Set-up errors in head and neck cancer treated with IMRT technique assessed by cone-beam computed tomography: a feasible protocol

Delishaj, D.; Ursino, Stefano; Pasqualetti, Francesco; Matteucci, Francesco; Cristaudo, Agostino; Soatti, Carlo Pietro; Barcellini, Amelia; Paiar, Fabiola

doi:10.3857/roj.2017.00493

Cited by 26 publications

(29 citation statements)

References 37 publications

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“…14,22 Table 3 outlines various studies estimating errors with CBCT scanning-based IGRT. [9][10][11][12]23,24 As shown, the errors obtained in the present study match those observed in previous studies, with the exception of random errors in the SI direction for daily IGRT. In conclusion, daily image guidance appears to be the best approach to reduce errors; however, it should be weighed against the dose received, on couch time, and the patient compliance.…”

Section: Discussionsupporting

confidence: 91%

Impact of different image guidance schedules in head and neck irradiation: A retrospective analysis

Bhatia¹,

Kothavade²,

Ramachandran³

2021

Precision Radiation Oncology

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Objective Is daily image‐guided radiation therapy justified for all patients? Here, we attempt to address this issue and present data obtained from various frequencies. Methods All consecutive head and neck cancer patients receiving radiation with curative intent and daily image‐guided radiation therapy using kV cone beam computed tomography scans were eligible. Displacements in the medial–lateral, superior–inferior (SI), and anterior–posterior directions were documented daily. The retrospectively simulated scenarios with reducing frequency were 50%, 30%, 20%, and 10%. The mean displacements, systematic errors, random errors, and planning target volume margins were calculated. Results A total of 831 cone beam computed tomography scans of 31 patients were analyzed, showing normally distributed mean displacements in the medial–lateral, SI, and anterior–posterior direction, except in SI for daily format. The mean displacements in the three directions was <0.1 cm, reflected in the systematic errors (<0.2 cm). In the SI direction, the random errors for daily format were 0.7 cm and 0.2 cm for simulated scenarios; these differences were demonstrated in planning target volume margin calculation, 1 cm in the SI direction based on daily data, and 0.5 cm based on simulated scenarios. The margin estimation was similar in the other directions for all formats. Conclusion The errors were similar across all scenarios, inconclusive of superiority for any schedule; however, a higher random error was observed with daily format in the SI direction. Our findings further validate the need for more data to determine the optimum image‐guided radiation therapy frequency.

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Section: Discussionsupporting

confidence: 91%

Impact of different image guidance schedules in head and neck irradiation: A retrospective analysis

Bhatia¹,

Kothavade²,

Ramachandran³

2021

Precision Radiation Oncology

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“…All data errors were derived from two aspects: system error and random error. The system error ∑ (represented by the mean value of all setup errors) was mainly derived from the mechanical parameter errors of the simulated positioning machine and the treatment accelerator; the random error δ (represented by the standard deviation of all setup errors) was mainly the difference in the repeatability of each setup during radiotherapy [ 17 ]. According to VanHerk's [ 18 ] study, the calculation formula of CTV to PTV expansion in X , Y , and Z directions was M PTV =2.5∑+0.7 δ .…”

Section: Methodsmentioning

confidence: 99%

Impact of Cold Weather on Setup Errors in Radiotherapy

Shu-xue

Zou

et al. 2021

Journal of Healthcare Engineering

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Objective. To investigate the influence of cold weather on setup errors of patients with chest and pelvic disease in radiotherapy. Methods. The image-guided data of the patients were collected from the Radiotherapy Center of Cancer Hospital Affiliated to Guangxi Medical University from October 2020 to February 2021. During this period, the cold weather days were December 15, 16, and 17, 2020, and January 7 and 8, 2021. For body fixation in radiotherapy, an integrated plate and a thermoplastic mold were employed in 18 patients with chest disease, while an integrated plate and a vacuum pad were applied in 19 patients with pelvic disease. All patients underwent cone beam computed tomography (CBCT) scans in the first five treatments and once a week thereafter. The obtained data were registered to the planning CT image to get the setup errors of the patient in the translational direction including X, Y, and Z axes and rotational direction including RX, RY, and RZ. Then, the Mann–Whitney U test was performed. The expansion boundary values of the chest and pelvis were calculated according to the formula M PTV = 2.5 ∑ + 0.7 δ . Results. A total of 286 eligible results of CBCT scans were collected. There were 138 chest CBCT scans, including 26 taken in cold weather and 112 in usual weather, and 148 pelvic CBCT scans, including 33 taken in cold weather and 115 in usual weather. The X-, Y-, and Z-axis translational setup errors of patients with chest disease in the cold weather group were 0.16 (0.06, 0.32) cm, 0.25 (0.17, 0.52) cm, and 0.35 (0.21, 0.47) cm, respectively, and those in the usual weather group were 0.14 (0.08, 0.29) cm, 0.23 (0.13, 0.37) cm, and 0.18 (0.1, 0.35) cm, respectively. The results indicated that there was a statistical difference in the Z-axis translational error between the cold weather group and the usual weather group (U = 935.5; p = 0.005 < 0.05 ), while there was no statistical difference in the rotational error between the two groups. The external boundary values of X, Y, and Z axes in the cold weather group were 0.57 cm, 0.92 cm, and 0.99 cm, respectively, and those in the usual weather group were 0.57 cm, 0.78 cm, and 0.68 cm, respectively. There was no significant difference in the translational and rotational errors of patients with pelvic disease between the cold weather group and the usual weather group ( p < 0.05 ). The external boundary values of X, Y, and Z axes were 0.63 cm, 0.79 cm, and 0.68 cm in the cold weather group and 0.61 cm, 0.79 cm, and 0.61 cm in the usual weather group, respectively. Conclusion. The setup error of patients undergoing radiotherapy with their bodies fixed by an integrated plate and a thermoplastic mold was greater in cold weather than in usual weather, especially in the ventrodorsal direction.

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“…According to Van Herk’s formula, the extended boundary (margin of planning target volume, MPTV) = 2.5∑ + 0.7σ, where ∑ represents the standard deviation of individual systematic errors of all patients, and the group random error σ is the standard deviation of individual random errors of all patients. 15 , 16 …”

Section: Methodsmentioning

confidence: 99%

Effect of Surgical Mask on Setup Error in Head and Neck Radiotherapy

Ding

et al. 2020

Technol Cancer Res Treat

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Purpose: With the widespread prevalence of Corona Virus Disease 2019 (COVID-19), cancer patients are suggested to wear a surgical mask during radiation treatment. In this study, cone beam CT (CBCT) was used to investigate the effect of surgical mask on setup errors in head and neck radiotherapy. Methods: A total of 91 patients with head and neck tumors were selected. CBCT was performed to localize target volume after patient set up. The images obtained by CBCT before treatment were automatically registered with CT images and manually fine-tuned. The setup errors of patients in 6 directions of Vrt, Lng, Lat, Pitch, Roll and Rotation were recorded. The patients were divided into groups according to whether they wore the surgical mask, the type of immobilization mask used and the location of the isocenter. The setup errors of patients were calculated. A t-test was performed to detect whether it was statistically significant. Results: In the 4 groups, the standard deviation in the directions of Lng and Pitch of the with surgical mask group were all higher than that in the without surgical mask group. In the head-neck-shoulder mask group, the mean in the Lng direction of the with surgical mask group was larger than that of the without surgical mask group. In the lateral isocenter group, the mean in the Lng and Pitch directions of the with surgical mask group were larger than that of the without surgical mask group. The t-test results showed that there was significant difference in the setup error between the 2 groups ( p = 0.043 and p = 0.013, respectively) only in the Lng and Pitch directions of the head-neck-shoulder mask group. In addition, the setup error of 6 patients with immobilization open masks exhibited no distinguished difference from that of the patients with regular immobilization masks. Conclusion: In the head and neck radiotherapy patients, the setup error was affected by wearing surgical mask. It is recommended that the immobilization open mask should be used when the patient cannot finish the whole treatment with a surgical mask.

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Set-up errors in head and neck cancer treated with IMRT technique assessed by cone-beam computed tomography: a feasible protocol

Cited by 26 publications

References 37 publications

Impact of different image guidance schedules in head and neck irradiation: A retrospective analysis

Impact of different image guidance schedules in head and neck irradiation: A retrospective analysis

Impact of Cold Weather on Setup Errors in Radiotherapy

Effect of Surgical Mask on Setup Error in Head and Neck Radiotherapy

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