Melanin granules morphology and distribution in human black hair investigated by focused ion beam scanning electron microscopy: Differences between Asian and Caucasian hair.

Melanin granules (melanosomes) in Asian and Caucasian black hairs were investigated by focused ion beam scanning electron microscopy (FIB-SEM). This technique facilitates a direct evaluation of the three-dimensional distribution and morphology of melanin granules without requiring their isolation from hair. Three-dimensional reconstructed images of melanin granule distribution in hair samples were obtained using serial SEM images observed by FIB-SEM. Melanin granules in black hair tended to be three-dimensionally dense in the outer periphery of the cortex. The morphometric parameters of melanin granules were calculated using the reconstructed three-dimensional images. The results confirmed that melanin granules in Caucasian black hair were much smaller those in Asian black hair. Moreover, it was indicated that the relative frequency distribution of the volume of melanin granules was significantly different between Asians and Caucasians.

The preoperative M2BPGi score predicts operative difficulty and the incidence of postoperative complications in laparoscopic liver resection.

BACKGROUND: Liver fibrosis or cirrhosis frequently makes parenchymal transection more difficult, but the difficulty score of laparoscopic liver resection (LLR), including the IWATE criteria, does not include a factor related to liver fibrosis. Therefore, this study aimed to evaluate M2BPGi as a predictor of the difficulty of parenchymal transection and the incidence of postoperative complications in LLR. METHODS: Data from 54 patients who underwent laparoscopic partial liver resection (LLR-P) and 24 patients who underwent laparoscopic anatomical liver resection between 2017 and 2019 in our institution were retrospectively analyzed. All cases were classified according to M2BPGi scores, and reserve liver function, intraoperative blood loss, and postoperative complications were compared among these groups. RESULTS: Sixteen cases (29.6%) were M2BPGi negative (cut-off index < 1.0), 25 cases (46.3%) were 1+ (1.0 ≤ cut-off index < 3.0), and 13 cases (24.1%) were 2+ (cut-off index ≥ 3.0). M2BPGi-positive cases had significantly worse hepatic reserve function (K-ICG: 0.16 vs 0.14 vs 0.08, p < 0.0001). Intraoperative bleeding was significantly greater in M2BPGi-positive cases [50 ml vs 150 ml vs 200 ml, M2BPGi (-) or (1+) vs M2BPGi (2+), p = 0.045]. Postoperative complications (Clavien-Dindo ≥ II) were significantly more frequent in M2BPGi-positive cases [0% vs 4% vs 33%, M2BPGi (-) or (1+) vs M2BPGi (2+), p = 0.001]. CONCLUSION: M2BPGi could predict surgical difficulty and complications in LLR-P. In particular, it might be better not to select M2BPGi (2+) cases as teaching cases because of the massive bleeding during parenchymal transection.

Chemical Degradation-Inspired Total Synthesis of the Antibiotic Macrodiolide, Luminamicin.

This article describes the first total synthesis of luminamicin using a strategy combining chemical degradation with synthesis. Chemical degradation studies provided a sense of the inherent reactivity of the natural product, and deconstruction of the molecule gave rise to a key intermediate, which became the target for chemical synthesis. The core structure of the southern part of luminamicin was constructed by a 1,6-oxa-Michael reaction to form an oxa-bridged ring, followed by coupling with a functionalized organolithium species. Modified Shiina macrolactonization conditions forged the strained 10-membered lactone containing a tri-substituted olefin. Diastereoselective α-oxidation of the 10-membered lactone completed the center part to provide the key intermediate. Inspired by the degradation study, an unprecedented enol ether/maleic anhydride moiety was constructed with a one-pot chlorosulfide coupling and thiol ß-elimination sequence. Finally, macrolactonization to the 14-membered ring in the presence of the highly electrophilic maleic anhydride moiety was accomplished using modified Mukaiyama reagents to complete the synthesis of luminamicin.

A multicenter, open-label, single-arm study of anamorelin (ONO-7643) in patients with cancer cachexia and low body mass index.

BACKGROUND: Cancer cachexia is a syndrome characterized by anorexia and decreased body weight. This study evaluated the efficacy and safety of anamorelin, an orally active, selective ghrelin receptor agonist, in patients with cancer cachexia and a low body mass index (BMI). METHODS: This multicenter, open-label, single-arm study enrolled Japanese patients with non-small cell lung cancer or gastrointestinal cancer with cancer cachexia (BMI < 20 kg/m2 , involuntary weight loss > 2% in the last 6 months, and anorexia). Patients were administered 100 mg of anamorelin once daily for up to 24 weeks. The primary end point was a composite clinical response (CCR) at 9 weeks, which was defined as an increase in body weight of ≥5% from the baseline, an increase of ≥2 points in the score of the 5-item Anorexia Symptom Scale of the Functional Assessment of Anorexia/Cachexia Therapy, and being alive. RESULTS: One hundred two patients were eligible and enrolled. The means and standard deviations for age and BMI were 71.0 ± 8.2 years and 17.47 ± 1.48 kg/m2 , respectively. The CCR rate at 9 weeks was 25.9% (95% confidence interval [CI], 18.3%-35.3%), which met the primary end point with a lower 95% CI exceeding the prespecified minimum of 8%. Improvements in body weight and anorexia were durable and were accompanied by improvements in patients' global impression of change for appetite/eating-related symptoms and overall condition. Adverse drug reactions occurred in 37 of 101 treated patients (36.6%), with the most common being glycosylated hemoglobin increases, constipation, and peripheral edema. CONCLUSIONS: Anamorelin improved body weight and anorexia-related symptoms in patients with cancer cachexia and a low BMI with durable efficacy and favorable safety and tolerability. LAY SUMMARY: Anamorelin is a drug that stimulates appetite and promotes weight gain. This clinical trial was aimed at determining its efficacy and safety in Japanese cancer patients with a low body mass index and cachexia, a syndrome associated with anorexia and weight loss. Anamorelin was found to improve body weight and anorexia-related symptoms in these patients, and these effects were durable for up to 24 weeks. Moreover, anamorelin was generally well tolerated. These findings suggest that anamorelin is a valuable treatment option for patients with cancer cachexia and a low body mass index.

Preoperative prognostic nutritional index predicts postoperative infectious complications and oncological outcomes after hepatectomy in intrahepatic cholangiocarcinoma.

BACKGROUND: In the surgical treatment of intrahepatic cholangiocarcinoma (ICC), postoperative complications may be predictive of long-term survival. This study aimed to identify an immune-nutritional index (INI) that can be used for preoperative prediction of complications. PATIENTS AND METHODS: Multi-institutional data from 316 patients with ICC who had undergone surgical resection were retrospectively analysed, with a focus on various preoperative INIs. RESULTS: Severe complications (Clavien-Dindo grade III-V) were identified in 66 patients (20.8%), including Grade V complications in 7 patients (2.2%). Comparison of areas under the receiver operating characteristic curve (AUCs) among various INIs identified the prognostic nutritional index (PNI) as offering the highest predictive value for severe complications (AUC = 0.609, cut-off = 50, P = 0.008). Multivariate analysis revealed PNI <  50 (odds ratio [OR] = 2.22, P = 0.013), hilar lesion (OR = 2.46, P = 0.026), and long operation time (OR = 1.003, P = 0.029) as independent risk factors for severe complications. In comparing a high-PNI group (PNI ≥ 50, n = 142) and a low-PNI group (PNI <  50, n = 174), the low-PNI group showed higher rates of both major complications (27% vs. 13.4%; P = 0.003) and infectious complications (14.9% vs. 3.5%; P = 0.0021). Furthermore, median survival time and 1- and 5-year overall survival rates were 34.2 months and 77.4 and 33.8% in the low-PNI group, respectively, and 52.4 months and 89.3 and 47.5% in the high-PNI group, respectively (P = 0.0017). CONCLUSION: Preoperative PNI appears useful as an INI correlating with postoperative severe complications and as a prognostic indicator for ICC.

Prognostic Utility of the Glasgow Prognostic Score for the Long-Term Outcomes After Liver Resection for Intrahepatic Cholangiocarcinoma: A Multi-institutional Study.

OBJECTIVE: The usefulness of the modified Glasgow prognostic score (GPS) as a prognostic tool remains unclear for patients undergoing curative surgery for intrahepatic cholangiocarcinoma (ICC). Therefore, this study investigated the prognostic usefulness of the GPS for patients who underwent ICC surgery. METHOD: All ICC patients who had a curative-intent hepatectomy at 17 institutions between 2000 and 2016 were included. The correlation was assessed between the preoperative GPS and the baseline characteristics of the patients, histopathological parameters, surgical parameters, and the postresection overall survival (OS). RESULT: There were 273 patients who met the eligibility criteria between the years 2000 and 2016. The postoperative OS rates at 1, 3, and 5 years were 83.8%, 56.3%, and 41.5%, respectively (median OS, 47.7 months). A multivariate analysis revealed the factors that were associated with a worse OS, which included an increased GPS (hazard ratio = 1.62; 95% confidence interval [CI]: 1.01-2.53; P = 0.03), an elevated carcinoembryonic antigen level (hazard ratio = 1.60; 95% CI: 1.06-2.41; P = 0.02), an elevated carbohydrate antigen 19-9 level (hazard ratio = 1.55; 95% CI: 1.05-2.30; P = 0.03), undifferentiated carcinoma (hazard ratio = 2.41; 95% CI: 1.56-3.67; P < 0.01), and positive metastasis to the lymph nodes (hazard ratio = 2.54; 95% CI: 1.76-3.67; P < 0.01). In ICC patients after a hepatectomy, an elevated GPS was associated with poorer OS, even if the tumour factors that affected GPS were eliminated by propensity-score matching. CONCLUSION: Preoperative GPS can be useful to predict the postoperative outcomes of ICC patients. Therefore, this relatively simple and inexpensive scoring system can be utilized to further refine patient stratification as well as to predict survival.

[Investigation of marginal ulcer after pancreatoduodenectomy].

BACKGROUND: Marginal ulcer after pancreatoduodenectomy (PD) is a relatively common complication, but if massive bleeding or ulcer perforation occurs together with the marginal ulcer, this condition may be fatal. OBJECTIVE: To identify the risk factors and management of marginal ulcer after PD. METHODS: In all, 438 patients who underwent PD from 2003 to 2017 were retrospectively reviewed and analyzed. After surgery, all patients were administered a histamine H2 receptor antagonist (H2RA) or a proton pump inhibitor (PPI), which was continued after discharge. Marginal ulcer was diagnosed by endoscopy or surgery. The risk factors for marginal ulcer were then investigated using univariate and multivariate analyses. RESULTS: After a median follow-up time of 2.7 years, 29 patients (6.6%) developed marginal ulcer. Seventeen patients developed marginal ulcer within 1 year after PD, and 7 patients developed marginal ulcer more than 3 years after PD. All 8 patients who underwent surgery for the treatment of marginal ulcer developed acute peritonitis. Two patients with acute peritonitis died within 1 month after surgery. A multivariate analysis found that discontinuation of PPI treatment was the only independent risk factor for marginal ulcer development (P<0.001). In contrast, sex, age, primary disease, procedure, operation time, volume of blood loss, pancreatic texture, development of postoperative pancreatic fistula, postoperative complications, poor glycemic control after PD, and discontinuation of H2RA therapy after PD were not significantly different between the patient group that developed marginal ulcer and the patient group that did not. Sixteen patients were not treated with antacids at the time of marginal ulcer development. The reason for discontinuation of antacids was the decision of the family physician in 8 cases and the decision of the patient in 3 cases. CONCLUSION: Marginal ulcer can still develop a long time after PD, and sometimes, it may be fatal. PPI administration should be continued even after a long time has passed, although this therapy is often discontinued for various reasons. It is therefore important for family physicians and patients to recognize the danger of marginal ulcer after PD.

Validation and performance of three-level procedure-based classification for laparoscopic liver resection.

BACKGROUND: A procedure-based laparoscopic liver resection (LLR) classification (IMM classification) stratified 11 different LLR procedures into 3 grades. IMM classification assessed the difficulty of LLR differently than an index-based LLR classification (IWATE criteria), which scored each procedure on an index scale of 12. We validated the difference of 3 IMM grades using an external cohort, evaluated the IMM classification using the scores of the IWATE criteria, and compared the performance of IMM classification with the IWATE criteria and the minor/major classification. METHODS: Patients undergoing LLR without simultaneous procedures were selected from a prospectively maintained database at the Institut Mutualiste Montsouris (IMM cohort) and from the database of 43 Japanese institutions (JMI cohort). Surgical and postoperative outcomes were evaluated according to the 3 IMM grades using the JMI cohort. The 11 LLR procedures included in the IMM classification were scored according to the IWATE criteria. The area under the curves (AUCs) for surgical and postoperative outcomes were compared. RESULTS: In the JMI (n = 1867) cohort, operative time, blood loss, conversion rate, and major complication rate were significantly associated with a stepwise increase in grades from I to III (all, P < 0.001). In the IMM (n = 433) and JMI cohorts, IMM grades I, II, and III corresponded to three low-scoring, two intermediate-scoring, and six high-scoring LLR procedures as per the IWATE criteria, respectively. Mean ± standard deviation among the IMM grades were significantly different: 3.7 ± 1.4 (grade I) versus 7.5 ± 1.7 (grade II) versus 10.2 ± 1.0 (grade III) (P < 0.001) in the IMM cohort and 3.6 ± 1.4 (grade I) versus 6.7 ± 1.5 (grade II) versus 9.3 ± 1.4 (grade III) (P < 0.001) in the JMI cohort. The AUCs for surgical and postoperative outcomes are higher for the 3-level IMM classification than for the minor/major classification. CONCLUSIONS: The difference of 3 IMM grades with respect to surgical and postoperative outcomes was validated using an external cohort. The 3-level procedure-based IMM classification was in accordance with the index-based IWATE criteria. The IMM classification performed better than the minor/major classification for stratifying LLR procedures.

Impact of Body Mass Index on Survival of Pancreatic Cancer Patients in Japan.

The impact of body mass index (BMI) on postoperative survival in Japanese patients with pancreatic cancer is unclear. We examined the relationship between preoperative BMI and the prognosis of Japanese patients who underwent surgery for pancreatic cancer to determine whether BMI affects these patients' prognosis. Of the patients who underwent pancreatectomy between January 2004 and August 2015 at our institution, 246 were pathologically diagnosed with pancreatic tubular adenocarcinoma; the cancer was located in the pancreatic head (n=161) and in the body and tail (n=85). We classified the patients by BMI: underweight (n=22), normal weight (n=190), and overweight/obese (n=34) groups. We retrospectively analyzed medical records for patient characteristics, lesion location, disease stage, postoperative complications, chemotherapy, and prognosis. Lesion location, disease stage, postoperative complications, and chemotherapy were not significantly different among the BMI groups. The median survival times were as follows (days): all patients, 686; underweight, 485; normal weight, 694; and overweight/obese, 839. In a multivariate analysis, after adjusting for competing risk factors, low BMI was associated with an increased risk of death (normal weight: HR 0.58, p=0.038; overweight/obese: HR 0.54, p=0.059). High BMI was not found to be a postoperative factor for poor prognosis in Japanese pancreatic cancer patients.

Compositional changes of human hair melanin resulting from bleach treatment investigated by nanoscale secondary ion mass spectrometry.

BACKGROUND/PURPOSE: It is important to understand the influence of bleach treatment on human hair because it is one of the most important chemical treatments in hair cosmetic processes. A comparison of the elemental composition of melanin between virgin hair and bleached hair would provide important information about the structural changes of melanin. To investigate the elemental composition of melanin granules in virgin black hair and bleached hair, these hair cross-sections are analyzed by using a nanoscale secondary ion mass spectrometry (NanoSIMS). METHODS: The virgin black hair and bleached hair samples were embedded in resin and smooth hair cross-sections were obtained using an ultramicrotome. NanoSIMS measurements were performed using a Cs(+) primary ion beam to detect negative secondary ions. RESULTS: More intensive (16) O(-) ions were detected from the melanin granules of bleached hair than from those of virgin black hair in NanoSIMS (16) O(-) ion image. In addition, it was indicated that (16) O(-) ion intensity and (16) O(-) /(12) C(14) N(-) ion intensity ratio of melanin granules in bleached hair were higher than those in virgin black hair. CONCLUSION: Nanoscale secondary ion mass spectrometry analysis of the cross-sections of virgin black hair and bleached hair indicated that the oxygen content in melanin granules was increased by bleach treatment.

[A case of a patient who underwent resection of the remnant pancreatic cancer following a distal pancreatectomy for invasive ductal carcinoma].

Herein, we report the case of a patient who underwent resection of the remnant pancreas for pancreatic cancer following a distal pancreatectomy for invasive ductal carcinoma. An 81-year-old woman underwent a distal pancreatectomy. The tumor was found to be pancreatic cancer. The tumor was histologically diagnosed as a poorly differentiated tubular adenocarcinoma (Stage I). An abdominal computed tomography (CT) performed 17 months later revealed a 13 mm tumor in the remnant pancreatic head. A remnant pancreatectomy was performed. The histological diagnosis was a moderately differentiated tubular adenocarcinoma (StageIII). Remnant pancreatic cancer is rare following a pancreatectomy for invasive ductal carcinoma. The course of remnant pancreatic cancer can be followed with imaging. Long-term follow-up of patients who have undergone a pancreatectomyis, therefore, essential.

Patterns of care for brachytherapy in Japan.

This study aimed to assess the current state of brachytherapy (BT) resources, practices and resident education in Japan. A nationwide survey was undertaken encompassing 177 establishments facilitating BT in 2022. Questionnaires were disseminated to each BT center, and feedback through online channels or postal correspondence was obtained. The questionnaire response rate was 90% (159/177), and every prefecture had a response in at least one center. The number of centers in each prefecture ranged from 0.6 to 3.6 (median: 1.3) per million population. The annual number of patients in each center ranged from 0 to 272 (median: 31). While most prefectures provided intracavitary (IC) BT for gynecological cancers and interstitial (IS) BT for prostate cancer, only one-third of the prefectures provided IS BT for cancer sites other than the prostate. The institutional image-guided BT implementation rate was 71%. IC and IS BT was performed for 15.4% of IC BT cases of gynecological cancer. Only 47% of the BT training centers answered that they could provide adequate training in BT for residents. The most common reason for this finding was the insufficient number of patients in each center. The results show that, although BT has achieved uniformity in terms of facility penetration, new technologies are not yet widespread enough. Furthermore, IS BT, which requires advanced skills, is limited to a few BT centers, and considerable number of BT training centers do not have sufficient caseloads to provide the necessary experience for their residents.

In vivo imaging of lymph node metastasis with telomerase-specific replication-selective adenovirus.

Currently available methods for detection of tumors in vivo such as computed tomography and magnetic resonance imaging are not specific for tumors. Here we describe a new approach for visualizing tumors whose fluorescence can be detected using telomerase-specific replication-competent adenovirus expressing green fluorescent protein (GFP) (OBP-401). OBP-401 contains the replication cassette, in which the human telomerase reverse transcriptase (hTERT) promoter drives expression of E1 genes, and the GFP gene for monitoring viral replication. When OBP-401 was intratumorally injected into HT29 tumors orthotopically implanted into the rectum in BALB/c nu/nu mice, para-aortic lymph node metastasis could be visualized at laparotomy under a three-chip color cooled charged-coupled device camera. Our results indicate that OBP-401 causes viral spread into the regional lymphatic area and selectively replicates in neoplastic lesions, resulting in GFP expression in metastatic lymph nodes. This technology is adaptable to detect lymph node metastasis in vivo as a preclinical model of surgical navigation.

Current status and issues with the dosimetric assay of iodine-125 seed sources at medical facilities in Japan: a questionnaire-based survey†.

In conducting dosimetric assays of seed sources containing iodine-125 (125I), several major guidelines require the medical physicist to verify the source strength before patient treatment. Japanese guidelines do not mandate dosimetric assays at medical facilities, but since 2017, three incidents have occurred in Japan wherein seeds with incorrect strengths were delivered to medical facilities. Therefore, this study aimed to survey the current situation and any barriers to conducting the dosimetric assay of iodine-125 seeds at medical facilities in Japan. We conducted a questionnaire-based survey from December 2020 to April 2021, to examine whether seed assay and verification of the number of seeds delivered were being performed. We found that only 9 facilities (16%) performed seed assay and 28 (52%) verified the number of seeds. None of the facilities used an assay method that ensured traceability. The reasons for not performing an assay were divided into two categories: lack of resources and legal issues. Lack of resources included lack of instruments, lack of knowledge of assay methods, shorthand, or all of the above, whereas legal issues included the inability to resterilize iodine-125 seeds distributed in Japan and/or purchase seeds dedicated to the assay. Dosimetric assays, including simple methods, are effective in detecting calibration date errors and non-radioactive seeds. The study findings suggest that familiarization of medical personnel with these assay methods and investigation of the associated costs of labor and equipment should be recommended, as these measures will lead to medical reimbursement for quality assurance.

Clinical implications and optimal extent of lymphadenectomy for intrahepatic cholangiocarcinoma: A multicenter analysis of the therapeutic index.

Aims: Lymph node metastases (LNM) are associated with lethal prognosis in intrahepatic cholangiocarcinoma (ICC). Lymphadenectomy is crucial for accurate staging and hopes of possible oncological treatment. However, the therapeutic implications and optimal extent of lymphadenectomy remain contentious. Methods: To clarify the prognostic value and optimal extent of lymphadenectomy, the therapeutic index (TI) for each lymph node was analyzed for 279 cases that had undergone lymphadenectomy in a multi-institutional database. Tumor localization was divided into hilar lesions (n = 130), right peripheral lesions (n = 60), and left peripheral lesions (n = 89). In addition, the lymph node station was classified as Level 1 (LV1: hepatoduodenal ligament node), Level 2 (LV2: postpancreatic or common hepatic artery nodes), or Level 3 (LV3: gastrocardiac, left gastric artery, or celiac artery nodes). Results: Lymph node metastases were confirmed in 109 patients (39%). Five-y survival rates were 45.3% for N0 disease, 27.1% for LV1-LNM, 22.9% for LV2-LNM, and 7.3% for LV3-LNM (P < 0.001). LV3-LNM were the most frequent and earliest recurrence outcome, including multisite recurrence, followed by LV2, LV1, and N0 disease. The 5-year TI (5year-TI) for lymphadenectomy was 7.2 for LV1, 5.5 for LV2, and 1.9 for LV3. Regarding tumor location, hilar lesions showed 5-year TI >5.0 in LV1 and LV2, whereas bilateral peripheral lesions showed 5-year TI > 5.0 in LV1. Conclusion: The implications and extent of lymphadenectomy for ICC appear to rely on tumor location. In the peripheral type, the benefit of lymphadenectomy would be limited and dissection beyond LV1 should be avoided, while in the hilar type, lymphadenectomy up to LV2 could be recommended.

Correction: Time course change of the insulin requirements during the perioperative period in hepatectomy and pancreatectomy by using an artificial pancreas STG-55.

[This corrects the article DOI: 10.1007/s13340-023-00623-3.].

Time course change of the insulin requirements during the perioperative period in hepatectomy and pancreatectomy by using an artificial pancreas STG-55.

Introduction: To investigate changes in insulin requirements over time in patients who underwent hepatectomy and pancreatectomy with perioperative glycemic control by an artificial pancreas (STG-55). Materials and methods: We included 56 patients (22 hepatectomies and 34 pancreatectomies) who were treated with an artificial pancreas in the perioperative period and investigated the differences in insulin requirements by organ and surgical procedure. Results: The mean intraoperative blood glucose level and total insulin doses were higher in the hepatectomy group than in the pancreatectomy group. The dose of insulin infusion increased in hepatectomy, especially early in surgery, compared to pancreatectomy. In the hepatectomy group, there was a significant correlation between the total intraoperative insulin dose and Pringle time, and in all cases, there was a correlation with surgical time, bleeding volume, preoperative CPR, preoperative TDD, and weight. Conclusions: Perioperative insulin requirements may be mainly dependent on the surgical procedure, invasiveness, and organ. Preoperative prediction of insulin requirements for each surgical procedure contributes to good perioperative glycemic control and improvement of postoperative outcomes.

[Technical Report: Quality Assurance for 125I Seed Sources in Permanent Prostate Brachytherapy].

This technical report provides useful information on the current status and issues of quality control in 125I seed source strength measurement for Permanent Prostate Brachytherapy in Japan.With the spread of 125I seed brachytherapy, the traceability of source strength measurements with the single-seed assay was established in Japan. This allows medical facilities to measure reference air kerma rate of 125I seeds with their own well-type of ionization chamber. However, it is difficult to maintain the traceability chain because the 125I reference air kerma rate standards have been hardly utilized by medical facilities so far. Meanwhile, some serious incidents of contamination of the different source strengths and dead seeds were reported in Japan.To address the specific issues in Japan, JASTRO Brachytherapy Subcommittee established a working group (WG) in 2021. The goal of this WG is to investigate the management methods of source strength measurement used in medical facilities, and to discuss the ideal and practicable methods of source management such as verifying the number of seeds and source strength. Initially, a questionnaire survey was conducted to facilities offering 125I seed brachytherapy in Japan. Sixty-seven out of 95 facilities responded (response rate 70.5%). This survey revealed that 41% of facilities did not perform either confirmation of the number of seeds or measurement of source strength. There are several reasons why the source strength was not measured in those facilities. For example, 125I seeds are provided under the sterilized conditions; quality assurance by source suppliers is reliable; and there is not sufficient staff.The single-seed assay is regarded as an internationally standardized and the most reliable measurement method. Therefore, it is an essential measurement technique to ensure traceability of source strength measurements. However, our survey found that most Japanese facilities do not perform single-seed assays. Meanwhile, some facilities have performed batch assay as an alternative method, in which all of the multiple sources in a batch are measured while loaded into sterilized cartridges. Although the measurement by the batch assay is less accurate than the one by the single-seeded assay, the batch assay does not require re-sterilization of the source and can be performed quickly. It might be useful to detect unexpected errors such as differences in the number of sources and abnormalities in source strength.In this report, we will introduce several methods of source strength measurement that have been implemented in medical facilities. The quality assurance of 125I seed sources in prostate interstitial brachytherapy should be provided not only by the source suppliers but also by the medical facilities that use sources to treat patients. We hope that medical facilities will refer to this technical report and use it as an aid to quality assurance in their own facilities.

A national survey on the medical physics workload of external beam radiotherapy in Japan†.

Several staffing models are used to determine the required medical physics staffing, including radiotherapy technologists, of radiation oncology departments. However, since Japanese facilities tend to be smaller in scale than foreign ones, those models might not apply to Japan. Therefore, in this study, we surveyed workloads in Japan to estimate the optimal medical physics staffing in external beam radiotherapy. A total of 837 facilities were surveyed to collect information regarding radiotherapy techniques and medical physics specialists (RTMPs). The survey covered facility information, staffing, patient volume, equipment volume, workload and quality assurance (QA) status. Full-time equivalent (FTE) factors were estimated from the workload and compared with several models. Responses were received from 579 facilities (69.2%). The median annual patient volume was 369 at designated cancer care hospitals (DCCHs) and 252 across all facilities. In addition, the median FTE of RTMPs was 4.6 at DCCHs and 3.0 at all sites, and the average QA implementation rate for radiotherapy equipment was 69.4%. Furthermore, advanced treatment technologies have increased workloads, particularly in computed tomography simulations and treatment planning tasks. Compared to published models, larger facilities (over 500 annual patients) had a shortage of medical physics staff. In very small facilities (about 140 annual patients), the medical physics staffing requirement was estimated to be 0.5 FTE, implying that employing a full-time medical physicist would be inefficient. However, ensuring the quality of radiotherapy is an important issue, given the limited number of RTMPs. Our study provides insights into optimizing staffing and resource allocation in radiotherapy departments.

Japanese Society for Radiation Oncology Consensus Guidelines of combined intracavitary and interstitial brachytherapy for gynecological cancers.

It has been postulated that the combination of intracavitary and interstitial brachytherapy (IC/IS) is effective and safe for large and irregularly shaped uterine cervical cancer patients. However, due to its invasiveness compared to conventional intracavitary brachytherapy (ICBT), it has to be said that the implementation speed of IC/IS is slow. Until now, there have been no guidelines for required equipment, human resources, and procedural guide focusing solely on IC/IS. The purpose of this guideline is to provide radiation oncologists and medical physicists who wish to start IC/IS with practical and comprehensive guidance for a safe IC/IS introduction and to help accelerate the spread of the utilization of IC/IS nationwide. This is the English translation of the Japanese IC/IS Guidelines, and it was created in an effort to share the Japanese approach to the management of locally advanced uterine cervical cancer worldwide.