Anatomy changes in radiotherapy detected using portal imaging

McDermott, L. N.; Wendling, M.; Sonke, Jan‐Jakob; Herk, Marcel van; Mijnheer, Ben J.

doi:10.1016/j.radonc.2006.04.003

Cited by 36 publications

(22 citation statements)

References 24 publications

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“…The dose distributions of proton beams are sensitive to changes in density in the lungs (9–11), and doses to critical structures such as the spinal cord and esophagus may exceed tolerances without proper planning and replanning during treatment (12). Furthermore, coverage of the internal clinical target volume (iCTV) may be compromised by changes in tumor shape, volume, or density over the course of the treatment.…”

Section: Introductionmentioning

confidence: 99%

Adaptive/Nonadaptive Proton Radiation Planning and Outcomes in a Phase II Trial for Locally Advanced Non-small Cell Lung Cancer

Koay

Lege

Mohan

et al. 2012

International Journal of Radiation Oncology*Biology*Physics

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Purpose To analyze dosimetric variables and outcomes after adaptive replanning of radiotherapy during concurrent high-dose protons and chemotherapy for locally advanced non-small cell lung cancer (NSCLC). Methods and Materials Nine of 44 patients with stage III NSCLC in a prospective phase II trial of concurrent paclitaxel/carboplatin with proton radiation [74 Gy(RBE) in 37 fractions] had modifications to their original treatment plans after re-evaluation revealed changes that would compromise coverage of the target volume or violate dose constraints; plans for the other 35 patients were not changed. We compared patients with adaptive plans with those with nonadaptive plans in terms of dosimetry and outcomes. Results At a median follow-up of 21.2 months (median overall survival, 29.6 months), no differences were found in local, regional, or distant failure or overall survival between groups. Adaptive planning was used more often for large tumors that shrank to a greater extent (median, 107.1 cm3 adaptive and 86.4 cm3 non-adaptive; median changes in volume, 25.3% adaptive and 1.2% non-adaptive; p<0.01). The median number of fractions delivered using adaptive planning was 13 (range, 4–22). Adaptive planning generally improved sparing of the esophagus (median absolute decrease in V70, 1.8%; range, 0–22.9%) and spinal cord (median absolute change in maximum dose, 3.7 Gy; range, 0–13.8 Gy). Without adaptive replanning, target coverage would have been compromised in 2 cases (57% and 82% coverage without adaptation vs. 100% for both with adaptation); neither patient experienced local failure. Radiation-related grade 3 toxicity rates were similar between groups. Conclusions Adaptive planning can reduce normal tissue doses and prevent target misses, particularly for patients with large tumors that shrink substantially during therapy. Adaptive plans seem to have acceptable toxicity and achieve similar local, regional, and distant control and overall survival, even in patients with larger tumors, versus non-adaptive plans.

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Section: Introductionmentioning

confidence: 99%

Adaptive/Nonadaptive Proton Radiation Planning and Outcomes in a Phase II Trial for Locally Advanced Non-small Cell Lung Cancer

Koay

Lege

Mohan

et al. 2012

International Journal of Radiation Oncology*Biology*Physics

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“…These include patient weight loss and tumour regression. If these are present and unaccounted for, they can subsequently alter PTV geometry, result in dosimetry changes and impact on patient outcomes 6,7 (F. Ali et al , unpublished data, 2008).…”

Section: Introductionmentioning

confidence: 99%

The effect of an intensive nutritional program on daily set‐up variations and radiotherapy planning margins of head and neck cancer patients

et al. 2009

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This is a prospective case-control study to assess nutritional supplementation in limiting weight loss and its impact on daily set-up variations and planning target volume (PTV) margins in head and neck (H&N) radiotherapy (RT). Twenty sequential H&N patients were recruited for this study. Ten patients had a percutaneous endoscopic gastrostomy (PEG) tube inserted prior to RT and 10 did not. PEG use was determined by departmental guidelines for patients considered at high risk for weight loss. Daily 2D electronic portal images were taken for orthogonal verification. Set-up variations were determined for both PEG and non-PEG patients by calculating systematic (Sigma) and random (sigma) errors, and PTV margins were derived. PEG patients lost less weight (P = 0.04) over the course of RT and had a reduction in set-up variation in the superior-inferior (SI) and anterior-posterior (AP) planes compared to those without. Mean correctional shifts in mm (range) for PEG patients were: Right-Left (RL) 0.1 (-1.9-2.1), SI -1.7 (-2.9-0.0), AP -0.4 (-2.0-0.8), and for non-PEG patients were: RL -0.2 (-2.7-1.3), SI -1.3 (-3.1-1.0), AP 0.4 (-1.5-2.8). The adapted PTV margins (mm) in the RL, SI and AP planes, respectively, for PEG patients were 4.1, 3.3 and 3.6, and for non-PEG were 3.9, 4.9 and 4.8. Intensive enteral support maintained weight stability in H&N patients considered at risk of weight loss during RT and this was associated with reduced set-up variation.

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“…Second, errors due to anatomical changes should be distinguished from those caused by inadequate setup. The problem could be circumvented by the approach reported by Mc Dermott et al [20]. They suggested using differences in images created by subtracting the first localization image from that of subsequent fractions was an efficient way to qualitatively detect anatomical changes during RT.…”

Section: Discussionmentioning

confidence: 99%

Impact of body-mass factors on setup displacement in patients with head and neck cancer treated with radiotherapy using daily on-line image guidance

et al. 2014

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BackgroundTo determine the impact of body-mass factors (BMF) before radiotherapy and changes during radiotherapy on the magnitude of setup displacement in patients with head and neck cancer (HNC).MethodsThe clinical data of 30 patients with HNC was analyzed using the alignment data from daily on-line on-board imaging from image-guided radiotherapy. BMFs included body weight, body height, and the circumference and bilateral thickness of the neck. Changes in the BMFs during treatment were retrieved from cone beam computed tomography at the 10th and 20th fractions. Setup errors for each patient were assessed by systematic error (SE) and random error (RE) through the superior-inferior (SI), anterior-posterior (AP), and medial-lateral (ML) directions, and couch rotation (CR). Using the median values of the BMFs as a cutoff, the impact of the factors on the magnitude of displacement was assessed by the Mann–Whitney U test.ResultsA higher body weight before radiotherapy correlated with a greater AP-SE (p = 0.045), SI-RE (p = 0.023), and CR-SE (p = 0.033). A longer body height was associated with a greater SI-RE (p = 0.002). A performance status score of 1 or 2 was related to a greater AP-SE (p = 0.043), AP-RE (p = 0.015), and SI-RE (p = 0.043). Among the ratios of the BMFs during radiotherapy, the values at the level of mastoid tip at the 20th fraction were associated with greater setup errors.ConclusionsTo reduce setup errors in patients with HNC receiving RT, the use of on-line image-guided radiotherapy is recommended for patients with a large body weight or height, and a performance status score of 1–2. In addition, adaptive planning should be considered for those who have a large reduction ratio in the circumference (<1) and thickness (<0.94) over the level of the mastoid tip during the 20th fraction of treatment.

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Anatomy changes in radiotherapy detected using portal imaging

Cited by 36 publications

References 24 publications

Adaptive/Nonadaptive Proton Radiation Planning and Outcomes in a Phase II Trial for Locally Advanced Non-small Cell Lung Cancer

Adaptive/Nonadaptive Proton Radiation Planning and Outcomes in a Phase II Trial for Locally Advanced Non-small Cell Lung Cancer

The effect of an intensive nutritional program on daily set‐up variations and radiotherapy planning margins of head and neck cancer patients

Impact of body-mass factors on setup displacement in patients with head and neck cancer treated with radiotherapy using daily on-line image guidance

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