K. Dalianis

Bio: K. Dalianis is an academic researcher. The author has contributed to research in topics: Positron emission tomography & Mediastinum. The author has an hindex of 1, co-authored 3 publications receiving 7 citations.

Doses to medical workers operating in a PET/CT department after the use of new dynamic techniques.

Abstract: Since new radiopharmaceuticals are used like [18F]-fluoro-3'-deoxy-3'-L- fluorothymidine and 18F fluoromethylcholine, also new dynamic techniques of imaging are used, measurements concerning the doses to medical staff are needed. The aim of this study was to measure the effective whole body dose of the personnel and compare them with the oldest. Estimation of equivalent dose for all members of the staff was monitored with the use of TLDs badges and electronic dosimeters. The duration of the study was year 2011 (983 patients).Concerning the nurses, we measured 10% increase in the wholebody doses and that is due to the longer time they spent near the patient (dynamic protocol). For technologist we measure 15-21% increase for they come near the patient immediately after administration. We can observe that there is an increase of the doses for technologists and nurses the numbers are significantly lower than the recommended annual dose limit by Euratrom 97/43.

Hypermetabolic Calcified Lymph Nodes on 18Fludeoxyglucose-Positron Emission Tomography/Computed Tomography in a Case of Treated Ovarian Cancer Recurrence: Residual Disease or Benign Formation?

Abstract: The contribution of positron emission tomography/computed tomography (PET/CT) with 18F-fludeoxyglucose (FDG) in evaluating ovarian cancer recurrence even after a prolonged disease-free interval, and in therapy response is well-described. Calcifications observed in CT, although usually attributed to benign conditions, may actually represent active disease. Such an example of calcified formations is psammoma bodies. We present a case of 56-y. o. patient with ovarian cancer relapse at the supraclavicular area 18 years after complete response and disease-free interval. The patient received chemotherapy and underwent 18F-FDG-PET/CT for the evaluation of treatment response. Both CT corrected and uncorrected PET images showed hypermetabolism in the massively calcified lymph nodes in the neck, mediastinum, axilla and abdomen, indicative of active residual disease.

Measurement of the Dose to the Family Members Taking Care of Thyroid Cancer Patients Undergoing I-131 Therapy in Nuclear Medicine Using TLD-100.

Abstract: The family members or friends of the patients undergoing treatment using radioiodine in nuclear medicine are inevitably exposed to ionization radiation. The purpose of this study is measurement of the dose received by the people taking care of the thyroid cancer patients treated by 131I. For this purpose, the dose amounts received by 29 people accompanying patients were measured using thermoluminescence dosimeters. A badge containing three TLD-100 chips was given to each caregiver. The people were asked to wear the badges for 24 days, when they are taking care of the patients. Finally the dose to each person was estimated by averaging the readings of the three TLDs. The measured dose amounts to the people were compared with the recommendations of international commitions. According to the results obtained in this study, the amounts of dose received by the caregivers were between 0.03 and 0.38 mSv, with the average of 0.12 mSv. By comparison of the results of this study with the recommendations of International Commission on Radiological Protection (ICRP), it can be observed that the dose to family members of the patients is less than the dose constraints. However, it is recommended that the caregivers be aware of the radiation protection principles in order to reduce their dose.

Finger Radiation Doses Received By Different Nuclear Medicine Working Professions in Three PET/ CT Centers.

Abstract: In the present study, we have investigated the finger radiation doses received by nuclear medicine staff involved in dispensing, administration of 18F-FDG and interacting with radioactive patients during imaging procedures in PET/ CT facility within three different diagnostic centers. Materials and methods: Using finger ring dosimeters delivered to physicists, technicians, and nurses, the readings were collected after one month of working. Each with his own assigned job task that varies according to the center’s policy. Results: Finger doses were found to be within the permissible limits. The mean prospective annual finger dose measurements, across the three centers show that the physicist group has the highest received prospective annual dose 440.01 mSv/year. The mean technician's prospective annual finger dosemeasurements, across the three centers, appeared to be the lowest scoring 94.83 mSv/year and nurses measured 115.8 mSv/year. Finally, there was no recorded significance for the studied categories across the three centers between their prospective annual finger dose measurements. The highest finger dose was recorded for the physicists who are likely exposed from the handling of the 18F-FDG multi-dose syringe, transferring the dose to the injection room and measuring the post-injection residual dose in the syringe. The nurse performed shorter part with ready-made individual radiopharmaceutical syringe and pre- intravenous time before and during administration. Also, the technicians spent the maximal time per study; however, they have the lowest finger dose because they are not exposed directly to handle the radioactive material.Conclusions: Finger doses are important indicator for the personal exposure especially for those workers who use their hands in dealing with radioactivematerials. The study revealed that the physicists are exposed higher than nurses and technologists in PET-CT facilities.

Statistical analysis of the occupational radiation doses in three different positron emission tomography-computed tomography centers in Egypt.

Abstract: In the present study, we investigated the radiation doses received by the positron emission tomography (PET)/computed tomography (CT) staff in three different diagnostic centers in Egypt. The whole-body effective dose measured by thermoluminescent dosimeters (TLDs) for staff working in PET and the effective dose per study received by physicist, technician, and nurse were measured by an electronic pocket dosimeter (EPD) during a period of 6 months. Statistical analysis was held between the measurements of the TLDs as well as for the EPD for the three studied PET-CT centers. After combining TLD and EPD prospective annual scores for the three studied categories in the three centers, the one-way ANOVA test results have shown that there were statistically significant differences between group means with respect to their TLD mean score (P = 0.041). The mean nurse group TLD score, across the three centers, appeared to be the lowest scoring 3.83 (standard deviation [SD] 0.012) compared to the physicist and technician who measured 4.62 (SD 0.231) and 6.92 (SD 0.018), respectively. Scheffe's test for complex comparisons revealed a significant difference between nurse group and technologist group (P = 0.001). Regarding the annual combined EPD scores, the post hoc test, namely Scheffe's test for complex comparisons, revealed a significant difference between nurse group and technologist group (P = 0.001). This was measured after the one-way ANOVA test results have shown that there were statistically significant differences between annual group EPD means (P = 0.032). Finally, there was no recorded significance for the studied categories across the three centers between their annual TLD and EPD dose scores (P = 0.072). Technicians group received the highest mean effective whole-body doses when compared with the International Commission on Radiological Protection dose limit, each individual worker can work with many more 18F-fluorodeoxyglucose (FDG) PET/CT studies for a (period time) without exceeding the occupational dose limits if the average received effective dose continues with the same rate. The study also confirmed that low levels of radiation dose are received by medical personnel involved in 18F-FDG PET/CT procedures in those centers due to implementing radiation protection measures and procedures.