Dissipative Kerr soliton microcombs for FEC-free optical communications over 100 channels.

The demand for high-speed and highly efficient optical communication techniques has been rapidly growing due to the ever-increasing volume of data traffic. As well as the digital coherent communication used for core and metro networks, intensity modulation and direct detection (IM-DD) are still promising schemes in intra/inter data centers thanks to their low latency, high reliability, and good cost performance. In this work, we study a microresonator-based frequency comb as a potential light source for future IM-DD optical systems where applications may include replacing individual stabilized lasers with a continuous laser driven microresonator. Regarding comb line powers and spectral intervals, we compare a modulation instability comb and a soliton microcomb and provide a quantitative analysis with regard to telecom applications. Our experimental demonstration achieved a forward error correction (FEC) free operation of bit-error rate (BER) <10-9 with a 1.45 Tbps capacity using a total of 145 lines over the entire C-band and revealed the possibility of soliton microcomb-based ultra-dense wavelength division multiplexing (WDM) with a simple, cost-effective IM-DD scheme, with a view to future practical use in data centers.

Clinical significance of completion of radium-223 treatment and acute adverse events in patients with metastatic castration-resistant prostate cancer.

Objectives: In the treatment of castration-resistant prostate cancer (CRPC) with bone metastases, radium-223 dichloride (Ra-223) is the only bone-targeted drug that shows survival benefits. Completing six courses of Ra-223 treatment is thought to be associated with better patient survival, but this treatment has a relatively high rate of acute adverse events. Methods: This retrospective study included 85 patients from 12 institutions in Japan to investigate the clinical significance of the completion of Ra-223 treatment and acute adverse events in CRPC patients. Results: Six courses of Ra-223 treatment were completed in 65.9% of the patients. Grade 3 or higher acute adverse events were observed in 27.1% of patients. The prostate specific antigen and alkaline phosphatase declined at 26.9% and 87.9%, respectively. The overall survival rates at 12 and 24 months were 80.7% and 63.2%, respectively. Both completion of six courses of Ra-223 treatment and absence of grade 3 or higher acute adverse events were associated with longer overall survival. In univariate analysis, factors related to the history of treatment (five or more hormone therapy agents and cytotoxic chemotherapy) and hematological parameters (Prostate specific antigen (PSA) doubling time, alkaline phosphatase, hemoglobin, albumin, and serum calcium) were associated with completing six courses of Ra-223 treatment without experiencing grade 3 or higher acute adverse events. Multivariate analysis showed that a history of chemotherapy, PSA doubling time, hemoglobin, and serum calcium showed statistical significance. We built a predictive score by these four factors. Patients with lower scores showed higher rates of treatment success (p<0.001) and longer overall survival (p<0.001) with statistical significance. Conclusions: Accomplishing six courses of Ra-223 treatment without grade 3 or higher acute adverse events was a prognostic factor in patients with mCRPC treated with Ra-223. We built a predictive score of treatment success and need future external validation.

Differences in patterns of recurrence of squamous cell carcinoma and adenocarcinoma after radiotherapy for stage III non-small cell lung cancer.

PURPOSE: To evaluate the differences in patterns of recurrence and treatment results by histology after definitive radiotherapy for stage III non-small cell lung cancer (NSCLC) in Japan. MATERIALS AND METHODS: Patients with stage III NSCLC who underwent definitive radiotherapy between 2000 and 2016 in our institution were included. A total of 217 patients were enrolled. Propensity score matching was used to exclude the following confounding factors: (1) age (≥70 years or <70 years), (2) gender, (3) T factor, (4) N factor, (5) Eastern Cooperative Oncology Group performance status score and (6) smoking status (Brinkman index ≥400 or <400). RESULTS: The median observation period for survivors was 55.1 months. After propensity score matching, the Sqcc and adenocarcinoma groups each included 62 paired patients. There was no significant difference in OS or PFS between the adenocarcinoma and Sqcc groups. However, rates of recurrence in the GTV-primary site (p = 0.009) and GTV-lymph node site (p = 0.037) were significantly higher in patients with Sqcc than in patients with adenocarcinoma. New metastatic recurrence was more frequent in patients with adenocarcinoma than in patients with Sqcc (p = 0.025). CONCLUSION: There were significant differences in patterns of recurrence after definitive (chemo)radiotherapy between patients with Sqcc and patients with adenocarcinoma.

The Long-Term Recovery of Parotid Glands in Nasopharyngeal Carcinoma Treated by Intensity-Modulated Radiotherapy.

BACKGROUND: Xerostomia is one of the most common adverse events of radiotherapy in head and neck cancer patients. There have been many reports on functional changes of the parotid gland after radiation therapy, but there have been few reports on the volume of the parotid gland and its relationship with oral quality of life (QOL) and even fewer reports on longitudinal change of the parotid gland volume. The purpose of this study was to evaluate the long-term change of the parotid gland volume after intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma and the relationship between parotid irradiation dose and xerostomia symptoms. METHODS: We retrospectively analyzed 26 patients with nasopharyngeal cancer treated by IMRT. Longitudinal changes of parotid gland volumes after IMRT were evaluated on CT images. The parotid gland volumes in each period were converted to the ratio to parotid gland volumes before radiotherapy (relative parotid volume). Dunnett's test was used to evaluate the longitudinal changes in relative parotid volumes at 0-6, 7-18, 19-30, 31-42, 43-54 and 55-66 months after IMRT. We assessed xerostomia 3 years or more after IMRT by measuring the degree of oral moisture using a moisture-checking device (Mucus, Life Co., Ltd.) and oral QOL evaluation by GOHAI (General Oral Health Assessment Index). RESULTS: The relative parotid volumes during radiotherapy and at 0-6, 7-18, 19-30, 31-42, 43-54 and 55-66 months after IMRT were 75.2 ± 14.3%, 67.2 ± 11.4%, 68.5 ± 15.9%, 72.4 ± 14.8%, 73.0 ± 13.8%, 76.2 ± 17.5%, and 77.1% ± 17.3%, respectively. The parotid volume had recovered significantly at 43-54 and 55-66 months after IMRT, especially in parotids receiving less than 40 Gy as the mean dose. The mean irradiated dose for bilateral parotids showed negative correlations with oral QOL score and oral moisture after a long period. CONCLUSIONS: The parotid volume recovered gradually but had not reached a plateau even 3 years after radiotherapy, especially in parotids receiving less than 40 Gy as the mean dose.

Hypofractionated Radiotherapy for Anaplastic Thyroid Carcinoma: 15 Years of Experience in a Single Institution.

BACKGROUND: Anaplastic thyroid carcinoma (ATC) is a rare cancer and has a poor prognosis. Several radiation protocols have been reported, but the results were not satisfactory. OBJECTIVE: The aim of this study was to determine the effect of hypofractionated radiotherapy. METHODS: Thirty-three patients who received radiotherapy for ATC between January 2000 and December 2014 were retrospectively included. We defined hypofractionated radiotherapy as a single dose ≥5 Gy. RESULTS: Nineteen patients were treated with hypofractionated radiotherapy. Twenty-eight patients died, and 27 of those patients died from ATC. Sixteen patients died from distant metastasis and 6 from local recurrence. In the hypofractionated radiotherapy group, local recurrence occurred in 5 patients and 1 of them died from active bleeding from a local tumor. There was local recurrence in 7 patients who received the other protocol, and 5 of them died from asphyxiation, active bleeding, or uncontrollable growth of a local tumor on the neck. The median overall survival (OS) was 5 months. In multivariate analysis, patients who received an equivalent dose in 2-Gy fractions (EQD2) ≥50 Gy had significantly better OS (p = 0.016). In univariate analysis, patients who received hypofractionated radiotherapy did not have significantly better OS (p = 0.872) or local control (p = 0.090). The χ2 test showed that significantly fewer patients died from local recurrence in the hypofractionated radiotherapy group (p = 0.025). CONCLUSIONS: Multivariate analysis showed that an EQD2 ≥50 Gy resulted in better OS, and hypofractionated radiotherapy decreased the rate of mortality from local recurrence.

Definitive Chemoradiotherapy for Advanced Pulmonary Sarcomatoid Carcinoma.

Pulmonary sarcomatoid carcinoma is a rare subtype of non-small cell lung cancer with a poor prognosis. We herein report on a case of pulmonary sarcomatoid carcinoma that was treated successfully by concurrent chemoradiotherapy. A 65-year-old man was diagnosed to have pulmonary pleomorphic carcinoma (clinical T4N2M0 stage IIIB). He received concurrent chemoradiotherapy (60 Gy of radiotherapy in 30 fractionations and two courses of chemotherapy with carboplatin and paclitaxel). After chemoradiotherapy, a significant reduction of the tumor size was observed. Two courses of adjuvant chemotherapy were performed. He is currently alive at 15 months after the first treatment without any recurrence or metastasis.