[Radiation exposure of surgical staff during sentinel node surgery. Is there a risk for the surgeon and his team?]

OBJECTIVE

Assess the radiation exposure of surgical staff during sentinel node surgery in gynecology using a radiotracer, the (99m)Tc-microalbumin.

MATERIALS AND METHODS

A monocentric, prospective study was conducted during 3 months representing 40 sentinel node surgical procedures with different dosimetric measurements. Dosimeters were used to evaluate the whole body and the fingers radiation exposure for all exposed workers (surgeon, nurse and surgical assistant). Another dosimeter was used to estimate the atmospheric radiation level. The activity of (99m)Tc-microalbumin was 50.1±2.4MBq when the surgery was performed the same day and 90.4±3.2MBq when the surgery was performed the day after.

RESULTS

Radioactive doses received during each procedure by the surgeon, surgical assistant and nurse are 5, 3.75 and 0μSv for whole body exposure and 17.5, 15.6 and 16.2μSv for extremities respectively. Atmosphere dosimeter does not detect any radiation over this period. On average, 200 procedures are performed each year in our hospital by 7 surgeons. Surgeon's radiation exposure remains below the threshold of 1mSv annual for whole body and 50mSv annual for fingers set for public by the International Commission on Radiological Protection.

DISCUSSION AND CONCLUSIONS

During sentinel node surgery radiation exposure of surgical staff is weak. Everyone, including the surgeon, receives a dose below the limits of the public radiation exposure. There is no need for special dosimetric monitoring or use radiation protective devices during the sentinel node surgery using (99m)Tc-microalbumin injection.

Spatial and temporal distribution in density and biomass of two Pseudodiaptomus species (Copepoda: Calanoida) in the Caeté river estuary (Amazon region - North of Brazil)

Spatial and temporal density and biomass distribution of the planktonic copepods Pseudodiaptomus richardi and P. acutus along a salinity gradient were investigated in the Caeté River Estuary (North-Brazil) in June and December, 1998 (dry season) and in February and May, 1999 (rainy season). Copepod biomass was estimated using regression parameters based on the relation of dry weight and body length (prosome) of adult organisms. The Caeté River Estuary was characterized by high spatial and temporal variations in salinity (0.8-37.2‰). Exponential length-weight relationships were observed for both Pseudodiaptomus species. Density and biomass values oscillated between 0.28-46.18 ind. m-3 and 0.0022-0.3507 mg DW. m-3 for P. richardi; and between 0.01-17.02 ind. m-3 and 0.0005-0.7181 mg DW. m-3 for P. acutus. The results showed that the contribution of P. richardi for the secondary production in the Caeté River Estuary is more important in the limnetic zone than in other zones where euhaline-polyhaline regimes were predominant. However, it was not possible to observe a clear pattern of spatial and temporal distribution for P. acutus.