Effect of ProSpare (PS), a rectal obturator, on inter- and intrafraction prostate motion and anorectal doses in prostate radiotherapy (RT).

2016 ◽  
Vol 34 (2_suppl) ◽  
pp. e633-e633
Author(s):  
Julia Murray ◽  
Helen McNair ◽  
Emma Alexander ◽  
Tuathan O'Shea ◽  
Karen Thomas ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Controlled Trial ◽  
Cone Beam Ct ◽  
Prostate Radiotherapy ◽  
Intrafraction Motion ◽  
Prostate Motion ◽  
Gi Toxicity ◽  
Single Use ◽  
Rectal Filling ◽  
To Receive

e633 Background: PS is a single use, self-insertable endorectal device designed as a daily image-guidance tool for prostate cancer RT. Rectal filling is a significant factor in prostate motion. We investigated the effect of PS on inter- and intrafraction prostate motion and its effect on anorectal dosimetry. Methods: 19 patients with localized prostate cancer were randomized to receive prostate RT with PS either in the 1st or 2nd half of treatment. For each patient two planning CT scans were acquired, without and with PS. Contours were delineated by one physician and planned with a forward multi-segment technique to a dose of 74Gy/37F. Dose surface histograms were created (VODCA). In all patients, 3 electromagnetic transponders (EM) were implanted into the prostate and daily online image-guided RT was performed using either cone-beam CT (Elekta) or Calypso–based localization with tracking. Interfraction systematic (Σ) and random (σ) errors were estimated for bone matching without and with PS using EM position as reference. CTV-PTV margins were generated using the Van Herk formula. In-house code was used to analyse intrafraction motion recorded by Calypso of the EM centroid in the RL, SI and AP planes for individual fractions. A 2-way ANOVA test (SPSS v22) was used to determine if PS had an effect on maximal intrafraction prostate displacement. Results: See Table. Conclusions: PS affects the dosimetric pattern to the anal canal and rectum and this may impact GI toxicity. Also, PS stabilizes the prostate, which could enable reduced planning margins. PS will now be assessed in post-prostatectomy RT within a randomized controlled trial, POPS. Clinical trial information: 11814. [Table: see text] [Table: see text] [Table: see text]

scholarly journals Gastrointestinal and genitourinary toxicity profiles of metformin versus placebo in men with prostate cancer receiving prostate radiotherapy: interim toxicity results of a double-blinded, multicenter, phase II randomized controlled trial

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Julian O. Kim ◽  
Megan O. McDonald ◽  
Aldrich Ong ◽  
Rashmi Koul ◽  
Arbind Dubey ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Randomized Controlled Trial ◽  
Controlled Trial ◽  
Gastrointestinal Toxicity ◽  
Pelvic Radiotherapy ◽  
Prostate Radiotherapy ◽  
Randomized Controlled ◽  
Genitourinary Toxicity ◽  
Chi Squared ◽  
Double Blinded

AbstractAndrogen deprivation therapy (ADT) used for prostate cancer (PCa) management is associated with metabolic and anthropometric toxicity. Metformin given concurrent to ADT is hypothesized to counteract these changes. This planned interim analysis reports the gastrointestinal and genitourinary toxicity profiles of PCa patients receiving ADT and prostate/pelvic radiotherapy plus metformin versus placebo as part of a phase 2 randomized controlled trial. Men with intermediate or high-risk PCa were randomized 1:1 to metformin versus placebo. Both groups were given ADT for 18–36 months with minimum 2-month neoadjuvant phase prior to radiotherapy. Acute gastrointestinal and genitourinary toxicities were quantified using CTCAE v4.0. Differences in ≥ grade 2 toxicities by treatment were assessed by chi-squared test. 83 patients were enrolled with 44 patients randomized to placebo and 39 randomized to metformin. There were no significant differences at any time point in ≥ grade 2 gastrointestinal toxicities or overall gastrointestinal toxicity. Overall ≥ grade 2 gastrointestinal toxicity was low prior to radiotherapy (7.9% (placebo) vs. 3.1% (metformin), p = 0.39) and at the end of radiotherapy (2.8% (placebo) vs 3.1% (metformin), p = 0.64). There were no differences in overall ≥ grade 2 genitourinary toxicity between treatment arms (19.0% (placebo) vs. 9.4% (metformin), p = 0.30). Metformin added to radiotherapy and ADT did not increase rates of ≥ grade 2 gastrointestinal or genitourinary toxicity and is generally safe and well-tolerated.

Effect of magnesium oxide on interfraction prostate motion and rectal filling in prostate cancer radiotherapy

2014 ◽  
Vol 190 (8) ◽  
pp. 758-761 ◽  
Author(s):  
Annemarie M. den Harder ◽  
Carla H. van Gils ◽  
Alexis N.T.J. Kotte ◽  
Marco van Vulpen ◽  
Irene M. Lips
Keyword(s):  
Prostate Cancer ◽  
Magnesium Oxide ◽  
Cancer Radiotherapy ◽  
Prostate Motion ◽  
Prostate Cancer Radiotherapy ◽  
Rectal Filling

scholarly journals Measuring Radiation Toxicity Using Circulating Cell-Free DNA in Prostate Cancer Patients

2021 ◽  
Author(s):  
Natalie A. Lockney ◽  
Randal H. Henderson ◽  
Steven G. Swarts ◽  
Zhenhuan Zhang ◽  
Bingrong Zhang ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Radiation Toxicity ◽  
Cell Free Dna ◽  
Free Dna ◽  
Dose Volume ◽  
Gu Toxicity ◽  
Patient Reported ◽  
Gi Toxicity ◽  
Grade 3 ◽  
To Receive

Abstract Background After radiation therapy (RT), circulating plasma cell-free DNA (cfDNA) released in response to RT damage to tissue can be measured within hours. We examined for a correlation between cfDNA measured during the first week of therapy and early and late gastrointestinal (GI) and genitourinary (GU) toxicity. Material and Methods Patients were eligible for enrollment if they planned to receive proton or photon RT for nonmetastatic prostate cancer in the setting of an intact prostate or after prostatectomy. Blood was collected before treatment and on sequential treatment days for the first full week of therapy. Toxicity assessments were performed at baseline, weekly during RT, and 6 months and 12 months after RT. Data were analyzed to examine correlations among patient-reported GI and GU toxicities. Results Fifty-four patients were evaluable for this study. Four (7%) and 3 (6%) patients experienced acute and late grade 2 GI toxicity, respectively. Twenty-two (41%) and 18 (35%) patients experienced acute and late grade 2 GU toxicity, respectively. No patients developed grade 3 or higher toxicity. Grade 2 acute GI toxicity, but not grade 2 acute GU toxicity, was significantly correlated with pre-RT cfDNA levels and on all days 1, 2, 3, 4, and 5 of RT (P < .005). Grade 2 late GI toxicity, but not GU toxicity, was significantly correlated with pre-RT cfDNA levels (P = .021). Conclusions Based on this preliminary study, cfDNA levels can potentially predict the subset of patients destined to develop GI toxicity during prostate cancer treatment. Given that the toxicity profiles of the various fractionations and modalities are highly similar, the data support the expectation that cfDNA could provide a biological estimate to complement the dose-volume histogram. A test of this hypothesis is under evaluation in a National Cancer Institute–funded multi-institutional study.

scholarly journals OC-0500: Randomized controlled trial of Cone Beam CT IGRT in prostate cancer

2018 ◽  
Vol 127 ◽  
pp. S258
Author(s):  
H. Tøndel ◽  
J. Lund ◽  
S. Lydersen ◽  
A. Wanderås ◽  
B. Aksnessæther ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Randomized Controlled Trial ◽  
Controlled Trial ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Randomized Controlled

INTRAFRACTIONAL PROSTATE SHIFTS DURING STEREOTACTIC RADIATION THERAPY

2017 ◽  
Vol 63 (2) ◽  
pp. 287-293
Author(s):  
Sergey Kanaev ◽  
Sergey Novikov ◽  
Roman Novikov ◽  
Yu. Melnik ◽  
N. Ilin ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cone Beam Ct ◽  
Cone Beam ◽  
Stereotactic Radiation Therapy ◽  
Fiducial Markers ◽  
Dose Delivery ◽  
Stereotactic Radiation ◽  
Intrafraction Motion ◽  
Treatment Table ◽  
Anterior Posterior

In this study we analyzed prostate intrafraction motion during the course of stereotactic radiotherapy (STRT). STRT (5 fraction of 7.25Gy) was performed in 31 primary patients with prostate cancer. At least 3 gold fiducial markers were implanted in prostate of every patient 3-5 days before simulation. Prostate position on treatment table was verified with cone beam CT just before and immediately after the end of each radiotherapy session. This data help to determine prostate displacement in cranio-caudal, anterior-posterior and lateral axes. Average values of intra-fractional prostate displacement were as follows: 0,8+/-1,2mm - in cranio-caudal, 0.9+/-1,0mm - in lateral and 1.3+/-1,3mm - in anterior-posterior directions. In 5%-8,3% cases prostate displacement in cranio-caudal and lateral directions exceeded 2mm with maximal value of 5mm. In accordance with obtained average shifts we recommend following PTV margins: 1mm - in anterior-posterior and 3mm - in all other directions. In this case average intrafractional prostate shifts would not compromise dose delivery to prostate (V100 - 98%, D90 - 101%) and in comparison with standard (3mm, 5mm, 5mm, 5mm) margins would permit 16% reduction of rectum volume incorporated in 80% isodose. We propose that small average intrafractional displacement of prostate permits the use of narrower PTV margins without compromising coverage of the target and significant reduction of rectum volume covered by 80% isodose.

Errors from field placement and organ motion during conformal radiotherapy for prostate cancer

2000 ◽  
Vol 2 (2) ◽  
pp. 65-73
Author(s):  
J. Wu ◽  
T. Haycocks ◽  
H. Alasti ◽  
G. Ottewell ◽  
N. Middlemiss ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Conformal Radiotherapy ◽  
Target Volume ◽  
Fiducial Markers ◽  
Positioning Error ◽  
Field Placement ◽  
Setup Errors ◽  
Prostate Radiotherapy ◽  
Bony Landmarks ◽  
Prostate Motion

Purpose. To evaluate the effect of positioning errors from setup and from prostate motion during escalated dose conformal prostate irradiation for localised prostate cancer. Methods. Thirteen patients with localised prostate cancer had lateral portal films taken three times weekly during escalated dose conformal prostate radiotherapy. Field placement errors were measured by matching corresponding bony landmarks to the simulator film. Prostate motion at the base, mid-gland and apex was measured by imaging the displacement of 3 gold fiducial markers implanted into the prostate before therapy. From these measurements a planning target volume (PTV) was derived that allowed for both the prostate motion and field placement errors.Results. The random isocentre positioning error was 2.2 mm (range 0.2–7.3 mm), and the mean systematic isocentre positioning error was 1.4 mm (range 0.2–3.3 mm).Mean prostatic motion at the base was anterior 1.5 mm (SD 2.9 mm, range posterior 11.8 mm to anterior 16.8 mm), and superior 0.2 mm (SD 2.1 mm, range inferior 6.8 mm to superior 10.8 mm). At mid-gland it was anterior 0.6 mm (SD 2.4 mm, range posterior 7.2 mm to anterior 9.2 mm). At the apex it was posterior 0.3 mm (SD 2.1 mm, range posterior 7.9 mm to anterior 9.4 mm), and superior 0.5 mm (SD 2.1 mm, range inferior 6.7 mm to superior 10.2 mm).The margin of PTV about the prostate needed to give a 99% probability of the GTV remaining within the 95% isodose line during the course of therapy for these patients is superior 5.8 mm, and inferior 5.6 mm. In the anterior and posterior direction, this margin is 7.2 mm at the base, 6.5 mm at the mid-gland and 6.0 mm at the apex.Conclusions. Systematic setup errors were minimised by patient immobilisation and real-time corrections of setup errors. Prostate motion contributes the largest source of error, and this motion is greatest at the base of the gland compared to the apex. A non-uniform planning margin will improve target coverage while limiting normal tissue exposure. Fiducial markers implanted in the prostate improved quality assurance for radiation delivery by allowing confirmation of organ position within the treatment field over the course of therapy.

scholarly journals Analysis of the Influence of Peripheral Anatomical Changes for CBCT-Guided Prostate Cancer Radiotherapy

2021 ◽  
Vol 20 ◽  
pp. 153303382110163
Author(s):  
Yingjie Zhang ◽  
Xiangbin Zhang ◽  
Jing Li ◽  
Liang Zeng ◽  
Xuetao Wang ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cone Beam Ct ◽  
Target Position ◽  
The Body ◽  
Target Dose ◽  
Body Contour ◽  
Volume Variation ◽  
Rectal Volume ◽  
The Mean ◽  
Rectal Filling

Purpose: To analyze the influence of the bladder and rectum filling and the body contour changes on the prostate target dose. Methods: A total of 190 cone-beam CT (CBCT) image data sets from 16 patients with prostate cancer were used in this study. Dose reconstruction was performed on the virtual CT generated by the deformable planning CT. Then, the effects of the bladder filling, rectal filling, and the patient’s body contour changes of the PCTV1 (the prostate area, B1) and PCTV2 (the seminal vesicle area, B2) on the target dose were analyzed. Correlation analysis was performed for the ratio of bladder and rectal volume variation and the variation of the bladder and rectal dose. Results: The mean Dice coefficients of B1, B2, bladder, and rectum were 0.979, 0.975, 0.888 and 0.827, respectively, and the mean Hausdorff distances were 0.633, 1.505, 2.075, and 1.533, respectively. With the maximum volume variations of 142.04 ml for the bladder and 40.50 ml for the rectum, the changes of V100, V95, D2, and D98 were 1.739 ± 1.762 (%), 0.066 ± 0.169 (%), 0.562 ± 0.442 (%), and 0.496 ± 0.479 (%) in PCTV1 and 1.686 ± 1.051 (%), 0.240 ± 0.215 (%), 1.123 ± 0.925 (%), and 0.924 ± 0.662 (%) in PCTV2, respectively. With a 10% increase in the volume of the bladder and rectum, the V75, V70, and V65 of rectum increased at 0.73 (%), 0.71 (%), and 1.18 (%), and the V75, V70, and V65 of bladder changed at −0.21 (%), −0.32 (%), and −0.39 (%), respectively. Conclusion: Significant correlations were observed between the volume variation and the dose variation of the bladder and rectum. However, when a bladder and rectal filling protocol was adopted, the target dose coverage can be effectively ensured based on CBCT guidance to correct the prostate target position.

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