A preliminary study on the outcomes of radiation therapy of bone hydatid disease in Meriones meridianus

Abstract

Objective According to radiation therapy (6WV-X line) on experimental gerbils which were successfully infected by echinococcus granulosus, the outcomes of bone hydatid disease after radiation therapy were studied. Methods Totally 240 gerbil models that were infected bone hydatid disease, were randomly divided into three groups (each group was further divided into three-month and six-month groups, 40 gerbils per group), one group as a control group, the 40 Gy/5 times and 50 Gy/5 times groups were given 6WV-X line radiation therapy. After 5 consecutive radiation therapies, stopped for two days and then repeated for five times. At the end of three and six months after radiotherapy, the rate of death and the ulceration or infection of the lesions was compared. Fifteen gerbils from each group were randomly selected to observe the deaths of scolex, protein and calcium concentration changes, the maximum diameter changes of the lesions, the changes of hydatid cyst wet weight and the rate of suppressing capsule, the bone destruction, and rebuilding situation of lesions under a microscope. Results At the end of three and six months after radiation therapy, with increasing dosage, the deaths decreased significantly (χ2 = 10.4, 17.4, all P 0.05); in the control and 40 Gy/5 times group, the ulceration or infection of the lesions gradually increased (χ2 = 5.5, 4.3, all P 0.05); in the 50 Gy/5 times group, the mortality rate of scolex was significantly increased (F = 212.6, P < 0.05); in 50 Gy/5 times group, the protein (calcium) concentration decreased (increased) significantly (F = 271.8, 84.7, all P < 0.05); the maximum diameters of the lesions increased gradually in the control group (F = 47.1, P < 0.05), in 50 Gy/5 times group, the maximum diameters of the lesions decreased gradually (F = 188.3, P < 0.05); in the control group, hydatid cyst wet weight increased significantly (F = 10.7, P < 0.05), in the 50 Gy/5 times group, hydatid cyst wet weight was significantly reduced (F = 68.5, P < 0.05); with increasing dosage, the damage of the bone matrix and the cells in lacunae of the lesions gradually increased, in the same group with time went on, in the control group, a few amount of bone cells in lacuna died, and in 40 Gy/5 times and 50 Gy/5 times groups, the bone matrix and bone cells were partially repaired. Conclusion The long-term effects of appropriate dosage (50 Gy/5 times) radiation on experiments hydatid diseased gerbils are affirmed, but it is still need a clinical validation. Key words: Radiotherapy dosage; Bone and bones; Echinococcus granulosus; Treatment outcome