PubMed · 4112975
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
B Merkel. 1972. [Our method for preparing cervical conizations for histological study].. https://pubmed.ncbi.nlm.nih.gov/4112975/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
PURPOSE: To investigate the use of a fluoroscopic electronic portal imaging device (EPID) and radiopaque markers to detect internal cervix movement. METHODS AND MATERIALS: For 10 patients with radiopaque markers clamped to the cervix, electronic portal images were made during external beam irradiation. Bony structures and markers in the portal images were registered with the same structures in the corresponding digitally reconstructed radiographs of the planning computed tomogram. RESULTS: The visibility of the markers in the portal images was good, but their fixation should be improved. Generally, the correlation between bony structure displacements and marker movement was poor, the latter being substantially larger. The standard deviations describing the systematic and random bony anatomy displacements were 1.2 and 2.6 mm, 1.7 and 2.9 mm, and 1.6 and 2.7 mm in the lateral, cranial-caudal, and dorsal-ventral directions, respectively. For the marker movement those values were 3.4 and 3.4 mm, 4.3 and 5.2 mm, 3.2 and 5.2 mm, respectively. Estimated clinical target volume to planning target volume (CTV-PTV) planning margins (approximately 11 mm) based on the observed overall marker displacements (bony anatomy + internal cervix movement) are only marginally larger than the margins required to account for internal marker movement alone. CONCLUSIONS: With our current patient setup techniques and methods of setup verification and correction, the required CTV-PTV margins are almost fully determined by internal organ motion. Setup verification and correction using radiopaque markers might allow decreasing those margins, but technical improvements are needed.
Cervical human papillomavirus (HPV) infections are at high risk of neoplastic progression if they persist. Persistence can be measured by repeated HPV DNA tests or by cytologic testing. Thus, it is useful to understand the relationship between these 2 measurements. To explore the relative timing of HPV DNA clearance versus cytologic regression, data were analyzed from 840 study participants who were followed-up by repeat thin-layer cytology and HPV testing by a hybrid capture test at 6-month intervals for 2 years. On average, HPV DNA detection persisted longer than related cytologic abnormalities (P<.001). HPV type-specific data from a subset of 448 women with complete polymerase chain reaction test data confirmed that HPV DNA persisted longer than cytologic abnormalities (P<.001). It appears that the natural history of HPV typically includes periods before and after cytologic abnormality, in which HPV DNA is the more sensitive indicator of infection.
Explore the source record for details and available documents.