Rectal Filling at Planning Does Not Predict Stability of the Prostate Gland during a Course of Radical Radiotherapy if Patients with Large Rectal Filling are Re-imaged

Stillie, Alison; Kron, Tomas; Fox, C.; Herschtal, Alan; Haworth, Annette; Thompson, Andrea; Owen, Robert; Tai, Keen‐Hun; Duchesne, Gillian; Foroudi, Farshad

doi:10.1016/j.clon.2009.09.001

Cited by 18 publications

(30 citation statements)

References 19 publications

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“…The ability to visualise the prostate in three dimensions and its position relative to surrounding healthy tissues has become essential. Motion of the prostate is influenced by a number of factors including variability in rectal activity (Roeske et al 1995, Stillie et al 2009), bladder filling (Ten haken et al 1991) and clenching of the pelvic floor muscles (Padhani et al 1999). Image-guided radiotherapy for the prostate involves one of many methods of identifying the location of the prostate, followed by adjustment of the treatment fields to target the prostate.…”

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confidence: 99%

4D ultrasound speckle tracking of intra-fraction prostate motion: a phantom-based comparison with x-ray fiducial tracking using CyberKnife

O’Shea¹,

Garcia²,

Rosser³

et al. 2014

Phys. Med. Biol.

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This study investigates the use of a mechanically-swept 3D ultrasound (3D-US) probe for soft-tissue displacement monitoring during prostate irradiation with emphasis on quantifying the accuracy relative to CyberKnife® x-ray fiducial tracking. An US phantom, implanted with x-ray fiducial markers was placed on a motion platform and translated in 3D using 5 real prostate motion traces acquired using the Calypso system. Motion traces were representative of all types of motion as classified by studying Calypso data for 22 patients. The phantom was imaged using a 3D swept linear-array probe (to mimic trans-perineal imaging) and, subsequently, the kV x-ray imaging system on CyberKnife. A 3D cross-correlation block matching algorithm was used to track speckle in the ultrasound data. Fiducial and US data were each compared with known phantom displacement. Trans-perineal 3D-US imaging could track superior-inferior (SI) and anterior-posterior (AP) motion to ≤ 0.81 mm root-mean-square error (RMSE) at a 1.7 Hz volume rate. The maximum kV x-ray tracking RMSE was 0.74 mm, however the prostate motion was sampled at a significantly lower imaging rate (mean: 0.04 Hz). Initial elevational (RL) US displacement estimates showed reduced accuracy but could be improved (RMSE < 2.0 mm) using a correlation threshold in the ultrasound tracking code to remove erroneous inter-volume displacement estimates. Mechanically-swept 3D-US can accurately track the major components of intra-fraction prostate motion accurately but exhibits some limitations. The largest US RMSE was for elevational (right-left) motion. For the AP and SI axes, accuracy was sub-millimetre. It may be feasible to track prostate motion in 2D only. 3D-US also has potential for improvement for high tracking accuracy in all circumstances. It would be advisable to use US in conjunction with a small (~ 2.0 mm) centre-of-mass displacement threshold in which case it would be possible to take full advantage of the accuracy and high imaging rate capability.

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mentioning

confidence: 99%

4D ultrasound speckle tracking of intra-fraction prostate motion: a phantom-based comparison with x-ray fiducial tracking using CyberKnife

O’Shea¹,

Garcia²,

Rosser³

et al. 2014

Phys. Med. Biol.

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“…It is also important to note that the agents used may produce varied results depending on where in the rectum they are positioned and the method of insertion. The effectiveness of the evacuation procedures described above are most probably due to the reduction of gas and hence the timing of enema insertion may impact the effectiveness in • A trend for decreased PM observed with intervention but not significant • Percentage of CBCT scans with feces = 31% (P b .001) gas = 47% (P = .001); and moving gas = 28% (P b .001) Stillie 20 Interfraction PM Laxative and rescanning • No relationship between rectal volume and inter-or intrafraction prostate motion; therefore intervention was reported as successful • PM: Range (mm). RL = -0.6 to 0.5; SI = −0.4 to 1.0; AP = -0.9 to 0.9…”

Section: Discussionmentioning

confidence: 93%

“…The majority (4) investigated laxatives in combination with diet, 8,9,14,19 1 study used diet, laxatives, and scheduling, 16 and 1 study used laxatives and rescanning. 20 The results were variable, although some effectiveness was reported in 4 of the 6 studies 9,16,19,20 (Table 2). The 2 remaining studies both used antiflatulent diets with laxative (magnesium oxide or milk of magnesia) and reported no significant difference in clinically relevant intrafraction prostate motion between the 2 groups 8,14 (Table 2).…”

Section: Oral and Intravenous Medicationmentioning

confidence: 94%

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A systematic review: Effectiveness of rectal emptying preparation in prostate cancer patients

McNair

Wedlake

Lips

et al. 2014

Practical Radiation Oncology

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“…In this study, we selected two surrogate measures for rectal distension using the rectal diameter (AP and lateral) taken at a mid-point level of the treatment volume, since in studies assessing PSA relapse [1] or prostate movement [8] where multiple parameters were calculated, the rectal diameter remained significant. Furthermore, the relative ease, reproducibility and consistency of this calculation allow it to remain clinically practical.…”

Section: Discussionmentioning

confidence: 99%

Degree of Rectal Distension Seen on Prostate Radiotherapy Planning CT Scan Is Not a Negative Prognostic Factor in the Modern Era of Image-Guided Radiotherapy

Silverman

Johnson²,

Perry³

et al. 2015

Oncology

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Background: Studies have shown that rectal distension has a significant impact on treatment failure in patients receiving radical radiotherapy for prostate cancer. A distended rectum contributes to excessive organ movement during treatment, resulting in significant underdosing of the target volume and higher treatment failure rates. The increasing use of highly conformal, precise radiotherapy techniques places greater importance on reducing this risk. We tested whether imaging during radiotherapy helps minimise the negative impact that rectal distension has on long-term tumour control. Findings: The rectal diameter (anterior/posterior and lateral) was prospectively measured at radiotherapy planning in 172 consecutive patients undergoing radical radiotherapy with three-dimensional conformal radiotherapy. Daily, and then weekly, imaging during radiotherapy ensured that prostate movement remained within predefined tolerances. Patients were followed up for a median of 72 months with regular prostate-specific antigen (PSA) measurements to ascertain biochemical PSA relapse and survival information. Conclusions: In this cohort of predominately high-risk localised prostate cancer, rectal distension had no significant impact on PSA relapse. We suggest that regular imaging during radiotherapy negates the risk caused by rectal distension on local treatment failure.

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Rectal Filling at Planning Does Not Predict Stability of the Prostate Gland during a Course of Radical Radiotherapy if Patients with Large Rectal Filling are Re-imaged

Cited by 18 publications

References 19 publications

4D ultrasound speckle tracking of intra-fraction prostate motion: a phantom-based comparison with x-ray fiducial tracking using CyberKnife

4D ultrasound speckle tracking of intra-fraction prostate motion: a phantom-based comparison with x-ray fiducial tracking using CyberKnife

A systematic review: Effectiveness of rectal emptying preparation in prostate cancer patients

Degree of Rectal Distension Seen on Prostate Radiotherapy Planning CT Scan Is Not a Negative Prognostic Factor in the Modern Era of Image-Guided Radiotherapy

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