Adaptive SBRT by 1.5 T MR-linac for prostate cancer: On the accuracy of dose delivery in view of the prolonged session time

Ruggieri, R.; Rigo, Michele; Naccarato, S.; Gurrera, Davide; Figlia, Vanessa; Mazzola, Rosario; Ricchetti, F.; Nicosia, Luca; Giaj-Levra, Niccolò; Cuccia, Francesco; Vitale, Claudio; Stavreva, N; Pressyanov, D.; Stavrev, Pavel; Pellegrini, Roberto; Alongi, Filippo

doi:10.1016/j.ejmp.2020.09.026

Cited by 21 publications

(23 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The intensity modulated radiation therapy (step-and-shoot) plans from the human planner (“manual”) conceived in this study were replanned from scratch by Monaco (5.59.13 research version, running on 2 Quadro-GV100 32GB Nvidia GPUs) on the 5 MRI scans and structure sets of the daily treatments, where the planning target volume (PTV) was obtained by isotropically expanding the clinical target volume (CTV) by 5 mm except by 3 mm posteriorly, by starting from the template of cost functions and parameter values of the original ATS plans. All plans computed here, similarly to our ATS plans detailed previously, 15 were based on 16 angularly equispaced static fields for a total of less than 100 segments and optimized by fixing the electron density to 1.0 for each tissue, but for the bone tissues (femoral heads, iliac wings, and sacrum), with bulk densities obtained from computed tomography. The segmentation settings were 8 mm as a minimum segment width, 5 cm 2 as a minimum segment area, “high” for fluence smoothing, and 9 as the minimum monitor units (MUs) per segment.…”

Section: Methodsmentioning

confidence: 99%

“…For prostate cancer (PC) stereotactic body radiation therapy (SBRT), typically given in 5 fractions, ATS workflow is generally the standard choice. The full involvement of an expert planner in such online optimization workflow, as previously detailed, 15 is a complex task. Thus, aiming to the potential substitution of the human expert by a trustworthy autoplanning system, we performed this preliminary plan comparison study as the first verification, to our knowledge, of the feasibility of using mCycle for PC-SBRT on the 1.5 T MR-linac.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Automated Planning for Prostate Stereotactic Body Radiation Therapy on the 1.5 T MR-Linac

Naccarato

Rigo

Pellegrini

et al. 2022

Advances in Radiation Oncology

Self Cite

View full text Add to dashboard Cite

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Automated Planning for Prostate Stereotactic Body Radiation Therapy on the 1.5 T MR-Linac

Naccarato

Rigo

Pellegrini

et al. 2022

Advances in Radiation Oncology

Self Cite

View full text Add to dashboard Cite

“…For both devices, given the relatively longer treatment time per session, the simulation process is a crucial factor in order to perform an accurate and refined treatment delivery. Based on available literature, most experiences reported a similar protocol in terms of bladder filling and rectal emptying ( [32][33][34][35][36][37][38]-see Table 1). For both the CT scan (performed for dose calculation purposes) and the MRI scan, patients were educated to have a half-full bladder in order to take into account residual volume changes during the plan adaptation phase (Figure 2).…”

Section: Mr-guided Radiotherapy: Present Evidencementioning

confidence: 99%

MR-Guided Hypofractionated Radiotherapy: Current Emerging Data and Promising Perspectives for Localized Prostate Cancer

Cuccia

Corradini

Mazzola

et al. 2021

Cancers

Self Cite

View full text Add to dashboard Cite

In this review we summarize the currently available evidence about the role of hybrid machines for MR-guided radiotherapy for prostate stereotactic body radiotherapy. Given the novelty of this technology, to date few data are accessible, but they all report very promising results in terms of tolerability and preliminary clinical outcomes. Most of the studies highlight the favorable impact of on-board magnetic resonance imaging as a means to improve target and organs at risk identification with a consequent advantage in terms of dosimetric results, which is expected to relate to a more favorable toxicity pattern. Still, the longer treatment time per session may potentially affect the patient’s compliance to the treatment, although first quality of life assessment studies have reported substantial tolerability and no major impact on quality of life. Finally, in this review we hypothesize some future scenarios of further investigation, based on the possibility to explore the superior anatomy visualization and the role of daily adapted treatments provided by hybrid MR-Linacs.

show abstract

“…Meanwhile, a full plan re-optimization was performed, a veri cation MRI-scan was acquired in order to assess any target and OARs movements. [15] Afterwards, the radiation oncologist and the physicist evaluated the new treatment plan and checked the absence of major movements by visual comparation (iso-to-iso) of the images and contours. In this case, the radiation treatment was delivered, otherwise a new ATP or ATS were started.…”

Section: Online Adaptive Work Ow and Dose Deliverymentioning

confidence: 99%

Mitigation on bowel loops daily variations by 1.5-T MR-guided daily-adaptive SBRT for abdomino-pelvic lymph-nodal oligometastases

Cuccia

Rigo

Gurrera

et al. 2021

J Cancer Res Clin Oncol

Self Cite

View full text Add to dashboard Cite

We report preliminary dosimetric data concerning the use of 1.5-T MR-guided daily-adaptive radiotherapy for abdomino-pelvic lymph-nodal oligometastases. We aimed to assess the impact of this technology on mitigating daily variations for both target coverage and organs-at-risk (OARs) sparing. MethodsA total of 150 sessions for 30 oligometastases in 23 patients were analyzed. All patients were treated with MR-guided stereotactic body radiotherapy (SBRT) for a total dose of 35Gy in 5 fractions. For each fraction, a quantitative analysis was performed for PTV volume, V35Gy and Dmean. Similarly, for OARs we assessed daily variations of volume, Dmean, Dmax. Any potential statistically signi cant change between baseline planning and daily-adaptive sessions was assessed using the Wilcoxon signed-rank test, assuming a p-value< 0.05 as signi cant. ResultsAverage baseline PTV, bowel, bladder and single intestinal loop volumes were respectively 8.9cc (range, 0.7-41.2cc), 1176cc (119-3654 cc), 95cc (39.7-202.9 cc), 18.3cc (9.1-37.7 cc). No signi cant volume variations were detected for PTV (p=0.21) bowel (p=0.36), bladder (p=0.47), except for single intestinal loops, which resulted smaller (p=0.026).Average baseline V35Gy and Dmean for PTV were respectively 85.6% (72-98.8%) and 35.6 Gy (34.6-36.1 Gy). We recorded a slightly positive trend in favor of daily-adaptive strategy vs baseline planning for improved target coverage, although not reaching statistical signi cance. (p=0.11 and p=0.18 for PTV-V35Gy and PTV-Dmean).Concerning OARs, a signi cant difference was observed in favor of daily-adapted treatments in terms of single intestinal loop Dmax [23.05 Gy (13.2-26.9 Gy) at baseline vs 20.5 Gy (12.1-24 Gy); p-value=0.0377] and Dmean [14.4 Gy (6.5-18 Gy) at baseline vs 13.0 Gy (6.7-17.6 Gy); p-value=0.0003].Speci cally for bladder, the average Dmax was 18.6 Gy (0.4-34.3 Gy) at baseline vs 18.3 Gy (0.7-34.3 Gy) for a p-value=0.28; the average Dmean was 7.0 Gy (0.2-16.6 Gy) at baseline vs 6.98 Gy (0.2-16.4 Gy) for a p-value=0.66. Concerning the bowel, no differences in terms of Gy) vs 5.6 Gy (1.4-10.5 Gy); p-value=0.23] were observed between after daily-adapted sessions. A statistically signi cant difference was observed for bowel Dmax [26.4 Gy (7.7-34 Gy) vs 25.8 Gy (7.8-33.1 Gy); p-value=0.0086]. ConclusionsDaily-adaptive MR-guided SBRT reported a signi cantly improved single intestinal loop sparing for lymphnodal oligometastases. Also bowel Dmax was signi cantly reduced with daily-adaptive strategy. A minor

show abstract

Adaptive SBRT by 1.5 T MR-linac for prostate cancer: On the accuracy of dose delivery in view of the prolonged session time

Cited by 21 publications

References 21 publications

Automated Planning for Prostate Stereotactic Body Radiation Therapy on the 1.5 T MR-Linac

Automated Planning for Prostate Stereotactic Body Radiation Therapy on the 1.5 T MR-Linac

MR-Guided Hypofractionated Radiotherapy: Current Emerging Data and Promising Perspectives for Localized Prostate Cancer

Mitigation on bowel loops daily variations by 1.5-T MR-guided daily-adaptive SBRT for abdomino-pelvic lymph-nodal oligometastases

Contact Info

Product

Resources

About