Correlation between tumor regression grade and rectal volume in neoadjuvant concurrent chemoradiotherapy for rectal cancer

다국어 초록 (Multilingual Abstract)

Purpose To determine whether large rectal volume on planning computed tomography (CT) results in lower tumor regression grade (TRG) after neoadjuvant concurrent chemoradiotherapy (CCRT) in rectal cancer patients.
Materials and Methods We reviewed medical records of 113 patients treated with surgery following neoadjuvant CCRT for rectal cancer between January and December 2012. Rectal volume was contoured on axial images in which gross tumor volume was included. Average axial rectal area (ARA) was defined as rectal volume divided by longitudinal tumor length. The impact of rectal volume and ARA on TRG was assessed.
Results Average rectal volume and ARA were 11.3 mL and 2.9 cm². After completion of neoadjuvant CCRT in 113 patients, pathologic results revealed total regression (TRG 4) in 28 patients (25%), good regression (TRG 3) in 25 patients (22%), moderate regression (TRG 2) in 34 patients (30%), minor regression (TRG 1) in 24 patients (21%), and no regression (TRG0) in 2 patients (2%). No difference of rectal volume and ARA was found between each TRG groups. Linear correlation existed between rectal volume and TRG (p = 0.036) but not between ARA and TRG (p = 0.058).
Conclusion Rectal volume on planning CT has no significance on TRG in patients receiving neoadjuvant CCRT for rectal cancer. These results indicate that maintaining minimal rectal volume before each treatment may not be necessary.

참고문헌 (Reference)

1 Fokas E, "Tumor regression grading after preoperative chemoradiotherapy for locally advanced rectal carcinoma revisited: updated results of the CAO/ARO/ AIO-94 trial" 32 : 1554-1562, 2014

2 Klint A, "Trends in survival of patients diagnosed with cancer of the digestive organs in the Nordic countries 1964-2003 followed up to the end of 2006" 49 : 578-607, 2006

3 Smitsmans MH, "The influence of a dietary protocol on cone beam CT-guided radiotherapy for prostate cancer patients" 71 : 1279-1286, 2008

4 Folkesson J, "Swedish Rectal Cancer Trial: long lasting benefits from radiotherapy on survival and local recurrence rate" 23 : 5644-5650, 2005

5 Teh BS, "Rectal wall sparing by dosimetric effect of rectal balloon used during intensity-modulated radiation therapy (IMRT) for prostate cancer" 30 : 25-30, 2005

6 Moore HG, "Rate of pathologic complete response with increased interval between preoperative combined modality therapy and rectal cancer resection" 47 : 279-286, 2004

7 Appelt AL, "Radiation dose-response model for locally advanced rectal cancer after preoperative chemoradiation therapy" 85 : 74-80, 2013

8 Chong I, "Quantification of organ motion during chemoradiotherapy of rectal cancer using cone-beam computed tomography" 81 : e431-e438, 2011

9 Dhadda AS, "Prognostic importance of Mandard tumour regression grade following pre-operative chemo/radiotherapy for locally advanced rectal cancer" 47 : 1138-1145, 2011

10 Janjan NA, "Prognostic implications of response to preoperative infusional chemoradiation in locally advanced rectal cancer" 51 : 153-160, 1999

11 Ki Y, "Probiotics for rectal volume variation during radiation therapy for prostate cancer" 87 : 646-650, 2013

12 Sauer R, "Preoperative versus postoperative chemoradiotherapy for rectal cancer" 351 : 1731-1740, 2004

13 Sauer R, "Preoperative versus postoperative chemoradiotherapy for locally advanced rectal cancer: results of the German CAO/ARO/AIO-94 randomized phase III trial after a median follow-up of 11 years" 30 : 1926-1933, 2012

14 Berger C, "Preoperative radiotherapy (RT) for rectal cancer: predictive factors of tumor downstaging and residual tumor cell density (RTCD): prognostic implications" 37 : 619-627, 1997

15 Chan AK, "Posttreatment TNM staging is a prognostic indicator of survival and recurrence in tethered or fixed rectal carcinoma after preoperative chemotherapy and radiotherapy" 61 : 665-677, 2005

16 Dworak O, "Pathological features of rectal cancer after preoperative radiochemotherapy" 12 : 19-23, 1997

17 de Crevoisier R, "Increased risk of biochemical and local failure in patients with distended rectum on the planning CT for prostate cancer radiotherapy" 62 : 965-973, 2005

18 Gerard JP, "Improved sphincter preservation in low rectal cancer with high-dose preoperative radiotherapy: the lyon R96-02 randomized trial" 22 : 2404-2409, 2004

19 Stasi M, "Emptying the rectum before treatment delivery limits the variations of rectal dose-volume parameters during 3DCRT of prostate cancer" 80 : 363-370, 2006

20 정규원, "Cancer Statistics in Korea: Incidence, Mortality, Survival and Prevalence in 2010" 대한암학회 45 (45): 1-14, 2013

21 Ostwald PM, "Assessment of mucosal underdosing in larynx irradiation" 36 : 181-187, 1996

22 Niroomand-Rad A, "Air cavity effects on the radiation dose to the larynx using Co-60, 6 MV, and 10 MV photon beams" 29 : 1139-1146, 1994

23 Li XA, "A systematic evaluation of air cavity dose perturbation in megavoltage x-ray beams" 27 : 1011-1017, 2000