Abdominal organ motion measured using 4D CT

Brandner, E; Wu, Andrew; Chen, Hungcheng; Heron, Dwight E.; Kalnicki, Shalom; Komanduri, Krishna; Gerszten, Kristina; Burton, S.A.; Ahmed, Irfan; Shou, Zhenyu

doi:10.1016/j.ijrobp.2005.12.042

Cited by 160 publications

(101 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This is a meaningful, if not altogether unexpected, result, implying smaller margins may be used in this population. Our findings were consistent with observations from the adult organ motion literature that maximum displacement is along the superior/inferior axis 8, 13, 14, 15, 16, 17. The findings in this paper are broadly applicable to pediatric cancers with tumors in the low thoracic or abdominal cavities.…”

Section: Discussionsupporting

confidence: 91%

Organ motion in pediatric high‐risk neuroblastoma patients using four‐dimensional computed tomography

Kannan

Teo

Solberg

et al. 2016

J Applied Clin Med Phys

View full text Add to dashboard Cite

Purpose/objective(s)High‐risk neuroblastoma (HR‐NBL) requires multimodality treatment, including external beam radiation of the primary tumor site following resection. Radiotherapy planning must take into account motion of the target and adjacent normal anatomy, both of which are poorly understood in the pediatric population, and which may differ significantly from those in adults.Methods/materialsWe examined 4DCT scans of 15 consecutive pediatric patients treated for HR‐NBL, most with tumors in the abdominal cavity. The diaphragm and organs at risk were contoured at full inhale, full exhale, and on free‐breathing scans. Maximum displacement of organs between full inhale and full exhale was measured in the anterior, posterior, superior, inferior, left, and right directions, as was displacement of centroids in the A/P, S/I, and L/R axes. Contours on free‐breathing scans were compared to those on 4D scans.ResultsMaximum displacement was along the S/I axis, with the superior aspects of organs moving more than the inferior, implying organ compression with respiration. Liver and spleen exhibited the largest motion, which correlated strongly with the S/I motion of the diaphragm. The maximum organ motion observed in the abdomen and thorax were 4.5 mm and 7.4 mm, respectively, while maximum diaphragm displacement was 5.7 mm. Overall findings mirrored observations in adults, but with smaller magnitudes, as expected. No consistent margins could be added to the free‐breathing scans to encompass the motion determined using 4DCT.ConclusionsOrgan motion within the pediatric abdomen and pelvis is similar to that observed in adults, but with smaller magnitude. Precise margins to accommodate motion are patient‐specific, underscoring the need for 4DCT scanning when possible.

show abstract

Section: Discussionsupporting

confidence: 91%

Organ motion in pediatric high‐risk neuroblastoma patients using four‐dimensional computed tomography

Kannan

Teo

Solberg

et al. 2016

J Applied Clin Med Phys

View full text Add to dashboard Cite

show abstract

“…Organ motion due to breathing during treatment delivery can result in an organ at risk (OAR) entering the treatment beam and subsequently exceed the tolerance dose while the target may move outside of the treatment beam, restricting the dose it receives to less than the intended prescription dose. Various CT and MR studies report kidney motion due to shallow respiration to occur in a complex pattern with the largest movement in the superior–inferior direction, an average of 6.7–19.0 mm 1 , 2 , 3 , 4 , 5 , 6 , 7 . In order to limit OAR and target motion, a variety of immobilization techniques are available and explained in detail by the report of AAPM Task Group 76, which contains the recommendation that in the cases where a

\geq 5 mm

range of motion is observed, respiratory management techniques should be employed 1 , 2 .…”

Section: Introductionmentioning

confidence: 99%

Evaluation of kidney motion and target localization in abdominal SBRT patients

Sonier

Chu

Lalani

et al. 2016

J Applied Clin Med Phys

View full text Add to dashboard Cite

The purpose of this study was to evaluate bilateral kidney and target translational/rotational intrafraction motion during stereotactic body radiation therapy treatment delivery of primary renal cell carcinoma and oligometastatic adrenal lesions for patients immobilized in the Elekta BodyFIX system. Bilateral kidney motion was assessed at midplane for 30 patients immobilized in a full‐body dual‐vacuum‐cushion system with two patients immobilized via abdominal compression. Intrafraction motion was assessed for 15 patients using kilovoltage cone‐beam computed tomography (kV‐CBCT) datasets (normaln=151) correlated to the planning CT. Patient positioning was corrected for translational and rotational misalignments using a robotic couch in six degrees of freedom if setup errors exceeded 1 mm and 1°. Absolute bilateral kidney motion between inhale and exhale 4D CT imaging phases for left–right (LR), superior–inferior (SI), and anterior–posterior (AP) directions was 1.51±1.00.15emmm,8.10±4.33.15emmm, and 3.08±2.11.15emmm, respectively. Residual setup error determined across CBCT type (pretreatment, intrafraction, and post‐treatment) for x (LR), y (SI), and z (AP) translations was 0.63±0.74.15emmm,1.08±1.38.15emmm, and 0.70±1.00.15emmm; while for x (pitch), y (roll), and z (yaw) rotations was 0.24±0.39°,0.19±0.34°, and 0.26±0.43°, respectively. Targets were localized to within 2.1 mm and 0.8° 95% of the time. The frequency of misalignments in the y direction was significant (p<0.05) when compared to the x and z directions with no significant difference in translations between IMRT and VMAT. This technique is robust using BodyFIX for patient immobilization and reproducible localization of kidney and adrenal targets and daily CBCT image guidance for correction of positional errors to maintain treatment accuracy.PACS number(s): 87.55.‐x, 87.56.‐v, 87.56.Da

show abstract

“…For these reasons, pretreatment determination of the composition of stones is essential. Since the early 1980s, studies have been conducted to determine stone composition on the basis of X-ray attenuation of stones in vitro [17][18][19][20][21][22] and in vivo [23][24][25].Organs in the upper part of the abdomen, including the liver, kidneys, and spleen, move considerably as a result of respiration [26] MATERIALS AND METHODS. The stones were placed in a jelly simulating the X-ray attenuation of the kidneys.…”

mentioning

confidence: 99%

“…Organs in the upper part of the abdomen, including the liver, kidneys, and spleen, move considerably as a result of respiration [26] MATERIALS AND METHODS. The stones were placed in a jelly simulating the X-ray attenuation of the kidneys.…”

mentioning

confidence: 99%

Characterization of Human Renal Stones with MDCT: Advantage of Dual Energy and Limitations Due to Respiratory Motion

Grosjean

Sauer

Guerra

et al. 2008

American Journal of Roentgenology

View full text Add to dashboard Cite

monohydrate stones are more resistant to extracorporeal lithotripsy [16] than are the other types of stones we describe. Failure of extracorporeal shock wave lithotripsy increases medical costs, necessitates alternative treatment, and results in undesirable exposure of the renal parenchyma to shock waves. For these reasons, pretreatment determination of the composition of stones is essential. Since the early 1980s, studies have been conducted to determine stone composition on the basis of X-ray attenuation of stones in vitro [17][18][19][20][21][22] and in vivo [23][24][25].Organs in the upper part of the abdomen, including the liver, kidneys, and spleen, move considerably as a result of respiration [26] MATERIALS AND METHODS. The stones were placed in a jelly simulating the X-ray attenuation of the kidneys. A dynamic platform was used to apply to the phantom free-breathing motion (sinusoidal motion in z-axis) and motion due to lack of maintenance of a breath-hold (5 mm·s −1 in z-axis). Determination of the chemical composition was performed with mean CT attenuation values obtained at 80 and 120 kV and with dual-energy CT attenuation values. G e n it o u r i n a r y I m ag i ng • O r ig i n a l R e s e a rc hRESULTS. Two hundred forty-one human urinary stones were classified into six groups: uric acid, cystine, struvite, weddellite (calcium oxalate dihydrate), whewellite (calcium oxalate monohydrate), and brushite. With no motion, the use of dual energy enabled differentiation of all of the types of stones with statistically significant differences. Uric acid (-20 ± 22 H), cystine (106 ± 19 H), struvite (271 ± 16 H), weddellite (323 ± 5 H), brushite (415 ± 30 H), and whewellite (510 ± 17 H) were identified as distinct groups. Motion-induced mean CT attenuation values were significantly different from those obtained with no motion. With motion, dual-energy CT attenuation values did not allow differentiation of all stone types.CONCLUSION. Dual-energy CT attenuation values can be used to predict the chemical composition of stones in vitro. However, when slight motion is applied to renal stones during image acquisition, the values become significantly different from those obtained with no motion. Consequently, confusion arises in differentiating stone types. A perfect breath-hold has to be performed for in vivo use of attenuation value to discern stone type.

show abstract

Abdominal organ motion measured using 4D CT

Cited by 160 publications

References 24 publications

Organ motion in pediatric high‐risk neuroblastoma patients using four‐dimensional computed tomography

Organ motion in pediatric high‐risk neuroblastoma patients using four‐dimensional computed tomography

Evaluation of kidney motion and target localization in abdominal SBRT patients

Characterization of Human Renal Stones with MDCT: Advantage of Dual Energy and Limitations Due to Respiratory Motion

Contact Info

Product

Resources

About