Real-time tumor-tracking radiotherapy with SyncTraX for primary liver tumors requiring isocenter shift†.

The SyncTraX series enables real-time tumor-tracking radiotherapy through the real-time recognition of a fiducial marker using fluoroscopic images. In this system, the isocenter should be located within approximately 5-7.5 cm from the marker, depending on the version, owing to the limited field of view. If the marker is placed away from the tumor, the isocenter should be shifted toward the marker. This study aimed to investigate stereotactic body radiotherapy (SBRT) outcomes of primary liver tumors treated with SyncTraX in cases where the isocenter was shifted marginally or outside the planning target volume (PTV). Twelve patients with 13 liver tumors were included in the analysis. Their isocenter was shifted toward the marker and was placed marginally or outside the PTV. The prescribed doses were generally 40 Gy in four fractions or 48 Gy in eight fractions. The overall survival (OS) and local control (LC) rates were calculated using the Kaplan-Meier method. All patients completed the scheduled SBRT. The median distance between the fiducial marker and PTV centroid was 56.0 (interquartile range [IQR]: 52.7-66.7) mm. By shifting the isocenter toward the marker, the median distance between the marker and isocenter decreased to 34.0 (IQR: 33.4-39.7) mm. With a median follow-up period of 25.3 (range: 6.9-70.0) months, the 2-year OS and LC rates were 100.0% (95% confidence interval: 100-100). An isocenter shift makes SBRT with SyncTraX feasible in cases where the fiducial marker is distant from the tumor.

Treatment outcomes of radiotherapy with concurrent weekly cisplatin in older patients with locally advanced head and neck squamous cell carcinoma.

BACKGROUND: Tri-weekly cisplatin and radiotherapy (CDDP + RT) is a standard of care for locally advanced head and neck squamous cell carcinoma (LA-HNSCC) but is sometimes challenging to complete in older patients. Weekly CDDP + RT has shown mild toxicity compared to tri-weekly CDDP + RT for LA-HNSCC and is a promising option for older adults. We aimed to report the treatment outcomes and prognostic factors in patients with LA-HNSCC treated with weekly CDDP + RT. METHODS: We analyzed patients aged ≥ 70 years who started weekly CDDP + RT for LA-HNSCC between July 2006 and October 2022. LA-HNSCC includes cancer in the oropharynx, hypopharynx, or larynx with a clinical stage of 3 or 4 without distant metastases based on the Union for International Cancer Control staging system 8th edition. The radiation dose of 70 Gy was delivered in 35 fractions by 3-dimensional conformal radiotherapy, intensity-modulated radiotherapy, or proton beam therapy. The primary endpoint was the 3-year overall survival (OS), and the secondary endpoints were the 3-year progression-free survival (PFS) and 3-year cause-specific survival (CSS). The Kaplan-Meier method was used to calculate survival rates, and the log-rank test was used to evaluate statistical significance. A Cox proportional hazards model was used for the multivariate analysis of prognostic factors. RESULTS: The median age of the 49 patients was 72 (range: 70-78) years. The median CDDP dose was 200 (40-280) mg/ m2, and 47 patients completed scheduled radiotherapy. Forty-eight patients (98.0%) had a performance status of ≥ 1 at the initial visit. The 3-year OS, PFS, and CSS were 80.9% (95% confidence interval [CI]: 64.8-90.7), 68.3% (95% CI 51.8-81.2), and 85.0% (95% CI 68.7-93.4), respectively. In the multivariate analysis, the cumulative CDDP dose (< 200 or ≥ 200 mg/m2) was a significant factor for OS (hazard ratio: 0.29 [95% CI 0.08-0.97], p = 0.044). There was one case of early mortality. Grade 3 or higher late adverse events were observed in four patients (8.2%). CONCLUSIONS: Weekly CDDP + RT in older patients led to good survival outcomes with an acceptable rate of adverse events. CDDP should be administered at a dose of at least 200 mg/m2 in older patients. Trial registration Retrospectively registered.

Endoscopic resection as an independent predictive factor of local control in patients with T1bN0M0 esophageal squamous cell carcinoma treated with chemoradiotherapy: a retrospective study.

BACKGROUND: Although chemoradiotherapy (CRT) is one of the curative treatments for thoracic esophageal squamous cell carcinoma (ESCC) with submucosal invasion, the risk of local recurrence after CRT remains a clinical problem. This retrospective study aimed to analyze the predictive factors for local recurrence after CRT. METHODS: Ninety-one patients with clinical or pathological (c/p) T1bN0M0 thoracic ESCC who underwent CRT from 2004 to 2017 in our institution were analyzed retrospectively. Sixty-three patients were diagnosed with pathological T1b after undergoing initial endoscopic resection (ER) and treated with additional CRT; meanwhile, 28 patients were clinically diagnosed with T1b and underwent definitive CRT. We investigated the predictors of disease-specific survival (DSS) and local recurrence-free survival (LRFS) by performing univariate and multivariate analyses. RESULTS: The median observation period was 59.8 months. The 5-year DSS and LRFS rates were 84.3% (95% confidence interval [CI]: 76.1-92.5) and 87.1% (95% CI: 79.1-95.1), respectively. The multivariate analysis revealed no significant predictors associated with DSS. On the contrary, ER (hazard ratio [HR]: 0.11, 95% CI: 0.02-0.48, p = 0.003) and tumor length (HR: 6.78, 95% CI: 1.28-36.05, p = 0.025) were recognized as independent predictive factors for LRFS. During follow-up, recurrence was observed in 18 patients (19.8%). With regard to the patterns of relapse, local recurrence was the most common in 11 patients, and salvage ER was performed in 9 of 11 patients. CONCLUSIONS: ER and tumor length were independent predictive factors for LRFS. Our study suggested that performance of ER prior to CRT improved the local control in patients with c/p T1bN0M0 ESCC. In addition, most of the patients who experienced local recurrence were treated with salvage ER, which contributed to preserving the organs.