PURPOSE:To develop, clinically implement, and use automated treatment planning for lung cancer radiotherapy (RT) via an in-house treatment planning optimization system, the expedited constrained hierarchical optimization (ECHO). METHODS:The ECHO system accepts segmented tumor and normal tissue contours and clinical dose/volume criteria as inputs and generates optimized fluence maps for intensity-modulated RT (IMRT) and leaf trajectories for volumetric-modulated arc therapy (VMAT). Dose/volume criteria for our clinically used seven lung cancer fractionation schedules were implemented in ECHO. For each schedule, ECHO internal optimization parameters were tuned using 5-7 previously treated patients and validated with additional 20-25 patients. RESULTS:Since May 2021, a total of 431 lung cancer patients have been treated with ECHO IMRT. Additionally, from April 2023, 93 lung SBRT patients were planned with ECHO VMAT. Treatment plans optimized with ECHO IMRT and VMAT provide more consistent target coverage and similar organ sparing compared with manually optimized plans. The average planning target volume was 390 cm3 (range: 12-3441) for IMRT and 17 cm3 (range: 2.5-56) for VMAT. The average optimization time was 33 min (range: 7-126) for IMRT and 56 min (range: 21-178) for VMAT. On average, ECHO-optimized plans save 1.5 h per plan compared to manual planning. CONCLUSIONS:We have implemented an automated system for lung RT treatment planning at our institution for seven fractionation schedules. Our ECHO approach is robust and adapts to changes in clinical criteria without requiring algorithm modifications or retraining. The proposed treatment planning automation framework saves resources and improves treatment plan quality and consistency.

As patient breathing irregularities can introduce a large uncertainty in targeting the internal tumor volume (ITV) of lung cancer patients, and thereby affect treatment quality, this study evaluates dose tolerance of tumor motion amplitude variations in ITV-based volumetric modulated arc therapy (VMAT). A motion-incorporated planning technique was employed to simulate treatment delivery of 10 lung cancer patients’ clinical VMAT plans using original and three scaling-up (by 0.5, 1.0, and 2.0 cm) motion waveforms from single-breath four-dimensional computed tomography (4DCT) and multi-breath time-resolved 4D magnetic resonance imaging (TR-4DMRI). The planning tumor volume (PTV = ITV + 5 mm margin) dose coverage (PTV D95%) was evaluated. The repeated waveforms were used to move the isocenter in sync with the clinical leaf motion and gantry rotation. The continuous VMAT arcs were broken down into many static beam fields at the control points (2°-interval) and the composite plan represented the motion-incorporated VMAT plan. Eight motion-incorporated plans per patient were simulated and the plan with the native 4DCT waveform was used as a control. The first (D95% ≤ 95%) and second (D95% ≤ 90%) plan breaching points due to motion amplitude increase were identified and analyzed. The PTV D95% in the motion-incorporated plans was 99.4 ± 1.0% using 4DCT, closely agreeing with the corresponding ITV-based VMAT plan (PTV D95% = 100%). Tumor motion irregularities were observed in TR-4DMRI and triggered D95% ≤ 95% in one case. For small tumors, 4 mm extra motion triggered D95% ≤ 95%, and 6–8 mm triggered D95% ≤ 90%. For large tumors, 14 mm and 21 mm extra motions triggered the first and second breaching points, respectively. This study has demonstrated that PTV D95% breaching points may occur for small tumors during treatment delivery. Clinically, it is important to monitor and avoid systematic motion increase, including baseline drift, and large random motion spikes through threshold-based beam gating.

PURPOSE:We report on the clinical performance of a fully automated approach to treatment planning based on a Pareto optimal, constrained hierarchical optimization algorithm, named Expedited Constrained Hierarchical Optimization (ECHO).METHODS AND MATERIALS:From April 2017 to October 2018, ECHO produced 640 treated plans for 523 patients who underwent stereotactic body radiation therapy (RT) for paraspinal and other metastatic tumors. A total of 182 plans were for 24 Gy in a single fraction, 387 plans were for 27 Gy in 3 fractions, and the remainder were for other prescriptions or fractionations. Of the plans, 84.5% were for paraspinal tumors, with 69, 302, and 170 in the cervical, thoracic, and lumbosacral spine, respectively. For each case, after contouring, a template plan using 9 intensity modulated RT fields based on disease site and tumor location was sent to ECHO through an application program interface plug-in from the treatment planning system. ECHO returned a plan that satisfied all critical structure hard constraints with optimal target volume coverage and the lowest achievable normal tissue doses. Upon ECHO completion, the planner received an e-mail indicating the plan was ready for review. The plan was accepted if all clinical criteria were met. Otherwise, a limited number of parameters could be adjusted for another ECHO run.RESULTS:The median planning target volume size was 84.3 cm3 (range, 6.9-633.2). The median time to produce 1 ECHO plan was 63.5 minutes (range, 11-340 minutes) and was largely dependent on the field sizes. Of the cases, 79.7% required 1 run to produce a clinically accepted plan, 13.3% required 1 additional run with minimal parameter adjustments, and 7.0% required ≥2 additional runs with significant parameter modifications. All plans met or bettered the institutional clinical criteria.CONCLUSIONS:We successfully implemented automated stereotactic body RT paraspinal and other metastatic tumors planning. ECHO produced high-quality plans, improved planning efficiency and robustness, and enabled expedited treatment planning at our clinic.

Background: Despite dosimetric benefits of volumetric modulated arc therapy (VMAT) in breast cancer patients with implant reconstruction receiving regional nodal irradiation (RNI), low dose to the thoracic structures remains a concern. Our goal was to report dosimetric effects of adding deep inspiration breath hold (DIBH) to VMAT in left-sided breast cancer patients with tissue expander (TE)/permanent implant (PI) reconstruction receiving RNI. Methods: Ten consecutive breast cancer patients with unilateral or bilateral TE/PI reconstruction who were treated with a combination of VMAT and DIBH to the left reconstructed chest wall and regional nodes were prospectively identified. Free breathing (FB) and DIBH CT scans were acquired for each patient VMAT plans for the same arc geometry were compared for FB versus DIBH. Prescription dose was 50 Gy in 25 fractions. Dosimetric differences were tested for statistical significance. Results: For comparable coverage and target dose homogeneity, the mean dose to the heart reduced on average by 2.9 Gy (8.2 to 5.3 Gy), with the addition of DIBH (p < 0.05). The maximum dose to the left anterior descending (LAD) artery was reduced by 9.9 Gy (p < 0.05), which related closely to the reduction in the maximum heart dose (9. 4 Gy). V05 Gy to the heart, ipsilateral lung, contralateral lung and total lung (p < 0.05) decreased on average by 29. 6%, 5.8%, 15.4% and 10.8% respectively. No significant differences were seen in the ipsilateral lung V20 Gy or mean dose as well as in the mean contralateral breast/implant dose. However, V04 Gy and V03 Gy of the contralateral breast/implant were respectively reduced by 13.2% and 18.3% using DIBH (p < 0.05). Conclusion: Combination of VMAT and DIBH showed significant dosimetric gains for low dose to the heart, lungs and contralateral breast/implant Not surprisingly, the mean and maximum dose to the heart and to the LAD were also reduced. DIBH should be considered with the use of VMAT in breast cancer patients with implant reconstructions receiving RNI.

To develop a CT-based radiomics signature and assess its ability for preoperatively predicting the early recurrence (≤1 year) of hepatocellular carcinoma (HCC).

In this study, we compared the registration effectiveness of 4D cone-beam computed tomography (CBCT) and 3D-CBCT for image-guided radiotherapy in 20 Stage IA non-small-cell lung cancer (NSCLC) patients. Patients underwent 4D-CBCT and 3D-CBCT immediately before radiotherapy, and the X-ray Volume Imaging software system was used for image registration. We performed automatic bone registration and soft tissue registration between 4D-CBCT or 3D-CBCT and 4D-CT images; the regions of interest (ROIs) were the vertebral body on the layer corresponding to the tumor and the internal target volume region. The relative displacement of the gross tumor volume between the 4D-CBCT end-expiratory phase sequence and 4D-CT was used to evaluate the registration error. Among the 20 patients (12 males, 8 females; 35-67 years old; median age, 52 years), 3 had central NSCLC and 17 had peripheral NSCLC, 8 in the upper or middle lobe and 12 in the lower lobe (maximum tumor diameter range, 18-27 mm). The internal motion range in three-dimensional space was 12.52 ± 2.65 mm, accounting for 47.8 ± 15.3% of the maximum diameter of each tumor. The errors of image-guided registration using 4D-CBCT and 3D-CBCT on the x (left-right), y (superior-inferior), z (anterior-posterior) axes, and 3D space were 0.80 ± 0.21 mm and 1.08 ± 0.25 mm, 2.02 ± 0.46 mm and 3.30 ± 0.53 mm, 0.52 ± 0.16 mm and 0.85 ± 0.24 mm, and 2.25 ± 0.44 mm and 3.59 ± 0.48 mm (all P < 0.001), respectively. Thus, 4D-CBCT is preferable to 3D-CBCT for image guidance in small pulmonary tumors because 4D-CBCT can reduce the uncertainty in the tumor location resulting from internal motion caused by respiratory movements, thereby increasing the image-guidance accuracy.

Use of proton beam therapy has expanded, with the number of proton centres rapidly increasing not only in the USA but also worldwide. The physical characteristics of the proton beam offer important advantages versus widely used photon techniques in terms of radiation precision. In head and neck cancer in particular, proton beam therapy is uniquely suited for the complex anatomy of tumours and sensitive surrounding organs. De-intensification and personalisation of treatment to limit toxicity are of renewed importance in the context of human papilloma virus-associated disease, in which young patients will be cured but bear the consequences of adverse effects for decades. Comparisons of radiation dose distributions between photon and proton techniques suggest considerable benefit in terms of toxicity sparing, but this has only recently been confirmed by substantial clinical data. In this Review, we attempt to define the role of this method in the contemporary multidisciplinary management of various types of head and neck cancer.

Purpose: Radiation therapy targeting axilla and groin lymph nodes improves regional disease control in locally advanced and high-risk skin cancers. However, trials generally used conventional two-dimensional radiotherapy (2D-RT), contributing towards relatively high rates of side effects from treatment. The goal of this study is to determine if three-dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), or volumetric-modulated arc therapy (VMAT) may improve radiation delivery to the target while avoiding organs at risk in the clinical context of skin cancer regional nodal irradiation. Materials and Methods: Twenty patients with locally advanced/high-risk skin cancers underwent computed tomography simulation. The relevant axilla or groin planning target volumes and organs at risk were delineated using standard definitions. Paired t-tests were used to compare the mean values of several dose-volumetric parameters for each of the 4 techniques. Results: In the axilla, the largest improvement for 3D-CRT compared to 2D-RT was for homogeneity index (13.9 vs. 54.3), at the expense of higher lung V20 (28.0% vs. 12.6%). In the groin, the largest improvements for 3D-CRT compared to 2D-RT were for anorectum Dmax (13.6 vs. 38.9 Gy), bowel D200cc (7.3 vs. 23.1 Gy), femur D50 (34.6 vs. 57.2 Gy), and genitalia Dmax (37.6 vs. 51.1 Gy). IMRT had further improvements compared to 3D-CRT for humerus Dmean (16.9 vs. 22.4 Gy), brachial plexus D5 (57.4 vs. 61.3 Gy), bladder D5 (26.8 vs. 36.5 Gy), and femur D50 (18.7 vs. 34.6 Gy). Fewer differences were observed between IMRT and VMAT. Conclusion: Compared to 2D-RT and 3D-CRT, IMRT and VMAT had dosimetric advantages in the treatment of nodal regions of skin cancer patients.

VMAT and DIBH have been independently used to improve target coverage and conformity while minimizing heart dose in left-sided breast cancer patients. Our purpose was to report the integration of both VMAT and DIBH in left-sided breast cancer patients receiving RNI. We prospectively identified 10 consecutive breast cancer patients who were treated with VMAT+DIBH to the left reconstructed breast/chest wall and regional nodes (RN). Two CT scans (1 free breathing [FB], 1 DIBH) were acquired per patient. Contouring was done by the treating MD on all scans. The clinical target volume (CTV) consisted of the reconstructed breast/chest wall and RN. The planning target volume (PTV) was CTV+5 mm, and included the skin in the reconstructed breast/chest wall region. Normal structures included the heart, left anterior descending (LAD) artery, ipsilateral lung, contralateral lung, total lung, and contralateral breast. VMAT plans were created using 2 partial arcs with 6-MV photons. Same arc geometry was maintained for both DIBH and FB plans. Prescription dose was 50 Gy in 25 fractions. Plans were normalized to PTV D95=95%. Criteria for coverage and homogeneity were IMN D95 ≥ 100%, PTV V95 ≥ 95%, and PTV D05 ≤ 110%. Dosimetric differences between DIBH+VMAT versus FB+VMAT were noted. Coverage and homogeneity criteria were met within ±1% of goal(s). Compared to FB, mean and maximum doses to the heart reduced on average by 2.9 Gy (1.5 Gy-4.3 Gy) and 9.4 Gy (0.1 Gy-19.4 Gy), respectively, with DIBH. V05 Gy to the heart, ipsilateral lung, contralateral lung, and total lung significantly decreased on average by 29.6%, 5.8%, 15.4% and 10.8%, respectively, with DIBH. No change was noted in the ipsilateral lung V20 Gy (refer to Table 1). Compared to FB, combining DIBH with VMAT significantly reduced the mean heart dose. Contralateral lung and ipsilateral lung V5 Gy were also significantly reduced, even though contralateral breast mean dose or ipsilateral lung V20 Gy were not meaningfully reduced. Hence DIBH should strongly be considered as an adjunct modality to VMAT when treating left-sided breast cancer patients requiring RNI.Abstract 3668; Table 1.OARDIBHFBHeart mean (Gy)5.3* (SD 1.0)8.2* (SD 1.4)Heart max (Gy)38.3* (SD 11.2)47.7* (SD 7.5)LAD max (Gy)30.8* (SD 12.6)40.7* (SD 12.1)Heart V05 Gy (%)35.3* (SD 9.9)64.9* (SD 14.2)Ipsilateral Lung V05 Gy (%)71.4* (SD 7.5)77.2* (SD 8)Contralateral Lung V05 Gy (%)33.1* (SD 18.3)48.5* (SD 12.9)Total lung V05 Gy (%)50.5* (SD 12.2)61.3* (SD 9.7)Ipsilateral lung V20 Gy (%)26.4 (SD 3.9)28.2 (SD 4.7)Contralateral breast mean (Gy)5.1 (SD 1.4)5.7 (SD 1.4)Table indicates mean values among 10 patients. SD= standard deviation.*P <0.05. Open table in a new tab

Background: Although intensity-modulated radiotherapy (IMRT) is a standard of care for many head and neck cancers, its use for carotid-sparing (CS) therapy in early-stage laryngeal carcinoma is controversial.Methods: 330 consecutive patients with early-stage laryngeal carcinoma were treated from 1/1989 to 5/2011, including 282 conventional radiotherapy (CRT) and 48 CS-IMRT patients. The median follow-up was 43 (CS-IMRT) and 66 (CRT) months.Results: There was no difference in local failure rates comparing patients undergoing CS-IMRT with CRT, with 3-year local control rates of 88% vs. 89%, respectively (p = 0.938). Using a 1 cm circumferential margin, the average dose to the left and right carotid arteries was 48.3 and 47.9 Gy, respectively. 88% of locoregional recurrences involved the ipsilateral true vocal cord, including all local recurrences in the IMRT group.Conclusions: These results warrant further prospective evaluation of CS-IMRT for early-stage glottic larynx cancer. (C) 2015 Elsevier Ltd. All rights reserved.

Patients treated for a thoracic malignancy carry a significant risk of developing other lung lesions. Locoregional control of intrathoracic recurrences is challenging due to the impact of prior therapies on normal tissues. We examined the safety and efficacy of thoracic re-irradiation using high-precision image-guided stereotactic body radiation therapy (SBRT).

Purpose: To assess the impact of immediate breast reconstruction on postmastectomy radiation (PMRT) using dose-volume histogram (DVH) data.Methods and Materials: Two hundred forty-seven women underwent PMRT at our center, 196 with implant reconstruction and 51 without reconstruction. Patients with reconstruction were treated with tangential photons, and patients without reconstruction were treated with en-face electron fields and customized bolus. Twenty percent of patients received internal mammary node (IMN) treatment. The DVH data were compared between groups. Ipsilateral lung parameters included V20 (% volume receiving 20 Gy), V40 (% volume receiving 40 Gy), mean dose, and maximum dose. Heart parameters included V25 (% volume receiving 25 Gy), mean dose, and maximum dose. IMN coverage was assessed when applicable. Chest wall coverage was assessed in patients with reconstruction. Propensity-matched analysis adjusted for potential confounders of laterality and IMN treatment.Results: Reconstruction was associated with lower lung V20, mean dose, and maximum dose compared with no reconstruction (all P < .0001). These associations persisted on propensity-matched analysis (all P < .0001). Heart doses were similar between groups (P=NS). Ninety percent of patients with reconstruction had excellent chest wall coverage (D95 > 98%). IMN coverage was superior in patients with reconstruction (D95 > 92.0 vs 75.7%, P < .001). IMN treatment significantly increased lung and heart parameters in patients with reconstruction (all P < .05) but minimally affected those without reconstruction (all P > .05). Among IMN-treated patients, only lower lung V20 in those without reconstruction persisted (P = .022), and mean and maximum heart doses were higher than in patients without reconstruction (P = .006, P = .015, respectively).Conclusions: Implant reconstruction does not compromise the technical quality of PMRT when the IMNs are untreated. Treatment technique, not reconstruction, is the primary determinant of target coverage and normal tissue doses. (C) 2012 Elsevier Inc.