What motivated medical students and residents to become radiation oncologists in Japan?—Questionnaire report by the radiotherapy promotion committee of JASTRO

This study aimed to clarify the motivations and timing of the decision to become radiation oncologists. Materials and methods: We conducted an online survey for new members of the Japanese Society for Radiation Oncology (JASTRO). Results: The response rate was 43.3%. Data of the 79 respondents who wanted to obtain a board-certification of JASTRO were analysed. We divided the respondents into two groups: Group A, those who entered a single radiation oncology department, and Group B, those who joined a radiology department in which the radiation oncology department and diagnostic radiology department were integrated. The most common period when respondents were most attracted to radiation oncology was “5th year of university” in Group A and “2nd year of junior residency” and “senior residency” in Group B. Furthermore, 79.5% of Group A and 40% of Group B chose periods before graduation from a university with a significant difference. The most common period when respondents made up their minds to become radiation oncologists was “2nd year of junior residency” in both groups. Internal medicine was the most common department to consider if they did not join the radiation oncology or radiology department. Conclusion: To increase the radiation oncologists, it is crucial to enhance clinical training in the fifth year of university for Group A and to continue an active approach to maintain interest in radiation oncology until the end of junior residency. In Group B facilities, it is desirable to provide undergraduates more opportunities to come in contact with radiation oncology

Leptomeningeal Metastases in a Patient with Castration-Resistant Prostate Cancer

A 42-year-old man visited a community hospital with chief complaints of lumbago and dyschesia. Computed tomography (CT) showed multiple lung, lymph node, and bone metastases and the irregular enlarged prostate with urinary bladder invasion. Serum prostate-specific antigen (PSA) was 544.0 ng/mL. Histological evaluation showed adenocarcinoma with the Gleason score 5+4, and the clinical stage was T4N1M1c as an initial diagnosis. Although androgen deprivation therapy was performed immediately, he had castration-resistant PCa after 3 months. Therefore, he received 6 courses of docetaxel chemotherapy every 3 weeks. Serum PSA was decreased to 0.2 ng/mL, and multiple metastases and prostate size were obviously reduced based on CT. He underwent robot-assisted radical prostatectomy and radiation therapy for prostatic fossa and multiple metastases. Although serum PSA level remained low, CT showed multiple liver metastases after 3 years from surgery. He received the combination therapy of cisplatin and etoposide (PE) every 4 weeks. Liver metastases had complete response. However, he visited our hospital with complaint of vomiting and a right drooping eyelid after 6 weeks from withdrawal of PE therapy. T2-weighted magnetic resonance imaging revealed multiple leptomeningeal metastases (LM). He received RT for the brain and was administered amrubicin. However, he died of PCa after 6 weeks from the diagnosis of LM

Preliminary Results from a Multi-center Prospective Study (JROSG 05-5) on Postoperative Radiotherapy for Patients with High-risk Ductal Carcinoma in situ with Involved Margins or Margin Widths 1 mm or less than

Abstract Purpose: This prospective study aimed to evaluate the effectiveness of postoperative radiotherapy (PORT) consisting of whole breast irradiation followed by boost irradiation in patients with high-risk ductal carcinoma in situ (DCIS) with margin widths less than 1 mm. Materials and Methods: A multi-center phase II study (Japanese Radiation Oncology Study Group: JROSG 05-5) was conducted to evaluate the effectiveness of PORT. PORT consisted of whole breast irradiation (50 Gy/25 fractions) followed by boost irradiation (10 Gy/5 fractions) using electron beams for patients with high-risk DCIS. Eligibility criteria were as follows: 1) DCIS without an invasive carcinoma component, 2) age between 20 and 80 years, 3) involved margins or margin widths less than 1 mm, 4) refusal of re-resection, 5) performance status of 0−2, and 6) written informed consent. The primary endpoint was ipsilateral breast tumor recurrence (IBTR), and secondary endpoints were overall survival, relapse-free survival, recurrence patterns, and adverse events. Conclusions: Our preliminary results suggest that this PORT schedule may be promising for patients with high-risk DCIS. However, to make any definitive conclusions, a longer follow-up time is required

The potential failure risk of the cone-beam computed tomography-based planning target volume margin definition for prostate image-guided radiotherapy based on a prospective single-institutional hybrid analysis

Abstract Background The purpose of this study was to evaluate the impact of markerless on-board kilovoltage (kV) cone-beam computed tomography (CBCT)-based positioning uncertainty on determination of the planning target volume (PTV) margin by comparison with kV on-board imaging (OBI) with gold fiducial markers (FMs), and to validate a methodology for the evaluation of PTV margins for markerless kV-CBCT in prostate image-guided radiotherapy (IGRT). Methods A total of 1177 pre- and 1177 post-treatment kV-OBI and 1177 pre- and 206 post-treatment kV-CBCT images were analyzed in 25 patients who received prostate IGRT with daily localization by implanted FMs. Intrafractional motion of the prostate was evaluated between each pre- and post-treatment image with these two different techniques. The differences in prostate deviations and intrafractional motions between matching by FM in kV-OBI (OBI-FM) and matching by soft tissues in kV-CBCT (CBCT-ST) were compared by Bland-Altman limits of agreement. Compensated PTV margins were determined and compensated by references. Results Mean differences between OBI-FM and CBCT-ST in the anterior to posterior (AP), superior to inferior (SI), and left to right (LR) directions were − 0.43 ± 1.45, − 0.09 ± 1.65, and − 0.12 ± 0.80 mm, respectively, with R2 = 0.85, 0.88, and 0.83, respectively. Intrafractional motions obtained from CBCT-ST were 0.00 ± 1.46, 0.02 ± 1.49, and 0.15 ± 0.64 mm, respectively, which were smaller than the results from OBI-FM, with 0.43 ± 1.90, 0.12 ± 1.98, and 0.26 ± 0.80 mm, respectively, with R2 = 0.42, 0.33, and 0.16, respectively. Bland-Altman analysis showed a significant proportional bias. PTV margins of 1.5 mm, 1.4 mm, and 0.9 mm for CBCT-ST were calculated from the values of CBCT-ST, which were also smaller than the values of 3.15 mm, 3.66 mm, and 1.60 mm from OBI-FM. The practical PTV margin for CBCT-ST was compensated with the values from OBI-FM as 4.1 mm, 4.8 mm, and 2.2 mm. Conclusions PTV margins calculated from CBCT-ST might be underestimated compared to the true PTV margins. To determine a reliable CBCT-ST-based PTV margin, at least the systemic error Σ and the random error σ for on-line matching errors need to be investigated by supportive preliminary FM evaluation at least once

Analysis of the relationship between prescribed dose and dosimetric advantage of real-time intraoperatively built custom-linked seeds in iodine-125 prostate brachytherapy

Abstract Background The purpose of this study was to investigate the differences in the dosimetric advantage of using intraoperatively built custom-linked (IBCL) seeds between permanent iodine-125 (I-125) seed implantation (PI) alone and PI followed by external-beam radiation therapy (EBRT) for prostate cancer. Methods We reviewed the records of 62 patients with localized prostate cancer who received transperineal interstitial brachytherapy with I-125 using free seeds or IBCL seeds. Twenty-four low- and intermediate-risk patients underwent PI alone with the prescribed dose of 160 Gy, and 39 high-risk patients underwent PI with 110 Gy, followed by EBRT with 45 Gy (PI + EBRT). Intraoperative and post-implant dosimetric parameters 1 month after implantation were collected and analyzed. Results The numbers of patients implanted with free seeds and IBCL seeds were 14 (58.3%) and 10 (41.7%), respectively, in the PI group and 25 (65.8%) and 13 (34.2%), respectively, in the PI + EBRT group. In the PI group, although there were significant differences in prostate V100 (p = 0.003) and D90 (p = 0.009) and rectum V100 (p = 0.026) on intraoperative dosimetry, these differences were not found on post-implant dosimetry. In the PI + EBRT group, the dosimetric parameters of IBCL seeds, such as prostate V200 (p = 0.013) and V250 (p = 0.010) and urethra D30 (p = 0.038), were better than those of free seeds on intraoperative dosimetry. Furthermore, even on post-implant dosimetry, prostate D90 (p = 0.004), V150 (p = 0.001), and homogeneity index (HI, p = 0.001), as well as V200 (p = 0.001) and V250 (p = 0.020), and urethra D5 (p = 0.008) as well as D30 (p = 0.003) had a better dosimetric quality in IBCL seeds than in free seeds. There was no significant difference in the operation time between free seeds and IBCL seeds in each PI and PI + EBRT group. Conclusions Our results reveal that greater dosimetric benefits could be obtained using IBCL seeds in the case of permanent implantation with a lower prescribed dose, such as PI + EBRT, rather than PI alone

Preliminary Results from a Multi-center Prospective Study (JROSG 05-5) on Postoperative Radiotherapy for Patients with High-risk Ductal Carcinoma in situ with Involved Margins or Margin Widths 1 mm or less than

Purpose: This prospective study aimed to evaluate the effectiveness of postoperative radiotherapy (PORT) consisting of whole breast irradiation followed by boost irradiation in patients with high-risk ductal carcinoma in situ(DCIS) with margin widths less than 1mm.Materials and Methods:A multi-center phase II study (Japanese Radiation Oncology Study Group: JROSG 05-5) was conducted to evaluate the effectiveness of PORT. PORT consisted of whole breast irradiation (50Gy/25 fractions) followed by boost irradiation (10Gy/5 fractions) using electron beams for patients with high-risk DCIS. Eligibility criteria were as follows:1)DCIS without an invasive carcinoma component, 2)age between 20 and 80 years, 3) involved margins or margin widths less than 1 mm, 4) refusal of re-resection, 5) performance status of 0−2, and 6) written informed consent. The primary endpoint was ipsilateral breast tumor recurrence (IBTR), and secondary endpoints were overall survival, relapse free survival, recurrence patterns, and adverse events