Clinical outcomes of stereotactic radiotherapy for stage I non-small cell lung cancer using a novel irradiation technique: patient self-controlled breath-hold and beam switching using a combination of linear accelerator and CT scanner

Oda, Hiroshi; Kuriyama, Kinya; Komiyama, Takafumi; Tanaka, Shiho; Sano, Nobuyuki; Marino, Kan; Ikenaga, Satoshi; Araki, Tsutomu; Uematsu, Minoru

doi:10.1016/j.lungcan.2004.01.004

Cited by 116 publications

(93 citation statements)

References 24 publications

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“…After completing treatment, the serial chest CT scans taken one month and every three months thereafter were used to evaluate the result and/or 18 FDG-PET scans were taken one month after the radiotherapy. The survival time was determined from the first day of stereotactic treatment and the local progression free survival and overall survival were calculated using the Kaplan-Meier method [16].…”

Section: Evaluation Of the Treatment Resultsmentioning

confidence: 99%

“…Uematsu et al reported the fusion of CT and linac (FOCAL) system for achieving the direct positioning of the target with a CT scanner and immediate radiotherapy using a linear accelerator [11,17]. Onishi et al also introduced a similar treatment unit to provide precise targeting of the tumor [18]. These systems shared a couch for CT scanning and treatment delivery, the patients did not need to move on the couch during verification and treatment.…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, more accurate modalities are needed for evaluating the tumor response and tumor recurrence. 18 FDG-PET scans are occasionally used as an alternative method for evaluating the treatment response, and it would be a promising modality for diagnosing the disease condition. When using 18 FDG-PET scans after radiotherapy, it should be noted that radiation can incite macrophage-mediated inflammation, which may be metabolically active on PET imaging, and these changes usually peak within six to 12 weeks after completing therapy [25,26].…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, it is important to determine the optimal scanning time after radiotherapy. Having the follow-up 18 FDG-PET scan one month after the completion of radiotherapy was not too rapid for evaluating the response to radiation in patients with a squamous cell carcinoma of the head and neck [27]. If this result can be used to evaluate the response of a lung tumor to stereotactic radiation therapy, it is possible that the initial response can be diagnosed before the appearance of pulmonary changes.…”

Section: Discussionmentioning

confidence: 99%

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Clinical results of stereotactic body frame based fractionated radiation therapy for primary or metastatic thoracic tumors

et al. 2006

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Section: Evaluation Of the Treatment Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Clinical results of stereotactic body frame based fractionated radiation therapy for primary or metastatic thoracic tumors

et al. 2006

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“…Specifically for lung SBRT, the Radiation Therapy Oncology Group (RTOG) protocols accept a range between 60% and 90% 13 , 14 , 15 . Various studies have reported prescription isodose lines at the 40%–48%, (16) 50%, (17) 60%, (18) 65%, 19 , 20 , 21 , 22 80%, 2 , 3 , 22 , 23 , 24 , 25 85%, (26) and 90% (27) levels.…”

Section: Introductionmentioning

confidence: 99%

Effect of the normalized prescription isodose line on the magnitude of Monte Carlo vs. pencil beam target dose differences for lung stereotactic body radiotherapy

Zheng

Liang

Zhu

et al. 2016

J Applied Clin Med Phys

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In lung stereotactic body radiotherapy (SBRT) cases, the pencil beam (PB) dose calculation algorithm is known to overestimate target dose as compared to the more accurate Monte Carlo (MC) algorithm. We investigated whether changing the normalized prescription isodose line affected the magnitude of MC vs. PB target dose differences. Forty‐eight patient plans and twenty virtual‐tumor phantom plans were studied. For patient plans, four alternative plans prescribed to 60%, 70%, 80%, and 90% isodose lines were each created for 12 patients who previously received lung SBRT treatments. Using 6 MV dynamic conformal arcs, the plans were individually optimized to achieve similar dose coverage and conformity for all plans of the same patient, albeit at the different prescription levels. These plans, having used a PB algorithm, were all recalculated with MC to compare the target dose differences. The relative MC vs. PB target dose variations were investigated by comparing PTV D95, Dmean, and D5 loss at the four prescription levels. The MC‐to‐PB ratio of the plan heterogeneity index (HI) was also evaluated and compared among different isodose levels. To definitively demonstrate the cause of the isodose line dependence, a simulated phantom study was conducted using simple, spherical virtual tumors planned with uniform block margins. The tumor size and beam energy were also altered in the phantom study to investigate the interplay between these confounding factors and the isodose line effect. The magnitude of the target dose overestimation by PB was greater for higher prescription isodose levels. The MC vs. PB reduction in the target dose coverage indices, D95 and V100 of PTV, were found to monotonically increase with increasing isodose lines from 60% to 90%, resulting in more pronounced target dose coverage deficiency at higher isodose prescription levels. No isodose level‐dependent trend was observed for the dose errors in the target mean or high dose indices, Dmean or D5. The phantom study demonstrated that the observed isodose level dependence was caused by different beam margins used for the different isodose levels: a higher prescription line required a larger beam margin, leading to more low‐density lung tissues in the field and, therefore, larger dose errors at the target periphery (when calculated with PB). The phantom study also found that the observed isodose level dependence was greater for smaller targets and for higher beam energies. We hereby characterized the effect of normalized prescription isodose line on magnitude of PTV dose coverage as calculated by MC vs. PB. When comparing reported MC dose deficiency values for different patients, the selection of prescription isodose line should be considered in addition to other factors known to affect differences in calculated doses between various algorithms.PACS number(s): 87.55.kh, 87.55.dk, 87.55.de

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Tracking and compensation of respiration pattern by an automatic compensation system

et al. 2017

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Clinical outcomes of stereotactic radiotherapy for stage I non-small cell lung cancer using a novel irradiation technique: patient self-controlled breath-hold and beam switching using a combination of linear accelerator and CT scanner

Cited by 116 publications

References 24 publications

Clinical results of stereotactic body frame based fractionated radiation therapy for primary or metastatic thoracic tumors

Clinical results of stereotactic body frame based fractionated radiation therapy for primary or metastatic thoracic tumors

Effect of the normalized prescription isodose line on the magnitude of Monte Carlo vs. pencil beam target dose differences for lung stereotactic body radiotherapy

Tracking and compensation of respiration pattern by an automatic compensation system

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