Uterine transposition versus uterine ventrofixation before radiotherapy as a fertility sparing option in young women with pelvic malignancies: Systematic review of the literature and dose simulation

BACKGROUND

(Chemo)radiation may be a required treatment in young women with pelvic malignancies. Irradiation may result in ovarian and uterine failure, compromising the fertility of those patients. While ovarian transposition is an established method to move the ovaries away from the irradiation field, similar surgical procedures regarding the uterus remain investigational. The aim of this study was to carry out a systematic review of the literature on uterine displacement techniques (ventrofixation/transposition) and to simulate the radiation dose received by the uterus in different heights place after the procedures.

METHODS

The systematic review was performed according PRISMA guidelines. PubMed, Scopus, Web of Science and EMBASE were queried to identify included study until March 2023. Retrospectively, a dosimetric study was also performed and Volumetric Modulated Arc Therapy (VMAT) radiotherapy treatment plans were calculated, to assess the dose received by the uterus according to hypothetical different displacement positions taking the case of irradiation for rectal or anal cancer as model.

RESULTS

A total of 187 studies were included, after the screening 9 studies were selected for synthesis. Data from the dose simulation revealed that the transposition approach was the most protective with a maximum dose of about 3 and 8 Gy for anal and rectal cancer respectively. None of the simulated ventrofixation positions received a Dmean surpassing 14 Gy.

CONCLUSION

According to the literature review and the simulation results of the present study we may conclude are feasible and safe as fertility sparing approach in young rectal/anal cancer patients.

Population pharmacokinetics and dose simulation of vancomycin in critically ill patients during high-volume haemofiltration

This study aimed to describe the population pharmacokinetics of vancomycin in critically ill patients with refractory septic shock undergoing continuous venovenous high-volume haemofiltration (HVHF) and to define appropriate dosing for these patients. This was a prospective pharmacokinetic study in the ICU of a university hospital. Eight blood samples were taken over one vancomycin dosing interval. Samples were analysed by a validated liquid chromatography-tandem mass spectrometry assay. Non-linear mixed-effects modelling was used to describe the population pharmacokinetics. Dosing simulations were used to define therapeutic vancomycin doses for different HVHF settings. Nine patients were included (five male). The mean weight and SOFA score were 70 kg and 11, respectively. Mean HVHF settings were: blood flow rate, 240 mL/min; and haemofiltration exchange rate, 100 mL/kg/h. A linear two-compartment model with zero-order input adequately described the data. Mean parameter estimates were: clearance, 2.9 L/h; volume of distribution of central compartment (V(1)), 11.8L; volume of distribution of peripheral compartment (V(2)), 18.0 L; and intercompartmental clearance, 9.3 L/h. HVHF intensity was strongly associated with vancomycin clearance (P < 0.05) and was a covariate in the final model. Simulations indicate that after a loading dose, vancomycin doses required for different HVHF intensities would be 750 mg every 12h (q12h) for 69 mL/kg/h, 1000 mg q12h for 100 mL/kg/h and 1500 mg q12h for 123 mL/kg/h. Continuous infusion would also be a valuable administration strategy. In conclusion, variable and much higher than standard vancomycin doses are required to achieve therapeutic concentrations during different HVHF settings.