• Radiation Oncology Journal
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• v.26 no.4
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• pp.271-279
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• 2008

Purpose: To evaluate the efficacy of a belly-board device (BBD) in reducing the volume of small bowel during four-field pelvic irradiation. Materials and Methods: Twenty-two cancer patients (14 uterine cervical cancer, 6 rectal cancer, and 2 endometrial cancer) scheduled to receive pelvic irradiation were selected for this study. Two sets of CT images were taken with and without the belly-board device using the Siemens 16 channel CT scanner. All patients were set in the prone position. The CT images were transferred to a treatment planning system for dose calculation and volume measurements. The external surfaces of small bowel and the bladder were contoured on all CT scans and the 4-pelvic fields were added. The dose-volume-histogram of the bladder and small bowel, with and without the BBD, were plotted and analyzed. Results: In all patients, the total small bowel volume included in the irradiated fields was reduced when the BBD was used. The mean volume reduction was 35% (range, $1{\sim}79%$) and was statistically significant (p<0.001). The reduction in small bowel volume receiving $10{\sim}100%$ of the prescribed dose was statistically significant when the BBD was used in all cases. Almost no change in the total bladder volume involved was observed in the field (<8 cc, p=0.762). However, the bladder volume receiving 90% of the prescribed dose was 100% in 15/22 patients (68%) and $90{\sim}99%$ in 7/22 patients (32%) with the BBD. In comparison, the bladder volume receiving 90% of the prescribed dose was 100% in 10/22 patients (45%), $90{\sim}99%$ in 7/22 patients (32%), and $80{\sim}89%$ in 5/22 patients (23%) without the BBD. When the BBD was used, an increase in the bladder volume receiving a high dose range was observed Conclusion: This study shows that the use of a BBD for the treatment of cancer in the pelvic area significantly improves small bowel sparing. However, since the BBD pushed the bladder into the treatment field, the bladder volume receiving the high dose could increase. Therefore it is recommended to be considerate in using the BBD when bladder damage is of concern.

• Progress in Medical Physics
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• v.18 no.4
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• pp.202-208
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• 2007

Various techniques were evaluated to determine the best method for reducing small bowel involvement in pelvic irradiation. Fourteen patients receiving radiation in pelvic area were enrolled for this study. Five sets of small bowel images were obtained. Patients were positioned on a simulation couch with full bladder in prone and supine positions and 2 sets of images were taken. Then they were asked to empty their bladder and 2 sets of images were taken in prone and supine positions. A belly board device (BBD) was placed and one set of images was obtained. Using a software, the area of small bowel inside treatment field was contoured, measured, and analyzed. In both full and empty bladder cases, small bowel area reduction was observed in prone position as compared to supine position. Especially statistically significant reduction is noted in lateral film. An average decreases of 13% in PA and 26% in lateral direction were noted with bladder distention as compared to empty bladder. With the use of BBD for empty bladder, a significant reduction of $62.8{\pm}27.1%$ and $63.1{\pm}32.9%$ in PA and lateral directions were observed as compared to without BBD in prone position, respectively. In conclusion, the best sparing of small bowel concerning the area included in the treatment fields was achieved with BBD in prone position with empty bladder. However, further reduction is expected if the bladder was filled fully because the analysed data with empty vs full bladder study shows increased sparing of small bowel with distended bladder.

• Radiation Oncology Journal
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• v.28 no.4
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• pp.231-237
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• 2010

Purpose: We investigated the effect of location changes in the inferior border of the belly board (BB) aperture by adding a bladder compression device (BCD). Materials and Methods: We respectively reviewed data from 10 rectal cancer patients with a median age 64 years (range, 45~75) and who underwent computed tomography (CT) simulation with the use of BB to receive pelvic radiotherapy between May and September 2010. A CT simulation was again performed with the addition of BCD since small bowel (SB) within the irradiated volume limited boost irradiation of 5.4 Gy using the cone down technique after 45 Gy. The addition of BCD made the inferior border of BB move from symphysis pubis to the lumbosacral junction (LSJ). Results: Following the addition of BCD, the irradiated volumes of SB and the abdominopelvic cavity (APC) significantly decreased ($174.3{\pm}89.5mL$ vs. $373.3{\pm}145.0mL$, p=0.001, $1282.6{\pm}218.7mL$ vs. $1,571.9{\pm}158mL$, p<0.001, respectively). Bladder volume within the treated volume increased with BCD ($222.9{\pm}117.9mL$ vs. $153.7{\pm}95.5mL$, p<0.001). The ratio of irradiated bladder volume to APC volume with BCD ($33.5{\pm}14.7%$) increased considerably compared to patients without a BCD ($27.5{\pm}13.1%$) (p<0.001), and the ratio of irradiated SB to APC volume decreased significantly with BCD ($13.9{\pm}7.6%$ vs. $24.2{\pm}10.2%$, p<0.001). The ratios of the irradiated SB volume and irradiated bladder volume to APC volume negatively correlated (p=0.001). Conclusion: This study demonstrated that the addition of BCD, which made the inferior border of BB move up to the LSJ, increased the ratio of the bladder to APC volume and as a result, decreased the irradiated volume of SB.

• Journal of radiological science and technology
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• v.36 no.1
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• pp.39-47
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• 2013

For radiotherapy in rectal cancer patients treated with small bowel displacement device (SBDD) and belly board, We will suggest new indication of using SBDD depending on obesity index by analyzing correlation between obesity and irradiated small bowel volume. In this study, We reviewed 29 rectal cancer patients who received pelvic radiation therapy with belly board and SBDD from January to April in 2012. We only analyzed those patients treated with three-field technique (PA and both LAT) on 45 Gy (1.8 Gy/fx). We measured patients' height, weight, body mass index (BMI), waist-hip ratio (WHR) and divided BMI into two groups.(${\geq}23$:BMI=group1, <23:BMI=group2) We performed a statistical analysis to evaluate correlation between total volume of bladder($TV_{bladder}$), obesity index and high dose volume of small bowel (small bowel volume irradiated at 90% of prescribed dose, $HDV_{sb}$), low dose volume of small bowel (small bowel volume irradiated at 33% of prescribed dose, $LDV_{sb}$). The result shows, gender, WHR and status of pre operative or post operative do not greatly affect $HDV_{sb}$ and $LDV_{sb}$. Statistical result shows, there are significant correlation between $HDV_{sb}$ and BMI (p<0.04), $HDV_{sb}$ and $TV_{bladder}$ (p<0.01), $LDV_{sb}$ and $TV_{bladder}$ (p<0.01). BMI seems to correlate with $HDV_{sb}$ but does not with $LDV_{sb}$ (p>0.05). There are negative correlation between $HDV_{sb}$ and BMI, $TV_{bladder}$ and $HDV_{sb}$, $TV_{bladder}$ and $LDV_{sb}$. Especially, BMI group1 has more effective and negative correlation with $HDV_{sb}$ (p=0.027) than in BMI group2. In the case of BMI group 1, $TV_{bladder}$ has significant negative correlation with $HDV_{sb}$ and $LDV_{sb}$ (p<0.04). In conclusions, we confirmed that Using SBDD with belly board in BMI group1 could more effectively reduce irradiated small bowel volume in radiation therapy for rectal cancer. Therefore, We suggest using belly board with SBDD in order to reduce the small bowel toxicity in rectal radiotherapy, if patients' BMI is above 23.

• The Journal of Korean Society for Radiation Therapy
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• v.26 no.1
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• pp.37-42
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• 2014

Purpose : At the time of the pelvis cancer radiation treatment using the belly board, set-up error is large because of a prone position. In order to improve the reproducibility, we made Vac-lock type belly board. In this study, we attempt to validate its utility. Materials and Methods : We compared belly board and Vac-lock type belly board through the OBI. OBI was performed three times with entire course of treatment and the setup errors in the direction of X axis, Y axis, Z axis were recorded and calculated the distance from the isocenter. Results : X axis, Y axis, Z axis setup errors with existing belly board were 0.32 cm, 0.41 cm, 0.29 cm. The setup errors with the vac-lock type belly board were 0.12 cm, 0.19 cm, 0.17 cm. Further, errors of 0~0.29 cm were increased from 48% to 83% when using VLT belly board. Error of 0.5 cm or more was reduced from 21% to 2%. Conclusion : Vac-lock type belly board is able to maintain the efficacy of existing and create to match the characteristics of the patient. Therefore We think that vac-lock type belly board is very useful in pelvic cancer patients.