Adaptive Radiotherapy Planning on Decreasing Gross Tumor Volumes as Seen on Megavoltage Computed Tomography Images

Woodford, Curtis; Yartsev, Slav; Dar, A. Rashid; Bauman, Glenn; Dyk, Jake Van

doi:10.1016/j.ijrobp.2007.07.2369

Cited by 159 publications

(169 citation statements)

References 26 publications

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“…However, Siker et al (2006) found no apparent correlations between tumor regression and chemotherapy, pathology, and the original tumor volume. The tumor regression rate had no important correlations with the original tumor volume, radiotherapy duration, pathological type and stage, and tumor density; specifically, the change in primary lesion tumor volume did not correlate with either patient-related properties or tumor-intrinsic characteristics (Woodford et al, 2007).…”

Section: Discussionmentioning

confidence: 82%

“…Additionally, the tumor volume shows no apparent change upon repeated localizations, it is not feasible to effectively reduce the dose volume parameter of the normal lung tissues. Therefore, there is no significant association with an increased irradiation dose (Woodford et al, 2007). The key to effectively reducing the dose volume parameter is to modify the treatment plan in a timely manner as the tumor volume shows an apparent change.…”

Section: Discussionmentioning

confidence: 99%

“…Compared with the initial CT localization, the median GTV of the secondary localization was reduced by 24.7% (range = -0.3-61.7%; P < 0.001), and the median GTV of the tertiary localization was reduced by 44.3% (range = 0.2-81.6%; P < 0.001). Woodford et al (2007) evaluated 17 NSCLC patients and found that after 30 cycles of conventional fractionated radiotherapy, the GTV was reduced by an average of 38% (range = 12-87%).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Clinical three-dimensional conformal radiotherapy research using repeated computed tomography scans for field reduction in older non-small-cell lung cancer patients

Fu¹,

Gu²,

Zhang³

et al. 2014

Genet. Mol. Res.

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ABSTRACT. This study investigated the curative and toxic effects of three-dimensional conformal radiotherapy (3D-CRT), using repeated CT scans for field reduction in older non-small-cell lung cancer (NSCLC) patients. 3D-CRT was administered to 36 older patients with NSCLC, and irradiation fields included the primary lesion and metastatic lymph nodes. After CT localization scanning, images were fed into a treatment planning system to delineate the gross tumor volume (GTV)1 and prepare Plan 1. After the DT50 (dose of the tumor is 50 Gy) increased from 50 Gy in 25 fractions to 54 Gy in 27 fractions, secondary CT localization scanning was performed to delineate GTV2 and prepare Plan 2; radiotherapy was administered continuously. When the DT increased to 60-65 Gy, tertiary CT scanning was performed to prepare another plan. The field was reduced to boost irradiation to the residual target volume until the total DT increased to 68-74 Gy. Compared with GTV1, the median absolute volume regression and median relative regression amounts for GTV2 were 68.85 cm 3 and 31.17%, respectively (Z = -2.673, P = 0.021). There were 8 cases of complete remission (22.2%), 20 of partial remission (55.6%), 7 of stable disease (19.4%), and 1 of progressive disease (2.8%). The total effectiveness rate was 77.8% and the 1-and 2-year survival rates were 63.9 and 27.8%, respectively. Radiation esophagitis and radiation pneumonia, the main toxic side effects, were tolerable. 3D-CRT, using repeated CT scans for field reduction in older NSCLC patients, could increase the local control and survival rates and relieve the toxic radiotherapy side effects.

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Section: Discussionmentioning

confidence: 82%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Clinical three-dimensional conformal radiotherapy research using repeated computed tomography scans for field reduction in older non-small-cell lung cancer patients

Fu¹,

Gu²,

Zhang³

et al. 2014

Genet. Mol. Res.

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“…This shrinkage of the gross tumor volume (GTV) indicates that irradiation field shapes and field sizes could or should be adapted during the treatment course, thus NSCLC patients are re-imaged and re-planned during the treatment is a possible strategy to improve treatment delivery. It is reported that if GTV decreases by greater than 30% at any point in the first 20 fractions of treatment, i.e., 40Gy, it may be appropriate to adapt the plan to improve sparing of normal tissues, adaptive planning is appropriate to further improve the therapeutic ratio (Woodford et al, 2007). On the other hand, acurate delineation of the primary tumor and involved lymph nodes is a key requisite for precise radiotherapy.…”

Section: Introductionmentioning

confidence: 99%

Feasibility of Shrinking Field Radiation Therapy through 18F-FDG PET/CT after 40 Gy for Stage III Non-Small Cell Lung Cancers

Ding¹,

Zhang²,

Li³

et al. 2012

Asian Pacific Journal of Cancer Prevention

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Objective: To explore the feasibility of shrinking field technique after 40 Gy radiation through 18F-FDG PET/ CT during treatment for patients with stage Ⅲ non-small cell lung cancer (NSCLC). Methods: In 66 consecutive patients with local-advanced NSCLC, 18F-FDG PET/CT scanning was performed prior to treatment and repeated after 40 Gy. Conventionally fractionated IMRT or CRT plans to a median total dose of 66Gy (range, 60-78Gy) were generated. The target volumes were delineated in composite images of CT and PET. Plan 1 was designed for 40 Gy to the initial planning target volume (PTV) with a subsequent 20-28 Gy-boost to the shrunken PTV. Plan 2 was delivering the same dose to the initial PTV without shrinking field. Accumulated doses of normal tissues were calculated using deformable image registration during the treatment course. Results: The median GTV and PTV reduction were 35% and 30% after 40 Gy treatment. Target volume reduction was correlated with chemotherapy and sex. In plan 2, delivering the same dose to the initial PTV could have only been achieved in 10 (15.2%) patients. Significant differences (p<0.05) were observed regarding doses to the lung, spinal cord, esophagus and heart. Conclusions: Radiotherapy adaptive to tumor shrinkage determined by repeated 18F-FDG PET/CT after 40 Gy during treatment course might be feasible to spare more normal tissues, and has the potential to allow dose escalation and increased local control.

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“…Tumor shrinkage is often observed during radiation therapy of NSCLC (1)(2)(3)(4)(5)(6). The most commonly proposed planning paradigm to handle tumor shrinkage is adaptive radiation therapy (ART) (7)(8)(9)(10).…”

Section: Introductionmentioning

confidence: 99%

Predictive Treatment Management: Incorporating a Predictive Tumor Response Model Into Robust Prospective Treatment Planning for Non-small Cell Lung Cancer

Zhang¹,

Yorke²,

Hu³

et al. 2012

International Journal of Radiation Oncology*Biology*Physics

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Purpose-We hypothesized that a treatment planning technique that incorporates predicted lung tumor regression into optimization, predictive treatment planning (PTP), could allow dose escalation to the residual tumor while maintaining coverage of the initial target without increasing dose to surrounding organs at risk (OARs).Methods and Materials-We created a model to estimate the geometric presence of residual tumors after radiation therapy using planning computed tomography (CT) and weekly cone beam CT scans of 5 lung cancer patients. For planning purposes, we modeled the dynamic process of tumor shrinkage by morphing the original planning target volume (PTV orig ) in 3 equispaced steps to the predicted residue (PTV pred ). Patients were treated with a uniform prescription dose to PTV orig . By contrast, PTP optimization started with the same prescription dose to PTV orig but linearly increased the dose at each step, until reaching the highest dose achievable to PTV pred consistent with OAR limits. This method is compared with midcourse adaptive replanning.Results-Initial parenchymal gross tumor volume (GTV) ranged from 3.6 to 186.5 cm 3 . On average, the primary GTV and PTV decreased by 39% and 27%, respectively, at the end of treatment. The PTP approach gave PTV orig at least the prescription dose, and it increased the mean dose of the true residual tumor by an average of 6.0 Gy above the adaptive approach.Conclusions-PTP, incorporating a tumor regression model from the start, represents a new approach to increase tumor dose without increasing toxicities, and reduce clinical workload compared with the adaptive approach, although model verification using per-patient midcourse imaging would be prudent.

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Adaptive Radiotherapy Planning on Decreasing Gross Tumor Volumes as Seen on Megavoltage Computed Tomography Images

Cited by 159 publications

References 26 publications

Clinical three-dimensional conformal radiotherapy research using repeated computed tomography scans for field reduction in older non-small-cell lung cancer patients

Clinical three-dimensional conformal radiotherapy research using repeated computed tomography scans for field reduction in older non-small-cell lung cancer patients

Feasibility of Shrinking Field Radiation Therapy through 18F-FDG PET/CT after 40 Gy for Stage III Non-Small Cell Lung Cancers

Predictive Treatment Management: Incorporating a Predictive Tumor Response Model Into Robust Prospective Treatment Planning for Non-small Cell Lung Cancer

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