Analysis of serial CT scans to assess template and catheter movement in prostate HDR brachytherapy

Mullokandov, Eduard; Gejerman, Glen

doi:10.1016/j.ijrobp.2003.08.020

Cited by 66 publications

(27 citation statements)

References 15 publications

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“…The average displacement (4.1 mm) between the first and second fractions (on average, 19.5 hours difference) in this study is quite small as compared with the average displacement noted in several reports ( 9 – 12 ) in the literature. Using fluoroscopy, Martinez et al (9) measured a mean displacement of 20 mm between the first and second fractions (at least 6 hours difference, and 36 hours between the first and the fourth fractions).…”

Section: Discussioncontrasting

confidence: 85%

“…These four HDR fraction studies in the literature ( 9 – 12 ) showed time‐dependent catheter displacement between fractions. The maximum catheter displacement occurred up to approximately 12 hours after the first fraction (20 mm before the second fraction, (9) 7.6 mm before the second fraction, (10) and 6 mm before the third fraction (12) ).…”

Section: Discussionmentioning

confidence: 93%

“…The maximum catheter displacement occurred up to approximately 12 hours after the first fraction (20 mm before the second fraction, (9) 7.6 mm before the second fraction, (10) and 6 mm before the third fraction (12) ). Displacement magnitude subsequently decreased for the following fraction.…”

Section: Discussionmentioning

confidence: 97%

“…Using a 5‐mm CT scan, Hoskin et al (11) reported that the average template movement was 1 mm and that catheter movement relative to the prostate was 9.7 mm between the first and second fractions (over a period of 18 – 24 hours). Mullokandov and Gejerman (12) reported that no displacement of catheters relative to the template occurred and that the mean consecutive catheter displacement was 2, 8, and 10 mm before the second, third, and fourth fractions. Because the time interval between fractions was 6 hours in their study, the measured displacement (10 mm) before the fourth fraction (minimum 18 hours difference) can be compared with our measurement (4.1 mm) before the second fraction.…”

Section: Discussionmentioning

confidence: 99%

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Measurement of craniocaudal catheter displacement between fractions in computed tomography–based high dose rate brachytherapy of prostate cancer

Kim

Hsu

Pouliot

2007

J Applied Clin Med Phys

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The objective of the present work was to measure the craniocaudal displacement of catheters occurring between consecutive fractions of transrectal ultrasound (TRUS)‐guided high dose rate (HDR) prostate brachytherapy. Ten consecutive patients were treated with 2 fractions of 9.5‐Gy TRUS‐guided HDR brachytherapy, with dental putty being used for the fixation of catheters. For each patient, a computed tomography (CT) scan with 3‐mm slice thickness was acquired before each of the 2 fractions. Two different references were used to measure the catheter displacement between fractions: the ischial bone as a bony marker (BM) and the center of two gold markers (COGM) implanted in the prostate. Catheter displacement was calculated by multiplying the thickness of the CT slice by the difference in number of CT slices between the reference slice and the slice containing the tip of a catheter. The average magnitude of caudal catheter displacement was 2.7 mm (range: −6.0 mm to 13.5 mm) for the BM method and 5.4 mm (range: −3.75 mm to 18.0 mm) for the COGM method. The measurement data obtained from the BM and COGM methods verified that prostate movement and catheter displacement both occurred independently between fractions. The most anterior and medial two catheters (catheter positions 8 and 12) had the greatest tendency to be displaced in the caudal direction because they were located at the most distant position from the fulcrum, making them susceptible to rotation of the dental putty in the lateral plane because of the movement of the patients’ legs between fractions. In conclusion, the combination of the BM and COGM methods can demonstrate prostate and catheter movement relative to the BM between fractions. Our technique found a pattern of catheter displacement. Based on that finding, further improvement of our results may be possible by modification of our current technique.PACS number: 87.53.Jw

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Section: Discussioncontrasting

confidence: 85%

Section: Discussionmentioning

confidence: 93%

Section: Discussionmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Measurement of craniocaudal catheter displacement between fractions in computed tomography–based high dose rate brachytherapy of prostate cancer

Kim

Hsu

Pouliot

2007

J Applied Clin Med Phys

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“…Third, this is a retrospective study based on patients’ imaging data. Fourth, although our landmark‐based registration optimizes the global catheter match between CT and ultrasound, too many (more than 1/4−1/3 of the total number) catheter slips35, 36, 37 could affect the registration and TCDR‐based prostate contour accuracy. For future study, we plan to conduct a prospective clinical trial to further develop and refine the TCDR‐based prostate HDR brachytherapy.…”

Section: Discussionmentioning

confidence: 99%

Improved prostate delineation in prostate HDR brachytherapy with TRUS‐CT deformable registration technology: A pilot study with MRI validation

Yang

Rossi

Jani

et al. 2017

J Applied Clin Med Phys

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Accurate prostate delineation is essential to ensure proper target coverage and normal‐tissue sparing in prostate HDR brachytherapy. We have developed a prostate HDR brachytherapy technology that integrates intraoperative TRUS‐based prostate contour into HDR treatment planning through TRUS‐CT deformable registration (TCDR) to improve prostate contour accuracy. In a perspective study of 16 patients, we investigated the clinical feasibility as well as the performance of this TCDR‐based HDR approach. We compared the performance of the TCDR‐based approach with the conventional CT‐based HDR in terms of prostate contour accuracy using MRI as the gold standard. For all patients, the average Dice prostate volume overlap was 91.1 ± 2.3% between the TCDR‐based and the MRI‐defined prostate volumes. In a subset of eight patients, inter and intro‐observer reliability study was conducted among three experienced physicians (two radiation oncologists and one radiologist) for the TCDR‐based HDR approach. Overall, a 10 to 40% improvement in prostate volume accuracy can be achieved with the TCDR‐based approach as compared with the conventional CT‐based prostate volumes. The TCDR‐based prostate volumes match closely to the MRI‐defined prostate volumes for all 3 observers (mean volume difference: 0.5 ± 7.2%, 1.8 ± 7.2%, and 3.5 ± 5.1%); while CT‐based contours overestimated prostate volumes by 10.9 ± 28.7%, 13.7 ± 20.1%, and 44.7 ± 32.1%. This study has shown that the TCDR‐based HDR brachytherapy is clinically feasible and can significantly improve prostate contour accuracy over the conventional CT‐based prostate contour. We also demonstrated the reliability of the TCDR‐based prostate delineation. This TCDR‐based HDR approach has the potential to enable accurate dose planning and delivery, and potentially enhance prostate HDR treatment outcome.

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Improving ultrasound‐based brachytherapy needle conspicuity by applying an echogenic coating

et al. 2022

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Background: Applicator conspicuity in ultrasound-guided brachytherapy procedures is commonly impaired by imaging artifacts or non-ideal imaging geometry, which can slow down applicator position digitization and increase the geometric uncertainty of the delivered dose distribution. Purpose: The purpose of this study was to improve the conspicuity of highdose rate (HDR) brachytherapy needles under B-mode ultrasound imaging by applying an echogenic surface coating. Our hypothesis was that an echogenic coating would reduce artifacts and improve needle visualization within regions of signal degradation. Methods: In this study, 17-gauge, 25-cm long titanium HDR brachytherapy needles were coated with acoustically reflective microspheres over a 2.5 cm region starting from the needle tip. Three coating thicknesses (27 µm, 40 µm, 64 µm) were compared against an uncoated control needle. The coated and uncoated needles were imaged using B-mode ultrasound in a tissue-equivalent prostate phantom and in a cadaverous male pelvis using a transrectal probe. Needle conspicuity was assessed under multiple conditions: a single needle implant, an implant with multiple needles between the probe and the needle of interest, and an angled needle implant. All images were assessed qualitatively for needle conspicuity and the presence of artifacts and quantitatively using grey-scale image intensity values. Results: The 64 µm echogenic coating reduced the magnitude of reverberation artifacts by 31 ± 14% and comet tail artifacts by 40%-70%. The echogenic coating also improved needle contrast, measured by the relative differences in signal intensity compared with the adjacent environment, when needles were angled up to 30 • with respect to the transducer probe in the cadaver. The improvements in conspicuity and artifact reduction increased with increasing coating thickness. The performance of the needles coated with the 64 µm thickness was qualitatively superior and yielded high-contrast,well-circumscribed signals in the cadaverous male pelvis, even under situations where a needle was acoustically shadowed by multiple other needles. Conclusions: An echogenic surface coating reduced imaging artifacts and improved needle conspicuity under realistic clinical conditions for ultrasoundbased prostate or gynecological brachytherapy. The improved conspicuity has the potential to improve the efficiency of needle placement and the accuracy of needle position digitization during brachytherapy procedures. K E Y W O R D Sbrachytherapy applicators, prostate brachytherapy, ultrasound-guided brachytherapy 1418

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Analysis of serial CT scans to assess template and catheter movement in prostate HDR brachytherapy

Cited by 66 publications

References 15 publications

Measurement of craniocaudal catheter displacement between fractions in computed tomography–based high dose rate brachytherapy of prostate cancer

Measurement of craniocaudal catheter displacement between fractions in computed tomography–based high dose rate brachytherapy of prostate cancer

Improved prostate delineation in prostate HDR brachytherapy with TRUS‐CT deformable registration technology: A pilot study with MRI validation

Improving ultrasound‐based brachytherapy needle conspicuity by applying an echogenic coating

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