Background: Specific immunotherapy is an important immune-modifying treatment for patients with allergic rhinitis (AR). We compared the early efficacy and safety of cluster and conventional immunotherapies for patients with AR. Methods: One hundred forty-nine patients with persistent AR were enrolled in a randomized and open-label trial and were divided into the following 4 groups: 60 children treated conventionally, 33 children treated using the cluster schedule, 23 adults treated conventionally, and 33 adults treated using the cluster schedule. Patients in the cluster groups reached the maintenance dose within 6 weeks, while those receiving conventional therapy reached the maintenance dose within 14 weeks. Symptom scores and skin prick test scores (SPTs) were used to evaluate clinical efficacy and adverse reactions. Results: After buildup phase of treatment, symptom scores, and SPTs were significantly lower than those prior to treatment in each group ( P < .05). No significant differences were found in the efficacy of nasal symptoms scores among four groups ( P > .05).However, the efficacy of SPTs using conventional schedule was higher than cluster schedule in children groups (group A and B, 57.7 vs 30.2%, P = .001). Besides, the efficacy of SPTs in adults was higher than children when using the cluster treatment (group D and B, 53.0 vs 30.2%, P = .008). No severe adverse reaction occurred. Conclusions: Conventional and cluster immunotherapy schedules have similar efficacies, which do not vary with age; both schedules are safe and reliable. Also, SPT facilitate evaluation of clinical efficacy.

Ex vivo bovine liver specimens were exposed to the MRI-guided HIFU with the focusing depth of 15 mm in the specimens and various acoustic power (50 W, 100 W, 150 W, 200 W, 250 W and 300 W). Our interest was focused on a case of 55° C in situ temperature. The temperature in situ was monitored via the T-map of MRI. The exposure time needed to reach 55° C in the focus for a acoustic power was recorded. The same procedure was repeated to new but similar bovine liver exposed to the US-guided HIFU with the same sonication parameters. The procedure was also monitored by a passive cavitation detection system. The results showed to reach 55° C in situ the exposure time decreased with the increase of acoustic power. The coagulative necrosis occurred when the acoustic power was 50 W, but no hyperecho in US images and half harmonic emission were found. The coagulative necrosis, hyperechoic US images and half harmonic emissions were observed when the acoustic power was 100 W or greater. At 55° C, since no boiling bubbles occurred, therefore we concluded that the hyperecho in US images were caused by acoustic cavitation whose occurrence is determined by the applied acoustic power. Keywords: MRI-guided HIFU, US-guided HIFU, Coagulative necrosis, hyperecho, Acoustic cavitation This work was supported by National Nature and Science Foundation of China (No. 30830040, 30970827)