PURPOSE: A direct relationship between the volume of small bowel irradiated and the degree of acute small bowel toxicity experienced during concurrent 5-fluorouracil (5-FU)-based chemoradiotherapy for rectal carcinoma is well recognized but poorly quantified. This study uses three-dimensional treatment-planning tools to more precisely quantify this dose-volume relationship. METHODS AND MATERIALS: Forty patients receiving concurrent 5-FU-based chemotherapy and pelvic irradiation for rectal carcinoma had treatment-planning CT scans with small bowel contrast. A median isocentric dose of 50.4 Gy was delivered using a posterior-anterior and opposed lateral field arrangement. Bowel exclusion techniques were routinely used, including prone treatment position on a vacuum bag cradle to allow anterior displacement of the abdominal contents and bladder distension. Individual loops of small bowel were contoured on each slice of the planning CT scan, and a small bowel dose-volume histogram was generated for the initial pelvis field receiving 45 Gy. The volume of small bowel receiving each dose between 5 and 40 Gy was recorded at 5-Gy intervals. RESULTS: Ten patients (25%) experienced Common Toxicity Criteria Grade 3+ acute small bowel toxicity. A highly statistically significant association between the development of Grade 3+ acute small bowel toxicity and the volume of small bowel irradiated was found at each dose level. Specific dose-volume threshold levels were found, below which no Grade 3+ toxicity occurred and above which 50-60% of patients developed Grade 3+ toxicity. The volume of small bowel receiving at least 15 Gy (V15) was strongly associated with the degree of toxicity. Univariate analysis of patient and treatment-related factors revealed no other significant predictors of severe toxicity. CONCLUSIONS: A strong dose-volume relationship exists for the development of Grade 3+ acute small bowel toxicity in patients receiving concurrent 5-FU-based chemoradiotherapy for rectal carcinoma.
PURPOSE: A direct relationship between the volume of small bowel irradiated and the degree of acute small bowel toxicity experienced during concurrent 5-fluorouracil (5-FU)-based chemoradiotherapy for rectal carcinoma is well recognized but poorly quantified. This study uses three-dimensional treatment-planning tools to more precisely quantify this dose-volume relationship. METHODS AND MATERIALS: Forty patients receiving concurrent 5-FU-based chemotherapy and pelvic irradiation for rectal carcinoma had treatment-planning CT scans with small bowel contrast. A median isocentric dose of 50.4 Gy was delivered using a posterior-anterior and opposed lateral field arrangement. Bowel exclusion techniques were routinely used, including prone treatment position on a vacuum bag cradle to allow anterior displacement of the abdominal contents and bladder distension. Individual loops of small bowel were contoured on each slice of the planning CT scan, and a small bowel dose-volume histogram was generated for the initial pelvis field receiving 45 Gy. The volume of small bowel receiving each dose between 5 and 40 Gy was recorded at 5-Gy intervals. RESULTS: Ten patients (25%) experienced Common Toxicity Criteria Grade 3+ acute small bowel toxicity. A highly statistically significant association between the development of Grade 3+ acute small bowel toxicity and the volume of small bowel irradiated was found at each dose level. Specific dose-volume threshold levels were found, below which no Grade 3+ toxicity occurred and above which 50-60% of patients developed Grade 3+ toxicity. The volume of small bowel receiving at least 15 Gy (V15) was strongly associated with the degree of toxicity. Univariate analysis of patient and treatment-related factors revealed no other significant predictors of severe toxicity. CONCLUSIONS: A strong dose-volume relationship exists for the development of Grade 3+ acute small bowel toxicity in patients receiving concurrent 5-FU-based chemoradiotherapy for rectal carcinoma.
Authors: Ted C Ling; Jerry M Slater; Rachel Mifflin; Prashanth Nookala; Roger Grove; Anh M Ly; Baldev Patyal; Jerry D Slater; Gary Y Yang Journal: J Gastrointest Oncol Date: 2015-04
Authors: Sergiu Scobioala; Christopher Kittel; Philipp Niermann; Heidi Wolters; Katharina Helene Susek; Uwe Haverkamp; Hans Theodor Eich Journal: Strahlenther Onkol Date: 2018-05-31 Impact factor: 3.621
Authors: Joan Manel Gasent Blesa; Javier Garde Noguera; Juan Bautista Laforga Canales; Vicent Giner Bosch; Antonio Alberola; Miguel Soler Tortosa; Miguel Peris Godoy; Jose Luis Sanchez; Mariano Provencio Pulla; Vicente Alberola Candel Journal: J Gastrointest Cancer Date: 2012-12