Optimizing Organ-Preservation Strategies Through Chemotherapy-Based Selection in Esophageal Squamous Cell Carcinoma: Results From the CROC Multi-Institutional Phase 2 Clinical Trial.

PURPOSE: This study aimed to assess the viability of definitive chemoradiotherapy (dCRT) as an organ-preservation strategy for remarkable responders who were downstaged to stage IA after receiving induction chemotherapy for resectable esophageal squamous cell carcinoma (ESCC). METHODS AND MATERIALS: Chemotherapy-naïve patients with resectable ESCC (stage IB-III, Union for International Cancer Control, International Cancer Control seventh edition) were eligible for the study. All patients received 3 cycles of docetaxel, cisplatin, and 5-FU (DCF) therapy (docetaxel 75 mg/m2 on day 1, cisplatin 75 mg/m2 on day 1, and 5-fluorouracil [5-FU] 750 mg/m2 on days 1-5, repeated every 3 weeks). Remarkable response was defined as a reduction in the tumor to T1, metastatic lymph nodes <1 cm on the short axis, and downstaging to stage IA after 3 cycles of DCF therapy. Remarkable responders then underwent dCRT, which included 2 courses of cisplatin 75 mg/m2 and 5-FU 1000 mg/m2 on days 1 to 4, repeated every 4 weeks, along with 50.4 Gy of concurrent radiation therapy. The primary endpoint was 1-year progression-free survival in remarkable responders following DCF therapy and subsequent dCRT. Secondary endpoints included 3-year overall survival (OS) and esophagectomy-free survival. RESULTS: Of the 92 patients registered, 90 were analyzed. A remarkable response to 3 courses of DCF therapy was observed in 58.4% of patients. Among these responders, 89.8% achieved a complete response after dCRT. During the median follow-up period of 33 months (range, 1-85 months), the 1-year progression-free survival was 89.8% (95% confidence interval [CI], 77.2%-95.6%, primary endpoint), and the 3-year OS was 83.7%. The 3-year OS and esophagectomy-free survival rates in the analysis group were 74.1% and 45.3%, respectively. An 18F-fluorodeoxyglucose-positron emission tomography response after 2 courses of DCF therapy was significantly associated with OS (P = .0049). CONCLUSIONS: In patients with resectable ESCC, dCRT for remarkable responders downstaging to stage IA after induction chemotherapy with 3 courses of DCF therapy is a feasible treatment option and provides an optimizing organ-preservation strategy of chemotherapy-based selection.

CdTe XG-Cam: A new high-resolution x-ray and gamma-ray camera for studies of the pharmacokinetics of radiopharmaceuticals in small animals.

BACKGROUND: The recent emergence of targeted radionuclide therapy has increased the demand for imagers capable of visualizing pharmacokinetics in developing radiopharmaceuticals in the preclinical phase. Some radionuclides emit hard x-rays and gamma-rays below 100 keV, in which energy range the performance of conventional NaI scintillators is poor. Multipinhole collimators are also used for small animal imaging with a good spatial resolution but have a limited field of view (FOV). PURPOSE: In this study, a new imager with high sensitivity over a wide FOV in the low-energy band ( < $<$ 100 keV) was developed for the pharmacokinetic study. METHODS: We developed an x-ray and gamma-ray camera for high-resolution spectroscopy, named "CdTe XG-Cam," equipped with a cadmium telluride semiconductor detector and a parallel-hole collimator using a metal 3D printer. To evaluate the camera-system performance, phantom measurements with single and dual nuclides ( 99 m Tc $^{\rm 99m}{\rm Tc}$ , 111 In $^{111}{\rm In}$ , and 125 I ) $^{125}{\rm I)}$ were performed. The performance for in vivo imaging was evaluated using tumor-bearing mice to which a nuclide ( 99 m Tc $^{\rm 99m}{\rm Tc}$ or 125 I ) $^{125}{\rm I)}$  administered. RESULTS: We simultaneously obtained information on 111 In $^{111}{\rm In}$ and 125 I $^{125}{\rm I}$ , which emit emission lines in the low-energy band with peak energies close to each other (23-26 keV for 111 In $^{111}{\rm In}$ and 27-31 keV for 125 I ) $^{125}{\rm I)}$ , and applied an analytical method based on spectral model fitting to determine the individual radioactivities accurately. In the small animal imaging, the distributions of the nuclide in tumors were accurately quantified and time-activity curves in tumors are obtained. CONCLUSIONS: The demonstrated capability of our system to perform in vivo imaging suggests that the camera can be used for applications of pharmacokinetics research.

Equivalent prognosis with no lymph node metastasis to pathological complete remission in patients with localized advanced esophageal cancer after neoadjuvant triplet chemotherapy with docetaxel, cisplatin, and 5-fluorouracil followed by curative surgery: a single-center retrospective cohort study.

Background: Adjuvant nivolumab therapy has become the standard therapy for patients with localized advanced esophageal cancer with non-pathological complete response after neoadjuvant chemoradiotherapy followed by curative surgery. However, the necessity of this therapy for patients after neoadjuvant chemotherapy (NAC) with docetaxel, cisplatin, and 5-fluorouracil (DCF) regimen followed by surgery is unclear, and the prognosis of grouping based on the presence or absence of pathological tumor and lymph node findings has not been analyzed. Therefore, our study aimed to address these questions. Methods: This retrospective cohort study included patients with cT1N1-3M0 and cT2-3N0-3M0 esophageal cancer according to the Japanese Classification of Esophageal Cancer, 11th edition, who received NAC with DCF followed by curative surgery between 2008 and 2020 at Jichi Medical University Hospital. We divided patients with ypT0-3N0-3M0 into four histological groups, namely ypT0N0, ypT+N0, ypT0N+, and ypT+N+, and we evaluated overall survival as the primary outcome and the prognostic relationship of lymph node metastasis as the secondary outcome. Results: A total of 101 patients were included in this study. Kaplan-Meier analysis showed that the curves of the ypT0N0 and ypT+N0 groups were almost identical, while they differed from the other two groups. The hazard ratio of ypN+ was 4.44 (95% confidence interval: 2.03-9.71; P<0.001). Conclusions: The prognosis of the ypT+N0 group after NAC with DCF followed by surgery was similar to that of pathological complete remission. Grouping patients according to pathological lymph node status is a reasonable predictor of prognosis.

A new simpler image quality index based on body size for FDG-PET/CT.

Noise equivalent count density (NEC density ) is often used to evaluate the image quality of whole-body fluorodeoxyglucose tomography tests. However, this index is calculated using the patient volume, which is difficult to obtain at every facility. In this study, we proposed new image quality indices that can be evaluated at all facilities. In total, 94 patients were enrolled in the study. The correlations of patients' body weight and BMI with volume were examined. New image quality indices normalized by body weight and BMI were defined as NEC bw and NEC bmi , respectively. Correlations between NEC bw , NEC bmi , and NEC density were examined. Further, the correlations between these two new indices and visual scores were evaluated. Good correlations were observed between volume and body weight (r = 0.861, P  < 0.001) and between volume and BMI (r = 0.728, P  < 0.001). NEC bw and NEC bmi correlated well with NEC density (r = 0.954 for NEC bw and r = 0.897 for NEC bmi , P  < 0.001). These correlations improved when the examined bed positions were set to the same number. Additionally, the correlations of visual scores with NEC bw and NEC bmi were similar to those between the visual score and NEC density . Our investigation indicated that the newly proposed image quality metrics, NEC bw and NEC bmi , were easily calculated and as useful as NEC density for evaluating image quality when subjects had similar physiques.