Published papers

Background: In definitive radiotherapy for localized prostate cancer, the seminal vesicle is included in the target volume for intermediate- and high-risk cases, though this increases the risk of toxicity to the bowel and rectum. This study retrospectively examined clinicopathological data to assess the absence of seminal vesicle invasion (SVI) in prostate cancer patients without radiological evidence of SVI using preoperative magnetic resonance imaging (MRI). Materials and methods: Patients with cT1c–cT3a prostate cancer who underwent radical prostatectomy between March 2010 and February 2024 were retrospectively selected, excluding those with distant metastasis, missing MRI data, preoperative systemic therapy, or delayed surgery post-biopsy. Preoperative risk factors [age, initial prostate-specific antigen (PSA), grade group (GG), clinical T stage, positive core ratio] and postoperative pathology were analyzed to assess SVI risk. The impact of GG changes between biopsy and postoperative pathology on risk classification and SVI treatment intensity in radiotherapy was also examined. Results: Of 368 patients, 308 met the inclusion criteria. SVI was observed in 26 patients (8.4%). Significant predictors of SVI included GG, initial PSA ≥ 8.6, and positive core ratio, with a positive core ratio < 0.5 and GG ≤ 3 indicating an SVI risk under 10%. GG discrepancies between biopsy and surgery were noted in 182 cases (59.1%), but had minimal impact on risk classification and SVI risk. Conclusions: Patients with a positive core ratio <0.5 had a low risk of SVI. GG discrepancies did not significantly underestimate prostate cancer risk, minimizing the risk of failing to treat true SVI.

Purpose: Local control (LC) is an important outcome of local cancer therapy, besides overall survival (OS). We conducted a comprehensive literature search to investigate whether a high LC rate contributes to good OS in radiotherapy for early-stage non-small cell lung cancer (ES-NSCLC). Materials and methods: Studies in patients receiving radiotherapy for peripheral ES-NSCLC, mainly staged as T1-2N0M0 were included for a systematic review. Relevant information was collected including, dose fractionation, T stage, median age, 3-year LC, cancer-specific survival (CSS), disease-free survival (DFS), distant metastasis-free survival (DMFS), and OS. Correlations between outcomes and clinical variables were evaluated. Results: After screening, 101 data points from 87 studies including 13,435 patients were selected for the quantitative synthesis. Univariate meta-regression analysis revealed that the coefficients between the 3-year LC and 3-year DFS, DMFS, CSS, and OS were 0.753 (95% confidence interval (CI): 0.307–1.199; p < 0.001), 0.360 (95% CI: 0.128–0.593; p = 0.002), 0.766 (95% CI: 0.489–1.044; p < 0.001), and 0.574 (95% CI: 0.275–0.822; p < 0.001), respectively. Multivariate analysis revealed that the 3-year LC (coefficient, 0.561; 95% CI: 0.254–0.830; p < 0.001) and T1 proportion (coefficient, 0.207; 95% CI: 0.030–0.385; p = 0.012) were significantly associated with the 3-year OS and CSS (coefficient for 3-year LC, 0.720; 95% CI: 0.468–0.972; p < 0.001 and T1 proportion, 0.002; 95% CI: 0.000–0.003; p = 0.012). Toxicities ≥ grade 3 were low (3.4%). Conclusions: Three-year LC was correlated with three-year OS in patients receiving radiotherapy for ES-NSCLC. A 5% increase in 3-year LC is expected to improve the 3-year CSS and OS rates by 3.8% and 2.8%, respectively.

Background: The safety of postmastectomy radiation therapy (PMRT) after autologous breast reconstruction remains unclear. Therefore, we conducted a systematic review and meta-analysis to investigate the effects of PMRT on patients with breast cancer who underwent autologous breast reconstruction. Methods: A comprehensive literature search of English and Japanese articles until March 2021 was performed using PubMed/MEDLINE, the Cochrane Library, and Ichushi-Web. We included studies that compared the outcomes of patients with breast cancer who underwent immediate autologous breast reconstruction with and without PMRT. Outcomes including major complications, fat necrosis, and cosmetic results were assessed. Pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated using a random effects model. Results: Ten studies (two retrospective case-controlled and eight retrospective cohort studies) comprising 3,123 cases were included. The rate of major complications was slightly higher in the PMRT group compared to the no PMRT group, but the difference was not statistically significant (13.2% vs. 12.2%, OR 1.58, 95% CI 0.93–2.68, P = 0.09). In contrast, the rate of fat necrosis was significantly increased in the PMRT group (17.2% vs. 8.1%, OR 2.71, 95% CI 1.58–4.65, P = 0.0003). Data on cosmetic outcomes were limited and not pooled for the meta-analysis. Conclusions: PMRT following autologous breast reconstruction was associated with a higher risk of fat necrosis, but not with a significantly increased rate of major complications. With careful patient selection and monitoring, PMRT after autologous breast reconstruction can be considered a safe and acceptable treatment option.

BACKGROUND: Implant-based breast reconstruction is the most commonly performed reconstructive technique following mastectomy. With an increasing number of patients undergoing implant-based breast reconstruction, concerns have arisen regarding the safety of postmastectomy radiation therapy (PMRT) in reconstructed breasts. This study aimed to investigate the safety of PMRT in implant-based breast reconstruction. METHODS: A comprehensive literature search was conducted for articles published up to March 2021. Eligible studies included clinical trials and observational studies comparing outcomes between patients with breast cancer undergoing immediate implant-based breast reconstruction with PMRT and those without PMRT. The primary outcomes included major complications, reconstruction failure, capsular contracture, and cosmetic outcomes. Pooled odds ratio (OR) with 95% confidence interval (CI) were calculated using a random-effects model. RESULTS: A total of 23 studies were identified, comprising one case-control study, one prospective cohort study, and 21 retrospective cohort studies. PMRT was significantly associated with increased rates of major complications (OR 2.62, 95% CI 1.82-3.77, P < 0.00001), reconstruction failure (OR 2.53, 95% CI 2.00-3.20, P < 0.00001), and capsular contracture (OR 9.63, 95% CI 5.77-16.06, P < 0.00001). Furthermore, cosmetic outcomes were significantly poorer in patients undergoing PMRT compared with those not receiving PMRT (OR 3.55, 95% CI 1.80-6.98, P < 0.003). CONCLUSIONS: This meta-analysis demonstrated that PMRT in implant-based breast reconstruction is associated with a significantly increased risk of adverse outcomes. Given these risks, treatment decisions should involve through discussions with patients to ensure that they are fully informed of the potential benefits and complications.

The Breast Cancer Clinical Practice Guidelines, organized by the Japanese Breast Cancer Society (JBCS), were published in 2022. We present the English version of the Radiation Therapy (RT) section of the guidelines. The JBCS formed a task force to update the 2018 version of the JBCS Clinical Practice Guidelines. The Background Questions (BQs) contain the standard treatments for breast cancer in clinical practice, whereas the Clinical Questions (CQs) address daily clinical questions that remain controversial. Future Research Questions (FRQs) explore the subjects that are considered important issues, despite there being insufficient data for inclusion as CQs. The task force selected the 12 BQs, 8 CQs, and 6 FRQs for the RT section. For each CQ, systematic literature reviews and meta-analyses were conducted according to the Minds Manual for Guideline Development 2020, version 3.0. The recommendations, strength of recommendation, and strength of evidence for each CQ were determined based on systematic reviews and meta-analyses, and finalized by voting at the recommendation decision meeting.

Purpose: Whole-prostate dose escalation in stereotactic body radiotherapy (SBRT) for localized prostate cancer (PCa) can improve oncological outcomes, albeit at the cost of increased toxicity. A focal boost to the dominant intraprostatic lesion (DIL) is gaining interest as an alternative approach. Herein, we investigate the safety and efficacy of this approach. Methods: This retrospective study enrolled patients with localized PCa who underwent five-fraction SBRT with a focal boost to the DIL at our institution between May 2016 and August 2021. The prescription doses to the whole prostate were 35 and 36.25 Gy for low- to favorable intermediate-risk PCa and unfavorable intermediate- to high-risk PCa, respectively. The focal boost to the DIL was up to 115–140% of the prescribed dose. None of the patients underwent pretreatment fiducial or perirectal hydrogel spacer placement. Acute and late genitourinary (GU) and gastrointestinal (GI) toxicities and oncological outcomes were assessed. Results: Among the 520 patients, 44% were categorized as patients with high-risk PCa. The median follow-up period was 42.9 months. No acute or late grade ≥3 toxicities were observed. Acute and late grade 2 GU toxicities were observed in 22.3 and 6.1%, respectively, while GI toxicities were observed in 2.1 and 0.8% of the patients. The 4‑year relapse-free survival rate was 94.8% among all patients. Conclusion: Our results indicate that SBRT with a focal boost without fiducials or perirectal hydrogel spacer for localized PCa has a promising toxicity profile and oncological outcomes. Longer follow-up studies are necessary to adequately evaluate late toxicities and efficacy.

Abstract Purpose The Japanese Breast Cancer Society (JBCS) Clinical Practice Guideline was revised in 2018. This article describes the revise points in the section on radiation therapy (RT). Methods and materials The JBCS formed task force to update the JBCS Clinical Practice Guideline 2015 edition. Background questions (BQs) deal with standard treatments of breast cancer in clinical practice. Clinical questions (CQs) highlight the important treatments in which controversy remains. The task force for RT section addressed the 10 BQs, the 10 CQs, and the 4 Future reseach questions (FQs). For each CQ, systematic literature reviews and meta-analyses were conducted, and recommendations, strength of recommendation and strength of evidence were determined according to the protocol in Morizane et al. (Minds Handbook for Clinical Practice Guideline Development, 2014). Results The recommendations, the strength of recommendation and the strength of evidence were determined based on the systematic literature reviews and the meta-analyses for each CQ. Conclusion The JBCS updated the Clinical Practice Guideline. RT represents a significant portion of the breast cancer treatment, and these recommendations regarding RT will be useful in individualized, shared decision making between physicians and patients.

Aim: Decisions regarding therapeutic plans for inoperable patients with hepatocellular carcinoma (HCC) adjacent to the gastrointestinal (GI) tract are challenging because radiofrequency ablation has the potential risk of thermal injury. Moreover, the response rate of transcatheter arterial chemoembolization is relatively low and stereotactic body radiotherapy (SBRT) is believed to be too toxic. We have applied hypofractionated radiotherapy (HFRT) for such lesions. This study investigated the outcomes and toxicities of this treatment. Methods: Among consecutive HCC patients treated with radiotherapy with curative intent at our institution between 2015 and 2019, we retrospectively extracted those outside of the indication for SBRT due to exceeding the constraint of the GI tract and who were treated using HFRT with a prescription dose of 42 Gy in 14 fractions and prophylactic proton pump inhibitor administration for 6 months. The oncological outcomes and toxicities were investigated. Results: A total of 66 patients with 73 lesions were eligible. The median follow-up period was 24.0 months. The local recurrence, intrahepatic recurrence, liver-related death, and overall survival rates at 2 years were 11.3%, 50.6%, 15.9%, and 60.4%, respectively. Six (9.1%) patients experienced Child–Pugh score deterioration ≥2 within 6 months following treatment. Two and one patient developed grades 2 and 3 gastroduodenal bleeding, respectively. Conclusions: HFRT can achieve good local control in patients with HCC adjacent to the GI tract, with low GI toxicity incidence. Our study demonstrated that HFRT can be a potentially curative treatment option for lesions.

Aim: To prospectively evaluate the efficacy and safety of stereotactic body radiotherapy (SBRT) for patients with previously untreated solitary primary hepatocellular carcinoma (HCC). Methods: The main eligibility criteria included the following: (1) primary solitary HCC; (2) no prior treatment for HCC; (3) Child–Turcotte–Pugh score of seven or less; and (4) unsuitability for or refusal of surgery and radiofrequency ablation (RFA). The prescribed dose of SBRT was 40 Gy in five fractions. The primary endpoint was 3-year overall survival (OS); the secondary endpoints included local progression-free survival (LPFS), local control (LC), and adverse events. The accrual target was 60 patients, expecting a 3-year OS of 70% with a 50% threshold. Results: Between 2014 and 2018, 36 patients were enrolled; enrollment was closed early because of slow accrual. The median tumor size was 2.3 cm. The median follow-up at the time of evaluation was 20.8 months. The 3-year OS was 78% (95% confidence interval [CI]: 53%–90%). The 3-year LPFS and LC proportion were 73% (95% CI: 48%–87%) and 90% (95% CI: 65%–97%), respectively. Grade 3 or higher SBRT-related toxicities were observed in four patients (11%), and grade five toxicities were not observed. Conclusions: This study showed acceptably low incidence of SBRT-related toxicities. LC and OS after SBRT were comparable for previously untreated solitary HCC for patients unfit for resection and RFA. Although a definitive conclusion cannot be drawn by this study, the promising results indicate that SBRT may be an alternative option in the management of early HCC.

Background: Developing strategies to prevent breast cancer-related arm lymphoedema (BCRAL) is a critical unmet need because there are no effective interventions to eradicate it once it reaches a chronic state. Certain strategies such as prospective surveillance programs and prophylactic lymphatic reconstruction have been reported to be effective in clinical trials. However, a large variation exists in practice based on clinician preference, organizational standards, and local resources. Methods: A two-round international Delphi consensus process was performed from February 27, 2023 to May 25, 2023 to compile opinions of 55 experts involved in the care and research of breast cancer and lymphoedema on such interventions. Findings: Axillary lymph node dissection, use of post-operative radiotherapy, relative within-arm volume increase one month after surgery, greater number of lymph nodes dissected, and high body mass index were recommended as the most important risk factors to guide selection of patients for interventions to prevent BCRAL. The panel recommended that prospective surveillance programs should be implemented to screen for and reduce risks of BCRAL where feasible and resources allow. Prophylactic compression sleeves, axillary reverse mapping and prophylactic lymphatic reconstruction should be offered for patients who are at risk for developing BCRAL as options where expertise is available and resources allow. Recommendations on axillary management in clinical T1–2, node negative breast cancer patients with 1–2 positive sentinel lymph nodes were also provided by the expert panel. Routine axillary lymph node dissection should not be offered in these patients who receive breast conservation therapy. Axillary radiation instead of axillary lymph node dissection should be considered in the same group of patients undergoing mastectomy. Interpretation: An individualised approach based on patients' preferences, risk factors for BCRAL, availability of treatment options and expertise of the healthcare team is paramount to ensure patients at risk receive preventive interventions for BCRAL, regardless of where they are receiving care. Funding: This study was not supported by any funding. RJC received investigator grant support from the Australian National Health and Medical Research Council (APP1194051).