Two-fractionated stereotactic magnetic resonance-guided adaptive radiation therapy for patients with prostate cancer (SMART PRO trial): protocol for a confirmatory clinical trial.

INTRODUCTION: In an MRI-guided linear accelerator (MR-LINAC) system, the planned doses for organs at risk and for tumours are assessed by MR imaging and re-contouring at every treatment. This allows treatment to be safer and more precise by ensuring that it is suitable for the state of the patient's organs on that day, as well as by allowing images to be acquired during radiation therapy to prevent radiation while organs are in motion.Here, we will conduct a confirmatory study of two-fractionated stereotactic magnetic resonance-guided adaptive radiation therapy for patients with localised prostate cancer. METHODS AND ANALYSIS: This will be a single-arm study to demonstrate the safety and efficacy of ultra-hypofractionated radiation (26 Gy/2 Fr) using an MR-LINAC system in patients with very low-intermediate risk prostate cancer.The primary endpoint will be the incidence of grade ≥2 acute urinary tract adverse events occurring within 90 days of the start of radiation therapy.The sample size has been determined to be 58. ETHICS AND DISSEMINATION: This study is performed in accordance with Ethical Guidelines for Medical and Health Research Involving Human Subjects, published by Japan's Ministry of Education, Science and Technology and the Ministry of Health, Labour and Welfare and the modified act on the Protection of Personal Information as well as the Declaration of Helsinki. This study was approved by the institutional ethics committee of the National Cancer Center on 20 November 2021.The findings of this trial will be submitted to an international peer-reviewed journal and the key findings will be presented at an international scientific conference.Authorship will be ascribed in accordance with the International Committee of Medical Journal Editors guidance. TRIAL REGISTRATION NUMBER: UMIN000049746.

A national survey of medical staffs' required capability and workload for accelerator-based boron neutron capture therapy.

This study aimed to identify the required capabilities and workload of medical staff in accelerator-based boron neutron capture therapy (BNCT). From August to September 2022, a questionnaire related to the capabilities and workload in the accelerator-based BNCT was administered to 12 physicians, 7 medical physicists and 7 radiological technologists engaged in BNCT and 6 other medical physicists who were not engaged in BNCT to compare the results acquired by those engaged in BNCT. Only 6-21% of patients referred for BNCT received it. Furthermore, 30-75% of patients who received BNCT were treated at facilities located within their local district. The median required workload per treatment was 55 h. Considering additional workloads for ineligible patients, the required workload reached ~1.2 times longer than those for only eligible patients' treatment. With respect to capabilities, discrepancies were observed in treatment planning, quality assurance and quality control, and commissioning between medical physicists and radiological technologists. Furthermore, the specialized skills required by medical physicists are impossible to acquire from the experience of conventional radiotherapies as physicians engaged in BNCT were specialized not only in radiation oncology, but also in other fields. This study indicated the required workload and staff capabilities for conducting accelerator-based BNCT considering actual clinical conditions. The workload required for BNCT depends on the occupation. It is necessary to establish an educational program and certification system for the skills required to safely and effectively provide BNCT to patients.

Impact of Durvalumab on the Duration and Complexity of Corticosteroid Therapy for Pneumonitis After Chemoradiotherapy.

INTRODUCTION: It is unclear how the duration and tapering pattern of corticosteroid therapy for pneumonitis changed after the introduction of durvalumab consolidation therapy. METHODS: We retrospectively evaluated the medical records of patients diagnosed with nonsmall cell lung cancer who received chemoradiotherapy between January 2014 and December 2020. RESULTS: Data for 135 patients treated before durvalumab approval and 100 patients treated with durvalumab after its approval were analyzed. In both groups, more than 70% were male, with a median age of 66 y. Approximately 85% were smokers, and the most common tumor histology was adenocarcinoma. Most patients were treated with doses of 60 and 66 Gy (n = 127 [94%] vs. n = 95 [95%]). Among the patients treated with durvalumab, 57%, 38%, and 5% had grade 1, grade 2, and grade 3 pneumonitis; none had grade 4 or 5 pneumonitis. Patients treated with durvalumab exhibited a longer duration of corticosteroid therapy for pneumonitis (17 wk; range: 2-88 wk) than patients not treated with durvalumab (7 wk; range: 0.4-21 wk; P < 0.001). Pneumonitis relapse was more frequent in patients treated with durvalumab (n = 8; 23%) than in patients not treated with durvalumab (n = 2; 7%). Among the 8 patients treated with durvalumab, 2 had recurrent pneumonitis, 1 could not terminate corticosteroids. CONCLUSIONS: Our data show that durvalumab prolongs the duration of corticosteroid therapy and increases the complexity of corticosteroid tapering patterns. This study can help manage pneumonitis caused by immune checkpoint inhibitors and other drugs used after chemoradiotherapy in routine practice and clinical trials.

Uptake of ultra-hypofractionated radiation therapy following breast-conserving surgery among patients with early-stage breast cancer: a multi-institutional questionnaire survey.

BACKGROUND: In patients with early-stage breast cancer following breast surgery, ultra-hypofractionated (UHF) breast/chest wall radiation therapy (RT) has been shown to be non-inferior to a moderate-hypofractionated (MHF) regimen, with a minimal risk of breast induration, in the FAST-Forward trial, and UHF is now becoming the standard regimen in Europe. Herein, we aimed to investigate Japanese patients' attitudes toward the UHF regimen. METHODS: A questionnaire-based survey was conducted at 13 RT centers in nine prefectures across Japan. All patients underwent breast-conserving surgery, followed by either conventional fractionation (2 Gy/fr) or MHF (2.66 Gy/fr) whole-breast irradiation (WBI) with or without a tumor bed boost. The questionnaire consisted of 13 questions mainly addressing quality-of-life during RT. Key questions included an 11-point scale (0-10) for rating the patients' enthusiasm for the UHF regimen and prioritization of the following treatment-related effects: treatment efficacy, acute/late adverse effects, physical/emotional/financial burden, and breast cosmesis. The patient and treatment characteristics were assessed by a physician. RESULTS: In total, 247 questionnaires were administered between November 2022 and June 2023. The age distribution was as follows: < 50:50 s:60 s: ≥ 70 = 59 (24%):76 (30%):63 (26%):49 (20%). Sixty-nine percent of patients rated their enthusiasm for the UHF regimen at ≥ 6 out of 10 points (45% rated 10/10). Treatment efficacy was the highest priority for most patients (89%), whereas breast cosmesis the lowest priority (53%). CONCLUSIONS: Patients' enthusiasm for UHF-WBI was observed across the cohort. These results could motivate researchers and clinicians to introduce UHF regimens in clinical practice.

Role of the gel spacer in safely delivering whole pelvic radiation therapy without central shielding in computed tomography-based image-guided adaptive brachytherapy for uterine cervical cancer patients.

BACKGROUND: To protect the rectum and bladder from high dose exposure, the Japanese guidelines for managing uterine cervical carcinoma recommend pelvic irradiation with central shielding (CS). Conversely, the European Society for Radiotherapy and Oncology (ESTRO) and the American Brachytherapy Society (ABS) guidelines recommend delivering ≥85 Gy to high-risk clinical target volume D90 (CTVHR D90%). In this study, we investigated whether a gel spacer can enable the safe delivery of the ESTRO/ABS-recommended doses to the target while observing dose constraints for the OARs without using CS in external beam radiation therapy (EBRT). MATERIALS AND METHODS: Twenty patients who received definitive radiation therapy without CS and were treated by brachytherapy with a gel spacer between 2017 and 2022 were retrospectively reviewed. The cumulative doses of EBRT and brachytherapy treatment outcomes and incidence of adverse events were also examined. RESULTS: The median cumulative CTVHR D90%, rectum D2cm3, and bladder D2cm3 were 86.6 Gy, 62.9 Gy, and 72.0 Gy, respectively. The 2-year local control rate was 95%. There were no CTCAE ≥Grade 3 late gastrointestinal or genitourinary adverse events. CONCLUSIONS: The use of gel spacer can enable ESTRO/ABS-recommended dose constraints even without using CS in EBRT, with favorable outcomes and low adverse event rates.

Neoadjuvant Chemotherapy Improves Feasibility of Larynx Preservation and Prognosis in Resectable Locally Advanced Cervical Esophageal Cancer.

BACKGROUND: The optimal strategy for cervical advanced esophageal cancer remains controversial in terms of oncologic outcome as well as vocal and swallowing function. Recently, in East Asian countries, neoadjuvant chemotherapy (NAC) has been a standard strategy for advanced esophageal cancer. METHODS: This study included 37 patients who underwent NAC, and 33 patients who underwent definitive chemoradiation therapy (dCRT) as larynx-preserving treatment for locally advanced cervical esophageal cancer from 2016 to 2021. This study retrospectively investigated outcomes, with comparison between NAC and dCRT for locally advanced cervical esophageal cancer. RESULTS: Larynx preservation was successful for all the patients with NAC and dCRT. After NAC, the rate of complete or partial response was 78.4%, and 30 patients underwent larynx-preserving surgery. On the other hand, after dCRT, the complete response rate was 71.9%, and 4 patients underwent larynx-preserving salvage surgery. Overall survival (OS) and progression free survival were similar between the two groups. However, for the patients with resectable cervical esophageal cancer (cT1/2/3), the 2-year OS rate was significantly higher with NAC (79.9%) than with dCRT (56.8%) (P = 0.022), and the multivariate analyses identified only NAC and cN0, one of the two as a significantly independent factor associated with a better OS (NAC: P = 0.041; cN0, 1: P = 0.036). CONCLUSION: The study showed that NAC as larynx-preserving surgery for resectable cervical esophageal cancer preserved function and had a better prognosis than dCRT. The authors suggest that NAC may be standard strategy for larynx preservation in patients with resectable cervical esophageal cancer.

A method for delivering the required neutron fluence in an accelerator-based boron neutron capture therapy system employing a lithium target.

Accelerator-based boron neutron capture therapy (BNCT) systems employing a solid-state lithium target indicated the reduction of neutron flux over the lifetime of a target, and its reduction could represent the neutron flux model. This study proposes a novel compensatory approach for delivering the required neutron fluence and validates its clinical applicability. The proposed approach relies on the neutron flux model and the cumulative sum of real-time measurements of proton charges. The accuracy of delivering the required neutron fluence for BNCT using the proposed approach was examined in five Li targets. With the proposed approach, the required neutron fluence could be delivered within 3.0%, and within 1.0% in most cases. However, those without using the proposed approach exceeded 3.0% in some cases. The proposed approach can consider the neutron flux reduction adequately and decrease the effect of uncertainty in neutron measurements. Therefore, the proposed approach can improve the accuracy of delivering the required fluence for BNCT even if a neutron flux reduction is expected during treatment and over the lifetime of the Li target. Additionally, by adequately revising the approach, it may apply to other type of BNCT systems employing a Li target, furthering research in this direction.

A preliminary study on rectal dose reduction associated with hyaluronic acid implantation in brachytherapy for prostate cancer.

Objectives: Hydrogel spacer (HS) was developed to reduce rectal toxicities caused by radiotherapy, but has been reported to cause major adverse events. Our institute has attempted to introduce a hyaluronic acid (HA) as an alternative spacer. This study aimed to compare rectal doses and geometric distributions between the HS and HA implantation in prostate cancer. Methods: HS and HA were inserted in 20 and 18 patients undergoing high-dose brachytherapy, respectively. The rectum spacer volumes injected were 10 mL and 22 mL, respectively. In the treatment planning system, 13.5 Gy was administered with common catheter positions. The rectal dose indices were assessed between the spacer groups for dosimetry evaluation. Distances between the prostate and rectum and configurations of the spacers were compared. Results: The mean doses irradiated to 0.1 and 2 mL of the rectum were 10.45 Gy and 6.71 Gy for HS, and 6.73 Gy and 4.90 Gy for HA (p<0.001). The mean minimum distances between the prostate and rectum were 1.23 cm and 1.79 cm for HS and HA, respectively (p<0.05). Geometrical configuration comparisons revealed that HA has a higher ability to expand the space than HS. Conclusion: The rectal dose reduction ability of HA is significantly greater than that of HS, suggesting its potential as a new spacer.

Dosiomics for intensity-modulated radiotherapy in patients with prostate cancer: survival analysis stratified by baseline prostate-specific antigen and Gleason grade group in a 2-institutional retrospective study.

OBJECTIVE: This study evaluated the prognostic impact of the quality of dose distribution using dosiomics in patients with prostate cancer, stratified by pretreatment prostate-specific antigen (PSA) levels and Gleason grade (GG) group. METHODS: A total of 721 patients (Japanese Foundation for Cancer Research [JFCR] cohort: N = 489 and Tokyo Radiation Oncology Clinic [TROC] cohort: N = 232) with localized prostate cancer treated by intensity-modulated radiation therapy were enrolled. Two predictive dosiomic features for biochemical recurrence (BCR) were selected and patients were divided into certain groups stratified by pretreatment PSA levels and GG. Freedom from biochemical failure (FFBF) was estimated using the Kaplan-Meier method based on each dosiomic feature and univariate discrimination was evaluated using the log-rank test. As an exploratory analysis, a dosiomics hazard (DH) score was developed and its prognostic power for BCR was examined. RESULTS: The dosiomic feature extracted from planning target volume (PTV) significantly distinguished the high- and low-risk groups in patients with PSA levels >10 ng/mL (7-year FFBF: 86.7% vs 76.1%, P < .01), GG 4 (92.2% vs 76.9%, P < .01), and GG 5 (83.1% vs 77.8%, P = .04). The DH score showed significant association with BCR (hazard score: 2.04; 95% confidence interval: 1.38-3.01; P < .001). CONCLUSION: The quality of planned dose distribution on PTV may affect the prognosis of patients with poor prognostic factors, such as PSA levels >10 ng/mL and higher GGs. ADVANCES IN KNOWLEDGE: The effects of planned dose distribution on prognosis differ depending on the patient's clinical background.

Gynecological technical notes for appropriate spacer injections.

BACKGROUND: Despite its efficacy, if adherence to dose constraints for surrounding normal tissues proves unattainable, the risk of late radiation-related adverse events after primary radiotherapy involving brachytherapy remains a noteworthy concern. Some studies suggest that similar to prostate radiotherapy, spacers may potentially reduce doses to surrounding healthy rectal or bladder tissues. However, guidance on spacer injections for gynecologic brachytherapy is scarce, and the optimal anatomical location for spacer placement remains undefined. We discuss maximizing the effects of spacers from an anatomical perspective. FINDINGS: As vesicovaginal and rectovaginal septa form part of the endopelvic fascia and are not uniform tissues, spacer injection resistance varies. In pelvic organ prolapse surgery, saline is injected into the anterior and posterior vaginal walls as a spacer, and the vagina, vesicovaginal septum, and bladder can be fluidly dissected. Relatively firm vesicovaginal septum tissue is used as a reconstructive organ, whereas rectovaginal septum tissue is less dense. Cervical cancer is invasive, involving surrounding fascia and ligaments. Ideally, the vesicovaginal and rectovaginal septa should be resected in radical hysterectomy. Here, spacer adaptation and the technical details of injection are described. When using ultrasound guidance for spacer injection, the target site should be adequately magnified, and the spacer ideally injected into the incision layer during radical hysterectomy. Finally, posthysterectomy, the intestinal tract may adhere to the vaginal cuffs. Therefore, artificial ascites may be useful; however, the spread depends on perioperative manipulation. CONCLUSIONS: Anatomical and surgical viewpoints are advantageous for safe, therapeutic, and replicable spacer injection administration.

A single-center retrospective analysis of prognoses in patients with melanoma brain metastases and effectiveness of treatment in Japan.

BACKGROUND: Melanoma brain metastasis (MBM) has a poor prognosis, although recent treatments, including immune checkpoint inhibitors and targeted therapy, have improved the prognosis. However, these systemic therapies have been reported to be less efficient for Asian patients. We investigated the survival of Asian patients with MBM and the effectiveness of systemic therapies. METHODS: We retrospectively reviewed the survival rates of patients diagnosed with MBM between January 2011 and December 2021 at the National Cancer Center Hospital in Tokyo, Japan. In addition, we identified factors associated with survival using Cox regression analysis. RESULTS: A total of 135 patients were included. The median overall survival (OS) after an MBM diagnosis was 7.8 months (95% confidence interval [CI] 6.1-9.6). The 6-month and 1-year survival rates were 60.7% and 34.8%, respectively. We identified the prognostic factors of MBM, including non-acral primary location, low serum LDH levels, systemic therapy of single-agent immune checkpoint inhibitors (ICIs) or targeted therapies (TTs), and radiotherapy of stereotactic irradiation (STI). We found no significant difference in effectiveness between single-agent ICIs, the combination of Nivolumab and Ipilimumab (COMBI-ICI), and TTs (COMBI-ICI vs. single-agent ICI, hazard ratio 0.71, 95% confidence interval 0.27-1.88, p = 0.49; COMBI-ICI vs. TT: hazard ratio 0.46, 95% confidence interval 0.14-1.55, p = 0.21). CONCLUSIONS: Systemic therapy and radiotherapy have improved the survival of MBM patients, but the survival of Asian patients remains poor. Our findings suggest that COMBI-ICIs are not significantly more effective than single-agent ICI or TT in treating MBM.

Acral cutaneous malignant melanoma treated with linear accelerator-based boron neutron capture therapy system: a case report of first patient.

This study reports the first patient treatment for cutaneous malignant melanoma using a linear accelerator-based boron neutron capture therapy (BNCT) system. A single-center open-label phase I clinical trial had been conducted using the system since November 2019. A patient with a localized node-negative acral malignant melanoma and the largest diameter of the tumor ≤ 15 cm who refused primary surgery and chemotherapy was enrolled. After administering boronophenylalanine (BPA), a single treatment of BNCT with the maximum dose of 18 Gy-Eq delivered to the skin was performed. The safety and efficacy of the accelerator-based BNCT system for treating localized cutaneous malignant melanoma were evaluated. The first patient with cutaneous malignant melanoma in situ on the second finger of the left hand did not develop dose-limiting toxicity in the clinical trial. After BNCT, the treatment efficacy was gradually observed, and the patient achieved PR within 6 months and CR within 12 months. Moreover, during the follow-up period of 12 months after BNCT, the patient did not exhibit a recurrence without any treatment-related grade 2 or higher adverse events. Although grade 1 adverse events of dermatitis, dry skin, skin hyperpigmentation, edema, nausea, and aching pain were noted in the patient, those adverse events were relieved without any treatment. This case report shows that the accelerator-based BNCT may become a promising treatment modality for cutaneous malignant melanoma. We expect further clinical trials to reveal the efficacy and safety of the accelerator-based BNCT for cutaneous malignant melanoma.

Correlation between L-amino acid transporter 1 expression and 4-borono-2-18 F-fluoro-phenylalanine accumulation in humans.

BACKGROUND: The correlation between L-type amino acid transporter 1 (LAT1) expression and 4-borono-2-18 F-fluoro-phenylalanine (18 F-FBPA) accumulation in humans remains unclear. This study aimed to investigate the correlation between LAT1 expression in tumor tissues and 18 F-FBPA accumulation in patients with head and neck cancer who participated in a clinical trial of 18 F-FBPA positron emission tomography (PET). METHODS: Altogether, 28 patients with head and neck cancer who participated in a clinical trial of 18 F-FBPA PET at our institution between March 2012 and January 2018 were included. Correlations between standardized uptake values (SUVs); the maximum SUV (SUVmax ), the mean SUV within a 1 cm3 sphere centered at a single point, that is, the SUVmax (SUVpeak ), the minimum SUV (SUVmin ), and the intensity of LAT1 expression (maximum and minimum LAT1 expressions) were investigated. RESULTS: Weak correlations were identified between SUVmax and LAT1 maximum score, SUVmin and LAT1 maximum score, and SUVmin and LAT1 minimum score (ρ = 0.427, 0.362, and 0.330, respectively). SUVmax and LAT1 minimum score, SUVpeak and LAT1 maximum score, and SUVpeak and LAT1 minimum score demonstrated moderate correlations (ρ = 0.535, 0.556, and 0.661, respectively). Boron neutron capture therapy (BNCT) was performed in 2 of the 4 patients with discrepancies between 18 F-FBPA accumulation and intensity of LAT1 expression, and the intensity of LAT1 expression was a better predictor of treatment response. CONCLUSION: 18 F-FBPA accumulation and the intensity of LAT1 expression demonstrated a moderate correlation; however, LAT1 expression may be a better predictor of treatment response of BNCT in patients with discrepancies.

Assessment of intrafractional motion of the cervix-uterus by MR-guided radiotherapy system†.

The uterus is known as one of the moving organs. We evaluated the movement of the uterus during irradiation and the effects of changes in the surrounding organs using a magnetic resonance (MR)-guided radiotherapy system. Seven patients with cervical cancer underwent pre- and posttreatment MR imaging to assess changes in the positioning of the uterus and cervix as well as the alterations in bladder and rectal volume. The study revealed that the movements of the uterus were greater than that of the cervix and showed a tendency to correlate with the bladder rather than the rectum. We also examined whether intrafractional motion could lead to insufficient dose coverage of the clinical target volume (CTV), specifically focusing on the D98% of the CTV in the uterine body and cervix. The impact of intrafractional motion on the D98% varied among patients, with one out of the seven patients experiencing an average dosimetric change of -2.6 Gy in the uterus, although larger planning target volume margins of 1.5 cm were applied, therefore, indicating the need for individualized optimal margins in each case. Online adaptive radiotherapy offers the advantage of modifying the treatment plan when irradiating moving organs, such as the uterus. However, it should be noted that this approach may result in longer overall treatment times compared with the traditional methods. Therefore, we must carefully consider the influence of intrafractional organ motions when opting for such a treatment.

Non-operative management involving chemoradiation therapy combined with high-dose-rate brachytherapy for T3 rectal cancer using a vaginal shielded cylindrical applicator: a technical report.

It has been shown that a group of rectal cancer patients will achieve a pathological complete response following preoperative chemoradiotherapy, and non-operative management has recently gained attention. To escalate the tumour dose and increase the likelihood of pathological complete response, brachytherapy can play an important role in safely increasing the total dose. However, at the time this report was published, an applicator dedicated to rectal brachytherapy was unaffordable in Japan. Here, we report two T3 rectal cancer patients who were inoperable or refused surgery and treated by chemoradiotherapy following intracavitary brachytherapy involving a vaginal cylinder applicator with lead shielding.

Relative biological effectiveness for epithermal neutron beam contaminated with fast neutrons in the linear accelerator-based boron neutron capture therapy system coupled to a solid-state lithium target.

This study aimed to quantify the relative biological effectiveness (RBE) for epithermal neutron beam contaminated with fast neutrons in the accelerator-based boron neutron capture therapy (BNCT) system coupled to a solid-state lithium target. The experiments were performed in National Cancer Center Hospital (NCCH), Tokyo, Japan. Neutron irradiation with the system provided by Cancer Intelligence Care Systems (CICS), Inc. was performed. X-ray irradiation, which was assigned as the reference group, was also performed using a medical linear accelerator (LINAC) equipped in NCCH. The four cell lines (SAS, SCCVII, U87-MG and NB1RGB) were utilized to quantify RBE value for the neutron beam. Before both of those irradiations, all cells were collected and dispensed into vials. The doses of 10% cell surviving fraction (SF) (D10) were calculated by LQ model fitting. All cell experiments were conducted in triplicate at least. Because the system provides not only neutrons, but gamma-rays, the contribution from the gamma-rays to the survival fraction were subtracted in this study. D10 value of SAS, SCCVII, U87-MG and NB1RGB for the neutron beam was 4.26, 4.08, 5.81 and 2.72 Gy, respectively, while that acquired by the X-ray irradiation was 6.34, 7.21, 7.12 and 5.49 Gy, respectively. Comparison of both of the D10 values, RBE value of SAS, SCCVII, U87-MG and NB1RGB for the neutron beam was calculated as 1.7, 2.2, 1.3 and 2.5, respectively, and the average RBE value was 1.9. This study investigated RBE of the epithermal neutron beam contaminated with fast neutrons in the accelerator-based BNCT system coupled to a solid-state lithium target.

Treatment planning comparison of high-dose-rate brachytherapy vs. robotic and conventional stereotactic body radiotherapy for ultrahypofractionated treatment of prostate cancer.

Background and purpose: Ultrahypofractionated radiation therapy is increasingly used in the treatment of prostate cancer. High-dose-rate brachytherapy (HDR-BT) and stereotactic body radiotherapy (SBRT) are representative methods of ultrahypofractionation. This study was performed to compare clinically applied treatment plans for patients who had been treated using HDR-BT vs. conventional or robotic SBRT. Materials and methods: Calculated dose-volume indices between HDR-BT without a perirectal spacer (n = 20), robotic SBRT without a spacer (n = 40), and conventional (non-robotic) SBRT with a spacer (n = 40) were compared. Percentages against the prescription dose regarding the planning target volume (PTV), bladder, rectum, and urethra were statistically compared. Results: The D50% of the PTV with HDR-BT (140.5% ± 4.9%) was significantly higher than that with robotic or conventional SBRT (116.2% ± 1.6%, 101.0% ± 0.4%, p < 0.01). The D2cm3 of the bladder with HDR-BT (65.6% ± 6.4%) was significantly lower than those with SBRT (105.3% ± 2.9%, 98.0% ± 1.3%, p < 0.01). The D2cm3 of the rectum with HDR-BT (60.6% ± 6.2%) was also significantly lower than those with SBRT (85.1% ± 8.8%, 70.4% ± 9.6%, p < 0.01). By contrast, the D0.1cm3 of the urethra with HDR-BT (117.1% ± 3.6%) was significantly higher than those with SBRT (100.2% ± 0.7%, 104.5% ± 0.6%, p < 0.01). Conclusions: HDR-BT could administer a higher dose to the PTV and a lower dose to the bladder and rectum, at the cost of a slightly higher dose to the urethra compared with SBRT.

Intensity-modulated radiation therapy for intermediate-risk prostate cancer: does ADT still have an impact in the dose-escalated external beam radiation therapy era?

BACKGROUND: This study aimed to investigate the effect of androgen deprivation therapy (ADT) on the survival of intermediate-risk prostate cancer (IR-PCA) patients treated with dose-escalated external beam radiation therapy (DE-EBRT), and to determine the group that will benefit from ADT. METHODS: We analysed 620 IR-PCA patients treated with DE-EBRT at two institutions. Variables were adjusted using the stabilised inverse probability of treatment weighting method (sIPTW) between radiation therapy (RT) and RT plus ADT groups. Biochemical relapse-free survival (bRFS) rate and overall survival (OS) rate were compared using Kaplan-Meier analysis and log-rank test. Cox proportional hazard analysis (CPH) was conducted to detect unfavorable risk factors. RESULTS: This study included 405 patients; with 217 and 188 patients in the RT and RT plus ADT groups, respectively. The prescribed radiation dose was 78 Gy in 39 fractions. The median follow-up time was 82.0 months. After sIPTW-adjustment, 214.3 and 189.7 patients were assigned to the RT and RT plus ADT groups, respectively. The 7-year bRFS and OS were 89.3% and 94.6% in RT group and 92.3% and 91.0% in RT plus ADT group, respectively. Before and after sIPTW adjustment, no statistically significant differences were found in these endpoints between treatment groups. Multivariate CPH for bRFS revealed Gleason score (GS) 4 + 3 as an unfavorable risk factor, and ADT improved biochemical control of them. CONCLUSION: ADT may not always be effective in all Japanese IR-PCA patients treated with DE-EBRT, but it can improve biochemical control in patients with GS 4 + 3.

Impact of interstitial lung abnormality on survival after adjuvant durvalumab with chemoradiotherapy for locally advanced non-small cell lung cancer.

INTRODUCTION: Concurrent chemoradiotherapy (CCRT) has been the standard of care for patients with locally advanced non-small cell lung cancer (LA-NSCLC). BACKGROUND AND PURPOSE: The results of the PACIFIC trial established the use of consolidative durvalumab after concurrent chemoradiotherapy (CCRT) as the standard of care for patients with locally advanced non-small cell lung cancer (LA-NSCLC). A subgroup analysis of the PACIFIC trial reported a better progression-free survival (PFS) in Asians. Although real-world data on LA-NSCLC patients who received CCRT plus durvalumab have been reported, there have been few large-scale reports on Asians. In this study, we investigated prognostic factors in the largest real-world data set in Asia of only Japanese LA-NSCLC patients treated with CCRT plus durvalumab. MATERIALS AND METHODS: One hundred and thirteen LA-NSCLC patients who received definitive CCRT and consolidative durvalumab at our institution between May 2018 and April 2021 were analyzed. Overall survival (OS), cause-specific survival (CSS), PFS, distant metastasis-free survival (DMFS), and in-field progression-free survival (IFPFS) were investigated as treatment outcomes using competing risk analyses. RESULTS: During a median follow-up of 24 months (range, 5-47) after the initiation of durvalumab therapy, 31 patients died, of whom 23 died of lung cancer. In the multivariate analysis, the pretreatment factors that correlated with OS were ILA scores, adenocarcinoma, and performance status at the initiation of durvalumab. Furthermore, ILA score and programmed cell death ligand 1 (PD-L1) tumor proportion score (TPS) ≥ 1 % were significantly correlated with CSS, and PD-L1 TPS ≥ 1 % was significantly correlated with PFS and IFPFS. CONCLUSION: Pretreatment ILA, adenocarcinoma, and performance status may have an impact on OS of LA-NSCLC patients receiving CCRT plus durvalumab.