA) to obese men with large anterior-posterior (AP) separations who would otherwise not be eligible to have their prostate localized and/or tracked if they were treated in a supine position. Four patients of large girth (weights 189-326 lbs) were treated. The A-P dimensions of these patients precluded electromagnetic localization and tracking when they were in a supine position. This is due to the specifications of the tracking system, which limits the maximum distance from the array to the transponders to prevent gantry collision. These patients were placed in the prone position for both the treatment planning CT as well as daily radiation treatments. The first patient was treated on a solid slab of Styrofoam. In an attempt to minimize prostate motion caused by respiration, the remaining three patients were treated on a conventional “belly board.” PTV prescription doses ranged from 77.4-79.2 Gy. Tracking limits were set to 5 mm for all dimensions except for 4 mm posterior. Localization and tracking were accomplished successfully for all 173 fractions. The tracking logs for all patients demonstrated patterns of prostate motion attributable to breathing, predominantly in the AP axis with lesser effect along the superior-inferior (SI) axis and no effect on the lateral axis. For the first patient, the excursions due to respiratory motion were typically ± 1 mm in the SI axis and ± 2 mm in the AP axis. When a “belly board” was used for the subsequent 3 patients, the excursions were decreased and were typically ± 0.5 mm in the SI axis and ± 1 mm in the AP axis. Beam pauses and/or interruptions for patient re-positioning were no more frequent than for more slender patients treated in the supine position. In our experience, prone positioning on a “belly board” allows electromagnetic localization and tracking technology to be used on all obese patients. Prostate motion from breathing is small and acceptable. As a result, high dose IMRT for prostate cancer can be delivered accurately and reliably to obese men.

Inter-fraction bladder filling variations and time trends for cervical cancer patients assessed with a portable 3-dimensional ultrasound bladder scanner

Background and Purpose For cervical cancer patients, bladder filling variations may result in inadequate EBRT target coverage, unless large safety margins are used. For a group of patients who received full bladder instructions, inter-fraction variations and time trends in bladder volume were quantified, and a 3D ultrasound (US) scanner was tested for on-line bladder volume measurements. Methods and materials For 24 patients, the bladder volume was measured with US at the time of the planning CT scan, and twice weekly during the course of RT. Comparisons of US with planning CT were used to assess the bladder scanner accuracy. Patients were treated in prone on a belly board, EPID images were acquired to correlate set-up errors with bladder filling variations. Results Measured US and CT bladder volumes were strongly correlated ( R = 0.97, slope 1.1 ± 0.1). The population mean bladder volume at planning of 378 ± 209 ml (1 SD) reduced to 109 ± 88 ml (1 SD) in week 6, a reduction by 71% (average reduction 46 ml/week), revealing a large inter-fraction time trend. Intra-patient variation in bladder volume during RT was 168 ml (1 SD) (range 70–266 ml). Rotation around the LR axis was significantly correlated with bladder volume changes. Conclusions Despite a full bladder instruction, bladder volumes reduced dramatically during treatment, implying large time trends in target position of these patients. The portable US scanner provides a quick and reliable measurement of the bladder volume, which might assist future online treatment adaptation.

Image-guidance protocol comparison: Supine and prone set-up accuracy for pelvic radiation therapy

Purpose. To investigate the impact of prone versus supine patient set-up and use of various image-guidance protocols on residual set-up error for radiation therapy of pelvic malignancies. We aim to identify an optimal frequency and protocol for image-guidance. Materials. Using daily online image-guidance mega-voltage CT data from 30 patients (829 MVCT; 299 prone set-up on belly board, 530 supine set-up), we retrospectively assessed the impact of various image-guidance protocols on residual set-up error. We compared daily image-guidance with three different No Action Level protocols (NAL), alternate day image-guidance with running mean and weekly image-guidance. Results. Of 5 IGRT protocols analyzed, the protocol with the highest imaging frequency, alternate day imaging with a running mean (50% imaging frequency), provided the best set-up error reduction. This protocol would have reduced the average length of 3D corrective vector shifts derived from daily image-guidance from 15.2 and 13.5 mm for prone and supine set-up, to 5 and 5.4 mm, respectively. A NAL protocol, averaging shifts of the first 3 fractions (NAL3), would have reduced the respective set-up variability to 6.3 (prone), and 7.5 mm (supine). An extended NAL (eNAL) protocol, averaging shifts of the first 3 fractions plus weekly imaging, would have reduced the daily positioning variability to 6 mm for both prone and supine set-ups. Daily image-guidance yielded set-up corrections >10 mm in 64.3% for prone and 70.3% for supine position. Use of the NAL3 protocol would have reduced the respective frequency to 14.4%, and 21.2% for prone, and supine positioning. In comparison, the alternate day running mean protocol would have reduced the frequency of shifts >10 mm to 5.5% (prone), and 8.3% (supine), respectively. Discussion. In this comparison, high frequency image-guidance provided the highest benefit with respect to residual set-up errors. However, both NAL and eNAL protocols provided significant set-up error reduction with lowered imaging frequency. While the mean 3D vector of corrective shifts was longer for prone set-up compared to the supine set-up, using any image-guidance protocol would have reduced shifts for prone set-up to a greater extent than for the supine set-up. This indicates a greater risk for systematic set-up errors in prone set-up, and larger random errors using a supine patient set-up.

A special device (double-hole belly board) and optimal radiation technique to reduce testicular radiation exposure in radiotherapy of rectal cancer

Purpose Patients with rectal cancer are treated in prone position on a belly board to reduce the volume of irradiated small bowel. With this technique the testes obtain radiation doses, which often result in partial or complete impairment of the spermatogenesis and a dose-dependent decrease of testosterone levels. We developed a double-hole belly board (DHBB) and evaluated its potential to reduce testicular dose. Methods and materials In nine consecutive male patients (3 very low tumor localisations [inguinal RT], 3 low [RT perineum], 3 high [lower border ischial tuberosities]) CT scans were performed on a conventional single-hole belly board (SHBB) and on a DHBB. Dose–volume histograms of the testes were analysed for both belly boards and for different treatment techniques (3-field and 4-field). Results To reduce testicular dose in high tumors, positioning on DHBB was most effective ( V 1.5Gy 20–30% vs. 60% for SHBB, V 4Gy 7% vs. 35%). In low tumors, a 3-field technique reduced high testicular doses ( V 14Gy 0–6% vs. 28–34% for 4-fields). In very low tumors a combination of DHBB and 3-fields led to a decrease of high dose exposure ( V 33Gy 0% vs. 24–78%). Conclusion In male patients with rectal cancer the use of a DHBB and a 3-field technique is recommended to reduce testicular radiation exposure.

A belly board reduces the volume of small bowel irradiated during IMRT for rectal cancer

A belly board reduces the volume of small bowel irradiated during IMRT for rectal cancer

Dose-volume relationships between enteritis and irradiated bowel volumes during 5-fluorouracil and oxaliplatin based chemoradiotherapy in locally advanced rectal cancer

Purpose. Radiation enteritis is the main acute side-effect during pelvic irradiation. The aim of this study was to quantify the dose-volume relationship between irradiated bowel volumes and acute enteritis during combined chemoradiotherapy for rectal cancer.Material and methods. Twenty-eight patients with locally advanced rectal cancer received chemoradiotherapy. The radiation therapy was given with a traditional multi-field technique to a total dose of 50 Gy, with concurrent 5-Fluorouracil (5-FU) and oxaliplatin (OXA) based chemotherapy. All patients underwent three-dimensional CT-based treatment planning. Individual loops of small and large bowel as well as a volume defined as “whole abdomen” were systematically contoured on each CT slice, and dose-volume histograms were generated. Diarrhea during treatment was scored retrospectively according to the NCI Common Toxicity Criteria scale.Results. There was a strong correlation between the occurrence of grade 2+diarrhea and irradiated small bowel volume, most notably at doses >15 Gy. Neither irradiated large bowel volume, nor irradiated “whole abdomen” volume correlated significantly with diarrhea. Clinical or treatment related factors such as age, gender, hypertension, previous surgery, enterostomy, or dose fractionation (1.8 vs. 2.0 Gy/fraction) did not correlate with grade 2+diarrhea.Discussion. This study indicates a strong dose-volume relationship between small bowel volume and radiation enteritis during 5-FU-OXA-based chemoradiotherapy. These findings support the application of maneuvers to minimize small bowel irradiation, such as using a “belly board” or the use of IMRT technique aiming at keeping the small bowel volume receiving more than 15 Gy under 150 cc.

Long-term results of intraoperative presacral electron boost radiotherapy (IOERT) in combination with total mesorectal excision (TME) and chemoradiation in patients with locally advanced rectal cancer

We analyzed the long-term results of patients with locally advanced rectal cancer using a multimodal approach consisting of total mesorectal excision (TME), intraoperative electron-beam radiation therapy (IOERT), and pre- or postoperative chemoradiation (CRT). Between 1991 and 2003, 210 patients with locally advanced rectal cancer (65 International Union Against Cancer [UICC] Stage II, 116 UICC Stage III, and 29 UICC Stage IV cancers) were treated with TME, IOERT, and preoperative or postoperative CHT. A total of 122 patients were treated postoperatively; 88 patients preoperatively. Preoperative or postoperative fluoropyrimidine-based CRT was applied in 93% of these patients. Median age was 61 years (range, 26-81). Median follow-up was 61 months. The 5-year actuarial overall survival (OS), disease-free survival (DFS), local control rate (LC), and distant relapse free survival (DRS) of all patients was 69%, 66%, 93%, and 67%, respectively. Multivariate analysis revealed that UICC stage and resection status were the most important independent prognostic factors for OS, DFS, and DRS. The resection status was the only significant factor for local control. T-stage, tumor localization, type of resection, and type of chemotherapy had no significant impact on OS, DFS, DRS, and LC. Acute and late complications > or =Grade 3 were seen in 17% and 13% of patients, respectively. Multimodality treatment with TME and IOERT boost in combination with moderate dose pre- or postoperative CRT is feasible and results in excellent long-term local control rates in patients with intermediate to high-risk locally advanced rectal cancer.

Intensity-modulated radiotherapy with a belly board for rectal cancer

Intensity-modulated radiotherapy (IMRT) techniques can reduce the irradiated small bowel volume in rectal cancer patients, but combined use of IMRT and a belly board is yet to be reported on for rectal cancer patients. The aim of this study was to determine whether additional use of a belly board reduced the irradiated small bowel volume observed using IMRT alone in rectal cancer patients. Twenty patients scheduled to receive preoperative radiotherapy for rectal cancer underwent two series of CT scans, with and without a belly board. IMRT planning was performed using 6-MV photon beams and seven equispaced fields. The bladder, small bowel, and planning target volume (PTV) were analyzed for doses between 10% and 100% of the prescribed dose at 10% intervals. Data were analyzed using Wilcoxon signed rank tests. There were no significant differences between patients undergoing IMRT with a belly board and those without a belly board in terms of total small bowel volumes, bladder, and PTV (p=0.571, p=0.841, and p=0.870, respectively). Statistical analysis showed that the irradiated small bowel volume with a belly board was smaller than that without a belly board (p<0.05 at 20-100% dose levels), with the mean relative reduction in the irradiated small bowel volume being 37.8+/-32.8%. IMRT with a belly board is more effective than IMRT alone in reducing the irradiated small bowel volume. These findings suggest that the use of a belly board with IMRT may reduce small bowel complications in preoperative radiotherapy.

The Effect of Belly Board Location in Rectal Cancer Patients Treated with Preoperative Radiotherapy

Aims To evaluate the effect of the belly board aperture location on the irradiated small bowel volume in rectal cancer patients treated with preoperative pelvic radiotherapy. Materials and methods Twenty patients with rectal cancer scheduled to receive preoperative pelvic radiotherapy were evaluated prospectively. Each patient underwent computed tomography with the belly board aperture lower border at three different locations relative to patient anatomy: the lumbosacral junction (location I), the lower end of the sacroiliac joint (location II) and the upper end of the symphysis pubis (location III). The irradiated small bowel volume was calculated for doses between 10 and 100% of the prescribed dose at 10% intervals. For each 10% dose increment, the effect of the belly board aperture at the three different locations on the irradiated small bowel volume was analysed using Wilcoxon signed rank and Wilcoxon rank sum tests. Results At 10–20% dose levels, the irradiated small bowel volume increased in the order of locations I, II and III, and the differences between each location were significant. At ≥30% dose levels, the irradiated small bowel volume increased in the order of locations III, II and I, and the differences between locations I and II were significant, but the differences between locations II and III were not significant. Conclusion The belly board aperture location can influence the irradiated small bowel volume differently at each dose level. When considering the use of a belly board in routine clinical practice, we recommend that the clinician take into account the patterns of irradiated small bowel volume according to belly board aperture location.

Combination of prone position and intensity-modulated radiation therapy (IMRT) reduces small bowel doses in radiation therapy for gynecologic malignancies

ObjectiveTo evaluate if the combination of both prone position on a belly board and intensity-modulated radiotherapy (IMRT) further reduces the radiation dose to small bowel in pelvic RT for gynecologic malignancies.MethodsConformal pelvic RT plans were computed in 13 patients with gynecologic malignancies who had pre-existing planning computed tomography (CT) scans in both the supine position and prone position on a belly board. There were 10 cervical cancer and 3 endometrial cancer patients. A limited arc technique (180° arc length) and an extended arc technique (340° arc length) were used in IMRT plans. Normal tissue regions of interest (ROI) included small bowel, large bowel and bladder. Dose and volume for normal tissue structures were traced and compared between supine and prone plans using the paired t-test.ResultsFor the limited arc technique, prone position using a belly board device improved small bowel sparing. Analysis of the results showed a 12∼26 Gy reduction of volume of small bowel irradiation compared to the supine position. With the extended arc technique, there was no obvious radiation reduction in the prone position. Large bowel and bladder dose showed no significant differences between prone and supine position with either technique.ConclusionProne positioning on a belly board decreases the small bowel dose in gynecologic pelvic IMRT, and the magnitude of improvement depended on the limited arc IMRT technique used.

Research in radiation therapy — an inescapable challenge

RadiographerVolume 52, Issue 3 p. 8-12 The Varian Award for achievement for radiation therapistsOpen Access Research in radiation therapy — an inescapable challenge Dr Jenny Cox, Dr Jenny Cox The University of Sydney, Sydney, New South Wales, AustraliaSearch for more papers by this author Dr Jenny Cox, Dr Jenny Cox The University of Sydney, Sydney, New South Wales, AustraliaSearch for more papers by this author First published: 02 October 2013 https://doi.org/10.1002/j.2051-3909.2005.tb00034.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat References 1Sackett D, Strauss E, Richardson W, Rosenberg W, Haynes R. Evidence-based medicine: How to practice and teach EBM. Edinburgh: Churchill Livingstone; 2000. 2Melnyk B, Fineout-Overholt E. Evidence-based practice in Nursing and Healthcare. Philadelphia: Williams & Wilkins; 2005. 3Heater B, Becker A, Olson R. Nursing interventions and patient outcomes: a meta-analysis of studies. Nurs Res 1998; 37 (5): 303– 7. 4Green N, Iba G, Smith W. Russell Measures to minimize small intestine injury in the irradiated pelvis. Cancer 1975; 35 (6): 1633– 1640. 5Green, N. The avoidance of small intestine injury in gynecologic cancer. Int J Rad Oncol Biol Phys 1983; 9 (9): 1385– 1390. 6Caspers R, Hop W. Irradiation of true pelvis for bladder and prostatic carcinoma in supine, prone or trendelenburg position. Int J Rad Oncol, Biol Phys 1983; 9 (4): 589– 593. 7Gallagher M, Brereton H, Rostock R, Zero J, Zekoski D, Poyss L, et al. A prospective study of treatment techniques to minimize the volume of pelvic small bowel with reduction of acute and late effects associated with pelvic irradiation. Int J Rad Oncol, Biol Phys 1986; 12: 1565– 1573. 8Shanahan T, Mehta M, Bertelrud K, Buchler D, Frank L, Gehring M, et al. Minimization of small bowel volume within treatment fields utilizing customized ‘belly boards’. Int J Rad Oncol, Biol Phys 1990; 19 (2): 469– 476. 9Herbert S, Curran W, Solin L, Stafford P, Lanciano R, Hanks G. Decreasing gastrointestinal morbidity with the use of small bowel contrast during treatment planning for pelvic irradiation. Int J Rad Oncol, Biol Phys 1991; 20 (4): 835– 842. 10Astill C. The belly board. Radiog 1992; 39 (1): 25– 28. 11Weiss E, Eberlein K, Pradier O, Schmidberger H, Hess C. The impact of patient positioning on the adequate coverage of the uterus in the primary irradiation of cervical carcinoma: A prospective analysis using magnetic resonance imaging. Radiother Oncol 2002; 63: 83– 87. 12Brackenridge S. Unpublished literature review. 2005; The University of Sydney Volume52, Issue3December 2005Pages 8-12 ReferencesRelatedInformation

Comparative Analysis of the Effects of Belly Board and Bladder Distension in Postoperative Radiotherapy of Rectal Cancer Patients

To compare the effect of reducing the irradiated small-bowel volume with the use of belly board, bladder distension or both methods combined, in patients with rectal cancer undergoing postoperative pelvic radiotherapy. This study enrolled 20 consecutive patients with rectal cancer who were scheduled to receive postoperative pelvic radiotherapy. All patients underwent four sets of CT scans under four different methods as follows: group I: empty bladder without the use of a belly board; group II: empty bladder with the use of a belly board; group III: bladder distension without the use of a belly board; group IV: bladder distension with the use of a belly board. The conventional three-field treatment plan was made using a three-dimensional treatment planning system. The irradiated small-bowel volume was calculated at 10% intervals from 10% to 100% of the prescribed dose. The volume of the irradiated small bowel decreased in the order of group I, group II, group III, and group IV at all dose levels (p < 0.001). In comparison to group I, the mean absolute volume reductions (relative volume reduction) of the irradiated small bowel were 41.5 +/- 20.1 cm(3) (33.9 +/- 12.9%) in group II, 76.6 +/- 30.5 cm(3) (55.1 +/- 17.8%) in group III, and 98.5 +/- 36.7 cm(3) (70.7 +/- 14.5%) in group IV. Bladder distension was a more effective method than the belly board for reducing the irradiated small-bowel volume in postoperative pelvic radiotherapy of rectal cancer patients. The combination of the belly board and bladder distension showed an additive effect and was the most effective method for reducing the irradiated small-bowel volume.

Comparison of the belly board device method and the distended bladder method for reducing irradiated small bowel volumes in preoperative radiotherapy of rectal cancer patients

To determine the most effective method to reduce the irradiated small bowel volume when using a belly board device (BBD), a distended bladder (DB), or both in patients with rectal cancer undergoing preoperative pelvic radiotherapy (RT). The study involved 20 patients with rectal cancer who were scheduled to receive preoperative pelvic RT. Patients were asked to empty their bladders and then drink 300 mL of water 2 h before the treatment planning computed tomographic (CT) scan. To identify the small bowel, an oral contrast solution (450 mL) was given 1 h before the CT scan. Two sets of transverse images were taken at 1-cm-thickness intervals with patients in the prone position with or without the BBD. After voiding, two additional sets of CT scans were obtained in prone positions with or without BBD. The conventional three-field treatment plan, composed of a 6-MV photon posterior-anterior field and 15-MV photon opposed lateral fields with wedges of 45 degrees, was made using a three-dimensional treatment planning system. The beam weights of the three-field plan were equal. The volume of irradiated small bowel was calculated for doses between 10% and 100% of the prescribed dose at 10% intervals. For each 10% dose increment, the effect of the BBD and the DB on the irradiated volume was analyzed using Kruskal-Wallis, Wilcoxon signed rank, and Wilcoxon rank-sum tests. All patients underwent four sets of CT scan under the conditions of four different methods as follows: Group I = empty bladder without the use of belly board; Group II = empty bladder with the use of belly board; Group III = distended bladder without the use of belly board; Group IV = distended bladder with the use of belly board. We found that the volume of irradiated small bowel decreased in the order of Group I, Group II, Group III, and Group IV at all dose levels (p < 0.05). Compared with Group I, the mean volume reduction rate (reduced volume) of irradiated small bowel in Group II varied between 14.5% and 65.4% (15.5-80.4 cm(3)), in Group III it varied between 48.1% and 82.0% (21.6-163.1 cm(3)), and in Group IV between 51.4% and 96.4% (28.6-167.1 cm(3)). The DB was more effective than the BBD for reducing the volume of irradiated small bowel in rectal cancer patients receiving pelvic RT. The combination of the BBD and DB showed an additive effect and was the most effective method for reducing the irradiated small bowel volume.

Long-term results using local excision after preoperative chemoradiation among selected T3 rectal cancer patients

To assess the pelvic failure among patients with T3 rectal cancer treated with local excision after preoperative chemoradiation. Between January 1990 and June 2002, 431 patients with clinically staged T3 rectal cancer were treated with preoperative chemoradiation followed by surgical resection. Full-thickness local excision [Kraske (n = 3) or a transanal excision (n = 23)] was performed in 26 patients because of patient refusal of abdominoperineal resection (APR) (n = 13), medical comorbidity (n = 4), physician preference after a complete clinical response (n = 6), and other reasons (n = 3). All patients were treated with continuous-infusion 5-fluorouracil (5-FU) (300 mg/m(2) Monday to Friday) and concomitant pelvic radiation (45 Gy in 25 fractions with a 3-field belly board technique). Ten local-excision patients received a concomitant boost during the last week of therapy (1.5-Gy second daily fractions) for a total dose of 52.5 Gy. Similar preoperative treatment was followed by total mesorectal excision in 405 patients. Among the local-excision patients, the median tumor size was 3.5 cm (range, 0.5-7 cm). Well-differentiated or moderately-differentiated histology was present in all but 3 cases, and endoscopic ultrasound staging examination was performed in 25 of 26 patients. Based on CT findings, 1 patient was node positive. The median circumference involved by tumor was 33%, (20%-75%). The median distance from the anal verge was 3 cm (range, 1-8 cm). The mean follow-up was 46 months (range, 5-109 months) in the local-excision group. In the local-excision group, 19 of 26 patients had only residual scarring noted on digital rectal examination and rigid proctoscopy before surgery. Fourteen patients (54%) had a complete histologic response to chemoradiation, 9 patients (35%) had microscopic residual disease, and 3 patients (12%) had gross residual disease. Two intrapelvic recurrences occurred at 76 and 20 months among the 26 patients treated with local excision (6% 5-year actuarial pelvic recurrence rate). This rate compared with an 8% 5-year actuarial pelvic recurrence rate among T3 patients treated with mesorectal excision and a 6% pelvic recurrence rate in the subgroup of mesorectal-excision patients with a complete clinical response to preoperative chemoradiation. One additional local-excision patient recurred in an inguinal lymph node after local excision and subsequently died of metastatic disease. A total of 2 local-excision patients died of metastatic rectal cancer. Actuarial overall survival at 5 years was 86% in the local-excision group compared with 81% among mesorectal-excision patients (p = NS), and 85% in patients with a complete clinical response to chemoradiation followed by mesorectal excision by APR or LAR (p = NS). In an experience stimulated by patient refusal of APR, highly selected patients who responded well to conventional external-beam radiotherapy (CXRT) were selected to undergo local excision. Most of these patients had pathologic complete response. Local control and survival rates are comparable to those achieved with chemoradiation followed by mesorectal excision. This strategy should be prospectively studied in a group of patients with low rectal cancer who have no clinical evidence of tumor after chemoradiation.

603 poster The impact of reduction of irradiated small bowl volume by the use of belly board and distended bladder in preoperative and postoperative radiotherapy of rectal cancer patients

603 poster The impact of reduction of irradiated small bowl volume by the use of belly board and distended bladder in preoperative and postoperative radiotherapy of rectal cancer patients

The national practice for patients receiving radiation therapy (RT) for carcinoma of the rectum (RC): Comparative analysis of treatment from the 1992–1994 and 1988–1989 patterns of care studies by academic (AC) vs. non-academic (NAC) centers

This retrospective analysis was performed on the PCS 1988–89s1992–94 RC datasets to determine if significant differences exist in the treatment approaches among patients (pts) managed at AC vs. NAC centers. Two PCS national RC surveys were conducted using a 2-stage stratified sampling technique. Information was collected on 406 pts (weighted sample size=11,846)s515 pts (21,676) with RC who received adjuvant pelvic RT at 69 and 57 facilities within the ’88–89s’92–94 survey periods, respectively. 12% of pts were treated at AC in both surveys. AC were defined as an NCI-comprehensive cancer center (CCC) or had 2 or more radiation oncology residents in the ’88–89 PCS, and as a CCC or primary teaching hospital of a medical school in ’92–94. Pts were staged according to 1988 AJCC TNM criteria. Eligibility criteriasstatistical methodology per SUDAAN software, to accurately reflect PCS sampling technique, has been previously described. For comparisons within groups (i.e. AC ’88–89 vs. AC ’92–94) or between groups (i.e. AC vs. NAC), tests for associations were performed using Pearson chi-square statistics. In treatment comparisons between ACsNAC for all pts from both surveys, AC were significantly more likely to use preop chemoradiation (CRT) [22% vs. 7%, p < 0.0001], while NAC displayed a preference for postop CRT (52% vs. 41%, p = 0.0003). AC were significantly more likely to use chemotherapy (CT) [71% vs. 63%, p = 0.002], concurrent CRT with 5-FU (93% vs. 78%, p < 0.0001),sinfusional 5-FU (54% vs. 36%, p = 0.0001). There was a significant increase in the use of bowel-sparing RT techniques at AC (prone position, belly board, 3-field plans, > 6 MV energy, small bowel contrast; all p values < 0.01). Surgical procedure types were similar amongst both groups. Comparisons between survey periods (’88–89 vs. ’92–94) demonstrated a significant decline in the use of RT without CT, most notably at AC (preop RT 13% vs. 2%, p < 0.0001; postop RT 45% vs. 8%, p < 0.0001) in ’88–89 vs. ’92–94 respectively. The use of preop CRT significantly increased (4% ’88–89 vs. 32% ’92–94, p < 0.0001) in AC, with an increase in the use of postop CRT at NAC (41% ’88–89 vs. 58% ’92–94, p < 0.0001). A dramatic change in the role of CT occurred, with a marked increase in the use of any CT (39% ’88–89 vs. 89% ’92–94, p < 0.0001) in AC, and a significant increase in the use of concurrent CRT with 5-FU (54% vs. 96%, p < 0.0001) at NAC. Surgical procedures also changed, as local excision rates were significantly increased at AC over the survey periods (4% ’88–89 vs. 19% ’92–94, p = 0.0009). Additionally, a significant increase in the use of bowel-sparing RT techniques was demonstrated between survey periods for both AC and NAC (prone position, 3-field plans, daily treatment of all fields, belly board; all p values < 0.01). Interestingly, the proportion of pts receiving a total dose (TD) < 54 Gy increased in AC (71% vs. 81%, p = 0.005), while the TD > 54 Gy increased (20% vs. 31%, p < 0.0001) at NAC. Treatment center comparisons from these two PCS RC datasets suggest: 1) only AC have significantly endorsed CT and preoperative CRT-based strategies over the survey periods. This increase in use of CRT strategies may have limited the ability for North American cooperative groups (NSABP R-03, RTOG-9401/INT-0147) to successfully define the optimal CRTssurgery sequence for T3/4 and/or N+ RC; 2) Sphincter-sparing local excision procedures were significantly increased at only AC; 3) AC > NAC have significantly increased the use of bowel-sparing RT planning and delivery techniques; however, 4) delivery of > 54 Gy RT was more common at NAC. [Supported by NCI Grant CA 65435]

Dose-volume histogram evaluation of prone and supine patient position in external beam radiotherapy for cervical and endometrial cancer

Background and purpose: To evaluate the influence of patient positioning on dose-volume histograms of organs at risk in external beam radiotherapy for cervical and endometrial cancer.Materials and methods: In 20 patients scheduled for definitive (7) or postoperative (13) external beam radiotherapy of the pelvis treatment planning CT scans were performed in supine and prone (belly board) positions. After volume definition of target and organs at risk treatment plans were calculated applying the four-field box technique. The dose-volume histograms of organs at risk were compared.Results: Radiotherapy in prone position causes a reduction of the bladder portion (mean 15%, p<0.001) and an increase of the rectum portion (mean 11%, p<0.001) within the 90% isodose. A reduction of the bowel portion could only be observed in postoperatively treated patients (mean 13%, p<0.001). In definitive radiotherapy the target volume increases in supine position (mean 7%, p=0.02) due to an anterior tumour/uterus movement, so that bowel portions within the 90% isodose are similar. The bladder filling correlates with a reduction of bladder and bowel (postoperatively treated patients) dose.Conclusions: External beam radiotherapy of the pelvis should be performed in prone position in postoperative patients because of best bowel protection. Considering the additional HDR brachytherapy rectum protection takes the highest priority in definitive treatment—the requirements are best met in supine position. An adequate bladder filling is important to reduce the irradiated bladder and bowel volumes.