A Prospective Study of IMRT Versus 3D-CRT for Post-Operative Cervical Cancer Patients.

Abstract

The use of intensity-modulated radiation therapy (IMRT) in postoperative cervical cancer is on the rise, yet there is still some controversy to adopt adjuvant IMRT as standard practice. The purpose of this study is to compare the difference between IMRT and three dimensional conformal radiation therapy (3D-CRT) especially in quality of life for pelvic radiation of postoperative treatment with cervical cancer. A total of 398 patients were enrolled from Oct 2015 to Oct 2017. They were selected randomly into two groups: IMRT group (n=190) and 3D-CRT group (n=208). Each patient received a prescribed dose of 45Gy/25F. Radiation dosimetry, the grade 2-4 in GI and GU; the score from functional assessment of cancer therapy scale-cervix (FACT-CX) scale and expanded prostate cancer index composite for clinical practice (EPIC-CP) scale were compared. (1) There was no significant difference on age, culture level, family economic condition and ratio of radiochemotherapy in two groups (P>0.05). (2) Dosimetric comparison: IMRT plans had a significant better conformity index (CI) of PTV compared with 3D-CRT (P<0.05). Compared with 3D-CRT plans , V40 of the small bowel, rectum, bladder, V20 and V10 of bone marrow were all significantly reduced (P<0.05). (3) The incidence of acute grade 2-3 gastriontestinal reaction was significantly high for 3D-CRT group versus the IMRT group(24.0%,15.8%; P=0.04). The incidence of acute grade 2-3 urinary toxicity was high for 3D-CRT group versus the IMRT group(25.5%,17.9%),but has no statistically difference P=0.07). (4) Quality of life scale: FACT-Cx score were 84.8±16.3 and 71.2±17.9 before and after radiation therapy in 3D-CRT group, 81.8±15.5 and 76.4±14.4 in IMRT group. FACT-Cx score was decreased significantly from beginning of radiation in 3D-CRT group ,it was reached 12.3±4.5,but it was only 5.1±2.3 in IMRT group(t=15.530, P=0.000). EPIC-CP scale score: EPIC-CP score were 15.4 ± 6.2 and 21.7±7.1 before and after radiation therapy in 3D-CRT group, 15.6 ± 6.9 and 18.4±7.2 in IMRT group. EPIC-CP score was increased significantly from beginning of radiation in 3D-CRT group ,it was reached 6.6±4.1,but it was only 3.1±4.2 in IMRT group(t=5.500, P=0.000). IMRT has shown a dosimetric advantage and also provided good quality of life for the postoperative patients with cervical cancer compared to 3D-CRT. Long term follow up will be needed to determine late toxicity and DFS/OS.