The analysis of respiration-induced pancreatic tumor motion based on reference measurement

Knybel, Lukáš; Cvek, Jakub; Otahal, B.; Jonszta, Tomáš; Molenda, Lukas; Czerný, Daniel; Skácelíková, Eva; Rybar, M.; Dvořák, Pavel; Feltl, David

doi:10.1186/1748-717x-9-192

Cited by 16 publications

(22 citation statements)

References 21 publications

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“…Several studies have demonstrated significant effects of the above‐listed immobilization devices in intrafraction motion mitigation, 21 , 23 , 29 , 30 the unconstrained condition was therefore not included in the study, since our goal was to quantify the level of immobilization in the abdomen–pelvis region as a function of patient setup position and selected immobilization devices. It should be noted that the condition “vacuum cushion” cannot be considered an unconstrained condition, since the MR scan was performed with the body matrix coil slightly tightened to the patient thorax and back (supine and prone position, respectively), mimicking the effects of a mild restraining belt.…”

Section: Methodsmentioning

confidence: 99%

“…Interfraction variations are determined by anatomical or physiological modifications, which potentially could be managed with pretreatment in‐room imaging and replanning tools (20) . Conversely, intrafraction variations are mainly introduced by periodic anatomical changes, such as breathing motion, especially in the superior–inferior (SI) direction 21 , 22 , 23 , 24 . Specific treatment planning schemes have been designed in order to account for breathing motion (25) .…”

Section: Introductionmentioning

confidence: 99%

“…Four‐dimensional CT and MR imaging yield a time‐resolved volumetric dataset composed by images describing the different breathing phases along the complete respiratory cycle. Pancreas motion has been investigated with the purpose of radiation therapy (RT) treatment with both CT and MR imaging 21 , 22 , 23 , 24 , 28 . However, those studies mainly focused on the range of motion specific to the lesion rather than characterizing pancreas motion in presence of typical RT/PT setup immobilization devices.…”

Section: Introductionmentioning

confidence: 99%

“…(20) Conversely, intrafraction variations are mainly introduced by periodic anatomical changes, such as breathing motion, especially in the superior-inferior (SI) direction. (21,22,23,24) Specific treatment planning schemes have been designed in order to account for breathing motion. (25) Respiratory gated particle irradiation, in particular, entails the delivery of the planned dose in correspondence of a predefined respiratory gate featuring the highest motion stability and repeatability of the anatomopathological configuration.…”

Section: Introductionmentioning

confidence: 99%

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MRI quantification of pancreas motion as a function of patient setup for particle therapy —a preliminary study

Fontana

Riboldi

Gianoli

et al. 2016

J Applied Clin Med Phys

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Particle therapy (PT) has shown positive therapeutic results in local control of locally advanced pancreatic lesions. PT effectiveness is highly influenced by target localization accuracy both in space, since the pancreas is located in proximity to radiosensitive vital organs, and in time as it is subject to substantial breathing‐related motion. The purpose of this preliminary study was to quantify pancreas range of motion under typical PT treatment conditions. Three common immobilization devices (vacuum cushion, thermoplastic mask, and compressor belt) were evaluated on five male patients in prone and supine positions. Retrospective four‐dimensional magnetic resonance imaging data were reconstructed for each condition and the pancreas was manually segmented on each of six breathing phases. A k‐means algorithm was then applied on the manually segmented map in order to obtain clusters representative of the three pancreas segments: head, body, and tail. Centers of mass (COM) for the pancreas and its segments were computed, as well as their displacements with respect to a reference breathing phase (beginning exhalation). The median three‐dimensional COM displacements were in the range of 3 mm. Latero–lateral and superior–inferior directions had a higher range of motion than the anterior–posterior direction. Motion analysis of the pancreas segments showed slightly lower COM displacements for the head cluster compared to the tail cluster, especially in prone position. Statistically significant differences were found within patients among the investigated setups. Hence a patient‐specific approach, rather than a general strategy, is suggested to define the optimal treatment setup in the frame of a millimeter positioning accuracy.PACS number(s): 87.55.‐x, 87.57.nm, 87.61

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

MRI quantification of pancreas motion as a function of patient setup for particle therapy —a preliminary study

Fontana

Riboldi

Gianoli

et al. 2016

J Applied Clin Med Phys

View full text Add to dashboard Cite

show abstract

“…The motion of the pancreas has been shown to preferentially move during respiration 1.5 to 2.0 cm in superior-inferior direction and 0.5 to 1.0 cm radially. 13,14 Respiratory-gating treatment is a technique where the beam is delivered to the tumor at a particular respiratory phase. The advantage of this technique is that the planning margins can be smaller so less normal tissue is irradiated.…”

Section: Target and Critical Organsmentioning

confidence: 99%

Ipsilateral kidney sparing in treatment of pancreatic malignancies using volumetric-modulated arc therapy avoidance sectors

Chan

Podgorsak

2015

Medical Dosimetry

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Evaluating motion of pancreatic tumors and anatomical surrogates using cine MRI in 0.35T MRgRT under free breathing conditions

Lewis

Guta

Shin

et al. 2023

J Applied Clin Med Phys

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Treatment tolerability is a significant limitation to pancreatic cancer treatment with radiotherapy due to proximity to highly radiosensitive organs and respiratory motion necessitating expanded target margins. Further, pancreatic tumors are difficult to visualize on conventional radiotherapy systems. Surrogates are often used to locate the tumor but are often inconsistent and do not provide strong positional relations throughout the respiratory cycle. This work utilizes a retrospective dataset of 45 pancreatic cancer patients treated on an MR-Linac system with cine MRI acquired for real-time target tracking. We investigated intra-fraction motion of tumors and two abdominal surrogates, leading to prediction models between the tumor and surrogate.Patient specific motion evaluation and prediction models were generated from 225 cine MRI series acquired during treatment. Tumor contours were used to evaluate the pancreatic tumor motion. Linear regression and principal component analysis (PCA) based models were used to predict tumor position from the anterior-posterior (AP) motion of the abdominal surface, the superior-inferior (SI) motion of the diaphragm, or a combination. Models were evaluated using mean squared error (MSE) and mean absolute error (MAE). Contour analysis showed the average pancreatic tumor motion range was 7.4 ± 2.7 mm and 14.9 ± 5.8 mm in the AP and SI directions, respectively. The PCA model had MSE of 1.4 mm 2 and 0.6 mm 2 , for the SI and AP directions, respectively, with both surrogates as inputs for the models. When only the abdomen surrogate was used, MSE was 1.3 mm 2 and 0.4 mm 2 in the SI and AP directions, while it was 0.4 mm 2 and 1.3 mm 2 when only the diaphragm surrogate was used. We evaluated intra-fraction pancreatic tumor motion and demonstrated prediction models between the tumor and surrogate. The models calculated the pancreatic tumor position from diaphragm, abdominal, or both contours within standard pancreatic cancer target margin, and the process could be applied to other disease sites in the abdominothoracic cavity.

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The analysis of respiration-induced pancreatic tumor motion based on reference measurement

Cited by 16 publications

References 21 publications

MRI quantification of pancreas motion as a function of patient setup for particle therapy —a preliminary study

MRI quantification of pancreas motion as a function of patient setup for particle therapy —a preliminary study

Ipsilateral kidney sparing in treatment of pancreatic malignancies using volumetric-modulated arc therapy avoidance sectors

Evaluating motion of pancreatic tumors and anatomical surrogates using cine MRI in 0.35T MRgRT under free breathing conditions

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