scholarly journals Evaluation of Small Bowel Motion and Feasibility of using the Peritoneal Space to Replace Bowel Loops for Dose Constraints during Intensity-Modulated Radiotherapy for Rectal Cancer

2020 ◽  
Author(s):  
Siyuan Li ◽  
Yanping Gong ◽  
Yongqiang Yang ◽  
Qi Guo ◽  
Jianjun Qian ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Small Bowel ◽  
Intensity Modulated Radiotherapy ◽  
Ct Scans ◽  
Dose Volume ◽  
Dose Constraint ◽  
Bowel Motion ◽  
Peritoneal Space ◽  
Pre Treatment ◽  
Constraint Method

Abstract Background: The goal of this study was to assess small bowel motion and explore the feasibility of using peritoneal space (PS) to replace bowel loops (BL) via the dose constraint method to spare the small bowel during intensity-modulated radiotherapy (IMRT) for rectal cancer. Methods: A total of 24 patients with rectal cancer who underwent adjuvant or neoadjuvant radiotherapy were selected. Weekly repeat CT scans from pre-treatment to the fourth week of treatment were acquired and defined as Plan, 1W, 2W, 3W, and 4W. The 4 weekly CT scans were co-registered to the Plan CT, BL and PS contours were delineated in all of the scans, an IMRT plan was designed on Plan CT using PS constraint method, and then copied to the 4 weekly CT scans. The dose-volume, normal tissue complication probability (NTCP) of the small bowel and their variations during treatment were evaluated. Results: Overall, 109 sets of CT scans from 24 patients were acquired, and 109 plans were designed and copied. The BL and PS volumes were 250.3 cc and 1339.3 cc. The V15 of BL and PS based plan of pre-treatment were 182.6 cc and 919.0 cc, the shift% of them were 28.9% and 11.3% during treatment (p=0.000), which was less in the prone position than in the supine position (25.2% vs 32.1%, p =0.000; 9.9% vs 14.9%, p=0.000). The NTCPC and NTCPA based plan of pre-treatment were 2.0% and 59.2%, the shift% during treatment were 46.1% and 14.0% respectively. Majority of BL’s Dmax and V15 were meet the safety standard during treatment using PS dose limit method except 3 times (3/109) of V15 and 5 times of Dmax (5/109).Conclusions: This study indicated that small bowel motion may lead to uncertainties in its dose volume and NTCP evaluation during IMRT for rectal cancer. The BL movements were significantly greater than PS, and the prone position was significantly less than the supine position. It is feasibility of using PS to replace BL to spare the small bowel, V15<830 cc is the dose constraint standard.

scholarly journals Evaluation of Small Bowel Motion and Feasibility of using the Peritoneal Space to Replace Bowel Loops for Dose Constraints during Intensity-Modulated Radiotherapy for Rectal Cancer

2020 ◽  
Author(s):  
Siyuan Li ◽  
Yanping Gong ◽  
Yongqiang Yang ◽  
Qi Guo ◽  
Jianjun Qian ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Small Bowel ◽  
Supine Position ◽  
Intensity Modulated Radiotherapy ◽  
Ct Scans ◽  
Intensity Modulated ◽  
Dose Volume ◽  
Dose Constraint ◽  
Bowel Motion ◽  
Peritoneal Space

Abstract Background The goal of this study was to assess small bowel motion and explore the feasibility of using peritoneal space (PS) to replace bowel loops (BL) via the dose constraint method to spare the small bowel during intensity-modulated radiotherapy (IMRT) for rectal cancer. Methods A total of 24 patients with rectal cancer who underwent adjuvant radiotherapy were selected. Weekly repeat CT scans from pre-treatment to the fourth week of treatment were acquired and defined as Plan, 1W, 2W, 3W, and 4W. BL and PS contours were delineated in all of the scans. Two IMRT plans called P PS and P BL were designed on Plan CT using two dose PS and BL constraint methods, respectively, and then copied to CT 1~4W. The shift%, dose volume, and NTCP of the small bowel in P PS and P BL during treatment were evaluated. Results Overall, 109 sets of CT scans from 24 patients were acquired, and 218 plans were designed and copied. The PS and BL volumes were 1339.28 cc and 250.27 cc. The BL and PS shift% V 15 was 28.48% and 11.79% ( p =0.000), which was less in the prone position than in the supine position (25.24% vs 32.10%, p =0.000; 9.9% vs 14.85%, p =0.000). On all of the CT scans, most P PS small bowel dose volumes were less than from P BL . V 15 was 170.07 cc vs 178.58 cc ( p =0.000), and they had a significant correlation. The NTCP of chronic and acute side effects from P PS was significantly less than P BL (2.80% vs 3.00%, p =0.018; 57.32% vs 58.64%, p =0.000). Conclusions This study indicated that small bowel motion may lead to uncertainties in its dose volume and NTCP evaluation during IMRT for rectal cancer. The BL movements were significantly greater than PS, and the prone position was significantly less than the supine position. Using PS instead of BL can spare the small bowel. V 15 <830 cc is the dose constraint standard.

scholarly journals Evaluation of Small Bowel Motion and Feasibility of using the Peritoneal Space to Replace Bowel Loops for Dose Constraints during Intensity-Modulated Radiotherapy for Rectal Cancer

2020 ◽  
Author(s):  
Siyuan Li ◽  
Yanping Gong ◽  
Yongqiang Yang ◽  
Qi Guo ◽  
Jianjun Qian ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Small Bowel ◽  
Supine Position ◽  
Intensity Modulated Radiotherapy ◽  
Ct Scans ◽  
Intensity Modulated ◽  
Dose Volume ◽  
Dose Constraint ◽  
Bowel Motion ◽  
Peritoneal Space

Abstract Background The goal of this study was to assess small bowel motion and explore the feasibility of using peritoneal space (PS) to replace bowel loops (BL) via the dose constraint method to spare the small bowel during intensity-modulated radiotherapy (IMRT) for rectal cancer. Methods A total of 24 patients with rectal cancer who underwent adjuvant radiotherapy were selected. Weekly repeat CT scans from pre-treatment to the fourth week of treatment were acquired and defined as Plan, 1W, 2W, 3W, and 4W. BL and PS contours were delineated in all of the scans. Two IMRT plans called PPS and PBL were designed on Plan CT using two dose PS and BL constraint methods, respectively, and then copied to CT 1 ~ 4W. The shift%, dose volume, and NTCP of the small bowel in PPS and PBL during treatment were evaluated. Results Overall, 109 sets of CT scans from 24 patients were acquired, and 218 plans were designed and copied. The PS and BL volumes were 1339.28 cc and 250.27 cc. The BL and PS shift% V15 was 28.48% and 11.79% (p = 0.000), which was less in the prone position than in the supine position (25.24% vs 32.10%, p = 0.000; 9.9% vs 14.85%, p = 0.000). On all of the CT scans, most PPS small bowel dose volumes were less than from PBL. V15 was 170.07 cc vs 178.58 cc (p = 0.000), and they had a significant correlation. The NTCP of chronic and acute side effects from PPS was significantly less than PBL (2.80% vs 3.00%, p = 0.018; 57.32% vs 58.64%, p = 0.000). Conclusions This study indicated that small bowel motion may lead to uncertainties in its dose volume and NTCP evaluation during IMRT for rectal cancer. The BL movements were significantly greater than PS, and the prone position was significantly less than the supine position. Using PS instead of BL can spare the small bowel. V15 < 830 cc is the dose constraint standard.

Predicting acute small-bowel toxicity in patients with rectal cancer treated with neoadjuvant chemoradiation: A comparison of peritoneal space versus small-bowel loop contouring techniques.

2012 ◽  
Vol 30 (4_suppl) ◽  
pp. 673-673
Author(s):  
Robyn Banerjee ◽  
Santam Chakraborty ◽  
Ian Nygren ◽  
Richie Sinha
Keyword(s):  
Rectal Cancer ◽  
Logistic Regression ◽  
Small Bowel ◽  
Cancer Patients ◽  
Locally Advanced ◽  
Neoadjuvant Chemoradiotherapy ◽  
Characteristic Analysis ◽  
Dose Volume ◽  
Peritoneal Space ◽  
Grade 3

673 Background: In lieu of contouring individual small bowel loops, the peritoneal space (PS) has been suggested as a possible surrogate volume for predicting small bowel toxicity. A dose-volume relationship for the PS has not been firmly established. The aim of this study was to determine whether contours of the PS better predict significant acute small bowel toxicity in neoadjuvant rectal cancer patients when compared with contours of individual small bowel loops. Methods: A standardized contouring method was developed for the PS and retrospectively applied to the radiation treatment plans of sixty-seven patients treated with neoadjuvant chemoradiotherapy for rectal cancer. All patients had locally advanced disease, no evidence of metastases, and received concurrent radiation and infusional 5-Fluorourocil chemotherapy. Dose-volume histogram (DVH) data was extracted and analyzed against patient toxicity. Receiver operating characteristic analysis and logistic regression was carried out for both contouring methods. Results: Grade ≥ 3 small bowel toxicity occurred in 16% (11/67) of patients. Volumes of the contoured small bowel loops correlated with grade ≥ 3 toxicity at each 5 Gray (Gy) dose level from 5 to 45 Gy, with the greatest area under the curve (AUC) measuring .964 (p=.000) associated with the volume receiving at least 25 Gy (V25). Volumes of the contoured PS predicted toxicity from 5 to 40 Gy, with the greatest AUC also at the V25 and measuring .896 (p=.000). Logistic regression analysis demonstrated a less than 15% risk of acute grade ≥ 3 toxicity was associated with a V25 of 215 cc for the small bowel and 710 cc for the PS. Conclusions: DVH analysis of peritoneal space volumes predicts grade ≥ 3 small bowel toxicity in neoadjuvant rectal cancer patients, suggesting the peritoneal space is a reasonable surrogate for contouring individual small bowel loops. However, contouring individual small bowel loops is a more sensitive method for predicting toxicity at each dose increment. For both contouring methods, the greatest sensitivity for predicting toxicity was associated with the volume receiving at least 25 Gy (V25).

Predictors of gastrointestinal toxicity during pelvic radiotherapy.

2013 ◽  
Vol 31 (4_suppl) ◽  
pp. 472-472
Author(s):  
T. Jonathan Yang ◽  
Jung Hun Oh ◽  
Christina Son ◽  
Aditya Apte ◽  
Joseph O. Deasy ◽  
...  
Keyword(s):  
Rectal Cancer ◽  
Anal Canal ◽  
Treatment Plan ◽  
Univariate Analysis ◽  
Intensity Modulated Radiotherapy ◽  
Female Gender ◽  
Relative Reduction ◽  
Pelvic Radiotherapy ◽  
Dose Volume ◽  
Gi Toxicity

472 Background: To identify clinical and dosimetric factors associated with acute gastrointestinal (GI) toxicities due to pelvic radiotherapy (PRT) in patients with rectal cancer. Methods: We analyzed 177 consecutive rectal cancer patients treated between 2007-2010. Clinical information including age, gender, stage, chemotherapy, and weekly proctitis and diarrhea grade (CTCAE 3.0) during PRT were obtained. The bowel, rectum, and anal canal were contoured on CT treatment planning images. Doses to GI structures were calculated using the original treatment plan, and dose-volume parameters were extracted for modeling using CERR software. Logistic regression models were used to test the association between GI toxicity grade and predictors. Results: The mean age was 59; 76 (43%) patients were women; 166 (94%) received concurrent 5-FU based chemotherapy. Over half (56%) were treated with intensity modulated radiotherapy (IMRT), 44% were treated with 3D conformal RT (3DCRT). Grade 2+ proctitis and diarrhea were seen in 57 (32%) and 44 (25%) patients, respectively. On univariate analysis, age inversely predicts for Grade 2+ proctitis (Rs=-0.22, p=0.009). 3DCRT (Rs=0.27, p=0.001) and female gender (Rs=0.28, p=0.0008) predict for Grade 2+ diarrhea. On multivariate analysis, the normal tissue complication model including volume of anal canal receiving >15Gy, anal canal minimal dose, and age was most predictive of Grade 2+ proctitis (AUC=0.67, Rs=0.25, p<0.001). The model including bowel volume receiving 45Gy, female gender, and use of 3DCRT was highly predictive of Grade 2+ diarrhea (AUC=0.76, Rs=0.35, p<0.001). Patients treated with IMRT had significantly less bowel volume receiving ≥ 45Gy compared to 3DCRT (V45Gy=10.9% vs. 21.7%, p<0.0001). Conclusions: In this analysis of a large cohort of patients receiving PRT for rectal cancer, we identified clinical and dosimetric predictors of acute GI toxicity. Younger patients and women have higher rates of acute Grade 2+ proctitis and diarrhea, respectively. IMRT resulted in a 50% relative reduction in bowel volume receiving 45Gy and a lower risk for clinically significant diarrhea. Dose-volume constraints using these parameters should be considered, particularly in higher risk patients.

Evaluating QUANTEC Small Bowel Dose-Volume Guidelines for Rectal Cancer Patients Treated Using a Couch Top Inclined Belly Board

2014 ◽  
Vol 45 (3) ◽  
pp. 218-222
Author(s):  
Vijayananda Kundapur ◽  
Gavin Cranmer-Sargison ◽  
Haresh Vachhrajani ◽  
Eileen Park-Somers ◽  
Stefan Kriegler
Keyword(s):  
Rectal Cancer ◽  
Small Bowel ◽  
Cancer Patients ◽  
Dose Volume ◽  
Belly Board
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