Assessment and validation of glottic motion using cone-beam CT and real-time cine MRI.

PURPOSE: This study aimed to assess the margin for the planning target volume (PTV) using the Van Herk formula. We then validated the proposed margin by real-time magnetic resonance imaging (MRI). METHODS: An analysis of cone-beam computed tomography (CBCT) data from early glottic cancer patients was performed to evaluate organ motion. Deformed clinical target volumes (CTV) after rigid registration were acquired using the Velocity program (Varian Medical Systems, Palo Alto, CA, USA). Systematic (Σ) and random errors (σ) were evaluated. The margin for the PTV was defined as 2.5 Σ + 0.7 σ according to the Van Herk formula. To validate this margin, we accrued healthy volunteers. Sagittal real-time cine MRI was conducted using the ViewRay system (ViewRay Inc., Oakwood Village, OH, USA). Within the obtained sagittal images, the vocal cord was delineated. The movement of the vocal cord was summed up and considered as the internal target volume (ITV). We then assessed the degree of overlap between the ITV and the PTV (vocal cord plus margins) by calculating the volume overlap ratio, represented as (ITV∩PTV)/ITV. RESULTS: CBCTs of 17 early glottic patients were analyzed. Σ and σ were 0.55 and 0.57 for left-right (LR), 0.70 and 0.60 for anterior-posterior (AP), and 1.84 and 1.04 for superior-inferior (SI), respectively. The calculated margin was 1.8 mm (LR), 2.2 mm (AP), and 5.3 mm (SI). Four healthy volunteers participated for validation. A margin of 3 mm (AP) and 5 mm (SI) was applied to the vocal cord as the PTV. The average volume overlap ratio between ITV and PTV was 0.92 (range 0.85-0.99) without swallowing and 0.77 (range 0.70-0.88) with swallowing. CONCLUSION: By evaluating organ motion by using CBCT, the margin was 1.8 (LR), 2.2 (AP), and 5.3 mm (SI). The margin acquired using CBCT fitted well in real-time cine MRI. Given that swallowing during radiotherapy can result in a substantial displacement, it is crucial to consider strategies aimed at minimizing swallowing and related motion.

Predictive Value of KLASS-02-QC Assessment Score on KLASS-02 Surgical Outcomes: Validation of Surgeon Quality Control and Standardization for D2 Lymphadenectomy.

OBJECTIVE: The aim of this study was to audit the 22 items and assessed each item's predictive value on surgical outcomes. BACKGROUND: The KLASS-02 trial revealed that the oncologic outcomes of laparoscopic distal gastrectomy are not inferior to open distal gastrectomy in patients with advanced gastric cancer. The surgeons participating in this trial were chosen based on the assessment scores from the KLASS-02-QC trial, which used 22 items for standardization of D2 lymphadenectomy and quality control. METHODS: We reviewed proficiency scores (PSs) for 22 items for 20 surgeons who participated in KLASS-02. The surgeons were divided into 2 groups according to PS, and the perioperative outcomes of 924 patients enrolled in KLASS-02 were compared between groups. Each item's predictive value for perioperative outcome was then assessed using multivariable regression models. RESULTS: Of the total 924 patients, 529 were operated on by high-score surgeons (high PS) and 395 were operated on by low-score surgeons (low-PS). High-PS group had less intraoperative blood loss, longer operation times, and fewer complications, major complications, reoperations, and shorter first flatus and hospital stay than low-PS group ( P =0.006, P <0.001, P <0.001, P <0.001, P =0.042, P =0.013, and P <0.001, respectively). Some items used in KLASS-02-QC predicted perioperative outcomes, such as intraoperative blood loss, major complications, reoperation, and hospital stay. CONCLUSIONS: Although this study only analyzed data associated with qualified surgeons, the 22 items effectively assessed the surgeons based on PS. A high score was associated with longer operation times, but better perioperative outcomes.

Evaluation of Optimal Assessment Schedules for Surveillance After Definitive Locoregional Treatment of Locally Advanced Head and Neck Cancer: A Retrospective Cohort Study With Parametric Modeling of Event-Free Survival.

Importance: In clinical practice, assessment schedules are often arbitrarily determined after definitive treatment of head and neck cancer (HNC), producing heterogeneous and inconsistent surveillance plans. Objective: To establish an optimal assessment schedule for patients with definitively treated locally advanced HNC, stratified by the primary subsite and HPV status, using a parametric model of standardized event-free survival curves. Design, Setting, and Participants: This was a retrospective study including 2 tertiary referral hospitals and a total of 673 patients with definitive locoregional treatment of locally advanced HNC (227 patients with nasopharyngeal cancer [NPC]; 237 patients with human papillomavirus-positive oropharyngeal cancer [HPV+ OPC]; 47 patients with HPV-negative [HPV-] OPC; 65 patients with hypopharyngeal cancer [HPC]; and 97 patients with laryngeal cancer [LC]). Patients had received primary treatment in 2008 through 2019. The median (range) follow-up duration was 57.8 (6.4-158.1) months. Data analyses were performed from April to October 2021. Main Outcomes and Measures: Tumor recurrence and secondary malignant neoplasms. Event-free survival was defined as the period from the end of treatment to occurrence of any event. Event-free survival curves were estimated using a piecewise exponential model and divided into 3 phases of regular follow-up. A 5% event rate criterion determined optimal follow-up time point and interval. Results: The median (range) age of the 673 patients at HNC diagnosis was 58 (15-83) years; 555 (82.5%) were men; race and ethnicity were not considered. The event rates of NPC, HPV+ OPC, HPV- OPC, HPC, and LC were 18.9% (43 of 227), 14.8% (35 of 237), 36.2% (17 of 47), 44.6% (29 of 65), and 30.9% (30 of 97), respectively. Parametric modeling demonstrated optimal follow-up intervals for HPC, LC, and NPC, respectively, every 2.1, 3.2, and 6.1 months; 3.7, 5.6, and 10.8 months; and 9.1, 13.8, and 26.5 months until 16.5, 16.5 to 25.0, and 25.0 to 99.0 months posttreatment (open follow-up thereafter). For HPV- OPC, assessment was recommended every 2.7, 4.8, and 11.8 months until 16.5, 16.5 to 25.0, and 25 to 99 months posttreatment, respectively. In contrast, HPV+ OPC optimal intervals were every 7.7, 13.7, and 33.7 months until 16.5, 16.5 to 25.0, and 25 to 99 months posttreatment, respectively. Five, 4, 12, 15, and 10 follow-up visits were recommended for NPC, HPV+ OPC, HPV- OPC, HPC, and LC, respectively. Conclusions and Relevance: This retrospective cohort study using parametric modeling suggests that the HNC assessment schedules should be patient tailored and evidence based to consider primary subsites and HPV status. Given limited health care resources and rising detection rates and costs of HNC, the guidelines offered by these findings could benefit patients and health systems and aid in developing future consensus guidelines.

Radiological assessment schedule for 1p/19q-codeleted gliomas during the surveillance period using parametric modeling.

BACKGROUND: There have been no evidence-based guidelines on the optimal schedule for the radiological assessment of 1p/19q-codeleted glioma. This study aimed to recommend an appropriate radiological evaluation schedule for 1p/19q-codeleted glioma during the surveillance period through parametric modeling of the progression-free survival (PFS) curve. METHODS: A total of 234 patients with 1p/19q-codeleted glioma (137 grade II and 97 grade III) who completed regular treatment were retrospectively reviewed. The patients were stratified into each layered progression risk group by recursive partitioning analysis. A piecewise exponential model was used to standardize the PFS curves. The cutoff value of the progression rate among the remaining progression-free patients was set to 10% at each scan. RESULTS: Progression risk stratification resulted in 3 groups. The optimal magnetic resonance imaging (MRI) interval for patients without a residual tumor was every 91.2 weeks until 720 weeks after the end of regular treatment following the latent period for 15 weeks. For patients with a residual tumor after the completion of adjuvant radiotherapy followed by chemotherapy, the optimal MRI interval was every 37.5 weeks until week 90 and every 132.8 weeks until week 361, while it was every 33.6 weeks until week 210 and every 14.4 weeks until week 495 for patients with a residual tumor after surgery only or surgery followed by radiotherapy only. CONCLUSIONS: The optimal radiological follow-up schedule for each progression risk stratification of 1p/19q-codeleted glioma can be established from the parametric modeling of PFS.

Radiological assessment schedule for high-grade glioma patients during the surveillance period using parametric modeling.

BACKGROUND: An optimal radiological surveillance plan is crucial for high-grade glioma (HGG) patients, which is determined arbitrarily in daily clinical practice. We propose the radiological assessment schedule using a parametric model of standardized progression-free survival (PFS) curves. METHODS: A total of 277 HGG patients (178 glioblastoma [GBM] and 99 anaplastic astrocytoma [AA]) from a single institute who completed the standard treatment protocol were enrolled in this cohort study and retrospectively analyzed. The patients were stratified into each layered risk group by genetic signatures and residual mass or through recursive partitioning analysis. PFS curves were estimated using the piecewise exponential survival model. The criterion of a 10% progression rate among the remaining patients at each observation period was used to determine the optimal radiological assessment time point. RESULTS: The optimal follow-up intervals for MRI evaluations of isocitrate dehydrogenase (IDH) wild-type GBM was every 7.4 weeks until 120 weeks after the end of standard treatment, followed by a 22-week inflection period and every 27.6 weeks thereafter. For the IDH mutated GBM, scans every 13.2 weeks until 151 weeks are recommended. The optimal follow-up intervals were every 22.8 weeks for IDH wild-type AA, and 41.2 weeks for IDH mutated AA until 241 weeks. Tailored radiological assessment schedules were suggested for each layered risk group of the GBM and the AA patients. CONCLUSIONS: The optimal schedule of radiological assessments for each layered risk group of patients with HGG could be determined from the parametric model of PFS.