Journal of Radiation Research最新文献

This study aimed to analyze the clinical outcomes and prognostic factors of postoperative adjuvant radiotherapy (RT) for vulvar cancer based on a retrospective Japanese nationwide survey. Data were collected from 108 institutions for patients diagnosed with vulvar cancer between January 2001 and December 2010. Patients with histologically confirmed squamous cell carcinoma, adenocarcinoma, or adenosquamous carcinoma who underwent curative surgery and adjuvant radiotherapy were included in this study. Survival outcomes were estimated using the Kaplan-Meier method, and prognostic factors were analyzed via univariate and multivariate models. A total of 139 patients were included, with a median follow-up of 44 months (range: 3-169). The 5-year overall survival (OS) rates (95% confidence interval [CI]) for stages I, II, III, and IV were 71.8% (50.8-92.8%), 61.3% (40.1-82.5%), 58.0% (45.8-70.2%), and 47.3% (27.5-67.1%), respectively. The corresponding 5-year cause-specific survival (CSS) rates (95% CI) for stages I, II, III, and IV were 71.8% (50.8-92.8%), 73.4% (53.0-93.8%), 62.2% (50.0-74.4%), and 47.3% (27.5-67.1%). Multivariate analysis identified age ≥70 years as an independent adverse prognostic factor for OS (hazard ratio [HR]: 1.848; 95% CI: 1.039-3.281; P = 0.042), while the presence of ≥2 inguinofemoral lymph node metastases was significantly associated with poorer CSS (HR: 2.179; 95% CI: 1.109-4.280; P = 0.030). Our analysis identified advanced age and a higher nodal burden as significant predictors of poorer survival outcomes in patients with vulvar cancer receiving postoperative adjuvant RT.

The influences of tumor volume and total radiation dose on pain relief outcomes have not been fully investigated. We investigated potential correlations between gross tumor volume (GTV), biologically effective dose (BED) and pain relief in patients receiving radiation therapy (RT) for painful tumors. As a secondary analysis of a three-center prospective observational study of 302 patients who received RT for painful tumors, patients treated at an academic hospital were analyzed. We used the Brief Pain Inventory short form to evaluate pain intensity and interference in patients' lives. We collected the Brief Pain Inventory and analgesic data at baseline and 1, 2, 3, 6, 9 and 12 months after the start of RT. Pain responses were assessed using the International Consensus Endpoint. The Fine and Gray models were used for univariable and multivariable analyses, to estimate the impact of clinical factors on pain response and pain progression. In total, 153 (59%) of the 258 patients experienced a pain response, and 45 (17%) patients experienced pain progression. In the univariable and multivariable analyses, GTV and BED did not significantly associate with pain response or pain progression. Furthermore, no significant interaction between GTV and BED was reported in terms of pain response or pain progression after adjusting for covariates. The impact of BED on pain response and pain progression did not vary according to the GTV.

There are no reports on shrinkage of multiple hepatocellular carcinomas (HCCs) after simultaneous treatment with radiotherapy. The purpose of the study was to examine the relationship between tumor shrinkage and treatment outcomes for several HCCs irradiated simultaneously using proton beam therapy (PBT). The subjects were 46 patients with multiple HCCs (95 lesions) who received PBT between January 2008 and December 2018. Overall survival (OS), local control (LC) and complete+partial response (CR + PR) rates were determined using the Kaplan-Meier method. The median follow-up period was 29.2 months and the 3-year OS was 50.3%. For the 95 lesions, the 3-year LC rate was 90.4% and the CR + PR rate was 85.2% at 3 years. Three combination protocols (referred to as A, B and C) were used for different lesions in the same patient: A (66 Gray (Gy) Relative biological effectiveness (RBE) in 10 fractions (fr))-B (72.6 Gy(RBE) in 22 fr) (22 lesions), A-C (74 Gy(RBE) in 37 fr) (15 lesions) and B-C (2 lesions). The 1-year CR + PR rates were 75.8% for A and 56.4% for B in A-B cases (P = 0.14), and 62.5% for A and 57.1% for C in A-C cases (P = 0.35). In the B-C group, there was only one patient with 2 lesions. The lesion treated with the B protocol reached CR + PR, while that treated with the C protocol did not reach CR + PR. These results show that some cases can have differences in tumor shrinkage after concurrent PBT for multiple HCCs, and that there is no significant relationship between dose and tumor shrinkage.

Despite the environmental significance of airborne particulates generated from mine tailings, there is limited information on exposure of people living in the neighbourhoods adjacent to such sites. The main objective of the study was to assess cancer risk due to enhanced radionuclides present in dust samples and to evaluate the exposure risk of populations living in three mining areas in the Free State and West Rand in South Africa. Soil and dust samples were collected between January 2016 and March 2018 in different seasons for determination of the level of naturally occurring radioactive materials in the samples. The samples were prepared and sealed for 4 weeks to attain secular equilibrium of the 238U and 232Th and their respective progenies, and thereafter analysed using gamma spectroscopy. Radiological parameters were calculated from the activity of the radionuclides to estimate exposure risk. The absorbed dose rate in air ranged from 76 to 137, 50 to 133 and 19 to 75 (nGy hr-1) for areas A, B and C, respectively. The mean excess lifetime cancer risk in all three mines was lower than the world average of 1.45 × 10-3; accordingly, the cancer risk was found to be negligible. The findings revealed that most radiological parameters were within the accepted international values; thus the soils in the areas could be considered to be safe for the humans living there.

Stereotactic body radiation therapy (SBRT) has emerged as a promising and minimally invasive treatment option for patients with renal cell carcinoma (RCC). This study presents our initial clinical experiences with treatments following our center's protocol, which was formulated based on both national and international evidence. Six patients who had undergone renal SBRT at our center from January 2021 to December 2023 were included. Treatment planning used computed tomography (CT) and magnetic resonance imaging, with respiratory management conducted through breath-hold or free-breathing techniques. The prescribed dose was primarily 48 Gy in three fractions, with increased fractionations when dose constraints were challenging to achieve. Dose constraints were met for all patients, and treatment planning adhered to protocol guidelines. After the confirmation of cone-beam CT (CBCT) images by physicians, radiation was delivered. Five out of six patients completed the planned treatment, whereas one discontinued the treatment midway (the causal relationship to radiation therapy was unclear). Dose-volume histogram analysis revealed that doses to organs at risk depended on the position and size of the planning target volume but remained within acceptable limits for all cases. The intrafractional patient motion was 2.7 mm, as calculated from the pre- and post-CBCT images, confirming the appropriateness of a 3-mm setup margin. Although this study provides initial insights, further clinical trials are warranted to establish standardized protocols and optimize treatment strategies for RCC. In the future, it is also necessary to generate evidence that is tailored to the current situation in Japan.

This study addresses the escalating radiation safety concerns among medical professionals due to the rising application of proton and carbon ion radiotherapy. It evaluates the occupational radiation exposure faced by therapists when utilizing the Siemens IONTRIS Proton-Carbon Ion System. Through random sampling of 80 patients treated between January and June 2024, we recorded particle types and counts and measured dose rates using a photon/neutron radiation dose meter. Notably, 1 min post-treatment, the dose rate peaked at 16.00 μSv/h near the tumor's skin surface, showing a significant correlation with particle count. The therapist's standing position and the surfaces of the range shifter and ripple filter registered average dose rates of 1.25 μSv/h and 3.63 μSv/h, 0.33 μSv/h, respectively. Other points averaged 0.08 μSv/h, with no neutron detection. The study concludes that the annual average occupational exposure for therapists, at ~300 μSv, is significantly below the International Commission on Radiological Protection's recommended dose equivalent limit, confirming the safety of the Siemens IONTRIS device in clinical settings.

Adult T-cell lymphoma/leukemia (ATL) is an aggressively malignant peripheral T-cell neoplasm. Only a few studies have reported the use of radiotherapy (RT) for ATL. Therefore, the aim of this study was to clarify the efficacy of RT for ATL. We retrospectively reviewed 90 courses of RT administered to 19 consecutive ATL patients between 2008 and 2023. The subtypes included lymphoma (n = 8), acute (n = 7), smoldering (n = 3) and unknown (n = 1). Ninety lesions (cutaneous = 72, extranodal = 10, nodal = 8) were treated at a mean dose of 39.1 Gy/3.2 Gy (range, 24-60 Gy). Administration of RT for ATL lesions resulted in a combined complete response and partial response rate of 92%. At a mean of 47.5 months of follow-up (range, 0-102 months), local recurrence was not observed in 98.9% of the courses. A treatment response in terms of clinical symptoms was observed in 92% of the courses. The median survival time was 918 days. No acute grade ≥3 toxicity or any late toxicity was noted. In conclusion, RT was confirmed to be effective and safe for the treatment of local ATL lesions.

The Japanese Society for Radiation Oncology (JASTRO) Guidelines for Radiotherapy Treatment Planning have been revised every four years to incorporate the latest findings since the publication of the first edition in 2004. This is a review which presents the 2024 JASTRO Guidelines for radiotherapy treatment planning for esophageal cancer in English. Regarding the treatment of esophageal cancer, various new findings have emerged over the past 4 years, leading to significant updates in the 2020 edition, particularly in the following six areas: (i) additional details on indications for superficial cancer, (ii) inclusion of clinical trial results (JCOG1109) for neoadjuvant chemotherapy and chemoradiotherapy in locally advanced cases in Japan, (iii) updated references on prophylactic lymph node irradiation, (iv) updates on IMRT, (v) revisions in accordance with the 5th edition of the Esophageal Cancer Treatment Guidelines, and (vi) additions of FOLFOX to concurrent chemotherapy regimens.

The rare abscopal effect in radiotherapy is thought to result from immune-activating damage-associated molecular patterns, such as high mobility group box-1 protein (HMGB1), released from cancer cells. While external irradiation of cancer cells increases HMGB1 release, it remains unclear whether internal radiotherapy with 131I-meta-iodobenzylguanidine (131I-MIBG) induces similar effects. This study aimed to determine if HMGB1 is released from human-derived cancer and normal cells after 131I-MIBG administration. The number of cells, extracellular lactate dehydrogenase (LDH) and HMGB1 were measured in H441 and human keratinocyte cell line (HaCaT) at 1 day after 2- and 10-Gy X-ray irradiation. Accumulations of 131I-MIBG in SH-SY5Y and HaCaT were measured at 60 min after 131I-MIBG (0.37, 1.85 and 3.7 MBq/well) administration. The number of cells, extracellular LDH and HMGB1 were measured at 1 day after 131I-MIBG treatment. Results: The total number of cells decreased in both H441 and HaCaT at 1 day after 10-Gy X-ray irradiation. Extracellular LDH and HMGB1 from H441 after 10-Gy X-ray irradiation were significantly increased, while no increase was observed in HaCaT after 2- and 10-Gy X-ray irradiation. After 1.85 MBq (~4-Gy by converting of PHITS simulation) and 3.7 MBq 131I-MIBG (8-Gy) administrations, the total number of cells decreased in both SH-SY5Y and HaCaT at 1 day after 131I-MIBG administration. Extracellular LDH and HMGB1 were both significantly increased in SH-SY5Y, but only extracellular LDH was significantly increased in HaCaT. HMGB1 was released from neuroblastoma cells but not from normal cells after 131I-MIBG administration. A combination of 131I-MIBG and immunotherapy may be feasible.

To evaluate the safety of a rotating gantry with scanning beams of carbon-ion radiotherapy (C-ion RT) for choroidal malignant melanoma. A prospective study of C-ion RT using a rotating gantry with scanning beams for choroidal malignant melanoma was initiated at the National Institute for Quantum Science and Technology, QST Hospital in March 2018. The inclusion criteria were as follows: (i) clinically diagnosed ocular/choroidal malignant melanoma; (ii) tumor measurable by imaging tests; (iii) score of 0-2 on the Eastern Cooperative Oncology Group Performance Status scale and (iv) ability to provide consent for treatment. All patients received 68 Gy in four fractions of C-ion RT by a rotating gantry with scanning beams. Between April 2018 and July 2019, 21 patients were enrolled and underwent C-ion RT as planned. All 21 patients completed the treatment schedule and the 3-year follow-up period. The median duration of follow-up was 43 months (range, 35.2-54.6 months). Regarding late normal tissue responses, three of the 21 patients developed grade 2 neovascular glaucoma; however, no other late grade ≥2 acute toxicities were observed. During the 3-year study period, all 21 patients survived with no local recurrence; none of the patients underwent enucleation. Three cases showed liver metastasis. The 3-year local control, overall survival and eye-retention rates were all 100%. The results of this prospective study confirmed that the effectiveness and safety of this method are equivalent to those of conventional passive irradiation methods, although the number of cases was small. The results of this prospective study confirmed that the effectiveness and safety of this method are equivalent to those of conventional passive irradiation methods, although the number of cases was small.