ABSTRACT
Objective To evaluate the treatment outcome, prognostic factors, radiation dose, and toxicities in patients with early-stage primary diffuse large B-cell lymphoma of Waldeyer's ring (WR-DLBCL) treated with intensity-modulated radiotherapy (IMRT).Methods This study included 80 patients with a confirmed diagnosis of stage Ⅰ-Ⅱ primary WR-DLBCL who were admitted to our hospital from 2008 to 2015.Only 3 patients received radiotherapy alone, and the other patients received radiotherapy and chemotherapy.After chemotherapy, 24 patients achieved complete remission (CR), and 53 patients achieved partial remission (PR).IMRT was given to the primary lesion and cervical lymphatic drainage region.Survival analysis was performed using the Kaplan-Meier method and log-rank test.The Cox model was used for analysis of prognostic factors.The toxicities were scored using the RTOG criteria.Results The median follow-up was 64 months.The 5-year locoregional control (LRC), overall survival (OS), and progression-free survival (PFS) rates were 94%, 88%, and 84%, respectively.The dose-volume histogram showed that the maximum, mean, and minimum doses to primary gross tumor volume were 54.47 Gy, 52.27 Gy, and 38.83 Gy, respectively.Prognostic analysis showed that age>60 years and increased lactate dehydrogenase (LDH) were influencing factors for OS (P=0.009 and 0.002), and that aged>60 years, IPI ≥2, and increased LDH were influencing factors for PFS (P=0.001, 0.035, and 0.007).Among all patients, 12, 53, and 8 experienced grade 1-3 radiation-induced acute oral mucositis, respectively, and 16 and 13 experienced grade 1 and 2 xerostomia as the late toxicity, respectively.Conclusions For patients with early-stage primary WR-DLBCL, IMRT results in satisfactory OS, PFS, and LRC and has tolerable early or late radiation-induced toxicities.
ABSTRACT
Objective To compare the dose distribution of mantle-field radiotherapy using conven-tional radiotherapy(CRT) and four intensity-modulated radiotherapy(IMRT) techniques in stage Ⅰ and Ⅱ Hodgkin's lymphoma(HL). Methods Ten patients with patholocally proved early stage HL underwent CT simulation. Then both CRT and IMRT planning performed using ECLIPS treatment planning system(TPS). The dosimetric parameters of different irradiation plans were analyzed, including conformal index (CI), homo-geneity index (HI), D95 and V95 of planning target volume (PTV), Dmax,Dmean,Dmin,V5,V10,V20 and V30 of the lung, as well as Dmax of the spinal cord. Results The isodose distribution and homogeneity of PTV were better in IMRT plans when compared with CRT plans. Target coverage, target dose conformity and homogene-ity were similar among all the four IMRT techniques. The V30 of the lung using IMRT was lower than using CRT,but the low-dose volume of the lung was higher. Among the four IMRT technique plans,the lung V20 and V30 were lower in plans with more-field technique,but the V5 and V10 were higher. The Dmax of the spinal cord using IMRT was all lower than that using CRT. Conclusions IMRT is better than CRT in target cov-erage, conformity, homogeneity and normal tissue sparing, especially in protecting the spinal cord and decrea-sing high-dose lung volume,though the low-dose lung volume is higher. Seven-field IMRT technique for man-de-field radiotherapy is recommanded.