The current state and future perspectives of radiotherapy for cervical cancer.

Radiotherapy is an effective treatment method for cervical cancer and is typically administered as external beam radiotherapy followed by intracavitary brachytherapy. In Japan, center shielding is used in external beam radiotherapy to shorten treatment time and reduce the doses delivered to the rectum or bladder. However, it has several challenges, such as uncertainties in calculating the cumulative dose. Recently, external beam radiotherapy has been increasingly performed with intensity-modulated radiotherapy, which reduces doses to the rectum or bladder without center shielding. In highly conformal radiotherapy, uncertainties in treatment delivery, such as inter-fractional anatomical structure movements, affect treatment outcomes; therefore, image-guided radiotherapy is essential for appropriate and safe performance. Regarding intracavitary brachytherapy, the use of magnetic resonance imaging-based image-guided adaptive brachytherapy is becoming increasingly widespread because it allows dose escalation to the tumor and accurately evaluates the dose delivered to the surrounding normal organs. According to current evidence, a minimal dose of D90% of the high-risk clinical target volume is significantly relevant to local control. Further improvements in target coverage have been achieved with combined interstitial and intracavity brachytherapy for massive tumors with extensive parametrical involvement. Introducing artificial intelligence will enable faster and more accurate generation of brachytherapy plans. Charged-particle therapies have biological and dosimetric advantages, and current evidence has proven their effectiveness and safety in cervical cancer treatment. Recently, radiotherapy-related technologies have advanced dramatically. This review provides an overview of technological innovations and future perspectives in radiotherapy for cervical cancer.

Evaluation of alterations in interstitial fluid dynamics in cases of whole-brain radiation using the diffusion-weighted image analysis along the perivascular space method.

In the current study, we assessed changes in interstitial fluid dynamics resulting after whole-brain radiotherapy using the diffusion-weighted image analysis along the perivascular space (DWI-ALPS) method, which is a simplified variation of the diffusion tensor image ALPS (DTI-ALPS) method using diffusion-weighted imaging (DWI) with orthogonal motion-probing gradients (MPGs). This retrospective study included 47 image sets from 22 patients who underwent whole-brain radiotherapy for brain tumors. The data for the normal control group comprised 105 image sets from 105 participants with no pathological changes. DWI was performed with the three MPGs applied in an orthogonal direction to the imaging plane, and apparent diffusion coefficient images for the x-, y-, and z-axes were retrospectively generated. The ALPS index was calculated to quantify interstitial fluid dynamics. The independent t-test was used to compare the ALPS index between normal controls and patients who underwent whole-brain radiotherapy. Patients were compared in all age groups and individual age groups (20-39, 40-59, and 60-84 years). We also examined the correlation between biologically equivalent doses (BEDs) and the ALPS index, as well as the correlation between white matter hyperintensity and the ALPS index. In the comparison of all age groups, the ALPS index was significantly lower (p < 0.001) in the postradiation group (1.32 ± 0.16) than in the control group (1.44 ± 0.17), suggesting that interstitial fluid dynamics were altered in patients following whole-brain radiotherapy. Significant age group differences were found (40-59 years: p < 0.01; 60-84 years: p < 0.001), along with a weak negative correlation between BEDs (r = -0.19) and significant correlations between white matter hyperintensity and the ALPS index (r = -0.46 for periventricular white matter, r = -0.38 for deep white matter). It was concluded that the ALPS method using DWI with orthogonal MPGs suggest alteration in interstitial fluid dynamics in patients after whole-brain radiotherapy. Further systematic prospective studies are required to investigate their association with cognitive symptoms.

Retrospective non-inferiority study of stereotactic radiosurgery for more than ten brain metastases.

AIM: This study aimed to investigate the clinical benefits of stereotactic radiosurgery (SRS) in patients with > 10 brain metastases (BM) compared to patients with 2-10 BM. METHODS: The study included multiple BM patients who underwent SRS between 2014 and 2022, excluding patients who underwent whole brain radiotherapy, had a Karnofsky Performance Status score < 60, suspected leptomeningeal disease, or a single BM lesion. Patients were divided into two groups (2-10 and > 10 BM groups) and matched 2:1 based on propensity scores. The primary endpoint was overall survival (OS) in the matched dataset, with intracranial progression-free survival (PFS) as the secondary endpoint. Non-inferiority was established if the upper limit of the 95% confidence interval (CI) of the adjusted hazard ratio was below 1.3. RESULTS: Of the 1042 patients identified, 434 met eligibility criteria. After propensity score matching, 240 patients were analyzed (160 in the BM 2-10 group and 80 in the > 10 BM group). The median OS was 18.2 months in the 2-10 BM group and 19.4 months in the > 10 BM group (P = 0.60). The adjusted hazard ratio was 0.86 (95% CI: 0.59-1.24), indicating non-inferiority. PFS was not significantly different between the groups (4.8 months vs. 4.8 months, P = 0.94). The number of BM did not significantly impact OS or PFS. CONCLUSIONS: SRS for selected patients with > 10 BM was non-inferior in terms of OS compared to those with 2-10 BM in a propensity score-matched dataset.

Iodinated Contrast Media Substitution to Prevent Recurrent Hypersensitivity Reactions: A Systematic Review and Meta-Analysis.

Background Changing iodinated contrast media (ICM) may reduce the risk of recurrent ICM-induced hypersensitivity reactions in patients with a prior reaction. Purpose To perform a systematic review on the effectiveness of ICM change in comparison with no change to prevent recurrent ICM immediate hypersensitivity reactions. Materials and methods Multiple data bases were searched without language restriction between January 1990 and August 2021 to identify comparative studies of any design that included patients with a prior ICM hypersensitivity reaction to low-osmolality ICM and re-exposure to intravascular ICM. The methods used included a duplicate assessment of eligibility, double extraction of quantitative data, validity assessment, and random-effects meta-analysis. The primary outcome was the incidence of all-grade immediate recurrent hypersensitivity reactions. Secondary outcomes were the incidence of severe immediate recurrent hypersensitivity reactions and other adverse events associated with ICM change. Results Six retrospective observational studies at moderate to severe risk of bias assessed 7155 adult patients (4329 in the ICM change group and 2826 in the no-change group). Studies adopted nonstandardized switching methods, and the proportions of the ICM change group ranged between 19% (five of 27 examinations) and 80% (3104 of 3880 examinations). A Bayesian meta-analysis revealed that changing ICM was associated with a reduced risk of recurrent hypersensitivity reaction by 61% (risk ratio = 0.39; 95% credible interval [CrI]: 0.24, 0.58). The wide-ranging estimates of risk reduction were not explained by the risk of bias ratings, the event rates in the no-change group, the index-reaction severity, or the co-administered nonstandard premedication. Rare severe recurrent reactions (five studies with five events) precluded a conclusion (risk ratio = 0.34, favoring ICM change; CrI: 0.01, 3.74). Adverse events associated with ICM change were not reported. Conclusion In observational evidence of limited quality, iodinated contrast media (ICM)-change was associated with a reduced risk of recurrent immediate hypersensitivity reaction in patients with a prior ICM-induced hypersensitivity reaction. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by McDonald in this issue.

Development of a high-resolution two-dimensional detector-based dose verification system for tumor-tracking irradiation in the CyberKnife system.

We aim to evaluate the basic characteristics of SRS MapCHECK (SRSMC) for CyberKnife (CK) and establish a dose verification system using SRSMC for the tumor-tracking irradiation for CK. The field size and angular dependence of SRSMC were evaluated for basic characterization. The output factors (OPFs) and absolute doses measured by SRSMC were compared with those measured using microDiamond and microchamber detectors and those calculated by the treatment planning system (TPS). The angular dependence was evaluated by comparing the SRSMC with a microchamber. The tumor-tracking dose verification system consists of SRSMC and a moving platform. The doses measured using SRSMC were compared with the doses measured using a microchamber and radiochromic film. The OPFs and absolute doses of SRSMC were within ±3.0% error for almost all field sizes, and the angular dependence was within ±2.0% for all incidence angles. The absolute dose errors between SRSMC and TPS tended to increase when the field size was smaller than 10 mm. The absolute doses of the tumor-tracking irradiation measured using SRSMC and those measured using a microchamber agreed within 1.0%, and the gamma pass rates of SRSMC in comparison with those of the radiochromic film were greater than 95%. The basic characteristics of SRSMC for CK presented acceptable results for clinical use. The results of the tumor-tracking dose verification system realized using SRSMC were equivalent to those of conventional methods, and this system is expected to contribute toward improving the efficiency of quality control in many facilities.

The importance of choosing the right strategy to treat small cell carcinoma of the cervix: a comparative analysis of treatments.

BACKGROUND: Standard treatments for small cell carcinoma of the cervix (SCCC) have not been established. In this study, we aimed to estimate the optimal treatment strategy for SCCC. METHODS: This was a multicenter retrospective study. Medical records of patients with pathologically proven SCCC treated between 2003 and 2016 were retrospectively analyzed. Overall survival (OS) was plotted using the Kaplan-Meier method. Log-rank tests and Cox regression analysis were used to assess the differences in survival according to stage, treatment strategy, and chemotherapy regimen. RESULTS: Data of 78 patients were collected, and after excluding patients without immunohistopathological staining, 65 patients were evaluated. The median age of the included patients was 47 (range: 24-83) years. The numbers of patients with International Federation of Gynecology and Obstetrics (FIGO) 2018 stages I-IIA, IIB-IVA, IVB were 23 (35%), 34 (52%), and 8 (12%), respectively. Of 53 patients who had undergone chemotherapy, 35 and 18 received SCCC and non-SCCC regimens as their first-line chemotherapy regimen, respectively. The 5-year OS for all patients was 49%, while for patients with FIGO stages I-IIA, IIB-IVA, IVB, it was 60, 50, and 0%, respectively. The 5-year OS rates for patients who underwent treatment with SCCC versus non-SCCC regimens were 59 and 13% (p < 0.01), respectively. This trend was pronounced in locally advanced stages. Multivariate analysis showed that FIGO IVB at initial diagnosis was a significant prognostic factor in all patients. Among the 53 patients who received chemotherapy, the SCCC regimen was associated with significantly better 5-year OS in both the uni- and multivariate analyses. CONCLUSION: Our results suggest that the application of an SCCC regimen such as EP or IP as first-line chemotherapy for patients with locally advanced SCCC may play a key role in OS. These findings need to be validated in future nationwide, prospective clinical studies.

Factors Influencing Sitting Ability During the Acute Post-Stroke Phase: A Multicenter Prospective Cohort Study in Japan.

OBJECTIVES: Sitting ability during the acute phase after stroke is a useful indicator of functional outcomes; however, factors that affect this ability have not been evaluated. Therefore, this study aimed to identify and evaluate factors that affect sitting ability in the acute phase after stroke. MATERIALS AND METHODS: This multicenter prospective cohort study included hemispheric stroke patients who underwent an inpatient rehabilitation program after acute stroke from five acute care hospitals. The effect of age, sex, lesion side, etiology, consciousness disorder, stroke and dementia history, stroke-related complications, National Institutes of Health Stroke Scale score, hemiparalysis, turn-over movement from the supine position and sit-up movement, and Scale for Contraversive Pushing on the "remain sitting" item in the revised version of the Ability of Basic Movement Scale at the time of acute hospital discharge were investigated. Factors affecting sitting ability were identified using binomial logistic regression analysis. RESULTS: We included 293 stroke patients. Age (odds ratio: 0.943, 95% confidence interval: 0.910-0.977, p=0.001), National Institutes of Health Stroke Scale score (odds ratio: 0.862, 95% confidence interval: 0.811-0.916, p<0.001), and Scale for Contraversive Pushing score (odds ratio: 0.543, 95% confidence interval: 0.419-0.705, p<0.001) were identified as independent predictors of sitting ability at the time of hospital discharge (median; 23.0 days). CONCLUSIONS: Older patients and those with high Scale for Contraversive Pushing and National Institutes of Health Stroke Scale scores experienced difficulties in regaining sitting ability. These results may guide physical therapy for patients with impaired sitting ability due to hemispheric stroke.

Retrospective analysis of definitive radiotherapy for neck node metastasis from unknown primary tumor: Japanese Radiation Oncology Study Group study.

OBJECTIVE: To investigate the optimal treatment method and risk factor of neck node metastasis from unknown primary tumors (NUP) treated by radiotherapy. METHODS: Retrospective case study based on a multi-institutional survey was conducted by the Japanese Radiation Oncology Study Group. Patients pathologically diagnosed as having NUP from 1998 to 2007 were identified. Univariate and multivariate analyses of overall survival (OS), progression free survival (PFS), neck progression free survival (NPFS) and mucosal progression free survival (MPFS) were evaluated. RESULTS: In total, 130 patients with median age of 65 years were included. Nodal stages N1, N2a, N2b and N2c were observed for 10, 26, 43, 12 and 39 patients, respectively. All the patients received radiotherapy (RT) with neck dissection in 60 and with chemotherapy in 67 cases. The median doses to the metastatic nodes, prophylactic neck and prophylactic mucosal sites were 60.0, 50.4 and 50.4 Gy, respectively. The median follow-up period for surviving patients was 42 months. Among 12 patients, occult primary tumors in the neck region developed after radiotherapy. The 5-year OS, PFS, NPFS and MPFS were 58.1%, 42.4%, 47.3% and 54.9%, respectively. Univariate analysis showed that lower N stage (N1-2b), non-bulky node (<6 cm) and negative extracapsular extension (ECE) status were the factors associated with favorable OS, PFS, NPFS and MPFS. Radical surgery proved to be a favorable factor of OS, NPFS and MPFS. On multivariate analysis, lower N stage and negative ECE status were correlated with improved survival. CONCLUSIONS: Lower nodal stage and negative ECE status showed a favorable impact on survival and disease control in patients with NUP treated by radiotherapy.

A multicenter survey of stage T1 glottic cancer treated with radiotherapy delivered in 2.25-Gy fractions in clinical practice: An initial 5-year analysis.

The purpose of this study was to evaluate the acute and late toxicity as well as local control (LC) in T1 glottic cancer (GC) patients treated with hypofractionated radiotherapy (RT) in clinical practice. The Tokai Study Group for Therapeutic Radiology and Oncology started RT treatment with a dose of 2.25 Gy for T1 GC in 2011. Ten institutions combined data from 104 patients with T1 squamous cell carcinoma between 2011 and 2015. In total, 104 patients with T1 GC were irradiated with a standard radiation dose of 63 Gy in 28 fractions.The median follow-up duration was 18 (3.7-49.5) months. Acute grade 3 adverse events were observed in 7 patients, with 4 patients (5%) having dermatitis and 3 patients (4%) having mucositis. Late adverse events above grade 3 were not observed. Two patients developed local recurrence. The rates of acute adverse events in the present study were comparable to those in previous studies that have used 2 Gy fractions of RT.

Does training sitting balance on a platform tilted 10° to the weak side improve trunk control in the acute phase after stroke? A randomized, controlled trial.

BACKGROUND: Trunk performance and sitting balance, especially lateral sitting control, are important predictors of functional outcome after stroke. However, no studies have focused only on trunk function in the frontal plane for persons with acute-phase stroke. OBJECTIVE: To investigate the effects of lateral sitting training on a tilting platform in persons with stroke. METHODS: An assessor-blinded, randomized, controlled trial was carried out involving inpatients at a stroke rehabilitation center. Patients were allocated to either an experimental group (n = 15) or a control group (n = 15). The experimental group sat without leg support on a platform tilted 10° to the paretic side in the frontal plane, while the controls sat on a horizontal platform. Both groups were asked to move their trunk laterally from the paretic side to the nonparetic side. In addition to conventional therapy, this training was performed 60 times/session, with 6 sessions/week. Trunk function was assessed using the Trunk Control Test (TCT), and the ability to move the trunk laterally was evaluated kinematically. Measurements were performed at baseline and after training. Two-way repeated measures analysis of variance was used to test the significance between and within treatments for each dependent variable. RESULTS: None of the demographic data differed between the groups. After training, a significant improvement was noted in the experimental group compared to the controls in the TCT and the ability for lateral trunk transference (P < 0.05, 1 - ß = 0.98, effect size = 0.4). CONCLUSION: Lateral sitting training on the tilting platform improved the impaired trunk function of persons with stroke.

Patterns of practice in the radiation therapy for bladder cancer: survey of the Japanese Radiation Oncology Study Group (JROSG).

OBJECTIVE: To retrospectively analyze the clinical outcomes of radiation therapy with or without chemotherapy for bladder cancer in Japan. METHODS: A questionnaire-based survey of patients with pathologically proven bladder cancer treated by definitive radiation therapy between 2002 and 2006 was conducted by the Japanese Radiation Oncology Study Group, and the clinical records of 159 patients were collected from 17 institutions. Concurrent intra-arterial chemoradiotherapy and concurrent systemic chemoradiotherapy were administered in 51 and 33 patients, respectively. RESULTS: The 5-year overall survival and bladder preservation rates were 48 and 39%, respectively. Eighty-nine (56%) patients developed recurrence (bladder, 48; regional lymph nodes, 4; distant sites, 41). The results of multivariate analysis revealed that adoption of chemotherapy was the only significant prognostic factor for overall survival (relative risk = 0.615 [95% confidence interval: 0.439-0.862], P = 0.005). The type of chemotherapy administered did not significantly affect the local control or overall survival rates. The actuarial 5-year overall survival rates and bladder preservation in the radiation therapy combined with intra-arterial chemotherapy group were 64 and 58%, respectively, and the corresponding rates in the radiation therapy combined with systemic chemotherapy group were 67 and 42%, respectively. CONCLUSIONS: The results of this survey revealed the current status of practice of radiation therapy for bladder cancer in Japan. A multi-institutional prospective study is needed based on the results of this study to determine the optimal radiotherapeutic approach, including the need for concurrent chemotherapy and the appropriate chemotherapy regimen for invasive bladder cancer.

Can we spot fake public comments generated by ChatGPT(-3.5, -4)?: Japanese stylometric analysis expose emulation created by one-shot learning.

Public comments are an important opinion for civic when the government establishes rules. However, recent AI can easily generate large quantities of disinformation, including fake public comments. We attempted to distinguish between human public comments and ChatGPT-generated public comments (including ChatGPT emulated that of humans) using Japanese stylometric analysis. Study 1 conducted multidimensional scaling (MDS) to compare 500 texts of five classes: Human public comments, GPT-3.5 and GPT-4 generated public comments only by presenting the titles of human public comments (i.e., zero-shot learning, GPTzero), GPT-3.5 and GPT-4 emulated by presenting sentences of human public comments and instructing to emulate that (i.e., one-shot learning, GPTone). The MDS results showed that the Japanese stylometric features of the public comments were completely different from those of the GPTzero-generated texts. Moreover, GPTone-generated public comments were closer to those of humans than those generated by GPTzero. In Study 2, the performance levels of the random forest (RF) classifier for distinguishing three classes (human, GPTzero, and GPTone texts). RF classifiers showed the best precision for the human public comments of approximately 90%, and the best precision for the fake public comments generated by GPT (GPTzero and GPTone) was 99.5% by focusing on integrated next writing style features: phrase patterns, parts-of-speech (POS) bigram and trigram, and function words. Therefore, the current study concluded that we could discriminate between GPT-generated fake public comments and those written by humans at the present time.

Palliative radiotherapy for painful non-bone lesions in patients with advanced cancer: a single center retrospective study.

PURPOSE: This retrospective study aimed to assess the efficacy and safety of palliative radiotherapy for painful non-bone lesions in patients with advanced cancer. MATERIALS AND METHODS: We enrolled patients with painful non-bone lesions who underwent conventional palliative radiotherapy between September 2018 and September 2022. The treatment targets included primary tumor lesions, lymph node metastases, non-bone hematogenous metastases, and other lesions. The primary endpoint was the overall pain response rate in evaluable patients, determined based on the International Consensus Pain Response Endpoint criteria. The secondary endpoints included overall survival, pain recurrence, and adverse events. RESULTS: Of the 420 screened patients, 142 received palliative radiotherapy for painful non-bone lesions, and 112 were evaluable. A pain response was achieved in 67 patients (60%) of the 112 evaluable patients within a median of 1.2 months. Among these patients, 25 exhibited complete response, 42 partial response, 18 indeterminate response, and 27 pain progression. The median survival time was 5.5 months, recorded at a median follow-up of 6.0 months, during which 67 patients died. Multivariate analysis identified poor performance status scores of 2-4, opioid use, and re-irradiation as independent factors associated with a reduced likelihood of achieving a pain response. Pain recurrence occurred in 18 patients over a median of 4.1 months. Seventeen patients had grade 1-2 adverse events, while none experienced grade 3 or higher toxicity. CONCLUSION: Palliative radiotherapy can potentially be a safe and well-tolerated modality for managing painful non-bone lesions, with a low rate of adverse events.

Reirradiation for recurrent gynecologic cancer using high-dose-rate brachytherapy in Japan: A multicenter survey on practice patterns and outcomes.

BACKGROUND AND PURPOSE: The aim of the study is to examine the present status of reirradiation with high-dose-rate (HDR) brachytherapy for recurrent gynecologic cancer in Japan and to determine the role of this therapy in clinical practice. MATERIALS AND METHODS: A retrospective multicenter chart review was performed for reirradiation for gynecologic cancer using HDR brachytherapy. Each center provided information on patient characteristics, treatment outcomes, and complications. RESULTS: The study included 165 patients treated at 9 facilities from 2000 to 2018. The analysis of outcomes included 142 patients treated with curative intent. The median follow-up time for survivors was 30 months (range 1-130 months). The 3-year overall survival (OS), progression-free survival (PFS), and local control (LC) rates were 53 % (95 %CI: 42-63 %), 44 % (35-53 %), and 61 % (50-70 %) for cervical cancer; 100 % (NA), 64 % (30-85 %), and 70 % (32-89 %) for endometrial cancer; and 54 % (13-83 %), 38 % (6-72 %), and 43 % (6-78 %) for vulvar and vaginal cancer, respectively. In multivariate analysis, interval to reirradiation (<1 year) was a significant risk factor for OS, PFS and LC; Gross Tumor Volume (≥25 cm3) was a significant risk factor for OS. Toxicities were analyzed in all enrolled patients (n = 165). Grade ≥ 3 late toxicities occurred in 49 patients (30 %). A higher cumulative EQD2 (α/ß = 3) was significantly associated with severe complications. CONCLUSION: Reirradiation with HDR brachytherapy for recurrent gynecologic cancer is effective, especially in cases with a long interval before reirradiation.

Weight of authorship evidence with multiple categories of stylometric features: A multinomial-based discrete model.

This study empirically demonstrates the efficacy of a two-level Dirichlet-multinomial statistical model (the Multinomial system) for computing likelihood ratios (LR) for linguistic, textual evidence with multiple stylometric feature types with discrete values. The LRs are calculated separately for each feature type, namely, word, character and part of speech N-grams (N = 1,2,3), which are combined as overall LRs through logistic regression fusion. The Multinomial system's performance is compared with that of a previously proposed system with the cosine distance (the Cosine system) using the same data (i.e., documents collated from 2160 authors). The experimental results show that: (1) the Multinomial system outperforms the Cosine system with the fused feature types by a log-LR cost of ca. 0.01 âˆ¼ 0.05 bits; and (2) the Multinomial system is more advantageous in performance with longer documents than the Cosine system. Although the Cosine system is more robust overall against the sampling variability arising from the number of authors included in the reference and calibration databases, the Multinomial system can achieve reasonable stability in performance; for example, the standard deviation value of the log-LR cost becomes lower than 0.01 (10 random samplings of authors for the reference and calibration databases) with 60 or more authors in each database.

Shifting-field-of-view technique enhancing the inflow effect for identifying tumor/vessel boundaries in MRI for radiotherapy treatment planning.

This study presents two cases of tumors in contact with the inferior vena cava during radiotherapy, and introduces a clinically useful technique for identifying tumor boundaries adjacent to blood vessels by adjusting the position of the field-of-view (FOV) to enhance the inflow effect in magnetic resonance imaging. We named this technique "Shifting-FOV." This method consists of three steps: (1) remove the upper and lower saturation pulses outside the FOV, (2) align the FOV to position the lower edge of the imaging slab as close to the tumor as possible, and (3) manually adjust the table position to locate the tumor at the center of the magnetic field. The proposed method allowed for accurate identification of the tumor/vessel boundaries in both cases. This is a useful technique that can be readily applied to other facilities. Furthermore, images obtained using this technique may enable accurate tumor contouring in radiotherapy treatment planning.

Optimized radiotherapy treatment strategy for early glottic carcinoma.

The local control rates of T1 bulky and T2 glottic carcinoma treated via radiation therapy alone are unsatisfactory; thus, we aimed to evaluate the efficacy and safety of our treatment protocol for early glottic carcinoma. Patients with early glottic squamous cell carcinoma treated via radiation therapy from January 2007 to November 2019 were reviewed. Patients were treated with: 63-67.5 Gy/28-30 fractions of radiation therapy alone for T1 non-bulky; concurrent chemoradiotherapy with S-1 and 60 Gy/30 fractions for T1 bulky and T2 favorable; and concurrent chemoradiotherapy with high-dose cisplatin and 66-70 Gy/33-35 fractions for T2 unfavorable glottic carcinoma. Local failure rates were estimated using the cumulative incidence function, overall and disease specific survival rates were estimated using Kaplan-Meier analysis, and adverse events were evaluated. Eighty patients were analyzed; the median age was 69.5 (range, 26-90) years, the median follow-up time for survivors was 40.1 (range, 1.9-128.4) months, and the 3-year local failure, disease specific survival, and overall survival rates were 5.8%, 98.3%, and 94.4%, respectively. In T1 bulky and T2 cases, the local failure rate was significantly lower in the concurrent chemoradiotherapy than in the radiation therapy alone group. Grade 3 acute dermatitis and mucositis were noted in nine and four patients, respectively. There were no acute adverse events of Grade 4 or higher, or late adverse events of Grade 2 or higher. The treatment protocol was effective and well-tolerated; thus, the efficacy of concurrent chemoradiotherapy was suggested in T1 bulky and T2 cases.

Urethral identification using three-dimensional magnetic resonance imaging and interfraction urethral motion evaluation for prostate stereotactic body radiotherapy.

Prostatic urethra identification is crucial in prostate stereotactic body radiotherapy (SBRT) to reduce the risk of urinary toxicity. Although computed tomography (CT) with a catheter is commonly employed, it is invasive, and catheter placement may displace the urethral position, resulting in possible planning inaccuracies. However, magnetic resonance imaging (MRI) can overcome these weaknesses. Accurate urethral identification and minimal daily variation could ensure a highly accurate SBRT. In this study, we investigated the usefulness of a three-dimensional (3D) T2-weighted (T2W) sequence for urethral identification, and the interfractional motion of the prostatic urethra on CT with a catheter and MRI without a catheter for implementing noninvasive SBRT. Thirty-two patients were divided into three groups. The first group underwent MRI without a catheter to evaluate urethral identification by two-dimensional (2D)- and 3D-T2W sequences using mean slice-wise Hausdorff distance (MSHD) and Dice similarity coefficient (DSC) of the contouring by two operators and using visual assessment. The second group provided 3-day MRI data without a catheter using 3D-T2W, and the third provided 3-day CT data with a catheter to evaluate the interfractional motion using MSHD, DSC, and displacement distance (Dd). The MSHD and DSC for the interoperator variability in urethral identification and visual assessment were superior in 3D-T2W than in 2D-T2W. Regarding interfractional motion, the Dd value for prostatic urethra was smaller in MRI than in CT. These findings indicate that the 3D-T2W yielded adequate prostatic urethral identification, and catheter-free MRI resulted in less interfractional motion, suggesting that 3D-T2W MRI without a catheter is a feasible noninvasive approach to performing prostate SBRT.