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BACKGROUND/AIM To compare five radiotherapy methods for prostate cancer. PATIENTS AND METHODS During 2005-2018, the data of patients with non-metastatic prostate cancer were retrospectively analysed. Patients were treated with high-dose-rate brachytherapy (HDR-BT); low-dose-rate brachytherapy (LDR-BT); or external-beam radiotherapy (EBRT), including conventionally fractionated radiotherapy (CFRT), moderate-hypofractionated radiotherapy (MHRT), and ultra-hypofractionated radiotherapy (UHRT). RESULTS In total, 496 patients (149, HDR-BT; 100, LDR-BT; 100, CFRT; 97, MHRT, and 50, UHRT) with a median follow-up of 4.3 years were enrolled. The incidence of grade ≥2 acute genitourinary toxicities was significantly lower with HDR-BT (p

Background/aim To examine the effectiveness of newly-installed high-dose-rate interstitial brachytherapy (HDR-ISBT) for buccal cancer. Patients and methods We retrospectively reviewed 36 patients (25 men and 11 women) with buccal cancer treated with curative brachytherapy with or without external radiotherapy with a median follow-up of 99 months. A total of 15 HDR-ISBT (median 48 Gy/ 8 fractions, range=24-60 Gy) patients were compared to conventional 15 cases LDR-ISBT (70 Gy, range=42.8-110 Gy) and 7 molds techniques (15 Gy, range=9-74 Gy). A total of 31 patients also underwent external radiotherapy (30 Gy, range=24-48 Gy). They comprised of 3T1, 23 T2, 8 T3, 3 T4 including 11 node positive cases. Results HDR-ISBT provided 82% of local control rate at 5 years, whereas conventional brachytherapy showed 72% [p=0.44; LDR-ISBT (65%), mold therapy (85.7%)]. Patients with early lesions (T1-2 or stage I-II) showed better local control rates than those with advanced lesions (T3-4 or stage III-IV). Severe late grade 3 complications developed in two patients treated with LDR-ISBT and EBRT. There is no significant difference in toxicity grade ≤2 between conventional brachytherapy (5/15=33%) and HDR-ISBT (7/32=32%, p=0.92). Conclusion HDR-ISBT achieved good and comparable local control rates to conventional brachytherapy without elevating the toxicity.

Aim To compare survival outcomes for charged particle radiotherapy (CP) and stereotactic body radiotherapy using CyberKnife (CK) in patients who had undergone re-irradiation for head and neck cancers. Patients and methods We conducted a retrospective multi-institutional matched-cohort analysis on 25 patients treated with CP and 25 matched patients treated with CK according to three prognostic factors (nasopharyngeal cancer or not, interval between initial radiotherapy and re-irradiation, and planning target volume). Results CP was used more often to treat non-squamous cell cancer ((non-SCC): 52% vs. 0%) with a higher prescribed dose (median=57.6 Gy(RBE)/16 fractions) than CK (32 Gy/5 fractions). The local control rate (LC) for patients treated with CP was 71.2% at 1 year and that for patients treated with CK was 63.8% (p=0.24). The 1-year overall survival (OS) rates were 67.1% for CP and 36.3% for CK (p=0.0002), respectively. Non-SCC patients showed better OS rates at 1 year than SCC patients. In the SCC sub-group analysis, the 1-year LC, OS rates were 65%, 58.3% in the CP group and 64%, 36.3% in the CK group (p=0.81, p=0.02), respectively. A total of 16 patients (32%) experienced grade 3 or worse toxicities (24% in CK and 40% in CP, p=0.36), including six grade 5 toxicities. Conclusion CP produced higher survival rates than CK, treated more non-SCC patients and used a higher prescribed dose. On the other hand, severe toxicities occurred in both groups, which, however, require further investigation.

To evaluate the role of hypofractionated stereotactic radiotherapy (hSRT) as a boost treatment for head and neck cancer.We conducted a multi-institutional retrospective review for the outcome of boost irradiation using CyberKnife for head and neck cancer patients from the charts of four Institutes. Twenty-five patients were treated with hSRT boost for primary site with a median follow-up of 28 months. Treatment sites were 11 nasopharynx, 7 oropharynx, one hypopharynx, 3 nasal cavity or paranasal sinus and three oral cancers. All patients underwent preceding conventional radiotherapy of 35 to 72 Gy (median, 50 Gy) in 1.2- to 2 Gy-fractions. The dose and fractionation scheme of the Cyberknife SRT boost was individualized and the prescribed dose ranged from 12 Gy to 35 Gy in 1 to 5 fractions (median, 15 Gy in 3 fractions).There were 18 complete responses, 6 partial responses and one progressive disease, resulting in 96% (24/25) response rate. Local control (LC) rates at 2- and 5-years were 89% and 71%, respectively. Progression-free survival (PFS) and overall survival (OS) at 2- and 5-years were 70%/ 83% and 70%/ 70%, respectively. Planning target volume (PTV) at boost treatment planning and initial response were predisposing factors for PFS and OS. Patients with PTV ≤ 20 cm(3) showed better PFS (92%) and OS (100%) than those with a PTV20 cm(3) (PFS, 61% and OS, 47%). Good initial response predicts better outcome in LC, PFS and OS.The results of the present study showed potential benefits of the CyberKnife hSRT boost. Smaller PTV and good initial response predict good outcome.

To longitudinally examine the late vaginal mucosal reactions in patients following high-dose-rate brachytherapy (BT).We examined late vaginal mucosal reactions in 100 patients using the modified Dische score at 6, 12, 18, 24, 36, and 60 months after treatment, which consisted of 37 interstitial BTs and 63 conventional intracavitary BTs, with a median follow-up of 41 months (range=6-144 months).There were no cases of lethal toxicity or severe toxicity requiring surgery. Bleeding or discharge grade 1 or more was exhibited by fewer than 2-4% of patients, and in most cases only until 1.5 years following treatment. Erythema was detected in approximately 30% (mainly grade 1) of the patients up to five years. With regard to ulceration, four patients (7%) developed superficial ulceration; however, no patient had ulceration lasting six months or longer. Telangiectasia increased gradually over time in approximately 91% of patients (grades 1 and 2=73% and 18%, respectively) in the five years following treatment. The pallor reaction also increased over time in 100% of patients (grades 1, 2, and 3=30%, 48%, and 22%, respectively) in the five years after treatment. Stenosis also increased with time in approximately 97% of patients (grades 1, 2, and 3=29%, 61%, and 7%, respectively) over five years. There was a close correlation between pallor reaction and stenosis.High-dose-rate BT caused mild-to-moderate toxicities. Almost all patients showed pallor reaction, telangiectasia, and stenosis up to five years after treatment, and pallor reaction correlated with stenosis.

To examine the role of the new grading system Prostate Cancer Risk Index (PRIX) with existing risk-grouping after high-dose-rate interstitial brachytherapy (HDR-ISBT) as monotherapy for localized prostate cancer.We analyzed outcome in 100 patients treated by HDR-ISBT as monotherapy using PRIX and compared this with D'Amico, the National Comprehensive Cancer Network (NCCN), and Seattle classifications. The median follow-up was 74 (range=48-109) months.Five-year prostate-specific antigen control and overall survival rates were 94% and 98%, respectively. PRIX separated the risks statistically significantly (p=0.004), while D'Amico (p=0.319), NCCN 2002 (p=0.126), NCCN 2012 (p=0.052) and Seattle (p=0.112) classifications failed to show a statistically significant separation.PRIX is a more useful risk classification system in high-risk patient selection than existing risk classification system in clinically localized prostate cancer after HDR-ISBT as monotherapy.

We report on a minimally invasive computed tomography (CT)/magnetic resonance imaging (MRI)-based image-guided intracavitary brachytherapy (ICBT) for an elder patient with endometrial cancer, who was unfit for anesthesia, using a fine and soft flexible applicator.The patient was an 82-year-old female. She was identified as having T1bN0M0 (stage IB) tumor, and histological findings revealed grade 2 adenocarcinoma. She was contraindicated for surgery because of advanced age and severe pulmonary emphysema; therefore, she was managed with CT/MRI-based ICBT alone. The total treatment dose was 26 Gy (6.5 Gy per fraction). The dose-volume histogram of the gross tumor volume, the clinical target volume, and organs at risk were calculated.The patient safely completed the ICBT course without pre-medication. Tumor growth was controlled, with complete disappearance after 32 months. No acute or late adverse effects were observed. MRI-guided ICBT can visualize the gross tumor volume in the uterine body, which cannot be detected by CT.We successfully and safely performed minimally invasive CT/MRI-based ICBT without pre-medication in a patient with endometrial cancer with high surgical risks, using a fine and soft, flexible applicator.

The evaluation of toxicity after high-dose-rate interstitial brachytherapy (HDR-ISBT) as monotherapy for localized prostate cancer.We analyzed early and late toxicities in 100 patients treated by HDR-ISBT as monotherapy at the National Hospital Organization Osaka National Hospital using both Common Terminology Criteria for Adverse Events version 3.0 (CTCAE v3.0) and Radiation Therapy Oncology Group (RTOG) score. The median follow-up was 72 (range=12-109) months.Late-gastrointestinal (GI) toxicities were 4% grade 1 and 2% grade 2 in CTCAE v3.0 and 5% grade 1 in RTOG score. Late genitourinary (GU) toxicities grade 1: grade 2: grade 3 were 29%: 5%: 2% in RTOG and 47%: 10%: 2% in CTCAE v3.0. CTCAE v3.0 GU score identified more grade 1-2 adverse reactions than the RTOG score (p=0.01). Early RTOG GI toxicity-positive patients showed 13% of late RTOG GI toxicity, whereas early RTOG GI negative patients showed 0% of RTOG (p=0.0172) and CTCAE v3.0 late-GI toxicity (p=0.007).CTCAE v3.0 GU score identified more grade 1-2 adverse reactions than the RTOG score. Early RTOG GI toxicity is well-correlated to late GI toxicity and absence of RTOG acute GI toxicity is a safe surrogate for late GI toxicity after HDR-ISBT as monotherapy for prostate cancer.

To examine the vaginal mucosal reaction in gynecological cancer patients after re-irradiation using interstitial brachytherapy (re-ISBT) compared to initial brachytherapy.A comparison was made between re-ISBT (n=14) and the initial brachytherapy group consisting of 63 cases of intracavitary brachytherapy (ICBT) and 37 of interstitial brachytherapy (ISBT). We examined the modified Dishe score at 6, 12, 18, 24, 36, and 60 months after treatment with a median follow-up time of 41 months (range: 6-144 months). Re-ISBT was performed using 42-51 Gy in 7-8 fractions in 2-5 days (twice a day) without external irradiation.For bleeding and discharge, fewer than 10% of patients exhibited grade 1 reactions and no statistically significantly differences were found between re-ISBT and initial brachytherapy. Re-ISBT increased erythema (grade 0/1/2=29%/57%/14%) compared with initial brachytherapy (grade 0/1/2=64%/31%/5%, p=0.03). Four out of 14 patients had grade 1 ulceration or higher after re-ISBT, whereas five patients experienced grade 1 ulceration after initial in brachytherapy (p=0.001). Notably, a fistula appeared in one patient in the re-ISBT group. There is no difference between re-ISBT and fresh brachytherapy with regard to telangiectasia, stenosis and pallor reactions. Increased cumulative (previous plus present treatment) equivalent dose in a 2-Gy fraction was correlated to a higher grade of erythema and ulceration.Re-ISBT increased the vaginal mucosal reaction, as shown by increased erythema and ulceration, more than initial brachytherapy, with a higher cumulative radiation dose, but the reaction was mild in almost all cases.

To examine late vaginal mucosal reactions in patients following interstitial brachytherapy (ISBT) compared with that of intracavitary brachytherapy (ICBT).We introduced a modified Dische score to examine late reactions in vaginal mucosa of patients with gynecological cancer who underwent vaginal brachytherapy at 6, 12, 18, 24, 36, and 60 months after treatment. A comparison was made between patients who underwent ISBT (n=37) and those under conventional ICBT (n=63) with a median follow-up time of 41 months. The ICBT group included only patients with newly diagnosed cervical cancer, whereas the ISBT group included 17 patients with recurrent and 20 with newly-diagnosed cancer.Grade 1 reactions of bleeding and discharge were exhibited by12% of patients. Erythema was detected in approximately 30% (mainly grade 1) of the patients. A total of two (3%) patients developed superficial ulceration after ICBT, whereas three (8%) grade 1 ulcers were detected in patients after ISBT. Telangiectasias were detected in approximately 70% (60% grade 1 and 10% grade 2) of patients. No statistically significant difference was found between the patients after ISBT and ICBT. After ISBT, patients have a higher stenosis rate than after ICBT (p=0.003). The pallor scores showed a strong correlation with stenosis (p0.0001) and were higher in patients after ICBT than in patients after ISBT (p=0.006).After ISBT, patients exhibited milder but similar late mucosal reactions compared to those after ICBT, except the fact that the stenosis was more severe and the pallor reaction was milder in these patients. It can be, therefore, concluded that the pallor reaction is related to stenosis.