No abstract

No abstract

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

BackgroundMetastatic head and neck cancers (HNCs) predominantly affect the lungs and have a two‐year overall survival (OS) of 15% to 50%, if amenable for pulmonary metastasectomy.MethodsRetrospective review of the two‐year local control (LC), local‐regional control (LRC) within the same lobe, OS, and toxicity rates in consecutive patients with metastatic pulmonary HNC who underwent stereotactic ablative radiotherapy (SABR) January 2007 to May 2018.ResultsEvaluated 82 patients with 107 lung lesions, most commonly squamous cell carcinoma (SCC; 64%). Median follow‐up was 20 months (range: 9.0‐97.6). Systemic therapy administered in 34%. LC, LRC, and OS rates were 94%, 90%, and 62%. Patients with oligometastatic disease had a higher OS than polymetastatic disease, 72% vs 44% (HR = 0.30, 95% CI: 0.14‐0.64; P = .008). OS in oligometastatic non‐SCC and SCC were 100% and 66% (P = .03). There were no grade ≥3 toxicities.ConclusionsMetastatic pulmonary HNCs after SABR have a two‐year OS rate comparable to pulmonary metastasectomy.

For locally advanced cervical cancer (LACC), anatomy correspondence with and without BT applicator needs to be quantified to merge the delivered doses of external beam radiation therapy (EBRT) and brachytherapy (BT). This study proposed and evaluated different deformable image registration (DIR) methods for this application. Twenty patients who underwent EBRT and BT for LACC were retrospectively analyzed. Each patient had a pre-BT CT at EBRT boost (without applicator) and a CT and MRI at BT (with applicator). The evaluated DIR methods were the diffeomorphic Demons, commercial intensity and hybrid methods, and three different biomechanical models. The biomechanical models considered different boundary conditions (BCs). The impact of the BT devices insertion on the anatomy was quantified. DIR method performances were quantified using geometric criteria between the original and deformed contours. The BT dose was deformed toward the pre-CT BT by each DIR method. The impact of boundary conditions to drive the biomechanical model was evaluated based on the deformation vector field and dose differences. The GEC-ESTRO guideline dose indices were reported. Large organ displacements, deformations, and volume variations were observed between the pre-BT and BT anatomies. Rigid registration and intensity-based DIR resulted in poor geometric accuracy with mean Dice similarity coefficient (DSC) inferior to 0.57, 0.63, 0.42, 0.32, and 0.43 for the rectum, bladder, vagina, cervix and uterus, respectively. Biomechanical models provided a mean DSC of 0.96 for all the organs. By considering the cervix-uterus as one single structure, biomechanical models provided a mean DSC of 0.88 and 0.94 for the cervix and uterus, respectively. The deformed doses were represented for each DIR method. Caution should be used when performing DIR for this application as standard techniques may have unacceptable results. The biomechanical model with the cervix-uterus as one structure provided the most realistic deformations to propagate the BT dose toward the EBRT boost anatomy.