Clinical Research On Intensity Modulated Radiation Therapy In Esophageal Cancer

Objective: To observe local control and survival rate in patients withesophageal cancer received intensity modulated radiation therapy (IMRT), toexplore the effect of related factors on them, and to provide reference forIMRT in the treatment of esophageal cancer.Methods: From April2006to April2012, a total of349cases ofesophageal cancer patients in accordance with the criterion wereretrospectively analyzed. The median age was65years old, including218(62.5%) male,131(37.5%) female; Squamous carcinoma342cases (97.9%),adenocarcinoma3(0.9%), adenosquamous carcinoma2(1.2%), sarcomatoidcarcinoma1(0.3%) and the small cell carcinoma1(0.3%) were involved; Theclinical stage Ⅰ was26(7.4%), stage II137(39.3%), stage Ⅲ183(52.4%)and stage Ⅳwas3(0.9%); The cases received radiotherapy only was169(48.4%), concurrent chemoradiotherapy121(34.7%), sequential chemoradio-therapy was59(16.9%); The number of cases received fractionated IMRT was222(63.6%), simultaneous addition was127(36.4%); The prescribed dose ofPTV was50~66Gy (median60Gy),1.8~2.2Gy/F,5F/W. The short-term effect,acute toxicity and1-,3-,5-year local control and survival rates were analyzed,and the effect of gender, age, tumor location, clinical stage, tumor length,tumor volume, radiation dose, lymph node metastasis, evaluation of short-termeffect and different treatment modality on local control rate and survival ratewere analyzed.Results: The short-term curative effect: the complete remission (CR) ratewas41.8%(146/349), the partial remission (PR) rate was55.3%(193/349),the non-remission (NR) was0.6%(2/349) and the total efficiency (CR+PR)was97.1%. For no esophageal barium meal and/or CT examination,8casescould not evaluate the short-term curative effect. The overall incidence of bone marrow suppression was68.8%(240/349), acute radiation pneumonitisoccurrence rate was25.5%(89/349), including50cases of grade I (14.4%),29cases of grade II (8.4%),8cases of grade III (2.3%) and2cases of grade IV(0.6%); The total occurrence rate of acute radiation esophagitis was71.3%(249/349), including71cases of grade I (20.5%),147cases of grade II(42.4%),28cases of grade III (8.1%) and3cases of grade IV (0.9%).1-,3-and5-year local control rates and overall survival rates were72.9%,61.2%,58.4%and66.5%,39.1%,24%, respectively, and the median survival timewas21months. A total of234dead patients died of local recurrence or notcontrol in97cases (41.5%), and58cases (24.8%) of distant metastasis. Thesubgroup analysis showed that:⑴The5-year local control rates in I, II, Ⅲ, IVstages had no significant difference (χ2=3.694, P=0.296), but5-year survivalrates had significant difference (χ2=10.121, P=0.018); Survival rates in I～IIstages were higher than that in III stage (χ2=4.667, P=0.031).⑵The1-,3-,5-year local control and survival rates among cervical, upper, middle andlower thoracic segments had no significant difference (χ2=4.013, P=0.260andχ2=5.993, P=0.112).⑶Patients were divided into＜5.0cm and≥5.0cmgroups, the1-,3-,5-year local control rates in＜5.0cm group were higherthose in≥5.0cm group (χ2=4.947, P=0.026), but1-,3-and5-year survivalrates had no significant difference (χ2=3.478, P=0.062);⑷According to themedian tumor volume, patients were divided into＜54.73cm3and≥54.73cm3groups,1-,3-,5-year local control and survival rates had significantdifference (χ2=5.316, P=0.021and χ2=15.104, P=0.000);⑸There had nosignificant difference about the1-,3-,5-year local control rates betweenlymph node metastasis group and without lymph node metastasis group(χ2=0.729, P=0.393), while1-,3-,5-year survival rates had significantdifference (χ2=8.562, P=0.003);⑹The1-,3-and5-year local control andsurvival rates among CR, PR and NR groups had significant difference(χ2=170.601, P=0.000and χ2=19.051, P=0.000);⑺The1-,3-,5-year localcontrol and survival rates had significant difference between dose＜60Gygroup and≥60Gy group (χ2=14.540, P=0.000and χ2=25.692, P=0.000); ⑻C ompared with those in the SIB-IMRT group the1-,3-,5-year survivalrates had significant difference in IMRT (χ2=5.943, P=0.015), but the1-,3-,5-year local control rates had no significant difference (χ2=1.207, P=0.272);⑼C ompared with those inradiotherapy only, the1-,3-and5-year localcontrol and survival rates among concurrent and sequential chemoradio-therapy groups had no significant difference (χ2=2.620P=0.270and χ2=4.699,P=0.095). In the radiotherapy only, the1-,3-and5-year local control andsurvival rates had no significant difference with those in sequentialchemoradiotherapy (χ2=0.461, P=0.497and χ2=0.000, P=0.983), while1-,3-and5-year survival rates in concurrent chemoradiotherapy improved thanthose in radiotherapy only (χ2=4.425，P=0.035), although1-,3-and5-yearlocal control rates had no significant difference (χ2=1.506，P=0.220).⑽The1-,3-,5-year local control rates and survival rates in cycle<4group hadsignificant difference with those in cycle≥4group (χ2=5.270, P=0.022andχ2=9.904, P=0.002);⑾The1-,3-and5-year local control and survival rates inFP and TP groups had no significant difference (χ2=0.089, P=0.766andχ2=0.330, P=0.566);⑿The1-,3-,5-year local control and survival rates inconcurrent chemoradiotherapy plus consolidation chemotherapy had nosignificant difference with without consolidation groups (χ2=0.402, P=0.526and χ2=0.402, P=0.526).⒀Prognostic factors analysis: tumor volume,short-term curative effect, lymph node metastasis and irradiation dose wereindependent factors for overall survival; Irradiation dose was an independentfactor for local control; Chemotherapy cycle and gender were independentfactors for survival in chemo-radiotherapy group; Tumor volume was anindependent factor for local control in chemoradiotherapy group.Conclusions:1The effect is well in patients with esophageal cancer received IMRT,and its toxicity is relatively low. Non-surgical stage can guide prognosis well.Patients with clinical stage Ⅰ~Ⅱ have higher survival rate than that withclinical stage Ⅲ;2The local control in patients whose tumor length <5.0cm are improved than those tumor length≥5.0cm, while survival rate has no relation to tumorlength;3The local control and survival advantage is obvious in the patientswhose tumor volume<54.73cm3or radiation dose≥60Gy than those whosetumor volume≥54.73cm3or radiation dose <60Gy;4The survival rate in patients without lymphatic metastasis is higher thanthat with lymphatic metastasis, and it is also higher in SIB-IMRT than inconventional IMRT, while their survival have no significant difference.5The evaluation of short-term curative effect have correlation with localcontrol and survival.6The survival rate in concurrent chemoradiotherapy is more increasedthan that in radiotherapy only, while their local control rates have nosignificant difference. Neither survival nor local control shows no significantdifference between concurrent and sequential chemoradiotherapy；7Chemotherapeutic circle≥4is recommended combined with IMRT foresophageal cancer. The local control and survival in FP and TP groups have nosignificant difference, meanwihile,consolidated chemotherapy after concurrentchemoradiotherapy shows no value.8Tumor volume, short-term curative effect, lymphatic metastasis andirradiation dose are independent factors for overall survival; Irradiation dose isan independent factor for local control.