Lymphoscintigraphy in patients with lymphedema after gynecological cancer treatment: assessment of injury of the lower limb lymphatic system / 中华核医学杂志

ABSTRACT

Objective To evaluate the lymphoscintigraphic imaging characteristics for the patients with lower limb lymphedema and to establish a novel grading system for the injury to lower limb lymphatic system. Methods One hundred and sixty six consecutive patients (332 lower limbs) with lower limb lymphedema after surgical and(or) radiotherapy treatment for gynecological cancer were recruited into this retrospective study. The lymphoscintigraphy studies were performed after subcutaneous injection of 111～185 MBq (0. 1～0. 15 ml) of 99Tcm-DX into the webbed space between the first and second toes of both feet. Based on the integrity of lymphatic vessel and the extension of dermal diffusion on lymphoscintigram,the lymphatic injury to the lower limb was graded as 0, 1,2 and 3 respectively. The lymphedema of the limb was staged as 0, Ⅰ , Ⅱ a, Ⅱ b, Ⅲ by the standard of Consensus Document of the International Society of Lymphology (ISL). Chi square test was carried out to validate the established grading system for the assessment of the injury to the lower limb lymphatic system. Results The lymphoscintigraphic imaging characteristics included lymphatic blockage, dermal backflow, no visualization of lymphatic or lymph node, lymphocele and lymph fistula in the lower limb, pelvis and abdomen. There were 65 (19.6%), 71 (21.4%),131 (39.5%), 62 (18.7%) and 3 (0.9%) limbs staged as 0, Ⅰ , Ⅱa, Ⅱb, and Ⅲ for lymphedema while 36(10.8%), 79(23.8%), 116(34.9%) and 101 (30.4%) limbs graded as 0, 1, 2, and 3 for lymphatic injury. There was a statistically significant correlation between the grading methods (χ2 =313.483, P <0.001). The patients who underwent radiotherapy had a higher incidence rate of grade 2 and 3 (70.5%, 158/224) than those who underwent surgery (53.6%, 59/108) (χ2 = 9.662, P = 0.022).The patients with erysipelas had a higher incidence rate of grade 3(73.1%, 38/52) than those without erysipelas (43.9%, 50/114) (χ2= 12.238, P<0.001). The incidence rate of grade 3 increased with the duration of lymphedema after treatment 36.6% (34/93) for less than 1.5 years, 72.3% (34/47) for between 1.5 to 5 years, and 76.9% (20/26) for more than 5 years (χ2 = 23.123, P<0.001). The grade of lymphatic injury showed no significant difference among 3 types of gynecological cancers (χ2 = 4.000, P =0.676), or between the patients with and without chemotherapy (χ2 =0.411, P=0.938). Conclusions Lymphoscintigraphy is a reliable modality to diagnose lower limb lymphedema after treatment for gynecological cancer. The injury grading system could provide objective assessment of the lymphatic damage.