ObjectiveTo estimate the radiation dose (RD) to the general public and nuclear medicine technicians from patients undergoing 99mTc-methoxy isobutyl isonitrile (MIBI) myocardial perfusion imaging. MethodsFrom January to June 2015, 55 patients including 30 males and 25 females aged between 25 and 87 years[averaging (63.6±15.1)years] ready to undergo myocardial perfusion scintigraphy with 99mTc-MIBI were prospectively recruited in this study. Approximately at hour 1.5 after injection of 99mTc-MIBI, whole-body dose-equivalent rate was measured with a radiation-survey meter at 0.3 meter and 1.0 meter from the patients. On the basis of human 99mTc-MIBI metabolic rate proposed by the International Commission of Radiological Protection and human social contact model proposed by the National Council on Radiation Protection and Measurements, the RDs to the general public from patients who had completed 99mTc-MIBI myocardial perfusion imaging and left nuclear medicine department were calculated. On the assumption that a nuclear medicine technician typically spent 5 minutes at a distance of 0.3 meter for positioning the patient, the technician's RD was also estimated. ResultsThe RD to a family member sleeping with the patient at night was predicted to be 42.88-160.55 μSv, to a family member contacting the patient at daytime 7.50-29.38 μSv, to a colleague 9.89-38.78 μSv and to a nearby passenger 124.48-466.06 μSv. The RD to a technician per 99mTc-MIBI myocardial perfusion imaging procedure was predicted to be 1.72-6.44 μSv. ConclusionThe predicted RDs to the general public and technicians from exposure of patients undergoing 99mTc-MIBI myocardial perfusion imaging are significantly lower than the regulatory dose limits.
Objective To summarize application effect and clinical experience of multimodal intraoperative neurophysiological monitoring (IONM) technology in the surgery of neurofibromatosis type 1 (NF1) related peripheral nerve tumors. Methods A retrospective study was conducted on NF1 patients, who admitted between January 2019 and December 2023 and treated with peripheral nerve tumor resection surgery assisted by multimodal IONM technology. There were 49 males and 45 females. The age ranged from 5 to 78 years, with an average of 33.7 years. Tumor morphological classification included 71 cases of nodular type, 13 cases of diffuse type, and 10 cases of mixed type. Target tumors were distributed in craniofacial region (47 cases), neck (11 cases), trunk (12 cases), and limbs (24 cases). Preoperatively, 44 cases had no obvious neurological symptoms, while the remaining patients had neurological symptoms, including 15 cases of visual impairment, 5 cases of hearing impairment, 16 cases of somatic movement disorders, and 31 cases of somatic sensory disorders, of which 7 cases had more than one symptom. IONM plans were selected based on the relevant nerves and adjacent important structures of the target tumor, including visual evoked potential (17 cases), somatosensory evoked potential (44 cases), motor evoked potential (88 cases), and electromyogram (94 cases).Results All surgeries were successfully completed. Ninety-three patients underwent total/near total resection and 1 patient underwent palliative resection. Pathological examination showed 80 cases of neurofibroma and 14 cases of malignant peripheral nerve sheath tumors. Complications included 2 cases of hematoma and 3 cases of incision infection. All patients were followed up 3-61 months (median, 15 months). During follow-up, no significant changes in neurological symptoms or tumor recurrence were found. Among the patients with preoperative visual impairment, there were 14 cases with no improvement in symptoms and 1 with improvement after surgery. Among the patients with somatic movement disorders, there were 11 cases with no improvement in symptoms, 3 cases with improvement, 2 cases with aggravation, 4 newly onset cases, and 1 case with significant impact on daily life after surgery. Among the patients with somatic sensory disorders, there were 17 cases with no improvement in symptoms, 14 cases with improvement, and 13 newly onset cases. The patients with hearing impairment showed improvement after surgery. Conclusion The clinical manifestations of NF1 related peripheral nerve tumors are complex. Multimodal IONM technology can provide real-time detection of nerve provocation and damage. Surgical treatment with multimodal IONM technology is safe and can reduce complications.