ABSTRACT
Objective To analyze the recurrence of breast cancer without use of chest wall bolus during adjuvant intensity modulated radiotherapy after modified radical mastectomy, so as to investigate the necessity of bolus use. Methods A total of 218 patients undergoing adjuvant intensity modulated radiotherapy after modified radical mastectomy during the period from January 2013 to June 2019 were enrolled as the study subjects. The chest wall bolus was not used during the whole period of radiotherapy after modified radical mastectomy, and the recurrence of breast cancer in the chest wall was analyzed after radiotherapy. Results The post-surgical follow-up through outpatient records, inpatients records, local residents’ health system and telephone was performed until June 31, 2021. The proportion of follow-up was 100%, and the mean follow-up period was 48.9 months. There were three cases with breast cancer recurrence in the chest wall, including one case with recurrence in the chest wall alone and two cases with recurrence in the chest wall and regional lymph nodes, and the overall recurrence of breast cancer was 1.4% in the chest wall. Among the 3 cases with breast cancer recurrence in the chest wall, there were two cases with N3 stage and positive for HER2, and one triple-negative breast cancer case, and all three cases developed distal metastases upon local recurrence. Among 218 study subjects, there were 5 cases with grade Ⅰ radioactive skin reaction, 3 cases with grade Ⅱ radioactive skin reaction, and no grade Ⅲ or Ⅳ radioactive skin reaction occurred. In addition, no grade Ⅲ or Ⅳ acute radioactive injury was seen in the chest wall skin among the 218 study subjects. Conclusion No use of chest wall bolus may be considered during adjuvant intensity modulated radiotherapy after modified radical mastectomy in presence of systemic therapy if tumor invasion into skin is not observed prior to therapy.
ABSTRACT
Objective To compare the difference of dosimetric results between 3-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT) with 5-field for thoracic middle esophageal carcinoma.Methods Ten patients with thoracic middle esophageal carcinoma were involved in this study.Four treatment plans were designed for each patient,including one 3D-CRT plan and three IMRT plans with 5-field and all evaluation contents were compared.Results There were no significant differences of cord Dmax,total-lung mean dose (Dmean),L-lung Dmean and R-lung V25,V30.Significant differences of heart V30,V40 and Dmean were obtained among the plans,with the lowest of 5IMRT2 (V30:28.67±15.97,V40:13.04±7.28,Dmean:2097.76±718.26) and 5IM RT3(27.39±14.96,13.00±7.32,2096.16±718.85),the highest of 5CRT (43.27±18.69,26.83±19.18,2393.48±896.12) and 5IMRT1 (41.81±17.16,23.08±11.17,2403.77±834.73).There were significant differences of L-lung V5,V10,V15,V20 V25 and V30.All IMRT plans reduce V20,V25 and V30.5IMRT1 did not increase V5 (54.39±7.58) and V10 (44.76±6.30),but reducesd V15 (20.86±5.16),5IMRT2 (V5:70.89±7.95,V10:50.94±8.71,V15:34.20±6.62) and 5IMRT3 (V5:70.26±7.94,V10:49.80±7.62,V15:34.60±5.40)increased V5,V10 and V15.There were also significant differences of R-lung V5.V10,V10,V20 and Dmean.All IMRT plans reduced V20,but increased Vs and V10.5IMRT1 did not increase V15 (23.67±5.73) and Dmean (923.49±182.34); 5IMRT2 did not increases V15 (26.72±±6.79) but increases Dmean (1060.34±205.02); 5IMRT3 increased both V15 (32.40±6.59) and Dmean (1100.54±197.84).Significant differences were found in Dmean,homogeneity index (HI) and conformity index (CI) of PTV,with the best Dmean of 5IMRT1 (6219.80±37.90),the second of 5IMRT3 (6268.91±56.26); the best HI of 5IMRT1 (0.0870±0.0219) and 5IMRT3 (0.0990±0.0219);the best CI of 5IRT2 (0.8682±0.0172) and 5IMRT3 (0.8667±0.0183).Conclusion 5-field IMRT plans have the advantages in the treatment of thoracic middle esophageal carcinoma with better HI,CI of target volume and sparing of lung (V20,V25 and V30) compared to 3D-CRT.5IMRT1 plan has the advantages in reducing low-dose volume (V5,V10,V15 and Dmean) of lung.