Studies of Intra-Fraction Prostate Motion During Stereotactic Irradiation in First Irradiation and Re-Irradiation

Taillez, A.; Bimbai, André-Michel; Lacornerie, T.; Deley, Marie‐Cécile Le; Lartigau, Éric; Pasquier, David

doi:10.3389/fonc.2021.690422

Cited by 9 publications

(9 citation statements)

References 43 publications

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“…The simulated percent of time within thresholds per patient shown in Figures 5 and 6 considering the vector extremes of a 'worst case' displacement for the imaging interval indicated that when aggregating motion per patient the mean percent of time patients CTV within 3 mm 96.2% (1. 7 in agreement with this finding [12]. Furthermore Curtis et al, also reports that the analysis was completed under the assumption that a perfect correction occurred immediately for each interval simulated from the real-time data and as such, their analysis estimates an upper bound of the gain possible from frequent repositioning whereas the methods used in the current study are likely to have more conservative results.…”

Section: Discussionsupporting

confidence: 77%

“…Kioke et al, analysed 16 patients treated with CyberKnife and reported an a mean and standard deviation (SD) of 0.03 (0.91), -0.01 (0.35) and -0.02 (1.04) mm with average imaging interval of 70 seconds taken as the total treatment time divided by the total number of acquired images [11]. Taillez et al, calculated translations and rotations from 162 patients treated wit CyberKnife in order to observe the changes in deviations over the length of the treatment [12].…”

Section: Introductionmentioning

confidence: 99%

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Intrafraction motion during CyberKnife® prostate SBRT: impact of imaging frequency and patient factors

et al. 2023

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To determine the relationship between imaging frequencies and prostate motion during CyberKnife stereotactic body radiotherapy (SBRT) for prostate cancer. Methods: Intrafraction displacement data for 331 patients who received treatment with CyberKnife for prostate cancer were retrospectively analysed. Prostate positions were tracked with a large variation in imaging frequencies. The percent of treatment time that patients remained inside various motion thresholds for both real and simulated imaging frequencies was calculated. Results: 84,920 image acquisitions over 1635 fractions were analysed. Fiducial distance travelled between consecutive images were less than 2, 3, 5, and 10 mm for 92.4%, 94.4%, 96.2%, and 97.7% of all consecutive imaging pairs respectively. The percent of treatment time that patients received adequate geometric coverage increased with more frequent imaging intervals. No significant correlations between age, weight, height, Motion during CyberKnife prostate SBRT BMI, rectal, bladder or prostate volumes and intrafraction prostate motion were observed. Conclusions: There are several combinations of imaging intervals and movement thresholds that may be suitable for consideration during treatment planning with respect to imaging and CTV-to-PTV margin calculation, resulting in adequate geometric coverage for approximately 95% of treatment time. Rectal toxicities and treatment duration need to be considered when implementing combinations clinically.

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Section: Discussionsupporting

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Intrafraction motion during CyberKnife® prostate SBRT: impact of imaging frequency and patient factors

et al. 2023

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“…These treatments times are much shorter than CyberKnife treatments and multiple studies have shown that the longer the treatment time, the larger magnitude motion shifts, 25,26 although studies have noted a plateau in motion magnitude after approximately 20 min. 27 In this study imaging intervals were relatively short when compared to the imaging intervals of previous CyberKnife studies. It has been shown that rapid prostate motions can occur, so the authors believe these shorter imaging intervals are warranted to allow for treatment to be halted after large shifts have occurred.…”

Section: Discussionmentioning

confidence: 86%

Section: Discussionmentioning

confidence: 99%

Reducing PTV margins for prostate SBRT with motion compensation and gating techniques

Goddard

Jeong

Tang

et al. 2022

J Applied Clin Med Phys

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The purpose of this study is to investigate the dosimetric accuracy of prostate SBRT when motion is considered. To account for target movement, motion compensation and gating techniques were investigated with PTV margins reduced to 2 mm. To allow for dosimetric measurements a Delta4 phantom, Gafchromic film, and Hexamotion motion platform were utilized. Four motion files were utilized that represent a range of motions. Analysis of measured prostate motions for fifteen patients was performed to ensure detected motions were similar to those previously reported and motion files utilized were suitable. Five patient plans were utilized to allow for the effects of MLC and target motion interplay to be investigated. For both motion compensation and gating techniques, plans were delivered to the stationary phantom and for each of four motion types with/without compensation/gating enabled. Using a 3%, 2 mm and 80% threshold gamma criteria, film measurements had an average pass rate of 80.5% for uncorrected deliveries versus 96.0% for motion compensated deliveries. For gated techniques average pass rates increased from 89.9% for uncorrected to 94.8% with gating enabled. Measurements with the Delta4 arrays were analyzed with a 3%, 2 mm and 10% threshold dose. An average pass rate of 83.8% was measured for uncorrected motions versus 94.8% with motion compensation. For the gated technique an average pass rate of 87.2% was found for uncorrected motions versus 96.9% with gating enabled. These results show that very high gamma pass rates are achievable when motion compensation or gating techniques are applied. When target motion is not accounted for shifts up to 5 mm in planned versus delivered isodose distributions were found. However, when motion compensation, or gated techniques were applied, much smaller differences between planned and delivered isodose distributions were found. With these techniques dose delivery accuracy is greatly improved, allowing for PTV margins to be reduced.

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“…According to the aforementioned latest systematic review of the literature [31], 18 articles are available in the current literature concerning salvage prostate Re-I, accounting for a total of 511 patients with a median follow-up of 22 months (range 9.6-77.6). However, more recent articles have been published in the last 2 years [60][61][62][63][64][65][66][67][68].…”

Section: Discussionmentioning

confidence: 99%

Linac-based stereotactic salvage reirradiation for intraprostatic prostate cancer recurrence: toxicity and outcomes

Cozzi

Ghersi

Bardoscia³

et al. 2023

Strahlenther Onkol

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Background The rates of local failure after curative radiotherapy for prostate cancer (PC) remain high despite more accurate locoregional treatments available, with one third of patients experiencing biochemical failure and clinical relapse occurring in 30–47% of cases. Today, androgen deprivation therapy (ADT) is the treatment of choice in this setting, but with not negligible toxicity and low effects on local disease. Therefore, the treatment of intraprostatic PC recurrence represents a challenge for radiation oncologists. Prostate reirradiation (Re-I) might be a therapeutic possibility. We present our series of patients treated with salvage stereotactic Re‑I for intraprostatic recurrence of PC after radical radiotherapy, with the aim of evaluating feasibility and safety of linac-based prostate Re‑I. Materials and methods We retrospectively evaluated toxicities and outcomes of patients who underwent salvage reirradiation using volumetric modulated arc therapy (VMAT) for intraprostatic PC recurrence. Inclusion criteria were age ≥ 18 years, histologically proven diagnosis of PC, salvage Re‑I for intraprostatic recurrence after primary radiotherapy for PC with curative intent, concurrent/adjuvant ADT with stereotactic body radiation therapy (SBRT) allowed, performance status ECOG 0–2, restaging choline/PSMA-PET/TC and prostate MRI after biochemical recurrence, and signed informed consent. Results From January 2019 to April 2022, 20 patients were recruited. Median follow-up was 26.7 months (range 7–50). After SBRT, no patients were lost at follow-up and all are still alive. One- and 2‑year progression free survival (PFS) was 100% and 81.5%, respectively, while 2‑year biochemical progression-free survival (bFFS) was 88.9%. Four patients (20%) experienced locoregional lymph node progression and were treated with a further course of SBRT. Prostate reirradiation allowed the ADT start to be postponed for 12–39 months. Re‑I was well tolerated by all patients and none discontinued the treatment. No cases of ≥ G3 genitourinary (GU) or gastrointestinal (GI) toxicity were reported. Seven (35%) and 2 (10%) patients experienced acute G1 and G2 GU toxicity, respectively. Late GU toxicity was recorded in 10 (50%) patients, including 8 (40%) G1 and 2 (10%) G2. ADT-related side effects were found in 7 patients (hot flashes and asthenia). Conclusion Linac-based SBRT is a safe technique for performing Re‑I for intraprostatic recurrence after primary curative radiotherapy for PC. Future prospective, randomized studies are desirable to better understand the effectiveness of reirradiation and the still open questions in this field.

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Studies of Intra-Fraction Prostate Motion During Stereotactic Irradiation in First Irradiation and Re-Irradiation

Cited by 9 publications

References 43 publications

Intrafraction motion during CyberKnife® prostate SBRT: impact of imaging frequency and patient factors

Intrafraction motion during CyberKnife® prostate SBRT: impact of imaging frequency and patient factors

Reducing PTV margins for prostate SBRT with motion compensation and gating techniques

Linac-based stereotactic salvage reirradiation for intraprostatic prostate cancer recurrence: toxicity and outcomes

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