Acto3D: an open-source user-friendly volume rendering software for high-resolution 3D fluorescence imaging in biology

Advances in fluorescence microscopy and tissue-clearing have revolutionised 3D imaging of fluorescently labelled tissues, organs and embryos. However, the complexity and high cost of existing software and computing solutions limit their widespread adoption, especially by researchers with limited resources. Here, we present Acto3D, an open-source software, designed to streamline the generation and analysis of high-resolution 3D images of targets labelled with multiple fluorescent probes. Acto3D provides an intuitive interface for easy 3D data import and visualisation. Although Acto3D offers straightforward 3D viewing, it performs all computations explicitly, giving users detailed control over the displayed images. Leveraging an integrated graphics processing unit, Acto3D deploys all pixel data to system memory, reducing visualisation latency. This approach facilitates accurate image reconstruction and efficient data processing in 3D, eliminating the need for expensive high-performance computers and dedicated graphics processing units. We have also introduced a method for efficiently extracting lumen structures in 3D. We have validated Acto3D by imaging mouse embryonic structures and by performing 3D reconstruction of pharyngeal arch arteries while preserving fluorescence information. Acto3D is a cost-effective and efficient platform for biological research.

Reirradiation for recurrent gynecologic cancer using high-dose-rate brachytherapy in Japan: A multicenter survey on practice patterns and outcomes

BACKGROUND AND PURPOSE

The aim of the study is to examine the present status of reirradiation with high-dose-rate (HDR) brachytherapy for recurrent gynecologic cancer in Japan and to determine the role of this therapy in clinical practice.

MATERIALS AND METHODS

A retrospective multicenter chart review was performed for reirradiation for gynecologic cancer using HDR brachytherapy. Each center provided information on patient characteristics, treatment outcomes, and complications.

RESULTS

The study included 165 patients treated at 9 facilities from 2000 to 2018. The analysis of outcomes included 142 patients treated with curative intent. The median follow-up time for survivors was 30 months (range 1-130 months). The 3-year overall survival (OS), progression-free survival (PFS), and local control (LC) rates were 53 % (95 %CI: 42-63 %), 44 % (35-53 %), and 61 % (50-70 %) for cervical cancer; 100 % (NA), 64 % (30-85 %), and 70 % (32-89 %) for endometrial cancer; and 54 % (13-83 %), 38 % (6-72 %), and 43 % (6-78 %) for vulvar and vaginal cancer, respectively. In multivariate analysis, interval to reirradiation (<1 year) was a significant risk factor for OS, PFS and LC; Gross Tumor Volume (≥25 cm3) was a significant risk factor for OS. Toxicities were analyzed in all enrolled patients (n = 165). Grade ≥ 3 late toxicities occurred in 49 patients (30 %). A higher cumulative EQD2 (α/β = 3) was significantly associated with severe complications.

CONCLUSION

Reirradiation with HDR brachytherapy for recurrent gynecologic cancer is effective, especially in cases with a long interval before reirradiation.

The influence of Gleason score ≤ 6 histology on the outcome of high-risk localized prostate cancer after modern radiotherapy

We aimed to retrospectively review outcomes in patients with high-risk prostate cancer and a Gleason score ≤ 6 following modern radiotherapy. We analyzed the outcomes of 1374 patients who had undergone modern radiotherapy, comprising a high-risk low grade [HRLG] group (Gleason score ≤ 6; n = 94) and a high-risk high grade [HRHG] group (Gleason score ≥ 7, n = 1125). We included 955 patients who received brachytherapy with or without external beam radio-therapy (EBRT) and 264 who received modern EBRT (intensity-modulated radiotherapy [IMRT] or stereotactic body radiotherapy [SBRT]). At a median follow-up of 60 (2-177) months, actuarial 5-year biochemical failure-free survival rates were 97.8 and 91.8% (p = 0.017), respectively. The frequency of clinical failure in the HRLG group was less than that in the HRHG group (0% vs 5.4%, p = 0.012). The HRLG group had a better 5-year distant metastasis-free survival than the HRHG group (100% vs 96.0%, p = 0.035). As the HRLG group exhibited no clinical failure and better outcomes than the HRHG group, the HRLG group might potentially be classified as a lower-risk group.

Albumin-bilirubin score is a useful predictor of worsening liver reserve after stereotactic body radiation therapy in elderly Japanese patients with hepatocellular carcinoma

The prognosis of patients with hepatocellular carcinoma (HCC) is closely related to their liver reserves. The Child-Pugh (CP) score has traditionally been used to evaluate this reserve, with CP Grade B (CP score ≥ 7) associated with a higher risk of radiation-induced liver disease after stereotactic body radiation therapy (SBRT). However, the CP score has limitations, as it does not accurately assess liver reserve capacity. The albumin-bilirubin (ALBI) score has been introduced as a meticulous indicator of liver reserve for the treatment of HCC. We retrospectively evaluated the role of the ALBI score in estimating the worsening liver reserve in 42 patients with HCC treated with SBRT using CyberKnife between 2015 and 2023. The median biologically effective dose (α/β = 10 Gy) was 100 Gy. For a median follow-up duration of 17.4 months, the 1-year overall survival (OS), local control (LC) and progression-free survival (PFS) rates were 100, 98 and 62%, respectively. Worsening liver reserve was defined as an increase in the modified ALBI grade or CP score within 1 year after SBRT. Univariate and multivariate analyses showed that the baseline ALBI score (≥-2.7 vs <-2.7) was the only significantly different predictor of worsening liver reserve. The OS and LC rates after SBRT for HCC were satisfactory. However, the PFS was poor, and recurrent HCC will require additional treatment. It is clinically important to predict the liver reserve capacity after SBRT, and the baseline ALBI score is a useful predictor.

Re-irradiation for isolated neck recurrence in head and neck tumor: impact of rN category

Unresectable, isolated lymph node recurrence after radiotherapy is rare but a candidate for re-irradiation. However, severe toxicity is anticipated. Therefore, this study aimed to explore the efficacy and toxicity of re-irradiation in isolated lymph node recurrence of head and neck lesions. We analyzed 46 patients who received re-irradiation for lymph node recurrence without local progression. The primary tumor sites included the oral cavity in 17 patients, the hypopharynx in 12, the oropharynx in seven, the larynx in three, the nasopharynx in two, and other sites. During a median follow-up time of 10 months, the median survival time was 10.6 months, and the 1-year overall survival rate was 45.5%. The 1-year local control and progression-free survival rates were 49.8% and 39.3%, respectively. According to univariate analysis, age (≥ 65 years), the interval between treatment (≥ 12 months), rN category (rN1), and gross tumor volume (GTV < 25 cm3) were predisposing factors for better survival. In the multivariate analysis, the rN category and interval were identified as statistically significant predictors. Late toxicity grade ≥ 3 occurred in four patients (8.6%). These were all Grade 5 carotid blowout syndrome, which associated with tumor invasion of the carotid artery and/ or high doses administration for the carotid artery. Small-volume rN1 tumor that recur after a longer interval is a feasible candidate for re-irradiation. However, strict patient selection and meticulous care for the carotid are required.

The Dosimetric Analysis of Duodenal and Intestinal Toxicity After a Curative Dose Re-irradiation Using the Intensity-Modulated Radiotherapy for Abdominopelvic Lymph Node Lesions

INTRODUCTION

This study aimed to examine the influence of dosimetric factors on gastrointestinal toxicity after radical re-irradiation for lymph node recurrence in the abdominopelvic region using a composite plan.

METHODS

Between January 2008 and March 2017, 33 patients underwent radical re-irradiation for lymph node recurrence in the abdominopelvic region with a complete overlap with previous radiation therapy (RT) with the median prescription dose of the second RT of 71.7 Gy10. Re-irradiation planning protocol for target volume and organs at risk (OARs) (duodenum, small and large intestines) was decided as follows: more than equal to 97% of the prescription dose was administered to the D95 (percentage of the minimum dose that covered 95% of the target volume) of planning target volume (PTV); minimal dose to the maximally irradiated doses delivered to 1cc [D1 cc] and 5cc [D5 cc] of OARs was set below 70 Gy3 and 50 Gy3, respectively; and D1 cc and D5 cc in the cumulative plans to OARs were 120 Gy3 and 100 Gy3. Kaplan-Meier analyses were performed to evaluate overall survival (OS) and univariate log-rank and multivariate Cox proportional hazards model analyses were performed to explore predictive factors. Using dose summation of the first and re-irradiation plans, we conducted a dosimetric analysis for grade ≥ 3 toxicities of the duodenum and intestine.

RESULTS

With a median follow-up of 18 months, the two-year OS rate was 45.5%. The number of RT fields (localized or multiple) was a significant predisposing factor for OS rate with a hazard ratio of 0.23 (95% confidence interval 0.07-0.73). The two-year OS of the patients with a localized RT field was 63.6% and 9.1% for multiple RT fields (p= 0.00007). Four patients experienced grade ≥3 gastrointestinal toxicity related to re-irradiation (4/33=12.1%). We could not find any predisposing dosimetric value in the comparisons with and without toxicity.

CONCLUSIONS

The dose constraints presented in this study are relatively low rates of toxicity, which may be useful when planning re-irradiation. Especially, for the patients who could be treated with localized RT field, radical re-irradiation with a high curative dose is a good option. No dosimetric predisposing factor was found for radical re-irradiation of abdominopelvic lesions in the composite plan.

Comparative dosimetric study of spot-scanning proton therapy versus volumetric-modulated radiation therapy for extrahepatic bile duct cancer

This study aimed to compare the dose distributions and clarify the dosimetric characteristics of spot-scanning proton therapy (SSPT) and photon volumetric modulated arc therapy (VMAT) for extrahepatic bile duct cancer (EBDC). This retrospective study included 10 patients with EBDC treated with real-time image-gated SSPT. Using the simultaneous integrated boost technique, the 2 prescription dose levels for planning target volumes were 72.6 and 44 Gy, delivered in 22 fractions. Plan quality comparisons were conducted by analyzing various parameters, including homogeneity, conformity, dose to organs at risk, and normal tissue complication probability (NTCP) for radiation-induced liver damage (RILD). The target dose distributions using SSPT were almost equivalent to those achieved using photon VMAT. There was a significant reduction in all liver dose parameters, the NTCP value for RILD, and kidney dose (mean, V12 Gy, and V18 Gy) in SSPT than in photon VMAT. No significant differences were observed in the intestinal doses in the high-dose area. Thus, compared with photon VMAT, SSPT for EBDC significantly reduced radiation doses to the liver and kidneys and has shown potential clinical benefits of reduced radiation-induced toxicity.

The Feasibility of Omitting Postoperative Radiotherapy in Japanese Patients With Ductal Carcinoma In Situ of Breast Treated With Breast-Conserving Surgery

Background To analyze the feasibility of omitting postoperative radiotherapy (PORT) after breast-conserving surgery (BCS) in Japanese patients with ductal carcinoma in situ (DCIS). Materials and methods We retrospectively analyzed 88 patients with small pure DCIS (median diameter 1.1 cm, ≤ 4 cm) who underwent BCS with (n = 39) or without (n = 49) PORT. The primary and secondary endpoints were ipsilateral breast tumor recurrence (IBTR) and overall survival (OS), respectively, between the groups that received PORT and those that did not. Results The PORT group included a high number of margin-positive cases. The incidence of IBTR was 2.4% (95% confidence interval (CI), 0.3-15.7%) and 2.8% (95% CI, 0.4-18.2%) at five years and 5.5% (95% CI, 1.4-20.6%) and 2.8% (95% CI, 0.4-18.2%) at 10 years in patients without and with PORT, respectively (p = 0.686). In the margin-negative group, only one patient showed IBTR without RT (2.3%), whereas no patient with PORT experienced IBTR (0%). To date, there have been no regional or distant metastases; therefore, no patient has experienced breast cancer-related deaths. The OS rates were 97.7% (95% CI, 84.9-99.6%) and 100% at 10 years in patients without and with PORT, respectively (p = 0.372). Conclusion This study suggests that the omission of PORT after BCS could be a feasible option for selected Japanese patients but requires further investigation to identify the low-risk factor in patients who can omit PORT.

Increasing rectum-prostate distance using a hydrogel spacer to reduce radiation exposure during proton beam therapy for prostate cancer

SpaceOAR, a polyethylene-glycol hydrogel, reduces rectal radiation exposure during radiation therapy for prostate cancer. Previously, our group reported the modified technique of hydrogel insertion, which achieves greater separated distance at prostate-apex. This study aimed to investigate the impact of separated distance at prostate-apex and our modifier technique, on radiation exposure reduction during proton beam therapy (PBT). We included 330 patients undergoing PBT with the relative biological effectiveness (RBE) of 63 Gray (Gy) for localized prostate cancer, and categorized them into groups 0 (no spacer, n = 141), 1 (separated distance of spacer at the prostate-apex level < 7.5 mm, n = 81), and 2 (distance ≥ 7.5 mm, n = 108). The rectal volumes to receive 30-60 Gy (RBE), was estimated and described as Rectal V30-60 (ml) in 10 Gy increments. The Rectal V30-60 (ml) was significantly lower in group 2 than in group 1, and in group 1 than in group 0. After propensity score matching, the multivariate logistic regression analysis revealed that the most significant factor to reduce radiation exposure was our modified technique of hydrogel insertion. Therefore, using a hydrogel spacer to expand the prostate-rectum distance not only at prostate-mid to prostate-base level but also at the prostate-apex level can reduce the radiation exposure in PBT for prostate cancer.

Proton beam therapy for extrahepatic biliary tract cancer: Analysis with prospective multi-institutional patients' registration database, Proton-Net

Background and purpose

To examine the role of proton beam therapy (PBT) in the treatment of extrahepatic biliary tract cancer (EBC).

Methods and materials

We analyzed the data accumulated in the Proton-Net database, which prospectively registered all individual patient data treated with PBT in all Japanese proton institutions from May 2016 to June 2019. The primary endpoint was overall survival (OS), and the secondary endpoints were local control (LC), progression-free survival (PFS), and toxicity.

Results

Ninety-three patients with unresectable and/or recurrent EBC were treated with PBT using a median prescribed dose of 67.5 Gy (RBE) (range, 50-72.6 Gy) in 25 (22-30 fractions). With a median follow-up of 16.3 months, the median survival time was 20.1 months and the 2-year OS was 37.8%. Two-year PFS and LC rates were 20.6% and 66.5%, respectively. Poor liver function (Child-Pugh B, C), a narrower distance between the tumor and digestive tract (2 cm >), and a larger tumor diameter (2 cm <) were identified as poor prognostic factors for OS. PBT-related grade 3 ≤ acute and late adverse events occurred in 5.4% and 4.3% of patients, respectively, including one gastrointestinal late toxicity (duodenal ulcer).

Conclusions

This is the largest prospectively accumulated series of PBT for EBC, and PBT showed favorable outcomes with acceptable toxicity profiles.

Initial tumor volume as an important predictor for indication of intra-cavitary brachytherapy, intra-cavitary/interstitial brachytherapy, and multi-catheter sole interstitial brachytherapy in cervical cancer patients treated with chemoradiotherapy

Purpose

Advances in three-dimensional image-guided brachytherapy technique allow for using intra-cavitary and interstitial brachytherapy (ICIS-BT), and sole interstitial brachytherapy (ISBT) in addition to conventional intra-cavitary brachytherapy (ICBT). However, no consensus has been reached regarding the choice of these techniques. The aim of this study was to propose the size criteria for indication of interstitial techniques.

Material and methods

We examined initial gross tumor volume (GTV) at presentation and at each brachytherapy session. Also, dose volume histogram parameters for each modality were compared in 112 patients with cervical cancer treated with brachytherapy (ICBT, 54; ICIS-BT, 11; and ISBT, 47).

Results

The average GTV at diagnosis was 80.9 cm³ (range, 4.4-343.2 cm³), which shrank to 20.6 cm³ (25.5% of initial volume, range, 0.0-124.8 cm³) at initial brachytherapy. GTV > 30 cm³ at brachytherapy and high-risk clinical target volume > 40 cm³ were good threshold values for indication of interstitial technique, and tumors with initial GTV > 150 cm³ could be candidates for ISBT. An ISBT dose of 89.10 Gy can be prescribed in equivalent dose in 2 Gy fractions (range, 65.5-107.6 Gy), which was higher than those of ICIS (73.94 Gy, range, 71.44-82.50 Gy) and ICBT (72.83 Gy, range, 62.50-82.27 Gy) (p < 0.0001).

Conclusions

Initial tumor volume is an important predictor for indication of ICBT and ICIS-BT. ISBT or at least an interstitial technique is recommended for initial GTV > 150 cm³.

Particle beam therapy versus photon radiotherapy for extrahepatic biliary cancer-systemic review and meta-analysis

Particle beam therapy (PT) is a potentially promising approach to the treatment of extrahepatic biliary cancer (EBC) because of its unique dose distribution using the Bragg peak. However, the superiority of PT to photon radiotherapy (XT) remains unclear. Therefore, we conducted a systematic review and meta-analysis to compare PT and XT for the treatment of EBC. The primary endpoint was overall survival (OS), which was pooled using a random-effects model. Nine articles comprising a total of 1558 patients (seven XT articles, n = 1488 patients; two PT articles, n = 70 patients) were screened. In addition, we compared the outcomes of XT and PT with the outcomes available from a prospective data registry (proton-net). The 1-year OS probability rates were 55, 65 and 72% for the XT group, PT group and PT registry, respectively. The 2-year OS probability rates were 26, 38 and 38% for the XT group, PT group and PT registry, respectively. The 3-year OS probability rates were 12, 35 and 18% for the XT group, PT group and PT registry, respectively. Although the difference between the 1-year OS rates of the XT group and PT registry was statistically significant, no other significant superiority was observed among these groups. In conclusion, the efficacy of PT was not superior to that of XT during this meta-analysis.

Radiotherapy for ductal carcinoma of the prostate: an analysis based on the Japanese radiation oncology study group survey

BACKGROUND

The clinical characteristics of prostate ductal carcinoma is still unclear, and treatment strategy has not yet been established due to its rarity. Therefore, we conducted a multicenter survey of radiation therapy for prostate ductal carcinoma in Japan.

METHOD

Data of patients with ductal carcinoma of the prostate treated with radiation therapy between 1996 and 2018 were extracted from the database of each facility.

RESULTS

Fifty-two treatment records of 41 patients were collected from nine institutions. The treatment purpose and situations were varied curative intent to palliation. Twenty-eight patients received curative treatments. The median follow-up period of these patients was 68 months. Androgen deprivation therapy was combined with radiation therapy in 26 cases (93%). X-ray and particle irradiation was used. Radiation dose range was 63-78 Gy; 5-year overall survival, progression-free survival and biochemical relapse-free survival were 87.0, 79.3 and 79.3%, respectively. One patient experienced Grade 3 radiation proctitis and one experienced Grade 3 radiation cystitis. There were no Grade 4 or worse adverse events.

CONCLUSION

Most patient received similar treatment with adenocarcinoma of prostate, and the clinical results were compatible. For more reliable evidence, further studies are required.

Particle Beam Therapy for Intrahepatic and Extrahepatic Biliary Duct Carcinoma: A Multi-Institutional Retrospective Data Analysis

To examine the efficacy and toxicity of particle beam therapy (PT) for biliary duct carcinoma (BDC) and compare the outcomes between extrahepatic BDC (eBDC) and intrahepatic BDC (iBDC). We analyzed multi-institutional data from May 2009 to December 2019. The primary endpoint was overall survival (OS), and the secondary endpoints were local control (LC), progression-free survival (PFS) and toxicity. We included 150 patients with unresectable BDC treated with PT using a median prescribed dose of 70.2 GyRBE (range, 44-77 GyRBE) in 25 fractions (range, 10-38 fractions). With a median follow-up of 13.0 months, median survival time (MST) was 21 months, and 2-year OS was 44.8%. For eBDC and iBDC, the MSTs were 20 and 23 months, respectively. Two-year PFS and LC rates were 20.6% and 66.5%, respectively. Vascular invasion, prescribed dose and serum tumor marker level (carcinoembryonic antigen: CEA) were identified as poor prognostic factors for OS. A higher radiation dose EQD2 ≥ 67 Gy showed superior OS, with a hazard ratio of 0.341. The radiation dose of PT is an important predisposing factor for overall survival. The MST for patients with eBDC given a higher radiation dose was 25 months, compared to 15 months for those given the lower dose and 23 months for patients with iBDC (all iBDC given higher doses). iBDC and eBDC duct carcinomas showed equivalent outcomes with PT, especially when treated with a high radiation dose. In detailed analysis, baseline CEA level in iBDC, and radiation dose and GTV in eBDC were statistically significant predicators for OS. Acute and late toxicity grade ≥3 occurred in 2.2% and 2.7% of patients, respectively, including two late grade-5 toxicities. In conclusion, PT showed good efficacy for BDC, both eBDC and iBDC, with a low incidence of severe toxicity.

Chemoradiation versus surgery for superficial esophageal squamous cell carcinoma after noncurative endoscopic submucosal dissection: comparison of long-term oncologic outcomes

Background

Esophagectomy is the standard adjuvant treatment for superficial esophageal squamous cell carcinoma (SESCC) following noncurative endoscopic submucosal dissection (ESD). However, recent reports have also shown that ESD with adjuvant chemoradiotherapy (CRT) has promising results. This retrospective study aimed to elucidate the efficacy of CRT compared to surgery in patients with SESCC after noncurative ESD.

Methods

This study retrospectively compared the long-term outcomes of patients who received adjuvant treatment with surgery or CRT after noncurative ESD for SESCC.

Results

Data were collected from 60 patients who developed SESCC after noncurative ESD, 34 of whom received adjuvant chemoradiotherapy (CRT) and 26 underwent esophagectomy. The median follow-up periods were 46 and 56 months in the CRT and esophagectomy groups, respectively. The median patient age was significantly higher in the CRT group than in the esophagectomy group (69 vs. 65 years, p = 0.0054). CRT was completed in all patients, and the incidence of grade ≥ 3 nonhematologic adverse events was 6%. The overall and disease-free survival did not significantly differ between the two groups.

Conclusions

CRT following ESD seems a promising nonsurgical strategy for optimizing the selection of therapies for high-risk SESCC and warrant further investigation.

Influence of Boron Neutron Capture Therapy on Normal Liver Tissue

Radiation-induced liver diseases, including liver fibrosis, occurs when radiation damages the liver. Basic research on hepatic fibrosis, which is a late radiation injury, is necessary for evaluating adverse liver events occurring after boron neutron capture therapy. This study was conducted to establish a method for analyzing the negative effect such as fibrosis in the liver tissue after boron neutron capture therapy. Female C57BL6 mice were injected with p-boronophenylalanine solution subcutaneously at 2 h before neutron irradiation. Masson trichrome staining was performed to determine the degree of liver fibrosis. The degree of fat accumulation in mouse normal liver tissue after boron neutron capture therapy was evaluated using hematoxylin and eosin staining and triglyceride quantification. Western blotting was performed to determine the expression level of Sonic Hedgehog. Liver fat accumulation and fibrosis were significantly increased in the neutron irradiation group injected with p-boronophenylalanine compared with control group. In addition, Sonic Hedgehog expression was increased in response to boron neutron capture therapy-induced liver injury and was involved in liver fibrosis. Hepatocellular fat accumulation and Hedgehog signaling activation may be indicators of adverse events related to boron neutron capture therapy associated with liver fibrosis.

Role of Brachytherapy Boost in Clinically Localized Intermediate and High-Risk Prostate Cancer: Lack of Benefit in Patients with Very High-Risk Factors T3b-4 and/or Gleason 9-10

Simple Summary

In general, brachytherapy (BT) improves biochemical control in intermediate-to high-risk prostate cancer. We previously reported that importance of very high-risk factors (VHR: T3b–4 or Gleason score 9–10) and patients with double VHR (VHR-2) showed the worst prognosis among high-risk groups. We explored the role of BT-boost in patients with VHR and compared it to intermediate- and other high-risk groups. We confirmed that BT-boost improved prostate-specific antigen (PSA) control but resulted in equivalent overall survival rates for the intermediate- and high-risk groups, except for the patients with VHR. In the VHR-1 group (single VHR), BT-boost showed superior PSA control to conventional-dose RT (EQD2 ≤ 72 Gy) but not to the dose-escalated radiotherapy group (EQD2 ≥ 74 Gy). In the VHR-2 group, BT-boost did not improve the biochemical control rate of either Conv RT or DeRT. BT-boost showed no benefit over modern DeRT in the patients with VHR.

Abstract

This study examined the role of brachytherapy boost (BT-boost) and external beam radiotherapy (EBRT) in intermediate- to high-risk prostate cancer, especially in patients with very high-risk factors (VHR: T3b–4 or Gleason score 9–10) as patients with double very high-risk factors (VHR-2: T3b–4 and Gleason score 9–10) previously showed worst prognosis in localized prostate cancer. We retrospectively reviewed multi-institutional data of 1961 patients that were administered radiotherapy (1091 BT-boost and 872 EBRT: 593 conventional-dose RT (Conv RT: equivalent to doses of 2 Gy per fraction = EQD2 ≤ 72 Gy) and 216 dose-escalating RT (DeRT = EQD2 ≥ 74 Gy). We found that BT-boost improved PSA control and provided an equivalent overall survival rate in the intermediate- and high-risk groups, except for patients within the VHR factor group. In the VHR-1 group (single VHR), BT-boost showed a superior biochemical control rate to the Conv RT group but not to the DeRT group. In the VHR-2 group, BT-boost did not improve outcomes of either Conv RT or DeRT groups. In conclusion, BT-boost showed no benefit to modern DeRT in the patients with VHR; therefore, they are not good candidates for BT-boost to improve outcome and may be amenable to clinical trials using multimodal intensified systemic treatments.

A deep learning method for translating 3D-CT to SPECT ventilation imaging: First comparison with 81m Kr-gas SPECT ventilation imaging

PURPOSE

This study aimed to evaluate the accuracy of deep learning (DL)-based computed tomography (CT) ventilation imaging (CTVI).

METHODS

A total of 71 cases who underwent single-photon emission CT ^81m Kr-gas ventilation (SPECT V) and CT imaging were included. Sixty cases were assigned to the training and validation sets and the remaining 11 cases were assigned to the test set. To directly transform 3DCT (free-breathing CT) images to SPECT V images, a DL-based model was implemented based on the U-Net architecture. The input and output data were 3DCT- and SPECT V-masked, respectively, except for whole-lung volumes. These data were rearranged in voxel size, registered rigidly, cropped, and normalized in pre-processing. In addition to a standard estimation method (i.e., without dropout during the estimation process), a Monte-Carlo Dropout (MCD) method (i.e., with dropout during the estimation process) was used to calculate prediction uncertainty. To evaluate the two models' (CTVI_{MCD U-Net} , CTVI_U-Net ) performance, we used five-fold cross-validation for the training and validation sets. To test the final model performances for both approaches, we applied the test set to each trained model and averaged the test prediction results from the five trained models to acquire the mean test result (bagging) for each approach. For the MCD method, the models were predicted repeatedly (sample size = 200), and the average and standard deviation maps were calculated in each voxel from the predicted results: the average maps were defined as test prediction results in each fold. As an evaluation index, the voxel-wise Spearman rank correlation coefficient (Spearman r_s ) and dice similarity coefficient (DSC) were calculated. The DSC was calculated for three functional regions (high, moderate, and low) separated by an almost equal volume. The coefficient of variation was defined as prediction uncertainty, and these average values were calculated within three functional regions. The Wilcoxon signed-rank test was used to test for a significant difference between the two DL-based approaches RESULTS: The average indexes with one standard deviation (1SD) between CTVI_{MCD U-Net} and SPECT V were 0.76 ± 0.06, 0.69 ± 0.07, 0.51 ± 0.06, and 0.75 ± 0.04 for Spearman r_s , DSC_high , DSC_moderate , and DSC_low , respectively. The average indexes with 1SD between CTVI_U-Net and SPECT V were 0.72 ± 0.05, 0.66 ± 0.04, 0.48 ± 0.04, and 0.74 ± 0.06 for Spearman r_s , DSC_high , DSC_moderate , and DSC_low , respectively. These indexes between CTVI_{MCD U-Net} and CTVI_U-Net showed no significance difference (Spearman r_s , p = 0.175; DSC_high , p = 0.123; DSC_moderate , p = 0.278; DSC_low , p = 0.520). The average coefficient of variations with 1SD were 0.27 ± 0.00, 0.27 ± 0.01, and 0.36 ± 0.03 for the high-, moderate-, and low-functional regions, respectively, and the low-functional region showed a tendency to exhibit larger uncertainties than the others.

CONCLUSION

We evaluated DL-based framework for estimating lung-functional ventilation images only from CT images. The results indicated that the DL-based approach could potentially be used for lung-ventilation estimation. This article is protected by copyright. All rights reserved.

＜Editors' Choice＞ Elective nodal irradiation versus involved field radiotherapy for limited disease small cell lung cancer: a single-institution experience

Elective nodal irradiation (ENI) and involved field radiotherapy (IFRT) are definitive radiotherapeutic approaches used to treat patients with limited-disease small cell lung cancer (LD-SCLC). However, no solid consensus exists on their optimal target volume. The current study aimed to assess the clinical outcomes of patients with LD-SCLC who received definitive ENI or IFRT. A retrospective single-institution study of patients who received definitive radiotherapy between 2008 and 2020 was performed. All patients underwent whole-body positron emission tomography/computed tomography before three-dimensional conformal radiotherapy. Among the 37 patients analyzed, 22 and 15 received ENI and IFRT, respectively. The thoracic radiotherapy dose was mostly either 60 Gy in 30 fractions delivered in 2-Gy fractions once daily or 45 Gy in 30 fractions delivered in 1.5-Gy fractions twice daily. The median follow-up period was 21.4 months. A total of 12 patients (32%) experienced locoregional relapse: 10 within and 2 outside the irradiation fields. One patient in the IFRT group experienced isolated nodal failure. Differences in locoregional relapse-free, progression-free, and overall survival rates between ENI and IFRT were not significant. Overall, IFRT did not promote a significant increase in locoregional recurrence compared to ENI. Our findings suggested the utility of IFRT in standard clinical practice and support its use for patients with LD-SCLC.

Repeated Stereotactic Body Radiotherapy for Lung Malignancies: Toxicity Can Be Reduced by Sparing Lung Irradiation

BACKGROUND/AIM

Evidence on the use of repeated stereotactic body radiotherapy (SBRT) is limited. We investigated the efficacy of repeated SBRT and predictors of lung toxicity.

PATIENTS AND METHODS

We reviewed 20 patients (27 lesions) with primary or metastatic lung cancer who underwent repeated SBRT with CyberKnife^® We generated a composite plan for dosimetric analysis based on equivalent doses in 2.0-Gy fractions (α/β=3). Predictors of Grade 2+ radiation pneumonitis (RP) were examined.

RESULTS

The median follow-up duration was 18.0 months. The 1-year and 2-year local control were both 95.2%. Five patients (25%) developed Grade 2+ RP, including a Grade 5 RP. The Grade 2+ RP group showed higher composite mean lung dose (MLD) and lower lung volumes spared from 5-20 Gy (VS5-VS20).

CONCLUSION

Repeated SBRT with CyberKnife^® showed favorable local control, but a high rate of Grade 2+ RP. Accumulated MLD and VS5-VS20 may predict RP.

Comparison of toxicities between ultrahypofractionated radiotherapy versus brachytherapy with or without external beam radiotherapy for clinically localized prostate cancer

To compare gastrointestinal (GI) and genitourinary (GU) toxicities in patients with localized prostate cancer treated with ultrahypofractionated radiotherapy (UHF) or brachytherapy [BT; low dose rate, LDR or high dose rate (HDR) with or without external beam radiotherapy (EBRT)]. We compared 253 UHF and 1664 BT ± EBRT groups. The main outcomes were the incidence and severity of acute and late GU and GI toxicities. The secondary endpoint was biochemical control rate. Cumulative late actuarial GU toxicity did not differ for grade ≥ 2 (8.6% at 5-years in UHF and 13.3% in BT ± EBRT, hazard ratio [HR], 0.7066; 95% CI, 0.4093–1.22, p = 0.2127). Actuarial grade ≥ 2 late GI toxicity was higher in UHF (5.8% at 5-years, HR: 3.619; 95% CI, 1.774–7.383, p < 0.001) than in BT ± EBRT (1.1%). In detailed subgroup analyses, the high-dose UHF group (H-UHF) using BED ≥ 226 Gy_1.5, showed higher GI toxicity profiles than the other subgroups (HDR + EBRT, LDR + EBRT, and LDR monotherapy, and L-UHF BED < 226 Gy_1.5) with equivalent GU toxicity to other modalities. With a median follow-up period of 32 months and 75 months, the actuarial biochemical control rates were equivalent between the UHF and BT ± EBRT groups. UHF showed equivalent efficacy, higher GI and equivalent GU accumulated toxicity to BT ± EBRT, and the toxicity of UHF was largely dependent on the UHF schedule.

Reirradiation for Rare Head and Neck Cancers: Orbit, Auditory Organ, and Salivary Glands

We analyzed the efficacy and toxicity following reirradiation for locoregional recurrence of rare head and neck tumors. We retrospectively analyzed 17 patients who had received reirradiation for rare head and neck tumors. Primary tumor sites included nine ears (auditory organ), four salivary glands, and four orbits. The median follow-up time was 13.2 months for surviving patients. The median survival time was 12.6 months with one- and two-year survival rates of 53.1% and 44.3%, respectively. Nine out of 17 patients experienced local failure. The one- and two-year local control rates were 42.4% and 31.8%, respectively. The median survival times were 12.6, 5.3, and 11.0 months for orbit, auditory organ, and salivary glands, respectively. Three patients experienced grade 3 toxicity, including meningitis, brain necrosis, and facial nerve disorders. No grade ≥4 toxicities were observed. Reirradiation of rare head and neck tumors is feasible, with acceptable toxicity.

Conventional dose versus dose escalated radiotherapy including high-dose-rate brachytherapy boost for patients with Gleason score 9-10 clinical localized prostate cancer

As several recent researches focus on the importance of Gleason 9-10, we examine the role of radiotherapy dose escalation in those patients. We analyzed 476 patients with Gleason score 9-10 prostate cancer treated with radiotherapy. Of them, 127 patients were treated with conventional-dose external beam radiotherapy (Conv RT) and 349 patients were treated with high-dose radiotherapy (HDRT; 249 patients received high-dose-rate brachytherapy boost + external beam radiotherapy [HDR boost] and 100 patients received intensity-modulated radiotherapy [IMRT]). We compared these treatment groups using multi-institutional retrospective data. The patients had a median follow-up period of 66.3 months. HDRT showed superior biochemical disease-free survival (bDFS) rate (85.2%; HDR boost 84.7% and IMRT 86.6%) to Conv RT (71.1%, p < 0.0001) at 5 years, with a hazard ratio of 0.448. There were borderline difference in prostate cancer-specific mortality (PCSM; 4.3% and 2.75%, p = 0.0581), and distant metastasis-free survival (DMFS; 94.4% and 89.6%, p = 0.0916) rates at 5-years between Conv RT and HDRT group. Dose escalated radiotherapy showed better bDFS, borderline improvement in PCSM, and equivocal outcome in DMFS in with clinically localized Gleason 9-10 prostate cancer.

A successful approach for angiosarcoma of the scalp using helical tomotherapy and customized surface mold brachytherapy: A case report

RATIONALE

Angiosarcoma of the scalp (ASS) is a rare solid tumor with a high risk of local recurrence. Effective treatment strategies are not currently available for angiosarcoma of the scalp (ASS). The aim of this study was to report the utility of high-dose-rate brachytherapy (HDRBT) as a boost treatment for ASS following total scalp irradiation using helical tomotherapy (HT). This is the first report of successful treatment of ASS using HT and HDRBT.

PATIENT CONCERNS

An 81-year-old woman presented with hemorrhagic nodular skin tumors of the scalp. The patient first noticed the scalp mass 3 months before consultation, which became significantly enlarged within a short period. The tumor was positioned mostly in the parietal area, although the skin color change was widely spread to the surrounding scalp.

DIAGNOSIS

The patient underwent biopsy of the skin lesion at the right parietal region, which revealed the presence of angiosarcoma on pathological examination. There was neither regional lymphadenopathy nor distant metastases on PET/CT.

INTERVENTIONS

Considering the patient's old age and poor performance status because of a history of cerebral infarction, we considered that she was eligible for definitive chemoradiotherapy of the scalp. We adopted an individual surface mold HDRBT boost of 18 Gy in three fractions following total scalp irradiation with 50 Gy in 25 fractions delivered using HT. Docetaxel (40 mg/m2) was administered every 4 weeks, concurrently with radiotherapy.

OUTCOMES

Treatment tolerance was good, and severe toxicity has not been observed to date. At 18 months after radiotherapy, the patient does not have any evidence of recurrence.

CONCLUSION

Customized surface mold HDRBT following total scalp irradiation using HT resulted in excellent disease control and minimal toxicity; thus, it may be a promising therapeutic option for ASS.

Novel Prognostic Index of High-Risk Prostate Cancer Using Simple Summation of Very High-Risk Factors

This study aimed to examine the role of very high-risk (VHR) factors (T3b-4 and Gleason score 9-10) for prognosis of clinically localized high-risk prostate cancer. We reviewed multi-institutional retrospective data of 1413 patients treated with radiotherapy (558 patients treated with external beam radiotherapy (EBRT) and 855 patients treated with brachytherapy (BT) ± EBRT. We introduced an index by simple summation of the number of VHR factors-VHR-0, VHR-1, and VHR-2. With median follow-up of 69.6 months, the 5-year biochemical disease free survival rate (bDFS), prostate cancer-specific mortality (PCSM), and distant metastasis-free survival (DMSF) rates were 59.4%, 7.65%, and 83.2% for the VHR-2 group, respectively; 86.7%, 1.50%, and 95.4% for the VHR-1 group, respectively; and 93.1%, 0.12%, and 98.2% for the VHR-0 group, respectively. The VHR-2 group had significantly worse bDFS, PCSM, and DMSF than the VHR-0 (hazard ratios: 4.55, 9.607, and 7.904, respectively) and VHR-1 (hazard ratios: 1.723, 2.391, and 1.491, respectively) groups. The VHR-2 group could be identified as a super high-risk group compared with other groups, and could be a good candidate for clinical trials using multimodal intensified treatments. Simple summation of the number of VHR factors is an easy and useful predictive index for bDFS, PCSM, and DMSF.

Multi-energy reconstructions, central electron temperature measurements, and early detection of the birth and growth of runaway electrons using a versatile soft x-ray pinhole camera at MST

A multi-energy soft x-ray pinhole camera has been designed, built, and deployed at the Madison Symmetric Torus to aid the study of particle and thermal transport, as well as MHD stability physics. This novel imaging diagnostic technique employs a pixelated x-ray detector in which the lower energy threshold for photon detection can be adjusted independently on each pixel. The detector of choice is a PILATUS3 100 K with a 450 μm thick silicon sensor and nearly 100 000 pixels sensitive to photon energies between 1.6 and 30 keV. An ensemble of cubic spline smoothing functions has been applied to the line-integrated data for each time-frame and energy-range, obtaining a reduced standard-deviation when compared to that dominated by photon-noise. The multi-energy local emissivity profiles are obtained from a 1D matrix-based Abel-inversion procedure. Central values of T_e can be obtained by modeling the slope of the continuum radiation from ratios of the inverted radial emissivity profiles over multiple energy ranges with no a priori assumptions of plasma profiles, magnetic field reconstruction constraints, high-density limitations, or need of shot-to-shot reproducibility. In tokamak plasmas, a novel application has recently been tested for early detection, 1D imaging, and study of the birth, exponential growth, and saturation of runaway electrons at energies comparable to 100 × T_e,0; thus, early results are also presented.

Challenge and Outcome for the Prostate Squamous Cell Carcinoma Which Developed 8 Years after Low-Dose-Rate Brachytherapy Approached by a Combined Multimodal Treatment with High-Dose-Rate Interstitial Brachytherapy, External Beam Radiation Therapy, and Chemotherapy

Prostate squamous cell carcinoma (pSCC) rarely develops as a secondary cancer after treatment with low-dose-rate brachytherapy (LDR-BT). There is no established effective treatment for the disease condition. Herein, we present a 78-year-old man who developed pSCC 8 years after LDR-BT. He was subsequently selected to receive a combined multimodal treatment with high-dose-rate interstitial brachytherapy (HDR-ISBT), external beam radiation therapy, and chemotherapy for his pSCC. Eleven months later, he displayed no biochemical failure nor clinical radiographic recurrence. However, MRI detected a newly developed prostatic-rectal fistula (grade 4), and a colostomy was performed to relieve pain and inflammation. To our knowledge, this is the first report to perform a combined multimodal treatment with HDR-ISBT for pSCC suspected as a secondary cancer due to LDR-BT.

Longitudinal association between polypharmacy and development of pruritus: a Nationwide Cohort Study in a Japanese Population

BACKGROUND

Although polypharmacy is known to cause side-effects due to drug-drug interactions, dermatological symptoms triggered by polypharmacy are not fully addressed.

OBJECTIVE

To investigate whether polypharmacy is associated with the risk of pruritus.

METHOD

A cohort study was performed to examine cross-sectional and longitudinal relationships between polypharmacy and pruritus in a general population. Data were collected from the Norm Study conducted in 2016 and 2017, which is a nationwide survey based on a self-administered questionnaire with Japanese representative participants aged 16-84 years. Presence of polypharmacy which was defined as concurrent use of ≥5 prescribed drugs. Primary outcomes were the presence of severe pruritus at baseline for the cross-sectional analysis and the development of severe pruritus after one year for the longitudinal analysis. Multivariable modified Poisson regression analyses were performed to estimate risk ratios (RRs) and 95% confidence intervals (95%CIs) with adjustment for potential confounders (age, gender, smoking habits, drinking habits, depressive symptoms, moderate activities based on IPAQ score and presence of 11 comorbid conditions including skin disease).

RESULTS

The study included 3126 participants (mean age, 48.7 years); nearly half (49.8%) were male. In all, 332 participants (10.3%) had polypharmacy in the cross-sectional analysis. Participants with polypharmacy were more likely to present with severe pruritus at baseline than those who were not using drugs (adjusted RR = 1.52 [95%CI 1.15-2.01, P = 0.003]). The longitudinal analysis (n = 1803) was limited to those without severe pruritus at baseline; participants with polypharmacy at baseline were more likely to develop severe pruritus after a one-year follow-up period than those not using drugs (adjusted RR = 1.46 [95%CI 1.14-1.87, P = 0.002]).

CONCLUSION

Polypharmacy was associated with the presence of pruritus at baseline and may predict the future risk of developing pruritus.

Measurement of axial phase difference of density fluctuations owing to spontaneously excited waves by using microwave reflectometer on GAMMA 10/PDX

In the GAMMA 10/PDX tandem mirror, plasma with strong ion-temperature anisotropy is produced by using the ion cyclotron range of frequency waves. This anisotropy of ion temperature causes several Alfvén-Ion-Cyclotron (AIC) waves to spontaneously excite in the frequency range just below the ion cyclotron frequency. In addition, difference-frequency (DF) waves are excited in the radial inner region of the plasma by wave-wave coupling among the AIC waves. The radial density profiles were measured at multi-axial positions using a frequency-modulation reflectometer with an axial array of microwave antennas, and an axial variation of the density was found to be significant. In addition, a relative phase difference of the DF wave between axially separated two points was first obtained by finely choosing the probing frequency of the reflectometers with a maximum coherence used as a measure, indicating that the DF wave is a propagating wave, while the pump AIC waves are standing waves in the axial region of measurement.

Definitive Radiotherapy for Penoscrotal Extramammary Paget's Disease: A Case Report with Long-Term Follow-Up

Penoscrotal extramammary Paget's disease (EMPD) is a rare intraepithelial adenocarcinoma in older male patients, and no effective nonsurgical treatment strategies are currently available. The aim of this study was to report the usefulness of external radiotherapy (RT) for penoscrotal EMPD in an inoperable elderly patient. This report presents the treatment of an 89-year-old man with widespread penoscrotal EMPD. A multidisciplinary treatment team decided on radical RT. The patient received a radiation dose of 61.8 Gy in 30 fractions through electron and photon beams. His treatment tolerance was good, and no severe toxicity had been observed up the last follow-up. At 6.5 years after the RT, the patient showed no evidence of recurrence. Definitive RT resulted in excellent disease control and minimal toxicity; thus, it could be a promising nonsurgical therapeutic option for penoscrotal EMPD, even in extremely elderly individuals.

Multi-Institutional Retrospective Analysis of the Outcomes of Proton Beam Therapy for Patients With 1 to 3 Pulmonary Oligometastases From Various Primary Cancers

Purpose

Our purpose was to evaluate the efficacy of proton beam therapy (PBT) in patients with 1 to 3 pulmonary oligometastases from various primary cancers in Japan.

Methods and Materials

This multi-institutional retrospective survey included 118 patients with 141 metastatic lung tumors from miscellaneous primary cancers, across 6 Japanese institutions, and involved the analyses of local progression-free rate (LPF), distant progression-free rate, progression-free survival rate, cause-specific survival rate, and overall survival rate (OS). Treatment-induced adverse effects of grade ≥2 were evaluated according to the Common Terminology Criteria for Adverse Events (version 4.0). Cox proportional hazards regression models were used in univariable analysis and multivariable analysis (MVA) for the identification of the prognostic factors of LPF and OS.

Results

The median follow-up duration from the time of PBT was 25.5 months. The major primary disease sites included colorectal cancer (42.4%), lung cancer (11.9%), head and neck cancer (8.5%), and kidney cancer (8.5%). For years 1, 2, and 3, LPFs were 92.2%, 86.3%, and 78.4%; distant progression-free rates were 59.1%, 44.1%, and 34.0%; progression-free survival rates were 49.6%, 31.7%, and 24.2%; cause-specific survival rates were 83.4%, 72.5%, and 64.8%; and OS rates were 79.0%, 67.8%, and 59.6%, respectively. Eight patients developed acute adverse effects (grade ≥2). Ten patients developed radiation pneumonitis (grade 2) as a late adverse effect. None of the patients developed severe late toxicity (grade ≥3). Colorectal cancer as the primary disease was the only prognostic factor associated with LPF that remained independently significant in the MVAs performed using 3 sets of parameters (hazard ratio [HR], 3.31-4.76 in 3 MVA sets). In the MVA, the significant prognostic factors for OS were performance status (HR, 2.78; 95% confidence interval, 1.01-7.67) and total tumor volume (HR, 1.01; 95% confidence interval, 1.00-1.02).

Conclusions

PBT provides promising outcomes for pulmonary oligometastasis with acceptable toxicities.

High-dose-rate brachytherapy with external beam radiotherapy versus low-dose-rate brachytherapy with or without external beam radiotherapy for clinically localized prostate cancer

To compare the outcomes of localized prostate cancer treatment with high-dose-rate brachytherapy (HDR-BT) and low-dose-rate brachytherapy (LDR-BT), we examined 924 patients treated with HDR-BT + external beam radiotherapy (EBRT) and 500 patients treated with LDR-BT ± EBRT using multi-institutional retrospective data. The HDR-BT treated advanced disease with more hormonal therapy than LDR-BT. To reduce background selection bias, we performed inverse probability of treatment weighting (IPTW) analysis using propensity scores and excluded patients with T3b-4 disease/ initial prostate-specific antigen (PSA) levels > 50 ng/ml. The actuarial 5-year biochemical control rates (5y-bNED) were 96.3% and 95.7% in the HDR-BT and LDR-BT groups, respectively. The corresponding values were 100% and 96.5% in the low-risk group; 97.4% and 97.1% in the intermediate-risk group (97.2% and 97% in the higher titer group and 97.5% and 94.6% in the lower titer group, respectively); and 95.7% and 94.9% in the selected high-risk group, respectively. IPTW correction indicated no significant difference among the groups. The 5y-bNED in the HDR-BT + EBRT, LDR-BT + EBRT, and LDR-BT alone groups were 96.3%, 95.5%, and 97%, respectively (P = 0.3011). The corresponding values were 97.4%, 94.7%, and 96.6% (P = 0.1004) in the intermediate-risk group (97.5%, 100%, and 94.5% in the lower titer group [P = 0.122] and 97.2%, 96.2%, and 100% [P = 0.664] in the higher titer group, respectively) and 95.7%, 95.5%, and 100% (P = 0.859) in the high-risk group, respectively. The HDR-BT group showed a lower incidence of acute grade ≥ 2 genitourinary toxicities; the incidence of other early and late grade ≥ 2 toxicities were similar between the HDR-BT and LDR-BT groups. Acute genitourinary toxicity predicted the occurrence of late genitourinary toxicity. EBRT increased the risk of grade ≥ 2 gastrointestinal toxicity. HDR-BT + EBRT is a good alternative to LDR-BT ± EBRT for low-, intermediate-, and selected high-risk patients.

A surveillance study of patterns of reirradiation practice using external beam radiotherapy in Japan

The aim of this study was to survey the present status and patterns of reirradiation (Re-RT) practice using external beam radiotherapy in Japan. We distributed an e-mail questionnaire to the Japanese Society for Radiation Oncology partner institutions, which consisted of part 1 (number of Re-RT cases in 2008-2012 and 2013-2018) and part 2 (indications and treatment planning for Re-RT and eight case scenarios). Of the 85 institutions that replied to part 1, 75 (88%) performed Re-RTs. However, 59 of these 75 institutions (79%) reported difficulty in obtaining Re-RT case information from their databases. The responses from 37 institutions included the number of Re-RT cases, which totaled 508 in the period from 2009 to 2013 (institution median 3; 0-235), and an increase to 762 cases in the period from 2014 to 2018 (12.5; 0-295). A total of 47 physicians responded to part 2 of the survey. Important indications for Re-RT that were considered were age, performance status, life expectancy, absence of distant metastases and time interval since previous radiotherapy. In addition to clinical decision-making factors, previous total radiation dose, volume of irradiated tissue and the biologically equivalent dose were considered during Re-RT planning. From the eight site-specific scenarios presented to the respondents, >60% of radiation oncologists agreed to perform Re-RT. Re-RT cases have increased in number, and interest in Re-RT among radiation oncologists has increased recently due to advances in technology. However, several problems exist that emphasize the need for consensus building and the establishment of guidelines for practice and prospective evaluation.

Clinical practice guidelines for the management of biliary tract cancers 2019: The 3rd English edition

BACKGROUND

The Japanese Society of Hepato-Biliary-Pancreatic Surgery launched the clinical practice guidelines for the management of biliary tract cancers (cholangiocarcinoma, gallbladder cancer, and ampullary cancer) in 2007, then published the 2nd version in 2014.

METHODS

In this 3rd version, clinical questions (CQs) were proposed on six topics. The recommendation, grade for recommendation, and statement for each CQ were discussed and finalized by an evidence-based approach. Recommendations were graded as Grade 1 (strong) or Grade 2 (weak) according to the concepts of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system.

RESULTS

The 31 CQs covered the six topics: (a) prophylactic treatment, (b) diagnosis, (c) biliary drainage, (d) surgical treatment, (e) chemotherapy, and (f) radiation therapy. In the 31 CQs, 14 recommendations were rated strong and 14 recommendations weak. The remaining three CQs had no recommendation. Each CQ includes a statement of how the recommendations were graded.

CONCLUSIONS

This latest guideline provides recommendations for important clinical aspects based on evidence. Future collaboration with the cancer registry will be key for assessing the guidelines and establishing new evidence.

Simultaneous Fluorescent Identification of Odontoblasts and Ameloblasts

The tooth is mainly composed of dentin and enamel. Identification of dentin-producing odontoblasts and enamel-producing ameloblasts using reporter techniques is useful to study tooth development and regeneration with tissue engineering. Ameloblasts express Amelogenin, Ameloblastin, Enamelin, and Amelotin, whereas odontoblasts express Dentin sialophosphoprotein (Dspp) and Dentin matrix protein1 (Dmp1). Although there are several transgenic lines using promoter elements or bacterial artificial chromosomes (BACs) to label odontoblasts and ameloblasts, there is a possibility that the expression patterns vary from the endogenous genes. Here, we established 2 lines of mice where tdTomato was knocked into the second exon of X-chromosomal Amelogenin (Amelx), and green fluorescent protein (GFP) was knocked into the second exon of Dspp. tdTomato and GFP were highly expressed on secretory ameloblasts and secretory and fully differentiated odontoblasts, respectively. In addition, DSPP and AMELX were not produced in the dentin matrix and enamel matrix of Dspp^GFP/GFP and Amelx^tdTomato male mice (as representative of Amelx^tdTomato/Y hemizygous male mice), respectively. Moreover, micro-computed tomography analysis of Amelx^tdTomato male mice revealed a notable reduction in enamel volume but increased dentin mineral density. Dspp^GFP/GFP mice had reduced dentin mineral density. To identify odontoblasts and ameloblasts from developing tooth, we examined the expression of mesenchymal cell surface molecules CD90, CD166 and epithelial cell surface molecules CD49f, Epcam1 with fluorescence on odontoblasts and ameloblasts in these mice. We found that GFP⁺ odontoblasts and tdTomato⁺ ameloblasts in tooth germ from 0.5-d-old Dspp^GFP/+ mice and Amelx^tdTomato male mice were enriched in CD45^-/Ter119^-/Epcam1^-/CD90⁺/Integrin α4⁺cell fractions and CD45^-/Ter119^-/Epcam1⁺/CD49f⁺/CD147⁺ cell fractions, respectively. By using antibodies against mesenchymal and epithelial cell surface molecules and fluorescence, we can easily distinguish odontoblasts from ameloblasts and isolate each cell for further studies. These mice would serve as useful models for tooth development and regeneration as well as provide concurrent observation for the differentiation processes of odontoblasts and ameloblasts in vivo and in vitro.

Comparison of Three Fractionation Schedules in Radiotherapy for Early Glottic Squamous Cell Carcinoma

BACKGROUND/AIM

Radiotherapy is widely accepted as the treatment of choice for early glottic squamous cell carcinoma (EGSCC), although it varies greatly with respect to dose, dose per fraction, and treatment techniques. The study aim was to evaluate the use of accelerated fractionation strategy (AFS) for EGSCC in standard clinical practice.

PATIENTS AND METHODS

Patients treated with definitive radiotherapy for EGSCC between 2008 and 2019 were retrospectively identified and received either conventional fractionation, hypofractionation, or hyperfractionation.

RESULTS

One hundred six patients were analyzed, and 19, 71, and 16 patients underwent conventional fractionation, hypofractionation, and hyperfractionation, respectively. The median follow-up was 56 months. The 5-year local control and overall survival rates were 79% and 83%; 78% and 79%; and 87% and 77%, respectively, and no significant difference was observed between the fractionation schedules.

CONCLUSION

Our findings confirmed the utility of AFS in standard clinical practice and support its use for patients with EGSCC.