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Purpose: 18 F-fluorothymidine (FLT) positron emission tomography (PET) enables sensitive imaging of bone marrow (BM) proliferation. Sequential FLT-PET/computed tomography scans before and during chemoradiation therapy (CRT) for non-small cell lung cancer were repurposed to investigate the dose-response effects of radiation on BM proliferation., Methods and Materials: Twenty-six non-small cell lung cancer patients underwent platinum-based CRT to 60 Gy in 30 fractions with FLT-PET/computed tomography scans at baseline, week 2 (20 Gy), and week 4 (40 Gy). FLT uptake in BM was isolated using Medical Image Merge software. Weeks 2 and 4 FLT-PET BM scans were fused with contemporaneous radiation isodose distributions. Relationships between radiation dose and FLT BM uptake (highest standardized uptake values within the volume and visual parameters) were analyzed using generalized linear and restricted cubic spline models. Percentage volumes of total BM without appreciable FLT uptake ("ablated") on weeks 2 and 4 FLT-PET scans were calculated by comparisons with baseline scans., Results: Thoracic FLT uptake was ablated in BM regions exposed to cumulative radiation doses ≥3 Gy by week 2. In all cases, BM FLT's highest standardized uptake values within the volume declined rapidly as the radiation dose increased. BM proliferation significantly decreased by >95% after ≥3 to 4 Gy at 2 weeks and ≥4 to 5 Gy at 4 weeks. The ablated BM volume increased from week 2 to week 4 as BM in the penumbra accumulated radiation dose. The median percentage of total BM ablated was 13.1% (range, 5.6%-20.3%) at 2 weeks and 15.7% (range, 9.2%-24.1%) at 4 weeks. Mean lymphocyte counts fell from a baseline of 2.01 × 10 9 /L to 0.77 at week 2 and 0.60 at week 4. Lymphocyte decline strongly correlated with the percentage of total BM ablated by week 4 (y = -46 to 1.64x; R 2 adj = 0.34; P = .001)., Conclusions: BM ablation associated with low-dose radiation exposure during CRT correlated significantly with lower week 4 lymphocyte counts. BM is a potential organ at risk, and reducing the BM volume exposed to ≥3 Gy may help preserve lymphocytes, which is essential for effective adjuvant immunotherapy., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: Stereotactic ablative body radiotherapy (SABR) is a novel option to treat primary renal cell carcinoma. However, a high radiation dose may be received by the treated kidney, which may affect its function posttreatment. This study investigates the dose-effect relationship of kidney SABR with posttreatment renal function., Methods and Materials: This was a prespecified secondary endpoint of the multicenter FASTRACK II (Focal Ablative STereotactic RAdiotherapy for Cancers of the Kidney phase II) clinical trial (National Clinical Trial 02613819). Patients received either 26 Gy in a single fraction (SF) for tumors with a maximal diameter of 4 cm or less or 42 Gy in 3 fractions (multifraction [MF]) for larger tumors. To determine renal function change, 99m Tc-dimercaptosuccinic acid (DMSA) single-photon emission computed tomography/computed tomography (SPECT/CT) scans were acquired, and the glomerular filtration rate was estimated at baseline, 12, and 24 months posttreatment. Imaging data sets were rigidly registered to the planning CT where kidneys were segmented to calculate dose-response curves., Results: From 71 enrolled patients, 36 (51%) and 26 (37%) patients were included in this study based on availability of posttreatment data at 12 and 24 months, respectively. The ipsilateral kidney glomerular filtration rate decreased from baseline by 42% and 39% in the SF cohort and by 45% and 62% in the MF cohort, at 12 and 24 months, respectively (P < .03). The loss in renal function was 3.6%/Gy ± 0.8%/Gy and 4.5%/Gy ± 1.0%/Gy in the SF cohort and 1.7%/Gy ± 0.1%/Gy and 1.7%/Gy ± 0.2%/Gy in the MF cohort at 12 and 24 months, respectively. The major loss in renal function occurred in high-dose regions, where dose-response curves converged to a plateau., Conclusions: For the first time in a multicenter study, the dose-effect relationship at 12 and 24 months post-SABR treatment for primary renal cell carcinoma was quantified. Kidney function reduces linearly with dose up to 100 Gy BED 3 ., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: Radiation therapy treatment for non-small cell lung cancer (NSCLC) may result in radiation damage to the perfused lung. The loss in perfusion may be measured from positron tomography emission (PET) perfusion imaging; however, this modality may not be widely available. Dual-energy computed tomography (DECT) with contrast may be an alternative to PET/CT. The purpose of this work is to investigate the equivalence of dose-response curves (DRCs) determined from PET and DECT in NSCLC., Methods and Materials: PET and DECT data sets from the prospective clinical trial HI-FIVE (NTC03569072) were included in this preplanned trial analysis. Patients underwent 68 Ga-macroaggregated albumin PET/CT examination and DECT with contrast on the same day at baseline and at 3 and 12 months after treatment. The perfused lung was defined from a threshold based on the maximum standardized uptake value (%SUVmax)/iodine concentration (%IoMax) in PET/DECT. The equivalence between PET and DECT DRC was established by comparing (1) the average of the normalized overlap of the 2 DRCs ranging from 0 (no overlap) to 1 (perfect overlap) and (2) the slope of a linear model applied to DRCs., Results: Of the 19 patients enrolled in the clinical trial, 14/10 patients had a posttreatment imaging session at a median of 4.5/13.5 months, respectively. With 30%SUVmax/35%IoMax, the average normalized overlap was maximized, and the difference between PET and DECT slopes of the linear model was minimized at each time point (slope = 0.76%/Gy / 0.75%/Gy at 3 months and 0.86%/Gy / 0.87%/Gy at 12 months determined from PET/DECT)., Conclusions: The dose-response relationship determined from DECT was comparable to that from PET at 3 and 12 months after treatment in patients with NSCLC., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Purpose: The TROG 13.01 (SAFRON II) trial was a phase 2 multicenter trial comparing single-fraction (SF) and multifraction (MF) stereotactic body radiation therapy. Patients with 1 to 3 peripheral pulmonary oligometastases were randomized 1:1 between 28 Gy in 1 fraction and 48 Gy in 4 fractions. There were no differences between arms in efficacy or toxicity. We performed an analysis to assess changes in pulmonary function tests (PFTs) between arms over time and assessed the effect of the number and total volume of targets on PFT change over time., Methods and Materials: A linear mixed model was used to describe the PFTs by treatment arm over time. The effect of number and volume of targets on PFTs at 6 and 12 months was assessed by a simple linear model., Results: Ninety patients were randomized; 87 were treated for 133 pulmonary oligometastases. Forty-four were randomized to the SF arm and 43 to the MF arm. There were no differences in absolute or relative PFT measures of forced expiratory volume in 1 second (FEV 1 ), diffusing capacity of the lungs for carbon monoxide (DLCO), or forced vital capacity (FVC) between the 2 arms. At 12 months, there was a reduction in absolute DLCO from baseline (-1.7 mL/min/mm Hg [95% CI, -2.5 to -1.0]), relative DLCO (-5.5% [95% CI, -8.4% to -2.6%]), absolute FEV 1 (-0.17 L [95% CI, -0.23 to -0.11]), and absolute FVC (-0.20 L [95% CI, -0.27 to -0.13]). In patients with multiple pulmonary targets, increase in target number (per lesion) was associated with a reduction in the absolute FEV 1 at 6 months of -0.10 L (95% CI, -0.18 to -0.03; P = .007), FEV 1 at 12 months of -0.10 L (95% CI, -0.20 to -0.01; P = .04), FVC at 6 months of -0.11 L (95% CI, -0.20 to -0.03; P = .014), and FVC at 24 months of -0.13 L (95% CI, -0.25 to -0.01; P = .036). Reduction in FEV 1 was also seen per 10-mL increase in PTV at 12 months (-0.03 L [95% CI, -0.06 to -0.00], P = .036). The number of targets and PTV were not associated with DLCO., Conclusions: Treating multiple targets resulted in increased loss of FEV 1 and FVC but not DLCO. There were no significant differences in PFT decline between SF and MF stereotactic body radiation therapy., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Purpose: Functional lung avoidance (FLA) radiation therapy aims to spare regions of functional lung to reduce toxicity. We report the results of the first prospective trial of FLA using 4-dimensional gallium 68 ventilation-perfusion positron emission tomography-computed tomography ( 68 Ga-4D-V/Q PET/CT)., Methods and Materials: Inclusion criteria required a diagnosis of stage III non-small cell lung cancer and the ability to undergo radical-intent chemoradiation therapy. Functional volumes were generated using planning 68 Ga-4D-V/Q PET/CT. These volumes were used to generate a clinical FLA plan to 60 Gy in 30 fractions. The primary tumor was boosted to 69 Gy. A comparison anatomic plan was generated for each patient. Feasibility was met if FLA plans (compared with anatomic plans) allowed (1) a reduction in functional mean lung dose of ≥2% and a reduction in the functional lung volume receiving 20 Gy (fV20Gy) of ≥4%, and (2) a mean heart dose ≤30 Gy and relative heart volume receiving 50 Gy of <25%., Results: In total, 19 patients were recruited; 1 withdrew consent. Eighteen patients underwent chemoradiation with FLA. Of the 18 patients, 15 met criteria for feasibility. All patients completed the entire course of chemoradiation therapy. Using FLA resulted in an average reduction of the functional mean lung dose of 12.4% (SD, ±12.8%) and a mean relative reduction of the fV20Gy of 22.9% (SD, ±11.9%). At 12 months, Kaplan-Meier estimates for overall survival were 83% (95% CI, 56%-94%) and estimates for progression-free survival were 50% (95% CI, 26%-70%). Quality-of-life scores were stable across all time points., Conclusions: Using 68 Ga-4D-V/Q PET/CT to image and avoid functional lung is feasible., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Purpose: The TROG 09.02 CHISEL trial compared conventional radiation therapy (CRT) with stereotactic body radiation therapy (SBRT) in patients with inoperable early-stage non-small cell lung cancer. Patients randomized to SBRT had less local failure and improved overall survival. This analysis reports differences in pulmonary function tests (PFTs) and the 6-minute walk test (SMWT) between patients who received SBRT and those who received CRT., Methods and Materials: We analyzed the PFTs and SMWTs of all patients recruited to the CHISEL [trial. During this trial, patients underwent serial PFTs. Linear regression models were used to compare parameters between SBRT and CRT at 3 and 12 months after treatment., Results: One hundred and one patients were enrolled; 33 patients were treated with CRT, 61 were treated with SBRT, and 7 did not receive treatment. Primary tumor size was similar between arms: SBRT 25 mm (standard deviation [SD], 9) and CRT 28 mm (SD, 9). On regression analysis, at 3 and 12 months, there was no evidence of a difference between arms in PFT decline or distance walked in the SMWT. Planning target volume size was significantly larger in the CRT arm, 142.79 cc (SD, 61.14), compared with the SBRT group, 46.15 cc (SD, 23.39). The mean biologically effective dose received by the target was significantly larger in the SBRT group, 125.92 Gy (SD, 21.58), compared with CRT, 65.49 Gy (SD, 6.32). Mean dose to the lungs minus the gross target volume incorporating motion was 8.9 Gy (SD, 2.34) in the CRT group and 4.37 Gy (SD, 1.42) in the SBRT group., Conclusions: Despite the considerably higher biologically effective doses delivered to the tumor in SBRT, there was no difference in decline in respiratory function observed between the 2 groups., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Purpose: Medical operability is prognostic for survival after SABR in primary malignancies. This study investigated the prognostic significance of medical operability and total versus subtotal ablation of all oligometastatic disease sites., Methods and Materials: Consecutive patients with 1 to 5 sites of active extracranial oligometastases had medical operability status and presence of subtotal versus total metastatic ablation recorded prospectively in an institutional database. We retrospectively compared overall survival (OS) and progression-free survival (PFS) for medically operable or inoperable patients and patients undergoing total or subtotal metastatic ablation. Secondary endpoints were patterns of failure, high-grade treatment toxic effects (Common Terminology Criteria for Adverse Events version 4.0), and freedom from systemic therapy. The threshold dose per fraction considered ablative was 8 Gy., Results: A total of 401 patients with 530 treated oligometastases were included, with a median follow-up of 3 years. Three hundred and two and 99 patients had metachronous and synchronous presentations of oligometastatic disease, respectively. Common histologies included prostate (24%), lung (18%), gastrointestinal (19%), and breast (11%). More than 90% of doses delivered were Biologically Effective Dose [BED 10 ] ≥60 Gy. Cumulative incidence at 5 years of local-only failure was 6%, local and distant 2%, and distant-only 58%. The 3- and 5-year OS [95% confidence intervals {CIs}] were 68% [62-73] and 54% [47-61], and PFS was 20% [15-25] and 14% [10-20]. The 3- and 5-year freedom from systemic therapy [95% CIs] were 40% [34-46] and 31% [24-37], respectively. Seventy-six patients were inoperable and 325 were operable. Operability status was not prognostic for OS (adjusted hazard ratio [HR], 1.0; 95% CI, 0.6-1.7; P = .9) or for PFS (adjusted HR, 1.1; 95% CI, 0.8-1.6; P = .5). Total metastatic ablation was prognostic for OS (adjusted HR, 0.8; 95% CI, 0.4-0.9; P = .032) and for PFS (adjusted HR, 0.6; 95% CI, 0.4-0.8; P = .003)., Conclusions: Medical operability was not prognostic in patients with oligometastatic disease treated with SABR. Total metastatic ablation was associated with superior OS and PFS compared with subtotal metastatic ablation. Our data support ablation of all sites of oligometastases wherever feasible., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: Fewer attendances for radiation therapy results in increased efficiency and less foot traffic within a radiation therapy department. We investigated outcomes after single-fraction (SF) stereotactic body radiation therapy (SBRT) in patients with oligometastatic disease., Methods and Materials: Between February 2010 and June 2019, patients who received SF SBRT to 1 to 5 sites of oligometastatic disease were included in this retrospective study. The primary objective was to describe patterns of first failure after SBRT. Secondary objectives included overall survival (OS), progression-free survival (PFS), high-grade treatment-related toxicity (Common Terminology Criteria for Adverse Events grade ≥3), and freedom from systemic therapy (FFST)., Results: In total, 371 patients with 494 extracranial oligometastases received SF SBRT ranging from 16 Gy to 28 Gy. The most common primary malignancies were prostate (n = 107), lung (n = 63), kidney (n = 52), gastrointestinal (n = 51), and breast cancers (n = 42). The median follow-up was 3.1 years. The 1-, 3-, and 5-year OS was 93%, 69%, and 55%, respectively; PFS was 48%, 19%, and 14%, respectively; and FFST was 70%, 43%, and 35%, respectively. Twelve patients (3%) developed grade 3 to 4 treatment-related toxicity, with no grade 5 toxicity. As the first site of failure, the cumulative incidence of local failure (irrespective of other failures) at 1, 3 and 5 years was 4%, 8%, and 8%, respectively; locoregional relapse at the primary was 10%, 18%, and 18%, respectively; and distant failure was 45%, 66%, and 70%, respectively., Conclusions: SF SBRT is safe and effective, and a significant proportion of patients remain FFST for several years after therapy. This approach could be considered in resource-constrained or bundled-payment environments. Locoregional failure of the primary site is the second most common pattern of failure, suggesting a role for optimization of primary control during metastasis-directed therapy., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose: Kilovoltage intrafraction monitoring (KIM) is a novel software platform implemented on standard radiation therapy systems and enabling real-time image guided radiation therapy (IGRT). In a multi-institutional prospective trial, we investigated whether real-time IGRT improved the accuracy of the dose patients with prostate cancer received during radiation therapy., Methods and Materials: Forty-eight patients with prostate cancer were treated with KIM-guided SABR with 36.25 Gy in 5 fractions. During KIM-guided treatment, the prostate motion was corrected for by either beam gating with couch shifts or multileaf collimator tracking. A dose reconstruction method was used to evaluate the dose delivered to the target and organs at risk with and without real-time IGRT. Primary outcome was the effect of real-time IGRT on dose distributions. Secondary outcomes included patient-reported outcomes and toxicity., Results: Motion correction occurred in ≥1 treatment for 88% of patients (42 of 48) and 51% of treatments (121 of 235). With real-time IGRT, no treatments had prostate clinical target volume (CTV) D98% dose 5% less than planned. Without real-time IGRT, 13 treatments (5.5%) had prostate CTV D98% doses 5% less than planned. The prostate CTV D98% dose with real-time IGRT was closer to the plan by an average of 1.0% (range, -2.8% to 20.3%). Patient outcomes showed no change in the 12-month patient-reported outcomes compared with baseline and no grade ≥3 genitourinary or gastrointestinal toxicities., Conclusions: Real-time IGRT is clinically effective for prostate cancer SABR., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose: Four-dimensional cone beam computed tomography (4DCBCT) facilitates verification of lung tumor motion before each treatment fraction and enables accurate patient setup in lung stereotactic ablative body radiation therapy. This work aims to quantify the real-time motion represented in 4DCBCT, depending on the reconstruction algorithm and the respiratory signal utilized for reconstruction., Methods and Materials: Eight lung cancer patients were implanted with electromagnetic Calypso beacons in airways close to the tumor, enabling real-time motion measurements. 4DCBCT scans were reconstructed from projections for treatment setup CBCT for 1 to 2 fractions of 8 patients with the Feldkamp-Davis-Kress (FDK) algorithm or the prior image constrained compressed sensing (PICCS) method and internal real-time Calypso beacon trajectories or an external respiratory signal (bellows belt). The real-time beacon centroid ("target") motion was compared with beacon centroid positions segmented in the 4DCBCT reconstructions. We tested the hypotheses that (1) the actual target motion was accurately represented in the reconstructions and (2) the reconstruction/respiratory signal combinations performed similarly in the representation of the real-time motion., Results: On average the target motion was significantly underrepresented and exceeded the 4DCBCT motion for 48%, 25%, and 40% of the time in the left-right (LR), superior-inferior (SI), and anterior-posterior (AP) directions, respectively. The average underrepresentation for the LR, SI, and AP direction was 1.7 mm, 4.2 mm, and 2.5 mm, respectively. No difference could be shown between the reconstruction algorithms or respiratory signals in LR direction (FDK vs PICCS: P = .47, Calypso vs bellows: P = .19), SI direction (FDK vs PICCS: P = .49, Calypso vs bellows: P = .22), and AP direction (FDK vs PICCS: P = .62, Calypso vs bellows: P = .34)., Conclusions: The 4DCBCT scans all underrepresented the real-time target motion. The selection of the reconstruction algorithm and respiratory signal for the 4DCBCT reconstruction does not have an impact on the reconstructed motion range., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: To investigate (68)Ga-ventilation/perfusion (V/Q) positron emission tomography (PET)/computed tomography (CT) as a novel imaging modality for assessment of perfusion, ventilation, and lung density changes in the context of radiation therapy (RT)., Methods and Materials: In a prospective clinical trial, 20 patients underwent 4-dimensional (4D)-V/Q PET/CT before, midway through, and 3 months after definitive lung RT. Eligible patients were prescribed 60 Gy in 30 fractions with or without concurrent chemotherapy. Functional images were registered to the RT planning 4D-CT, and isodose volumes were averaged into 10-Gy bins. Within each dose bin, relative loss in standardized uptake value (SUV) was recorded for ventilation and perfusion, and loss in air-filled fraction was recorded to assess RT-induced lung fibrosis. A dose-effect relationship was described using both linear and 2-parameter logistic fit models, and goodness of fit was assessed with Akaike Information Criterion (AIC)., Results: A total of 179 imaging datasets were available for analysis (1 scan was unrecoverable). An almost perfectly linear negative dose-response relationship was observed for perfusion and air-filled fraction (r(2)=0.99, P<.01), with ventilation strongly negatively linear (r(2)=0.95, P<.01). Logistic models did not provide a better fit as evaluated by AIC. Perfusion, ventilation, and the air-filled fraction decreased 0.75 ± 0.03%, 0.71 ± 0.06%, and 0.49 ± 0.02%/Gy, respectively. Within high-dose regions, higher baseline perfusion SUV was associated with greater rate of loss. At 50 Gy and 60 Gy, the rate of loss was 1.35% (P=.07) and 1.73% (P=.05) per SUV, respectively. Of 8/20 patients with peritumoral reperfusion/reventilation during treatment, 7/8 did not sustain this effect after treatment., Conclusions: Radiation-induced regional lung functional deficits occur in a dose-dependent manner and can be estimated by simple linear models with 4D-V/Q PET/CT imaging. These findings may inform future studies of functional lung avoidance using V/Q PET/CT., (Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.)

Purpose: Measuring changes in lung perfusion resulting from radiation therapy dose requires registration of the functional imaging to the radiation therapy treatment planning scan. This study investigates registration accuracy and utility for positron emission tomography (PET)/computed tomography (CT) perfusion imaging in radiation therapy for non-small cell lung cancer., Methods: (68)Ga 4-dimensional PET/CT ventilation-perfusion imaging was performed before, during, and after radiation therapy for 5 patients. Rigid registration and deformable image registration (DIR) using B-splines and Demons algorithms was performed with the CT data to obtain a deformation map between the functional images and planning CT. Contour propagation accuracy and correspondence of anatomic features were used to assess registration accuracy. Wilcoxon signed-rank test was used to determine statistical significance. Changes in lung perfusion resulting from radiation therapy dose were calculated for each registration method for each patient and averaged over all patients., Results: With B-splines/Demons DIR, median distance to agreement between lung contours reduced modestly by 0.9/1.1 mm, 1.3/1.6 mm, and 1.3/1.6 mm for pretreatment, midtreatment, and posttreatment (P < .01 for all), and median Dice score between lung contours improved by 0.04/0.04, 0.05/0.05, and 0.05/0.05 for pretreatment, midtreatment, and posttreatment (P < .001 for all). Distance between anatomic features reduced with DIR by median 2.5 mm and 2.8 for pretreatment and midtreatment time points, respectively (P = .001) and 1.4 mm for posttreatment (P > .2). Poorer posttreatment results were likely caused by posttreatment pneumonitis and tumor regression. Up to 80% standardized uptake value loss in perfusion scans was observed. There was limited change in the loss in lung perfusion between registration methods; however, Demons resulted in larger interpatient variation compared with rigid and B-splines registration., Conclusions: DIR accuracy in the data sets studied was variable depending on anatomic changes resulting from radiation therapy; caution must be exercised when using DIR in regions of low contrast or radiation pneumonitis. Lung perfusion reduces with increasing radiation therapy dose; however, DIR did not translate into significant changes in dose-response assessment., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Purpose: Clinical validation and quantitative evaluation of computed tomography (CT) image autosegmentation using Smart Probabilistic Image Contouring Engine (SPICE)., Methods and Materials: CT images of 125 treated patients (32 head and neck [HN], 40 thorax, 23 liver, and 30 prostate) in 7 independent institutions were autosegmented using SPICE and computational times were recorded. The number of structures autocontoured were 25 for the HN, 7 for the thorax, 3 for the liver, and 6 for the male pelvis regions. Using the clinical contours as reference, autocontours of 22 selected structures were quantitatively evaluated using Dice Similarity Coefficient (DSC) and Mean Slice-wise Hausdorff Distance (MSHD). All 40 autocontours were evaluated by a radiation oncologist from the institution that treated the patients., Results: The mean computational times to autosegment all the structures using SPICE were 3.1 to 11.1 minutes per patient. For the HN region, the mean DSC was >0.70 for all evaluated structures, and the MSHD ranged from 3.2 to 10.0 mm. For the thorax region, the mean DSC was 0.95 for the lungs and 0.90 for the heart, and the MSHD ranged from 2.8 to 12.8 mm. For the liver region, the mean DSC was >0.92 for all structures, and the MSHD ranged from 5.2 to 15.9 mm. For the male pelvis region, the mean DSC was >0.76 for all structures, and the MSHD ranged from 4.8 to 10.5 mm. Out of the 40 autocontoured structures reviews by experts, 25 were scored useful as autocontoured or with minor edits for at least 90% of the patients and 33 were scored useful autocontoured or with minor edits for at least 80% of the patients., Conclusions: Compared with manual contouring, autosegmentation using SPICE for the HN, thorax, liver, and male pelvis regions is efficient and shows significant promise for clinical utility., (Copyright © 2013 Elsevier Inc. All rights reserved.)