A randomized study of intensity-modulated radiation therapy versus three dimensional conformal radiation therapy for pelvic radiation in patients of post-operative treatment with gynecologic malignant tumor / 中华妇产科杂志

ABSTRACT

Objective To study the difference between intensity-modulated radiation therapy (IMRT) and three dimensional conformal radiation therapy (3D-CRT) for pelvic radiation of post-operative treatment with gynecologic malignant tumor. Methods A prospective investigation study was conducted on 183 patients of post-operative patients with whole pelvic radiation therapy of cervical cancer or endometrial cancer in Zhejiang Cancer Hospital [IMRT group (n=85) and 3D-CRT group (n=98)] from Oct. 2015 to Oct. 2016. The two groups received same dose (45 Gy in 25 fractions). Comparison of two groups with radiation dosimetrythe score according to the Radiation Therapy Oncology Group (RTOG) acute radiation injury grading standards before and after radiotherapy reaction, 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 also analyzed. Results (1) There were no significant effect with age, culture level, family economic condition and ratio of radiochemotherapy between two groups (all P>0.05). (2) Dosimetric comparison for IMRT vs 3D-CRTthe average dose of planning target volume (PTV) decreased(46.1 ± 0.4) vs(46.4 ± 0.5)Gy, V45 dose percentage increased(95.2 ± 1.0)%vs (93.3 ± 2.0)%, intestinal bag dose of V40 decreased(24.4 ± 6.8)%vs (36.5 ± 15.9)%, rectal V40 dose percentage decreased(73.9 ± 12.3)%vs (85.4 ± 8.4)%, and lower rectal V45 dose percentage(32.8 ± 13.4)%vs (71.5 ± 13.7)%, bladder V40 dose percentage decreased(55.5 ± 13.0)% vs (84.4 ± 13.0)%. Bone marrow V20 lower(67.9 ± 5.4)% vs (79.5 ± 6.6)%, V10 lower(82.1 ± 6.0)% vs (86.3 ± 6.6)%; there were significant differences (all P0.05). (3) Acute radiation injury classification for IMRT vs 3D-CRTbig or small intestineⅡ-Ⅲreaction [13%(11/85) vs 24% (24/98); χ2=3.925, P=0.048], there was significant difference. Bladder Ⅲ reaction [19% (16/85) vs 26% (25/98); χ2=1.171, P=0.279], there was no significant difference. Radiochemotherapy of bone marrow suppressionⅢ-Ⅳreaction (14/20), the incidence rate [26%(14/54) vs 31%(20/65);χ2=0.339, P=0.562], the difference was not statistically significant. (4) Quality of life scale by FACT-Cx scale in IMRT vs 3D-CRTthere were no significant difference before radiotherapy (82 ± 16 vs 85 ± 16;t=1.279, P=0.203), while there was significant difference after radiotherapy (76 ± 14 vs 71 ± 18;t=-2.160, P=0.032). EPIC-CP scale scorebefore radiotherapy they were (16±7 vs 15±6;t=-0.174, P=0.862) ,but after radiotherapy (18±7 vs 22± 7; t=3.158, P=0.002), there was significant difference between them. Before and after radiotherapy, the increased EPIC-CP scale of the IMRT group vs 3D-CRT group were 3 ± 4 and 6 ± 4, the 3D-CRT group was significantly higher, the difference was statistically significant (t=5.500, P=0.000). Conclusion IMRT has shown that there are a significant benefit for the post-operative patients with cervical cancer and endometrial cancer compared to 3D-CRT.