Matches in SemOpenAlex for { <https://semopenalex.org/work/W2023433831> ?p ?o ?g. }
Showing items 1 to 74 of
74
with 100 items per page.
- W2023433831 endingPage "S90" @default.
- W2023433831 startingPage "S90" @default.
- W2023433831 abstract "Purpose: High-dose-rate (HDR) applicator position undergoes changes and varies the prescription and reference point doses between insertions have stressed the need of studying applicator position changes in HDR brachytherapy (HDRB). Hence an attempt is made to study the anatomic variation of fixed reference points (Point A, Point B, Bladder and rectum) during the time interval between first and second HDRB. Materials and Methods: To carry out the study, the AP and lateral radiographs of 50 patients, treated in HDR are taken and anatomical planning is carried out, by taking the anatomical origin instead or external OS. In the coronal plane, the X-axis was defined as joining the superior portion of the femoral heads and Y-axis was defined as bisecting the pelvis. In the sagittal plane, the Z-axis was defined at the superior portion of the femoral heads and the Y-axis as the midpoint between the sacral promontory and the pubic symphysis. The dose prescription points AL, AR, BL and BR (on both sides of the tandem) and ICRU 38 reference points’ rectum (R) and bladder (B) are marked on the radiographs, taking into consideration its magnification. Then a treatment plan is executed by using the Plato™ BPS v13.7 treatment planning system (Nucletron B.V., Veenendaal, The Netherlands) with prescription of dose at point A as 10 Gy. Now the x, y, z co-ordinates of the reference points AL, AR, BL, BR, B and R along with dose and % of dose is recorded. It is repeated in the second insertion and the co-ordinates of the reference points from the first plan are fed to the computer as dose points through the key board. Now the TPS gives two set of dose information one for the second insertion and the other for the first insertion. Similarly the dose contribution from the first implant to the reference points defined by second implant was also calculated. The spatial movement of the reference points from the first to the second implant was determined by simple vector subtraction. The magnitude and direction of the spatial movement of the reference points was described in terms of spherical coordinate system, by transforming the Cartesian coordinates. Results: The mean variation of reference points are found to vary between –4.76 to 2.52 mm (n = 50). In the case of individual patient this variation is between –145.6mm to 60.7 mm. The percentage of dose variation is found to be –206.6 to 85.8 in individual patients. The mean dose variation is found to be –13.15 to 5.75%. The mean dose rate variation is found to be –10.21 to 45.22 %. Grigsby et al., (1993) have reported the movement of x, y, z co-ordinates from 0 to 6 mm for various reference points and dose rate variations up to 35% in LDR. The present study demonstrates that the reference points move posterior and caudal in the pelvis. The average shift is from - 7.69 to 2.52 mm for the individual points. For individual patient, the minimum and maximum shift is -106 mm and 61 mm. This clearly demonstrates the existence of variation between successive insertions. Conclusions: The study reveals, the movement of reference points towards posterior and caudally, during the gap between first and second HDR insertion. More movement and variation of dose is found on the left side of the patient and this may be due to (i) tumor shrinkage and fibrosis of normal tissue over time or (ii) method of brachytherapy applicator insertion. It is also found that the packing is weighted more on the right side of the applicator, thereby causing more variations on the left side. The physicians mostly use their right hand during HDRB and hence have a tendency of packing the right side of the applicator more, leaving more freedom to the left ovoid." @default.
- W2023433831 created "2016-06-24" @default.
- W2023433831 creator A5027916317 @default.
- W2023433831 creator A5049868616 @default.
- W2023433831 creator A5062042534 @default.
- W2023433831 date "2010-04-01" @default.
- W2023433831 modified "2023-10-16" @default.
- W2023433831 title "Anatomic Variation of Gynecologic Prescription and Reference Points in High-Dose-Rate Brachytherapy" @default.
- W2023433831 doi "https://doi.org/10.1016/j.brachy.2010.02.162" @default.
- W2023433831 hasPublicationYear "2010" @default.
- W2023433831 type Work @default.
- W2023433831 sameAs 2023433831 @default.
- W2023433831 citedByCount "0" @default.
- W2023433831 crossrefType "journal-article" @default.
- W2023433831 hasAuthorship W2023433831A5027916317 @default.
- W2023433831 hasAuthorship W2023433831A5049868616 @default.
- W2023433831 hasAuthorship W2023433831A5062042534 @default.
- W2023433831 hasBestOaLocation W20234338311 @default.
- W2023433831 hasConcept C105702510 @default.
- W2023433831 hasConcept C120665830 @default.
- W2023433831 hasConcept C121332964 @default.
- W2023433831 hasConcept C126838900 @default.
- W2023433831 hasConcept C13483470 @default.
- W2023433831 hasConcept C141071460 @default.
- W2023433831 hasConcept C178910020 @default.
- W2023433831 hasConcept C19527891 @default.
- W2023433831 hasConcept C2777416452 @default.
- W2023433831 hasConcept C2778357063 @default.
- W2023433831 hasConcept C2778688959 @default.
- W2023433831 hasConcept C2781074409 @default.
- W2023433831 hasConcept C2989005 @default.
- W2023433831 hasConcept C3017588741 @default.
- W2023433831 hasConcept C36454342 @default.
- W2023433831 hasConcept C4144372 @default.
- W2023433831 hasConcept C509974204 @default.
- W2023433831 hasConcept C71924100 @default.
- W2023433831 hasConceptScore W2023433831C105702510 @default.
- W2023433831 hasConceptScore W2023433831C120665830 @default.
- W2023433831 hasConceptScore W2023433831C121332964 @default.
- W2023433831 hasConceptScore W2023433831C126838900 @default.
- W2023433831 hasConceptScore W2023433831C13483470 @default.
- W2023433831 hasConceptScore W2023433831C141071460 @default.
- W2023433831 hasConceptScore W2023433831C178910020 @default.
- W2023433831 hasConceptScore W2023433831C19527891 @default.
- W2023433831 hasConceptScore W2023433831C2777416452 @default.
- W2023433831 hasConceptScore W2023433831C2778357063 @default.
- W2023433831 hasConceptScore W2023433831C2778688959 @default.
- W2023433831 hasConceptScore W2023433831C2781074409 @default.
- W2023433831 hasConceptScore W2023433831C2989005 @default.
- W2023433831 hasConceptScore W2023433831C3017588741 @default.
- W2023433831 hasConceptScore W2023433831C36454342 @default.
- W2023433831 hasConceptScore W2023433831C4144372 @default.
- W2023433831 hasConceptScore W2023433831C509974204 @default.
- W2023433831 hasConceptScore W2023433831C71924100 @default.
- W2023433831 hasLocation W20234338311 @default.
- W2023433831 hasOpenAccess W2023433831 @default.
- W2023433831 hasPrimaryLocation W20234338311 @default.
- W2023433831 hasRelatedWork W1975047227 @default.
- W2023433831 hasRelatedWork W1975313596 @default.
- W2023433831 hasRelatedWork W2010859941 @default.
- W2023433831 hasRelatedWork W2019564805 @default.
- W2023433831 hasRelatedWork W2082447543 @default.
- W2023433831 hasRelatedWork W2155318011 @default.
- W2023433831 hasRelatedWork W2943654241 @default.
- W2023433831 hasRelatedWork W3025213175 @default.
- W2023433831 hasRelatedWork W3031450153 @default.
- W2023433831 hasRelatedWork W4288697704 @default.
- W2023433831 hasVolume "9" @default.
- W2023433831 isParatext "false" @default.
- W2023433831 isRetracted "false" @default.
- W2023433831 magId "2023433831" @default.
- W2023433831 workType "article" @default.