Dosimetric comparison of two treatment planning systems for spine SBRT

Lee, Young Kyung; Munawar, Iram; Mashouf, Shahram; Sahgal, Arjun; Ruschin, Mark

doi:10.1016/j.meddos.2019.07.001

Cited by 2 publications

(7 citation statements)

References 21 publications

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“…Monte Carlo-based calculations are expected to obtain higher D 0.01cc (or Dmax) when compared with convolution-based calculations. 13 Second, the reported differences between Pinnacle plans and Monaco plans in our study are partially due to mechanical differences in treatment machine geometries (larger MLC leaf width and longer SAD) and the presence of the magnetic field in MRL. 2,16 The MUs of the 13 beam plans and 9 beam plans were 50% and 28% higher than the Pinnacle plans, respectively, and this is consistent with other authors reporting that MRL plans could require >50% more MUs than clinical VMAT plans.…”

Section: Discussionmentioning

confidence: 66%

“…First, different TPSs optimize and convert plans differently. Monte Carlo‐based calculations are expected to obtain higher D 0.01cc (or Dmax) when compared with convolution‐based calculations 13 . Second, the reported differences between Pinnacle plans and Monaco plans in our study are partially due to mechanical differences in treatment machine geometries (larger MLC leaf width and longer SAD) and the presence of the magnetic field in MRL 2,16 …”

Section: Discussionmentioning

confidence: 72%

“…[9][10][11][12] Lee et al reported a statistically significant increase in target coverage in the Monaco treatment planning system (TPS) compared with other TPSs for conventional Linac treatment plans. 13 In our previous study, which showed a potential for spine SBRT on MRL through planning and delivery using an anthropomorphic spine phantom, 8 we found that the Monaco TPS can generate a plan for MRL similar to those generated by conventional TPSs. However, the mean spinal cord dose was increased in the adapted plans by up to 8.0% compared with the reference plans during the adapt-to-position (ATP) workflow.…”

Section: Introductionmentioning

confidence: 79%

“…As Lee et al. explained, whereas Pinnacle uses weight‐driven optimization such as Dmax, which penalizes individual hot voxels, Monaco uses constrained optimization that allows a small but controlled number of hot voxels, which often results in improvement of target coverage 13 . This GTV dose escalation with better visualization of the spinal cord by onboard MRI would fill a need for improved tumor control while safely sparing the spinal cord in cases where the tumor is adjacent to the spinal cord.…”

Section: Discussionmentioning

confidence: 99%

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Dosimetric analysis of MR‐LINAC treatment plans for salvage spine SBRT re‐irradiation

Han

Yeboa

Briere

et al. 2022

J Applied Clin Med Phys

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Purpose We investigated the feasibility of thoracic spine stereotactic body radiotherapy (SBRT) using the Elekta Unity magnetic resonance‐guided linear accelerator (MRL) in patients who received prior radiotherapy. We hypothesized that Monaco treatment plans can improve the gross tumor volume minimum dose (GTVmin) with spinal cord preservation and maintain consistent plan quality during daily adaptation. Methods Pinnacle clinical plans for 10 patients who underwent thoracic spine SBRT (after prior radiotherapy) were regenerated in the Monaco treatment planning system for the Elekta Unity MRL using 9 and 13 intensity‐modulated radiotherapy (IMRT) beams. Monaco adapt‐to‐position (ATP) and adapt‐to‐shape (ATS) workflow plans were generated using magnetic resonance imaging with a simulated daily positional setup deviation, and these adaptive plans were compared with Monaco reference plans. Plan quality measures included target coverage, Paddick conformity index, gradient index, homogeneity index, spinal cord D0.01cc, esophagus D0.01cc, lung V10, and skin D0.01cc. Results GTVmin values from the Monaco 9‐beam and 13‐beam plans were significantly higher than those from Pinnacle plans (p < 0.01) with similar spinal cord dose. Spinal cord D0.01cc, esophagus D0.01cc, and lung V10 did not statistically differ among the three plans. The electron‐return effect did not induce remarkable dose effects around the lungs or skin. While in the ATP workflow, a large increase in GTVmin was observed at the cost of a 10%–50% increase in spinal cord D0.01cc, in the ATS workflow, the spinal cord dose increase was maintained within 3% of the reference plan. Conclusion These findings show that MRL plans for thoracic spine SBRT are safe and feasible, allowing tumor dose escalation with spinal cord preservation and consistent daily plan adaptation using the ATS workflow. Careful plan review of hot spots and lung dose is necessary for safe MRL‐based treatment.

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Section: Discussionmentioning

confidence: 66%

Section: Discussionmentioning

confidence: 72%

Section: Introductionmentioning

confidence: 79%

Section: Discussionmentioning

confidence: 99%

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Dosimetric analysis of MR‐LINAC treatment plans for salvage spine SBRT re‐irradiation

Han

Yeboa

Briere

et al. 2022

J Applied Clin Med Phys

View full text Add to dashboard Cite

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“…In radiation therapy, the typical practice is to avoid radiation beams directly entering through the metal implants as recommended by TG 63, where the focus was on bulky implant such as the hip prosthesis. For patients with spine metastases, stereotactic body radiation therapy (SBRT) has been a prevalent treatment option, achieving fast pain relief, excellent local control, and low toxicity 2 . In these patients, spinal prostheses are frequently present; choosing beams to avoid the prostheses is not feasible due to the concaved tumor shape that surrounds the spinal cord and the prostheses.…”

Section: Introductionmentioning

confidence: 99%

The dosimetric impact of titanium implants in spinal SBRT using four commercial treatment planning algorithms

Liu

Cho

Magnelli

et al. 2023

J Applied Clin Med Phys

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To evaluate the dosimetric impact of titanium implants in spine SBRT using four dose calculation algorithms. Twenty patients with titanium implants in the spine treated with SBRT without density override (DO) were selected. The clinical plan for each patient was created in Pinnacle and subsequently imported into Eclipse (AAA and AcurosXB) and Raystation (CC) for dose evaluation with and without DO to the titanium implant. We renormalized all plans such that 90% of the tumor volume received the prescription dose and subsequently evaluated the following dose metrics: (1) the maximum dose to 0.03 cc (Dmax), dose to 99% (D99%) and 90% (D90%) of the tumor volume; (2) Dmax and volumetric metrics of the spinal cord. For the same algorithm, plans with and without DO had similar dose distributions. Differences in Dmax, D99% and D90% of the tumor were on average <2% with slightly larger variations up to 5.58% in Dmax using AcurosXB. Dmax of the spinal cord for plans calculated with DO increased but the differences were clinically insignificant for all algorithms (mean: 0.36% ± 0.7%). Comparing to the clinical plans, the relative differences for all algorithms had an average of 1.73% (−10.36%–13.21%) for the tumor metrics and −0.93% (−9.87%–10.95%) for Dmax of the spinal cord. A few cases with small tumor and spinal cord volumes, dose differences of >10% in both D99% and Dmax of the tumor, and Dmax of the spinal cord were observed. For all algorithms, the presence of titanium implants in the spine for most patients had minimal impact on dose distributions with and without DO. For the same plan calculated with different algorithms, larger differences in volumetric metrics of >10% could be observed, impacted by dose gradient at the plan normalization volume, tumor volumes, plan complexity, and partial voxel volume interpolation.

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Dosimetric comparison of two treatment planning systems for spine SBRT

Cited by 2 publications

References 21 publications

Dosimetric analysis of MR‐LINAC treatment plans for salvage spine SBRT re‐irradiation

Dosimetric analysis of MR‐LINAC treatment plans for salvage spine SBRT re‐irradiation

The dosimetric impact of titanium implants in spinal SBRT using four commercial treatment planning algorithms

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