Validation of a robust strategy for proton spot scanning for oesophageal cancer in the presence of anatomical changes

Møller, D.S.; Alber, M.; Nordsmark, Marianne; Nyeng, T.B.; Lutz, Christina; Hoffmann, Lone

doi:10.1016/j.radonc.2018.09.018

Cited by 19 publications

(25 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Many studies have reported that these anatomical changes affected the dose to the target and OARs. 20 , 21 Other studies reported a similar trend in the dose changes to the OARs. However, its effect on the dose to the target was little.…”

Section: Discussionmentioning

confidence: 70%

“…The dose to the OARs on the distal side of the beam increased, and the doses to the contralateral optic apparatus, optic chiasm, and brainstem tended to increase significantly (Table 2 and Figure 1c–j). Many studies have reported that these anatomical changes affected the dose to the target and OARs 20,21 . Other studies reported a similar trend in the dose changes to the OARs.…”

Section: Discussionmentioning

confidence: 83%

See 1 more Smart Citation

Trend analysis of the dosimetric impact of anatomical changes during proton therapy for maxillary sinus carcinoma

Narita

Katō

Ono

et al. 2021

J Applied Clin Med Phys

View full text Add to dashboard Cite

Purpose Anatomical changes, such as shrinkage and aeration, can affect dose distribution in proton therapy (PT) for maxillary sinus carcinoma (MSC). These changes can affect the dose to the target and organs at risk (OARs); however, when these changes occur during PT is unclear. This study aimed to investigate the dosimetric impact of anatomical changes during PT. Materials and Methods Fifteen patients with MSC were enrolled in this study. Initial PT plans were generated based on initial computed tomography (CT) images. Several repeat CT images were obtained to confirm anatomical changes during PT. Evaluation PT plans were generated by copying initial PT plans to repeat CT images. The dose differences of the target and OARs were evaluated by comparing both the plans. Results At 3–4 weeks after the initiation of PT, the target volume reduced by approximately 10% as compared with the initial volume. Consequently, the target volumes gradually varied until the end of treatment. The value of V95 (volume that received 95% of the prescription dose) in the clinical target volume of the evaluation PT plan was similar to that of the initial PT plan. However, the dose to OARs, such as the contralateral optic nerve, contralateral eyeball, brainstem, and optic chiasm, increased significantly from the middle to the later phases of the treatment course. In contrast, there was a slight dose difference in the ipsilateral optic apparatus. Conclusion The trend analysis in this study showed that anatomical changes appeared 3–4 weeks after the start of PT, and the dose to the OARs tended to increase. Therefore, it is recommended to check the status of tumor 3–4 weeks after the start of treatment to avoid the deterioration of dose distribution due to these changes.

show abstract

Section: Discussionmentioning

confidence: 70%

Section: Discussionmentioning

confidence: 83%

Trend analysis of the dosimetric impact of anatomical changes during proton therapy for maxillary sinus carcinoma

Narita

Katō

Ono

et al. 2021

J Applied Clin Med Phys

View full text Add to dashboard Cite

show abstract

“…Indeed, similar robustness to anatomical changes have been found by a number of authors through a similarly careful selection of beam angles, 16,17 the use of robust optimizaton 18 or through reduced in-field modulation of plans. 19 Myth 2: the Bragg peak is the sharpest gradient The distal fall-off of a Bragg peak in water is indeed sharp, as seen in Figures 1 and 3. Indeed, for a SOBP with a range of 15 cm in water, corresponding to a maximum energy of about 150 MeV, the distal 80-20% fall-off is 4.5 mm (Figure 1).…”

mentioning

confidence: 79%

Myths and realities of range uncertainty

Lomax

2019

The British Journal of Radiology

View full text Add to dashboard Cite

Range uncertainty is a much discussed topic in proton therapy. Although a very real aspect of proton therapy, its magnitude and consequences are sometimes misunderstood or overestimated. In this article, the sources and consequences of range uncertainty are reviewed, a number of myths associated with the effect discussed with the aim of putting range uncertainty into clinical context and attempting to de-bunk some of the more exaggerated claims made as to its consequences.

show abstract

“…A thorough checking with manual adjustments was performed in this study, to cope with this issue. Furthermore, it has been shown in other studies that it is possible to combine deformable image registration algorithms for contour propagation with other (semi)automatic techniques like a watershed-cuts algorithm to improve the accuracy of the contours [42]. where several reconstruction methods for 1-min acquisitions were compared for image quality and a common framework for evaluation of reconstruction methods was built [15].…”

Section: Discussionmentioning

confidence: 99%

“…Additionally, anatomical changes such as pleural effusion, (resolving) atelectasis, gastric and bowel filling variations, mediastinal deformations and target volume changes may also affect PBS-PT treatment, [29,34,[36][37][38][39][40][41][42]. All these motion types can influence the breathing motion and cause target deformations and displacements, and also cause tissue density changes along the beam paths [43,44].…”

Section: Moving Targetsmentioning

confidence: 99%

Motion monitoring for moving targets treated with pencil beam scanned proton therapy

Otter¹

View full text Add to dashboard Cite

Motion monitoring for moving targets treated with pencil beam scanned proton therapyProefschrift ter verkrijging van de graad van doctor aan de Rijksuniversiteit Groningen op gezag van de rector magnificus prof. dr. C. Wijmenga en volgens besluit van het College voor Promoties. De openbare verdediging zal plaatsvinden op woensdag 20 oktober 2021 om 14.30 uur door Lydia Anneke den Otter geboren op 10 januari 1991 te Zeist Promotores Prof. dr. S. Both Prof. dr. J.A. Langendijk Beoordelingscommissie Prof. dr. S. Brandenburg Prof. dr. F. Verhaegen Prof. dr. D. De RuysscherContents 1 General introduction 2 Reproducibility of the lung anatomy under active breathing coordinator control: Dosimetric consequences for scanned proton treatments 3 Investigation of inter-fraction target motion variations in the context of pencil beam scanned proton therapy in non-small cell lung cancer patients 4 4D cone-beam CT reconstruction from sparse-view CBCT data for daily motion assessment in pencil beam scanned proton therapy (PBS-PT) 5 Diaphragm based position verification to improve daily target dose coverage in proton and photon radiotherapy treatment of distal esophageal cancer 6 Summarizing discussion and future perspectives 7 Nederlandse samenvatting Appendices 6 Chapter 1 General introduction 7 Chapter 1ABC lung anatomy reproducibility for scanned proton treatments difference of 0.9 Gy (range: -0.3 to 4.6 Gy). For 14/23 simulations the increment was beyond the allowed maximum dose of 63.0 Gy, though remained under 66.0Gy (110% of the prescribed dose of 60.0 Gy). Organs at risk doses differed little compared to the planned doses (difference in mean doses <0.9 Gy for the heart and lungs, <1.4% difference in V 35 [%] and V 20 [%] to the esophagus and lung).Conclusions: When treating under ABC controlled breath-hold, robustly optimized IMPT plans show limited dosimetric consequences due to anatomical variations between repeated ABC breathholds for most cases. Thus, the combination of robustly optimized IMPT plans and the delivery under ABC controlled breathhold presents a safe approach for PBS lung treatments.

show abstract

Validation of a robust strategy for proton spot scanning for oesophageal cancer in the presence of anatomical changes

Cited by 19 publications

References 26 publications

Trend analysis of the dosimetric impact of anatomical changes during proton therapy for maxillary sinus carcinoma

Trend analysis of the dosimetric impact of anatomical changes during proton therapy for maxillary sinus carcinoma

Myths and realities of range uncertainty

Motion monitoring for moving targets treated with pencil beam scanned proton therapy

Contact Info

Product

Resources

About