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1.
Pediatr Blood Cancer ; 71(6): e30976, 2024 Jun.
Article En | MEDLINE | ID: mdl-38577760

PURPOSE: Survival rates of patients with high-risk neuroblastoma are unacceptable. A time-intensified treatment strategy with delayed local treatment to control systemic diseases has been developed in Japan. We conducted a nationwide, prospective, single-arm clinical trial with delayed local treatment. This study evaluated the safety and efficacy of delayed surgery to increase treatment intensity. PATIENTS AND METHODS: Seventy-five patients with high-risk neuroblastoma were enrolled in this study between May 2011 and September 2015. Delayed local treatment consisted of five courses of induction chemotherapy (cisplatin, pirarubicin, vincristine, and cyclophosphamide) and myeloablative high-dose chemotherapy (melphalan, etoposide, and carboplatin), followed by local tumor extirpation with surgery and irradiation. The primary endpoint was progression-free survival (PFS). The secondary endpoints were overall survival (OS), response rate, adverse events, and surgical complications. RESULTS: Seventy-five patients were enrolled, and 64 were evaluable (stage 3, n = 8; stage 4, n = 56). The estimated 3-year PFS and OS rates (95% confidence interval [CI]) were 44.4% [31.8%-56.3%] and 80.7% [68.5%-88.5%], resspectively. The response rate of INRC after completion of the treatment protocol was 66% (42/64; 95% CI: 53%-77%; 23 CR [complete response], 10 VGPR [very good partial response], and nine PR [partial response]). None of the patients died during the protocol treatment or within 30 days of completion. Grade 4 adverse effects, excluding hematological adverse effects, occurred in 48% of patients [31/64; 95% CI: 36%-61%]. Major Surgical complications were observed in 25% of patients [13/51; 95% CI: 14%-40%]. CONCLUSION: This study indicates that delayed local treatment is feasible and shows promising efficacy, suggesting that this treatment should be considered further in a comparative study of high-risk neuroblastoma.


Antineoplastic Combined Chemotherapy Protocols , Doxorubicin/analogs & derivatives , Neuroblastoma , Humans , Neuroblastoma/drug therapy , Neuroblastoma/therapy , Neuroblastoma/mortality , Neuroblastoma/pathology , Female , Male , Child, Preschool , Infant , Child , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Japan/epidemiology , Prospective Studies , Survival Rate , Adolescent , Induction Chemotherapy , Etoposide/administration & dosage , Follow-Up Studies , Vincristine/administration & dosage , Vincristine/therapeutic use , Combined Modality Therapy , Cyclophosphamide/administration & dosage , Cyclophosphamide/therapeutic use , Prognosis , Doxorubicin/administration & dosage , Doxorubicin/therapeutic use , Melphalan/administration & dosage , Melphalan/therapeutic use , Cisplatin/administration & dosage , Cisplatin/therapeutic use
2.
Jpn J Radiol ; 42(2): 182-189, 2024 Feb.
Article En | MEDLINE | ID: mdl-37874526

PURPOSE: To investigate the dose stability of craniospinal irradiation based on irradiation method of proton beam therapy (PBT). METHODS AND MATERIALS: Twenty-four pediatric and young adult brain tumor patients (age: 1-24 years) were examined. Treatment method was passive-scattered PBT (PSPT) in 8 patients and intensity-modulated PBT (IMPT) in 16 patients. The whole vertebral body (WVB) technique was used in 13 patients whose ages were younger than 10, and vertebral body sparing (VBS) technique was used for the remaining 11 patients aged 10 and above. Dose stability of planning target volume (PTV) against set-up error was investigated. RESULTS: The minimum dose (Dmin) of IMPT was higher than that of PSPT (p = 0.01). Inhomogeneity index (INH) of IMPT was lower than that of PSPT (p = 0.004). When the irradiation field of the cervical spinal cord level (C level) was shifted, the maximum dose (Dmax) was lower in IMPT, and mean dose (Dmean) was higher than PSPT as movement became greater to the cranial-caudal direction (p = 0.000-0.043). Dmin was higher and INH was lower in IMPT in all directions (p = 0.000-0.034). When the irradiation field of the lumber spinal cord level (L level) was shifted, Dmax was lower in IMPT as movement became greater to the cranial direction (p = 0.000-0.028). Dmin was higher and INH was lower in IMPT in all directions (p = 0.000-0.022). CONCLUSIONS: The PTV doses of IMPT and PSPT are robust and stable in both anterior-posterior and lateral directions at both C level and L level, but IMPT is more robust and stable than PSPT for cranial-caudal movements. TRIAL REGISTRY: Clinical Trial Registration number: No. 04-03.


Brain Neoplasms , Craniospinal Irradiation , Proton Therapy , Radiotherapy, Intensity-Modulated , Adolescent , Adult , Child , Child, Preschool , Humans , Infant , Young Adult , Brain Neoplasms/radiotherapy , Craniospinal Irradiation/methods , Organs at Risk/radiation effects , Proton Therapy/methods , Protons , Radiotherapy Dosage , Radiotherapy Planning, Computer-Assisted/methods , Radiotherapy, Intensity-Modulated/methods
3.
Jpn J Radiol ; 41(12): 1331-1334, 2023 Dec.
Article En | MEDLINE | ID: mdl-37440159

Cancer of the adolescent and young adult (AYA) generation has received increasing attention in recent years, however, there were few reports on radiotherapy for this area. As for pediatric cancer, many cancer of the AYA generation were treated with radiation therapy as the multidisciplinary treatment. In this article, we will review reproductive complications, which are considered to be particularly important complications of radiation therapy for AYA generation, and describe investigation of radiation therapy for cancers of the AYA generations at the Hyogo Cancer Center and the Hyogo Ion Beam Medical Center Kobe Proton Center. Germ cells are highly radiosensitive, and even low doses of radiation can cause infertility. Therefore, patients should be treated with sufficient knowledge to prevent fertility. Proton beam therapy for cancer of the AYA generation was useful therapy as pediatric cancer. However, proton beam therapy used less frequently. Insurance coverage, publicity, and access to facilities were considered issues for future study.


Neoplasms , Child , Humans , Adolescent , Young Adult , Neoplasms/radiotherapy , Etoposide , Fertility
5.
Adv Radiat Oncol ; 8(5): 101251, 2023.
Article En | MEDLINE | ID: mdl-37408669

Purpose: This study compared craniospinal irradiation using proton beam therapy (PBT) according to irradiation method and investigated the initial effects. Methods and Materials: Twenty-four pediatric patients (1-24 years old) who received proton craniospinal irradiation were examined. Passive scattered PBT (PSPT) and intensity modulated PBT (IMPT) were used in 8 and 16 patients, respectively. The whole vertebral body technique was used for 13 patients <10 years old, and the vertebral body sparing (VBS) technique was used for the remaining 11 patients aged ≥10 years. The follow-up period was 17 to 44 (median, 27) months. Organ-at-risk and planning target volume (PTV) doses and other clinical data were examined. Results: The maximum lens dose using IMPT was lower than that using PSPT (P = .008). The mean thyroid, lung, esophagus, and kidney doses were lower in patients treated using the VBS technique compared with the whole vertebral body technique (all P < .001). The minimum PTV dose of IMPT was higher than that of PSPT (P = .01). The inhomogeneity index of IMPT was lower than that of PSPT (P = .004). Conclusions: IMPT is better than PSPT at reducing the dose to the lens. The VBS technique can decrease the doses to neck-chest-abdomen organs. The PTV coverage of IMPT is superior to that of PSPT.

6.
J Radiat Res ; 64(Supplement_1): i16-i24, 2023 Jun 16.
Article En | MEDLINE | ID: mdl-37036770

This study aimed to evaluate the efficacy and safety of particle therapy (proton beam therapy and carbon-ion radiotherapy) for esophageal cancer by analyzing prospective nationwide registry data from particle therapy facilities throughout Japan. Patients diagnosed with esophageal cancer who received particle therapy between May 2016 and June 2018 were recruited from the registries of 12 particle therapy centers in Japan. Eventually, we enrolled 174 patients who met the inclusion criteria. Of the 174 patients, 137 (78.7%) were male, with a median age of 69 years (range: 41-88 years). Clinical stages included I (n = 55; 31.6%), II (n = 31; 17.8%), III (n = 82; 47.1%), IV (n = 3; 1.7%) and unknown (n = 3; 1.7%) (Union for International Cancer Control, seventh edition), and the median follow-up period was 908 days (range: 76-1669 days) for all patients. The 3-year overall survival (OS) rate, the 3-year progression-free survival (PFS) rate and the 3-year local control (LC) rates were 60.5, 53.2 and 72.7%, respectively. For each clinical stage, the 3-year OS rates were I, 84.8%; II, 60.3% and III, 42.9%; the 3-year PFS rates were I, 71.9%; II, 58.3% and III, 37.0% and the 3-year LC were I, 78.4%; II, 79.8% and III, 65.2%, respectively. Notably, four patients (2.3%) with ≥Grade 3 cardiopulmonary toxicities were observed (Common Terminology Criteria for Adverse Events, version 5.0). Our study showed that particle therapy for esophageal cancer has lower rates of adverse cardiopulmonary events than X-ray radiotherapy.


Carcinoma, Non-Small-Cell Lung , Esophageal Neoplasms , Lung Neoplasms , Proton Therapy , Humans , Male , Adult , Middle Aged , Aged , Aged, 80 and over , Female , Prospective Studies , Carcinoma, Non-Small-Cell Lung/radiotherapy , Proton Therapy/adverse effects , Esophageal Neoplasms/radiotherapy , Lung Neoplasms/radiotherapy
7.
J Immunol ; 210(8): 1086-1097, 2023 04 15.
Article En | MEDLINE | ID: mdl-36883861

Fatty acid-binding protein 4 (FABP4) is a critical immune-metabolic modulator, mainly expressed in adipocytes and macrophages, secreted from adipocytes in association with lipolysis, and plays essential pathogenic roles in cardiovascular and metabolic diseases. We previously reported Chlamydia pneumoniae infecting murine 3T3-L1 adipocytes and causing lipolysis and FABP4 secretion in vitro. However, it is still unknown whether C. pneumoniae intranasal lung infection targets white adipose tissues (WATs), induces lipolysis, and causes FABP4 secretion in vivo. In this study, we demonstrate that C. pneumoniae lung infection causes robust lipolysis in WAT. Infection-induced WAT lipolysis was diminished in FABP4-/- mice or FABP4 inhibitor-pretreated wild-type mice. Infection by C. pneumoniae in wild-type but not FABP4-/- mice induces the accumulation of TNF-α- and IL-6-producing M1-like adipose tissue macrophages in WAT. Infection-induced WAT pathology is augmented by endoplasmic reticulum (ER) stress/the unfolded protein response (UPR), which is abrogated by treatment with azoramide, a modulator of the UPR. C. pneumoniae lung infection is suggested to target WAT and induce lipolysis and FABP4 secretion in vivo via ER stress/UPR. FABP4 released from infected adipocytes may be taken up by other neighboring intact adipocytes or adipose tissue macrophages. This process can further induce ER stress activation and trigger lipolysis and inflammation, followed by FABP4 secretion, leading to WAT pathology. A better understanding of the role of FABP4 in C. pneumoniae infection-induced WAT pathology will provide the basis for rational intervention measures directed at C. pneumoniae infection and metabolic syndrome, such as atherosclerosis, for which robust epidemiologic evidence exists.


Adipose Tissue, White , Chlamydophila Infections , Fatty Acid-Binding Proteins , Pneumonia, Bacterial , Animals , Mice , Adipose Tissue, White/pathology , Chlamydophila pneumoniae , Fatty Acid-Binding Proteins/metabolism , Lung/microbiology , Lung/pathology , Chlamydophila Infections/pathology , Pneumonia, Bacterial/pathology
8.
Oncol Lett ; 24(6): 452, 2022 Dec.
Article En | MEDLINE | ID: mdl-36380878

Infantile fibrosarcoma (IFS) commonly harbors ETS variant transcription factor 6 (ETV6)-neurotrophic receptor tyrosine kinase 3 (NTRK3) fusion. However, the recent accessibility to clinical next-generation sequencing (NGS) has revealed ETV6-NTRK3 negative spindle cell sarcomas resembling IFS morphologically, involving NTRK1/2, MET, RET and BRAF. The present report describes a pediatric case of spindle cell sarcoma with KIAA1549-BRAF resembling IFS morphologically. A 20-month-old female patient was referred to Kobe Children's Hospital (Kobe, Japan) for the treatment of intrathoracic spindle cell sarcoma. Pathologically, the intrathoracic tumor cells were composed of spindle cells with focal hemagiopericytomatous pattern. In immunohistochemistry analysis, the intrathoracic tumor cells focally expressed desmin and WT-1 and were negative for pan-tropomyosin receptor kinase (TRK), S-100 and CD34. Fluorescence in situ hybridization analysis for ETV6 and capicua transcriptional repressor revealed negative split signals. Although the patient was initially diagnosed with IFS morphologically, KIAA1549-BRAF fusion transcript was detected by comprehensive genomic profiling with NGS using intrathoracic tumor tissues and confirmed by reverse transcription-PCR. Chemotherapy induced a reduction in the tumor size. At present, the patient is alive with the disease and has been receiving therapy for 8 months since the initiation of chemotherapy. Review of BRAF-altered spindle cell sarcomas resembling IFS morphologically revealed the inconsistency in immunohistochemical expression patterns and the diversity of BRAF fusion genes and mutations. Therefore, the elucidation of genomic profiling by NGS may assist in making an appropriate diagnosis and selecting novel alternative therapies in ETV6-NTRK3-negative spindle cell sarcomas resembling IFS morphologically.

9.
Jpn J Clin Oncol ; 52(5): 486-492, 2022 May 05.
Article En | MEDLINE | ID: mdl-35137156

BACKGROUND: In Japan, allogeneic hematopoietic stem cell transplantation is widely performed for recurrent neuroblastomas. This retrospective study aimed to investigate the prognosis of recurrent neuroblastoma in Japan and explore the effectiveness of allogeneic hematopoietic stem cell transplantation. METHODS: Clinical characteristics and data on the treatment of patients with high-risk neuroblastoma who experienced first progression between 2003 and 2010 after attaining complete remission or partial remission were collected from hospitals participating in the Japanese Neuroblastoma Research Group. RESULTS: Data from 61 patients who fulfilled these criteria were collected. The median interval from disease onset to first progression was 19 months (range, 7-65 months), whereas the median observation time of the surviving patients was 18 months (range, 1-69 months). All patients were treated with chemotherapy, where 22 and 3 patients received allogeneic and autologous hematopoietic stem cell transplantation, respectively. Seven patients were alive in second complete remission, and 39 died, including two in complete remission. The 3-year progression-free survival and overall survival rates were 15.3% (SE: 6.1%) and 16.9% (SE: 6.5%), respectively. For patients with allogeneic hematopoietic stem cell transplantation, the 3-year progression-free survival and overall survival were 28.3% (standard error, 12.0%) and 24.3% (standard error, 11.5%), respectively, and for patients without allogeneic hematopoietic stem cell transplantation, the 3-year progression-free survival and overall survival were 6.0% (standard error 5.5%) and 12.0% (standard error 7.6%), respectively. The duration of initial remission (≥ 18 months) and implementation of allogeneic hematopoietic stem cell transplantation were independently predictive of progression-free survival (P = 0.002 and P = 0.017), whereas for overall survival, only allogeneic hematopoietic stem cell transplantation was predictive (P = 0.012). CONCLUSION: Although allogeneic hematopoietic stem cell transplantation contributed to some improvement in prognosis, it was insufficient.


Hematopoietic Stem Cell Transplantation , Neuroblastoma , Child , Humans , Japan/epidemiology , Neoplasm Recurrence, Local/therapy , Neuroblastoma/therapy , Retrospective Studies , Transplantation, Autologous , Treatment Outcome
11.
Cancer Med ; 11(6): 1502-1510, 2022 03.
Article En | MEDLINE | ID: mdl-35137555

INTRODUCTION: This study aimed to evaluate acute toxicities associated with irradiation between the X-CSI (photon beam craniospinal irradiation) and P-CSI (proton beam craniospinal irradiation) groups in children with brain tumors. METHODS: Sixty-two consecutive patients who received initial craniospinal irradiation (CSI) for brain tumors in our center between January 1, 2011 and May 31, 2021, were included in the study. Acute toxicities were retrospectively evaluated during CSI using Common Terminology Criteria for Adverse Events version 5.0. Maximum grades of fatigue, headache, insomnia, nausea, vomiting, dermatitis, constipation, abdominal pain, oropharyngeal mucositis, and hematological toxicities were evaluated. RESULTS: Thirty-six patients received X-CSI, and 26 patients received P-CSI. The median dose of CSI was 18.0 Gy in the X-CSI group and 23.4 Gy (relative biological effectiveness) in the P-CSI group (p < 0.001). The P-CSI group had a lower incidence of more than grade 2 nausea (11.5% vs. 69.4%, p = 0.008) and vomiting (7.7% vs. 38.8%, p < 0.001), compared with the X-CSI group. Multivariate logistic regression analysis with adjustments for potential confounding factors of doses of CSI showed that proton radiation therapy was associated with a marked reduced risk of more than grade 2 nausea and vomiting during CSI (adjusted odds ratio, 0.050; 95% confidential interval, 0.011-0.24; p < 0.001). CONCLUSION: The present study suggests that P-CSI reduces the acute gastrointestinal toxicities associated with irradiation.


Brain Neoplasms , Craniospinal Irradiation , Proton Therapy , Brain Neoplasms/drug therapy , Child , Craniospinal Irradiation/adverse effects , Humans , Nausea/etiology , Proton Therapy/adverse effects , Protons , Radiotherapy Dosage , Retrospective Studies , Vomiting/etiology
12.
Int J Clin Oncol ; 27(2): 281-300, 2022 Feb.
Article En | MEDLINE | ID: mdl-35022887

The Japan Society of Clinical Oncology (JSCO) published the "JSCO Clinical Practice Guidelines 2017 for Fertility Preservation in Childhood, Adolescent, and Young Adult Cancer Patients" in 2017. This was the first guideline in cancer reproductive medicine in Japan. In the field of cancer reproductive medicine, close cooperation between an oncologist and a physician for reproductive medicine is important from before treatment initiation until long after treatment. The guideline takes into consideration disease specificity and provides opinions from the perspective of oncologists and specialists in reproductive medicine that are in line with the current state of the Japanese medical system. It is intended to serve as a reference for medical staff in both fields regarding the availability of fertility preservation therapy before the start of cancer treatment. Appropriate use of this guideline makes it easier to determine whether fertility preservation therapy is feasible and, ultimately, to improve survivorship in childhood, adolescent, and young adult cancer patients. In this article (Part 2), we describe details by organ/system and also for pediatric cancer.


Fertility Preservation , Neoplasms , Oncologists , Adolescent , Child , Humans , Japan , Medical Oncology , Neoplasms/therapy , Young Adult
13.
Int J Clin Oncol ; 27(2): 265-280, 2022 Feb.
Article En | MEDLINE | ID: mdl-34973107

In 2017, the Japan Society of Clinical Oncology (JSCO) published the JSCO Clinical Practice Guidelines 2017 for Fertility Preservation in Childhood, Adolescent, and Young Adult Cancer Patients. These were the first Japanese guidelines to address issues of oncofertility. In this field of medicine, sustained close cooperation between oncologists and reproductive specialists is essential from the diagnosis of cancer until many years after completion of cancer treatment. These JSCO guidelines were intended to guide multidisciplinary medical staff in considering the availability of fertility preservation options and to help them decide whether to provide fertility preservation to childhood, adolescent, and young adult cancer patients before treatment starts, with the ultimate goal of improving patient survivorship. The guidelines are presented as Parts 1 and 2. This article (Part 1) summarizes the goals of the guidelines and the methods used to develop them and provides an overview of fertility preservation across all oncology areas. It includes general remarks on the basic concepts surrounding fertility preservation and explanations of the impacts of cancer treatment on gonadal function by sex and treatment modality and of the options for protecting/preserving gonadal function and makes recommendations based on 4 clinical questions. Part 2 of these guidelines provides specific recommendations on fertility preservation in 8 types of cancer (gynecologic, breast, urologic, pediatric, hematologic, bone and soft tissue, brain, and digestive).


Fertility Preservation , Neoplasms , Oncologists , Adolescent , Child , Female , Humans , Japan , Medical Oncology , Neoplasms/therapy , Young Adult
14.
J Pediatr Hematol Oncol ; 44(8): 465-470, 2022 11 01.
Article En | MEDLINE | ID: mdl-35091519

Poorly differentiated chordoma (PDC) is a rare, aggressive subtype of chordoma. A two-year-old girl presented with cervical pain, limb paralysis and respiratory failure. Magnetic resonance imaging and positron emission tomography-computed tomography revealed a tumor compressing the pons at the clivus and osteoblastic metastatic lesions of the left upper arm and right iliac bone. Her tumors shrank substantially after treatment with chemotherapy and proton beam therapy. Our initial diagnosis was an atypical teratoma/rhabdoid tumor, but final diagnosis of PDC was made on the basis of the immunohistochemical expression of brachyury. In addition, the detection of SMARCB1/INI1 mutation confirmed the diagnosis of PDC.


Chordoma , Neuroblastoma , Rhabdoid Tumor , Teratoma , Female , Child , Humans , Child, Preschool , Chordoma/genetics , Chordoma/diagnosis , SMARCB1 Protein/genetics , Rhabdoid Tumor/diagnosis , Cranial Fossa, Posterior/metabolism , Biomarkers, Tumor
15.
Neuro Oncol ; 24(4): 503-515, 2022 04 01.
Article En | MEDLINE | ID: mdl-34671804

Primary CNS germ cell tumors (GCTs) are rare neoplasms predominantly observed in the pediatric and young adult populations. In line with the hypothesis that the primordial germ cell is the cell-of-origin, histopathological examinations for this pathology involve a diverse range of components mirroring the embryogenic developmental dimensions. Chemotherapy and radiotherapy are the mainstays of treatment, with surgery having a limited role for diagnosis and debulking of residual tissue after treatment. While better management has been achieved over recent decades by modifying radiation coverage and selecting appropriate chemotherapy, standardization of treatment remains challenging, partly due to the low volume of cases encountered in each institution. As the incidence is higher in East Asia, including Japan, the Japan Society for Neuro-Oncology established a multidisciplinary task force to create an evidence-based guideline for CNS GCTs. This guideline provides recommendations for multiple dimensions of clinical management for CNS GCTs, with particular focus on diagnostic measures including serum markers, treatment algorithms including surgery, radiotherapy, and chemotherapy, and under-investigated but important areas such as treatment for recurrent cases, long-term follow-up protocols, and long-term sequelae. This guideline serves the purpose of helping healthcare professionals keep up to date with current knowledge and standards of management for patients with this rare disease in daily clinical practice, as well as driving future translational and clinical research by recognizing unmet needs concerning this tumor.


Central Nervous System Neoplasms , Neoplasms, Germ Cell and Embryonal , Central Nervous System/pathology , Central Nervous System Neoplasms/diagnosis , Central Nervous System Neoplasms/epidemiology , Central Nervous System Neoplasms/therapy , Child , Combined Modality Therapy , Humans , Japan/epidemiology , Neoplasms, Germ Cell and Embryonal/diagnosis , Neoplasms, Germ Cell and Embryonal/therapy , Young Adult
16.
Pract Radiat Oncol ; 12(3): 226-235, 2022.
Article En | MEDLINE | ID: mdl-34801769

PURPOSE: The purpose of this study is to improve the placement of a hydrogel spacer in patients with prostate cancer receiving radiation therapy. METHODS AND MATERIALS: A total of 160 patients with prostate cancer were classified into 3 groups: No spacer (group 1; n = 30), spacer placed using conventional technique (group 2; n = 100), and spacer placed using new technique (group 3; n = 30). When placing the spacer, the tip of the needle is placed at the middle of the prostate gland (group 2), or at a level corresponding to a cranial:caudal ratio of 6:4 and as close to the prostate gland as possible (group 3). The separation effect was examined and compared among the groups. RESULTS: The separation in group 2 was larger than that in group 1 from the base to the apex level of the prostate (4 mm), but the separation in group 3 was larger than that in group 2 from the middle to the apex level of the prostate (4 mm). The separation values for the middle to the apex, the spacer thickness from the apex level to the apex (10 mm), the rectal exclusion from the middle to the apex, and the laterality were correlated with the 50 and 60 Gy relative biologic effectiveness (Gy[RBE]) rectal dose (P = 4.1 × 10-9 - .046). The separation vales were strongly correlated with the spacer thickness at the apex (10 mm) and the apex (4 mm; P = 1.1 × 10-18 - 1.8 × 10-17). The rectal volumes at 10 to 60 Gy(RBE) differed among the groups (P = 5.1 × 10-19 - 5.4 × 10-3). The rectal volumes in group 2 were smaller than those in group 1 at all dose levels, but those in group 3 were smaller than those in group 2 at dose levels of 30 to 50 Gy(RBE). CONCLUSIONS: The separation, spacer thickness, and rectal exclusion from the middle to the apex of the prostate and the laterality of the hydrogel spacer affected the reduction in the rectal dose. The rectal dose can be further reduced by implanting a spacer on the caudal and prostate side.


Hydrogels , Prostatic Neoplasms , Humans , Hydrogels/therapeutic use , Male , Prostate , Prostatic Neoplasms/radiotherapy , Radiotherapy Dosage , Rectum/radiation effects
17.
Mol Clin Oncol ; 16(1): 25, 2022 Jan.
Article En | MEDLINE | ID: mdl-34909203

The aim of the present study was to investigate the effects on the dose distribution and beam delivery time in spot scanning proton beam therapy (PBT) incorporating the spot deletion technique. A spot scanning plan was created for 30 patients with prostate cancer. The plan was then modified via two processes: Spots with lower weighting depositions were deleted (process A) and spots that were distant from the clinical target volume (CTV) were deleted (process B). The dose distribution to the organs at risk (OAR), the expanded CTV (exCTV), which was defined by a uniform expansion of the CTV by a radius of 5 mm, and the beam delivery time were compared among initial and modified plans. The V50 Gy [relative biological effectiveness (RBE)] to the rectum and bladder, and V60 Gy(RBE) to the urethral bulb, inhomogeneity index (INH) of the exCTV showed a difference (P=1.1x10-14, P=6.4x10-14, P=2.7x10-7, P=3.2x10-17), although only changes by process B were significant. Modified plan by process B showed the V50 Gy(RBE) to the rectum and bladder decreased by -2.4±1.6 and -2.3±1.4%, and the V60 Gy (RBE) to the urethral bulb decreased by -15.9±19.4%. The INH of the exCTV increased by 0.05±0.03%. On the other hand, modification of the initial plan by process A did not affect the dose of the OAR, exCTV or beam delivery time. In spot scanning PBT, modification of the initial radiotherapy plan by systemic deletion of spots distant from the CTV could result in a dose reduction to the OAR.

18.
Oncol Lett ; 22(2): 635, 2021 Aug.
Article En | MEDLINE | ID: mdl-34295382

The present study simulated the effect of spot-scanning proton beam therapy (PBT) performed using a device equipped with a multi-leaf collimator (MLC) to calculate the dose distribution. Simulation studies using 18 pediatric patients with brain tumors in the posterior fossa were performed. Treatment plans were created for the MLC at different stages: Fully open (initial plan), fully closed to allow an irradiated area extending to 15 mm from the clinical target volume (CTV) (15-mm plan), or closing only the leaves where an organ at risk (OAR) overlapped with a border at 10 or 5 mm from the CTV (10- and 5-mm plans, respectively). The mean dose values for the brainstem, cervical cord, brain and cochlea in all MLC closure plans decreased as the MLC was closed (P=9.9×10-10, P=1.3×10-17, P=2.1×10-16 and P=2.0×10-5, respectively). The maximum dose (Dmax) values of the cervical cord and cochlea in all MLC closure plans were also decreased as the MLC was closed (P=3.0×10-4 and P=1.1×10-5, respectively). The dose to the CTV was almost unchanged. In 10 patients, the Dmax of the brain in all MLC-closure plans was higher than that of the initial plan, but the maximum increase was only 0.8 gray relative biological effectiveness [Gy(RBE)]. In conclusion, the existing MLC installed in the treatment device can be used to decrease the OAR dose significantly using spot-scanning PBT without a large capital investment. The dose from the scattered particles was small.

19.
J Radiat Res ; 62(5): 877-883, 2021 Sep 13.
Article En | MEDLINE | ID: mdl-34230962

We attempted to re-evaluate the efficacy of prophylactic cranial irradiation (PCI) in limited-stage small cell lung cancer (LS-SCLC) with more recent data. A total of 179 patients with LS-SCLC received radical thoracic radiotherapy and chemotherapy at our institution between 1998 and 2018. One hundred twenty-eight patients who achieved complete response (CR), good partial response (PR), and PR without progression for at least for one year after initial therapy were enrolled in this study. These patients were divided into a PCI group (group A, n = 43), and a non-PCI group (group B, n = 85). Survival outcomes were retrospectively evaluated. Because several background factors differed significantly between groups A and B, propensity score (PS) matching was performed as 1:1 match of the two groups. Finally, we analyzed 64 patients (group A/B = 32/32). Median follow-up periods were 53 and 31 months in groups A and B, respectively. There were no significant differences between the groups' backgrounds. Two-year overall survival (OS) rates were 77% in group A and 62% in group B (p = 0.224). Two-year brain metastasis free survival (BMFS) rates were 85% in group A and 57% in group B (p = 0.008). The number of patients who underwent a brain imaging test for confirmation of no brain metastasis (BM) after radical thoracic radiotherapy and chemotherapy (before PCI) was 84 (group A/B = 32/52). A PS matched analysis for cases of pre-PCI brain imaging group, two-year OS rates for group A/B were 73/59% (p = 0.446). Two-year BMFS rates for group A/B were 91/52% (p = 0.021). Retrospectively, PS matched analysis revealed that adding PCI to LS-SCLC patients who achieved good thoracic control significantly improved BMFS, but OS did not improve.


Brain Neoplasms/secondary , Cranial Irradiation/methods , Lung Neoplasms/pathology , Small Cell Lung Carcinoma/secondary , Aged , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Brain Neoplasms/prevention & control , Combined Modality Therapy , Disease Progression , Female , Follow-Up Studies , Humans , Kaplan-Meier Estimate , Lung Neoplasms/drug therapy , Lung Neoplasms/radiotherapy , Male , Middle Aged , Neoplasm Staging , Progression-Free Survival , Propensity Score , Small Cell Lung Carcinoma/pathology , Small Cell Lung Carcinoma/prevention & control , Small Cell Lung Carcinoma/therapy , Treatment Outcome
20.
Cureus ; 13(4): e14627, 2021 Apr 22.
Article En | MEDLINE | ID: mdl-34055504

Background This study was conducted to evaluate late toxicities in adolescent and young adult (AYA) patients who received photon or proton therapy. Methodology A total of 106 AYA patients who received proton and photon therapy and were followed-up for more than two years were retrospectively evaluated. The median age of patients was 22 years (range, 15-29 years). A total of 47 patients were male and 59 were female. A total of 35 and 71 patients received photon and proton therapy, respectively. All but one patient received radiotherapy with curative intent. The target disease was benign and malignant in 28 and 78 patients, respectively. Results The median follow-up period in all patients was 62 months (range: 24-293 months). Grade 3 or higher toxicity was observed in 20 patients. There was one case of grade 5 toxicity (myelodysplastic syndrome), which was probably due to chemotherapy. No other secondary cancers were observed. Regarding life events, 15 and 88 patients were married and unmarried at the start of radiotherapy, respectively. Of the 88 unmarried patients, five were married after radiotherapy. Occupation and education were evaluated in 71 patients. Of the 71 patients, 33 were students, 21 were employed, and 16 were unemployed. Of the 33 students, eight were employed and 11 were at a higher educational grade after radiotherapy. Of the 21 employed patients, 17 had the same jobs and four had lost their jobs after radiotherapy. For the 16 unemployed patients, all remained unemployed. Conclusions This study is one of the largest studies to focus on life after radiation therapy among AYAs and suggests that cancer treatment has an influence on life events.

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