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.

Initial tumor volume as an important predictor for indication of intra-cavitary brachytherapy, intra-cavitary/interstitial brachytherapy, and multi-catheter sole interstitial brachytherapy in cervical cancer patients treated with chemoradiotherapy.

Purpose: Advances in three-dimensional image-guided brachytherapy technique allow for using intra-cavitary and interstitial brachytherapy (ICIS-BT), and sole interstitial brachytherapy (ISBT) in addition to conventional intra-cavitary brachytherapy (ICBT). However, no consensus has been reached regarding the choice of these techniques. The aim of this study was to propose the size criteria for indication of interstitial techniques. Material and methods: We examined initial gross tumor volume (GTV) at presentation and at each brachytherapy session. Also, dose volume histogram parameters for each modality were compared in 112 patients with cervical cancer treated with brachytherapy (ICBT, 54; ICIS-BT, 11; and ISBT, 47). Results: The average GTV at diagnosis was 80.9 cm3 (range, 4.4-343.2 cm3), which shrank to 20.6 cm3 (25.5% of initial volume, range, 0.0-124.8 cm3) at initial brachytherapy. GTV > 30 cm3 at brachytherapy and high-risk clinical target volume > 40 cm3 were good threshold values for indication of interstitial technique, and tumors with initial GTV > 150 cm3 could be candidates for ISBT. An ISBT dose of 89.10 Gy can be prescribed in equivalent dose in 2 Gy fractions (range, 65.5-107.6 Gy), which was higher than those of ICIS (73.94 Gy, range, 71.44-82.50 Gy) and ICBT (72.83 Gy, range, 62.50-82.27 Gy) (p < 0.0001). Conclusions: Initial tumor volume is an important predictor for indication of ICBT and ICIS-BT. ISBT or at least an interstitial technique is recommended for initial GTV > 150 cm3.

HDR-brachytherapy for accelerated partial breast irradiation: Long-term experience from a Japanese institution.

Purpose: We investigated the long-term oncological outcome of high-dose-rate (HDR) multicatheter interstitial brachytherapy (MIB) for adjuvant accelerated partial breast irradiation (APBI) after breast conserving surgery in Japanese patients. Material and methods: Between June 2002 and October 2011, 86 breast cancer patients were treated at National Hospital Organization Osaka National Hospital (trial number of the local institutional review board, 0329). Median age was 48 years (range, 26-73 years). Eighty patients had invasive and 6 patients non-invasive ductal carcinoma. Tumor stage distribution was pT0 in 2, pTis in 6, pT1 in 55, pT2 in 22, and pT3 in one patient, respectively. Twenty-seven patients had close/positive resection margins. Total physical HDR dose was 36-42 Gy in 6-7 fractions. Results: At a median follow-up of 119 months (range, 13-189 months), the 10-year local control (LC) and overall survival rate was 93% and 88%, respectively. Concerning the 2009 Groupe Européen de Curiethérapie-European Society for Therapeutic Radiology and Oncology risk stratification scheme, the 10-year LC rate was 100%, 100%, and 91% for patients considered as low-risk, intermediate-risk, and high-risk, respectively. According to the 2018 American Brachytherapy Society risk stratification scheme, the 10-year LC rate was 100% and 90% for patients 'acceptable' and 'unacceptable' for APBI, respectively. Wound complications were observed in 7 patients (8%). Risk factors for wound complications were the omission of prophylactic antibiotics during MIB, open cavity implantation, and V100 ≥ 190 cc. No grade ≥ 3 late complications (CTCVE version 4.0) were observed. Conclusions: Adjuvant APBI using MIB is associated with favorable long-term oncological outcomes in Japanese patients for low-risk, intermediate-risk, and acceptable groups of patients.

Effect of a lead block on alveolar bone protection in image-guided high-dose-rate interstitial brachytherapy for tongue cancer: using model-based dose calculation algorithms to correct for inhomogeneity.

PURPOSE: The purpose of this study was to evaluate the effect of a lead block for alveolar bone protection in image-guided high-dose-rate interstitial brachytherapy for tongue cancer. MATERIAL AND METHODS: We treated 6 patients and delivered 5,400 cGy in 9 fractions using a lead block. Effects of lead block (median thickness, 4 mm) on dose attenuation by distance were visually examined using TG-43 formalism-based dose distribution curves to determine whether or not the area with the highest dose is located in the alveolar bone, where there is a high-risk of infection. Dose re-calculations were performed using TG-186 formalism with advanced collapsed cone engine (ACE) for inhomogeneity correction set to cortical bone density for the whole mandible and alveolar bone, water density for clinical target volume (CTV), air density for outside body and lead density, and silastic density for lead block and its' silicon replica, respectively. RESULTS: The highest dose was detected outside the alveolar bone in five of the six cases. For dose-volume histogram analysis, median minimum doses delivered per fraction to the 0.1 cm3 of alveolar bone (D0.1cm3 TG-43, ACE-silicon, and ACE-lead) were 344.3 (range, 262.9-427.4) cGy, 336.6 (253.3-425.0) cGy, and 169.7 (114.9-233.3) cGy, respectively. D0.1cm3 ACE-lead was significantly lower than other parameters. No significant difference was observed between CTV-related parameters. CONCLUSIONS: The results suggested that using a lead block for alveolar bone protection with a thickness of about 4 mm, can shift the highest dose area to non-alveolar regions. In addition, it reduced D0.1cm3 of alveolar bone to about half, without affecting tumor dose.

Reirradiation for recurrent head and neck carcinoma using high-dose-rate brachytherapy: A multi-institutional study.

AIM: This study presents multi-institutional individual data of reirradiation (ReRT) for head and neck cancer using brachytherapy (ReRT-BT) collected by national surveillance in Japan. METHODS AND MATERIALS: We distributed an e-mail-based questionnaire to 153 institutions equipped with high-dose-rate (HDR) brachytherapy facilities and received responses from 76 institutions (49.7%). Of these 76 institutions, only four (5.2%) performed ReRT-BT for head and neck cancers, and three provided individual patient's data. RESULTS: Six ReRT-BT cases of patients with recurrent head and neck cancer, treated with HDR brachytherapy in seven ReRT sessions, were identified from three institutions. Three patients (two cases of lips and one case of gingiva) who underwent curative-intent treatment achieved complete response at the treated area. Three patients who received palliative treatment (one case of tongue and two cases of maxillary sinus) had sustained tumor growth at the treated site, but with improvement in symptoms. No grade ≥3 toxicity was found after HDR ReRT-BT. CONCLUSIONS: ReRT-BT for head and neck cancer using HDR brachytherapy is a safe and useful approach to treat recurrent cancer after initial radiotherapy with curative and palliative intent. However, the scarce availability of ReRT-BT is a barrier to the wider utility of this effective procedure.

A Japanese prospective multi-institutional feasibility study on accelerated partial breast irradiation using multicatheter interstitial brachytherapy: clinical results with a median follow-up of 60 months.

BACKGROUND: We carried out the first multi-institutional prospective study on accelerated partial breast irradiation (APBI) via multicatheter interstitial brachytherapy in a shorter period for early breast cancer in Japan. METHODS: Patient eligibility criteria included positive hormone receptors, tumors ≤ 3 cm and TNM stage pN0M0. After breast-conserving surgery (Japanese cylindrical resection) and histological confirmation of negative surgical margins and the absence of lymph node metastasis, applicator implantation was performed either postoperatively or intraoperatively. High-dose-rate brachytherapy of 36 Gy in 6 fractions was delivered. RESULTS: Forty-six patients from six institutions received this treatment regimen, and the median follow-up time was 60 months (range 57-67 months). The median resected breast tissue volume was 81 cm3 (range 28-260 cm3). No Grade 4 late sequela, local recurrence nor death due to breast cancer were observed. Grade 2-3 sequelae such as rib fracture (2%), soft tissue necrosis (9%), fibrosis (20%), and breast pain (9%) were observed. The resected breast tissue volumes of the patients who had Grade ≥ 2 fibrosis and Grade < 2 fibrosis were 105.9 ± 32.3 cm3 and 76.3 ± 45.6 cm3, respectively, p = 0.02. The overall cosmetic outcome score of Excellent/Good was 74% at 60 months after APBI. Grade ≥ 1 fibrosis was observed in 44% and 92% of patients who scored Excellent/Good and Fair/Poor, respectively, p = 0.004. CONCLUSIONS: This study showed excellent local control and survival results with minimal late sequelae.

Comparison of Physician-recorded Toxicities and Patient-reported Outcomes of Five Different Radiotherapy Methods for Prostate Cancer.

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<0.001) than with any other radiotherapy. The cumulative incidence of late grade ≥2 genitourinary toxicities was the highest with UHRT and significantly higher (p=0.005) with UHRT than with HDR-BT. Higher symptom score peaks were noted 4 weeks after therapy for LDR-BT than for EBRT. CONCLUSION: Physician-recorded toxicities were slightly lower with HDR-BT and patient-reported outcomes tended to be worse with LDR-BT.

Influence of transitioning of planning techniques in high-dose-rate brachytherapy monotherapy for clinically localized prostate cancer from two- to three-dimensional planning.

PURPOSE: The purpose of this study was to examine the influence of transitioning treatment planning techniques in high-dose-rate interstitial brachytherapy monotherapy for localized prostate cancer. METHODS AND MATERIALS: We compared 113 patients treated with initial two-dimensional treatment planning (2D: 74% received 54 Gy/nine fractions) to 240 patients treated with three-dimensional planning (3D: 70 CT image-guided 3D [CT-3D]: 84% 45.5 Gy/seven fractions and 170 MRI image-guided [MRI-3D]: 87% received 49 Gy/nine fractions). RESULTS: The actuarial 5-year biochemical failure-free survival rates for 2D and 3D planning were 88.4% and 95.1% (p = 0.0285 between 2D and 3D) (89.4% in CT-3D and 97.5% in MRI-3D), respectively; the rates for 2D and 3D planning were not available and 100% in the low-risk group (100% and 100%), 97.7% and 94.5% (p = 0.7626) (85.1% and 100%) in the intermediate-risk group, and 82.5% and 94.4% (p = 0.0507) (93.8% and 94.7%) for the high-risk group. Late gastrointestinal (GI) toxicity Grade 1, Grade 2, and Grade 3 was found in 13%, 4%, and 1% in 2D, whereas 8%, 2%, and 0% in 3D group (p = 0.0699), respectively. 3D decreased GI toxicity Grade 2 ≤ than 2D (19% and 10%, p = 0.0169). Late genitourinary toxicity Grade 1, Grade 2, and Grade 3 was 21%, 12%, and 3% for 2D and 32%, 18%, and 3% for 3D, respectively (p = 0.0217). CONCLUSIONS: The 3D technique has the potential to reduce GI toxicity and improve biochemical control rate compared to 2D planning, whereas 3D resulted in increased mild genitourinary toxicity.

Effect of Androgen Deprivation Therapy on Other-Cause of Mortality in Elderly Patients with Clinically Localized Prostate Cancer Treated with Modern Radiotherapy: Is There a Negative Impact?

The influence of androgen deprivation therapy (ADT) on other-cause of mortality (OCM) was investigated in patients with localized prostate cancer treated with modern high-dose radiotherapy. A retrospective review was conducted on 1125 patients with localized prostate cancer treated with high-dose radiotherapy, including image-guided, intensity-modulated radiotherapy or brachytherapy with a median follow-up of 80.7 months. Overall survival rate was no different between ADT (+) and ADT (-) group in high-, intermediate-, and low-risk groups. OCM was found in 71 patients, consisting of 4% (10/258) in the ADT (-) group and 7% (61/858) in the ADT (+) group (p = 0.0422). The 10-year OCM-free survival rate (OCMFS), if divided by the duration of ADT (ADT naïve (ADT (-)), ADT <2-year, and ADT ≥2-year groups), showed statistical significance, and was 90.7%, 88.2%, and 78.6% (p = 0.0039) for the ADT (-), ADT <2-year, and ADT ≥2-year groups, respectively. In patients aged ≥75 years, 10-year OCMFS for ADT (-), ADT <2-, and ADT ≥2-year groups was 93.5% (at 115.6 months), 85.6%, and 60.7% (p = 0.0189), respectively, whereas it was 90.7%, 89.9%, and 89.0% (p = 0.4716), respectively, in their younger counterparts. In localized prostate cancer patients, treatment with longer ADT for ≥2 years potentially increases the risk of OCM, especially in patients aged ≥75 years.

A new implant device to prevent edema-associated underdosage in high-dose-rate interstitial brachytherapy of mobile tongue cancer.

PURPOSE: Tongue edema is a potential cause of treatment target underdosage in high-dose-rate interstitial brachytherapy (HDR-ISBT) of mobile tongue cancer. To prevent such edema-associated alteration of dosimetry, we developed a special silicon device. In this report we communicate our initial experience with two mobile tongue cancer patients whom we treated using this new device. MATERIAL AND METHODS: The device consists of silicone tubes with a fixed width and scalable length depending on tongue size. These tubes are lined and fixed like a palisade, allowing the device to be used also as a template. The device is placed next to the lateral border of the tongue and on the floor of the mouth. In addition, a vinyl template can be placed on the dorsal tongue surface with both devices combined for implantation guidance. Between June and August 2012, two patients with locally confined tongue cancer were treated. RESULTS: Between June and August 2012, two mobile tongue cancer patients classified as cT2N0M0 were treated with HDR-ISBT using the silicone device. They underwent ISBT as monotherapy with fractional doses of 6.0 Gy up to a total physical dose of 54.0 Gy. The D90 (CTV) values of both patients were 6.3 Gy and 6.6 Gy and the D2cc (mandible) values were 3.4 Gy and 2.6 Gy, respectively. At present, both patients remain without local disease recurrence at 60 and 56 months after ISBT, respectively. CONCLUSIONS: The described silicone device has the potential to prevent underdosage to the treatment target related to tongue edema. It has been shown to be safe and easy to implement.

High-dose-rate brachytherapy monotherapy versus low-dose-rate brachytherapy with or without external beam radiotherapy for clinically localized prostate cancer.

BACKGROUND: To compare the outcome of high-dose-rate interstitial brachytherapy (HDR-BT) monotherapy and low-dose-rate brachytherapy (LDR-BT) with or without external beam radiotherapy (EBRT) for localized prostate cancer. METHODS AND MATERIALS: We compared 352 patients treated with HDR-BT as monotherapy (median follow-up time 84 months, NCCN risk classification; low: intermediate: high = 28:145:179) and 486 patients with LDR-BT with or without EBRT (90 months, 194:254:38). HDR-BT treated advanced disease with more hormonal therapy than LDR-BT. LDR-BT excluded patients with T3b-T4 tumor and initial PSA >50 ng/ml. Inverse probability of treatment weighting (IPTW) involving propensity scores was used to reduce background selection bias. RESULTS: The actuarial 5-year biochemical failure-free survival rates (bNED) were 92.9% and 95.6% (p = 0.25) in the HDR-BT and LDR-BT groups, respectively, and it was 100% and 97.3% (p = 0.99) in the low-risk, 95.6% and 94.3% (p = 0.19) in the intermediate, 89.6% and 94.9% (p = 0.26) in the high-risk groups, and 93.1% and 94.9% (p = 0.98) in selected high-risk group excluding T3b-4 and initial PSA ≥50. IPTW correction also indicated no difference in bNED between LDR-BT and HDR-BT groups. LDR-BT showed a higher incidence of genitourinary (GU) toxicity grade ≥2 than that of HDR-BT in the acute phase and grade 1 toxicity in late phase. Acute GU toxicity grade ≥1 predicted late GU toxicity grade ≥2. External beam radiotherapy plus LDR-BT elevated GI toxicity than LDR-BT only group. Accumulated incidence of late grade ≥2 GU and GU toxicity was equivalent between HDR-BT and LDR-BT. No grade 4 or 5 toxicities were detected in either modality. CONCLUSION: HDR-BT monotherapy showed an equivalent outcome to that of LDR-BT with or without EBRT for low-, intermediate- and selected high-risk patients. LDR-BT showed equivalent incidence of grade ≥2 late GI and GU toxicities and higher grade ≥2 acute GU toxicity as that of HDR-BT as a monotherapy.

Radiothrerapy for Elderly Patients Aged ≥75 Years with Clinically Localized Prostate Cancer-Is There a Role of Brachytherapy?

We compared radiotherapy outcomes between 241 elderly patients aged ≥75 years and 867 younger controls (age <75 years) with clinically localized prostate cancer. The elderly group showed an equivalent actuarial seven-year biochemical failure-free survival rate (7y-bNED) (94.9%) to the younger control group (96.4%, p = 0.593). The incidence of late genitourinary (GU) and gastrointestinal (GI) toxicities grade ≥2 was also similar between the elderly and younger cohorts, while no grade ≥4 adverse events occurred. We also examined the role of brachytherapy (BT) in the elderly group, in comparison with image-guided intensity-modulated radiotherapy (IG-IMRT). BT showed superior 7y-bNED (94.1%) than IG-IMRT (84.6%, p = 0.0183) in elderly patients, which was 100% (100% for BT and 100% for IG-IMRT, p > 0.999) for the low-risk group, 94.6% (92.8% and 100%, p = 0.203) for the intermediate-risk group, and 80.5% (91.2% and 73.6%, p = 0.0195) for the high-risk group. BT showed higher GU toxicity and equivalent GI toxicity to IG-IMRT. In conclusion, elderly patients showed bNED and toxicity that were equivalent to those observed in younger controls, and BT is a plausible option also for healthy elderly with potential to improve bNED, with higher but acceptable GU toxicity.

Comparison of three moderate fractionated schedules employed in high-dose-rate brachytherapy monotherapy for clinically localized prostate cancer.

BACKGROUND: Herein, we report the outcomes of 3 schedules of high-dose-rate interstitial brachytherapy (HDR-BT) monotherapy for localized prostate cancer. PATIENTS AND METHODS: A total of 347 patients were treated with 45.5 Gy/7 fractions (n = 86; 45.5 Gy arm, median follow-up time 131 months), 49 Gy/7 fractions (n = 149; 49 Gy arm, 75.9 months), and 54 Gy/9 fractions (n = 112; 54 Gy arm, 68 months). RESULTS: The actuarial 5-year biochemical failure-free survival rates were 86.8%, 94.1%, and 88.5% (p = 0.2023) for the 45.5 Gy, 49 Gy, and 54 Gy arms in the high-risk group; 90.4%, 100%, and 97.4% (p = 0.0818) in the intermediate-risk group; and not available, 100%, and 100% in the low-risk group, respectively. The 5-year distant metastasis-free (and overall) survival rates were 94.4%, 98.2%, and 96.3% (100%, 92.8%, and 99.1%) for the 45.5 Gy, 49 Gy, and 54 Gy arms (p = 0.5454 and p = 0.0028), respectively. At 5 years, accumulated incidence of grade ≥2 gastrointestinal toxicity was 1.2%, 2.7%, and 3.4% for the 45.5 Gy, 49 Gy, and 54 Gy arms (p = 0.5605), respectively. For genitourinary toxicity, the 49 Gy arm showed a higher grade ≥2 toxicity of 20.5% than those observed in the 45.5 Gy (2.4%) and 54 Gy arms (10.1%). No grade 4 or 5 of either type of toxicity was detected. CONCLUSIONS: The 3 schedules showed equivocal outcomes in each risk group, with different toxicity profiles. HDR-BT monotherapy with these schedules is an acceptable treatment option for localized prostate cancer.

High-Dose-Rate Brachytherapy Monotherapy versus Image-Guided Intensity-Modulated Radiotherapy with Helical Tomotherapy for Patients with Localized Prostate Cancer.

The aim of this paper is to compare outcomes between high-dose-rate interstitial brachytherapy (HDR-BT) monotherapy and image-guided intensity-modulated radiotherapy (IG-IMRT) for localized prostate cancer. We examined 353 HDR-BT and 270 IG-IMRT patients. To reduce background selection bias, we used the method of inverse probability treatment weighting (IPTW) with propensity scores. The actuarial five-year biochemical failure-free survival rates were 92.9% and 96.7% (p = 0.1847; p = 0.077 in IPTW) for HDR-BT and IG-IMRT, respectively; they were 100% and 95.8% (p = 0.286) for the low-risk group, 95.6% and 92% (p = 0.42) for the intermediate-risk group, 90.4% and 84.9% (p = 0.1059; p = 0.04 in IPTW) for the high-risk group, and 87.1% and 89.2% (p = 0.3816) for the very-high-risk group. In the assessment of accumulated incidences of grade ≥ 2 toxicity (Common Terminology Criteria for Adverse Events version 4.0) at five years, HDR-BT monotherapy showed higher genitourinary toxicity (11.9%) than IG-IMRT (3.3%) (p < 0.0001). The gastrointestinal toxicity was equivalent for HDR-BT (2.3%) and IG-IMRT (5.5%) (p = 0.063). No Grade 4 or 5 toxicity was detected in either modality. HDR-BT showed higher genitourinary toxicity than IG-IMRT. HDR-BT and IG-IMRT showed equivalent outcomes in low-, intermediate-, and very-high-risk groups. For high-risk patients, HDR-BT showed potential to improve prostate-specific antigen (PSA) control rate compared to IG-IMRT.

Case report of a dose-volume histogram analysis of rib fracture after accelerated partial breast irradiation: interim analysis of a Japanese prospective multi-institutional feasibility study.

We initiated the first multi-institutional prospective study of accelerated partial breast irradiation for early breast cancer in Japan. Our early clinical results showed that the treatment methods were technically reproducible between institutions and showed excellent disease control at a median follow-up of 26 months in our previous report. At present, total 46 patients from six institutions underwent the treatment regimen from October 2009 to December 2011, and the median follow-up time was 60 months (range, 57-67 months). In 46 patients, we experienced one patient who had rib fracture as a late complication. The dose-volume histogram (DVH) result of this patient was analyzed. The D0.01cc, D0.1cc, and D1cc values of the patient were 913, 817, and 664 cGy per fraction, respectively. These values were the highest values in 46 patients. The average D0.01cc, D0.1cc, and D1cc values of the other 45 patients were 546, 500, and 419, respectively, cGy per fraction. From this result, DVH values showing high-dose irradiated volume (D0.01cc, D0.1cc, and D1cc) seem to be a good predictive factor of rib fracture for accelerated partial breast irradiation. However, further investigation is necessary because of the small number of patients investigated.

Brachytherapy for Buccal Cancer: From Conventional Low Dose Rate (LDR) or Mold Technique to High Dose Rate Interstitial Brachytherapy (HDR-ISBT).

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.

Effect of intratumoral abscess/necrosis on the outcome for head and neck cancer patients treated by hypofractionated stereotactic re-irradiation using CyberKnife®.

The aim of the present study was to elucidate the effect of intratumoral abscess/necrosis (AN) on the outcome of patients with recurrent head and neck cancer (HNC) treated by stereotactic radiotherapy. The records of 67 patients treated with CyberKnife® in four institutes between August 2000 and July 2010 were reviewed. The frequency of AN appeared to be increased in younger postoperative patients with large ulcerative tumors. The AN+ group exhibited a better initial response rate compared with the AN- group (64 vs. 33%, respectively; P=0.04). The 1-year local control rate was 51 and 75% in the AN+ and AN- groups, respectively (P=0.01), while the respective 1-year overall survival rates were 53 and and 71% (P=0.0004). A total of 21 patients (31%) experienced grade ≥3 toxicities, and carotid blowout syndrome (CBOS) was found in 11 patients, resulting in 8 deaths. A significantly larger proportion of patients in the AN+ group developed CBOS (8/18; 44%) compared with the AN- group (3/49; 6%) (P=0.001). Therefore, AN may be an important prognostic factor for patients with recurrent HNC, as well as a predictor of lethal toxicity due to CBOS.

Uncertainty of cosmetic evaluation after accelerated partial breast irradiation: interim analysis of a Japanese prospective multi-institutional feasibility study.

PURPOSE: We conducted a multi-institutional prospective study on accelerated partial breast irradiation (APBI) using interstitial brachytherapy. The clinical results over a minimum follow-up period of 30 months are presented here. MATERIALS AND METHODS: Forty-six patients with breast cancer were treated with breast-conserving surgery and postoperative APBI. After confirmation of negative surgical margins and negative lymph nodes, a high-dose-rate brachytherapy protocol of 36 Gy/6 fractions was carried out. All clinical data were prospectively collected using the Common Terminology Criteria for Adverse Events ver. 3.0. RESULTS: No recurrence was observed. Cumulative rates of grade 2 or higher late sequelae were 25% for fibrosis, 2% for fractures, 9% for pain, and 9% for soft tissue necrosis. Rates of excellent or good cosmetic results as assessed by the physician and patient were 93 and 89% at the 12-month follow-up and 76 and 74% at the 30-month follow-up, respectively. Large volumes of resected tissue in small breasts were associated with fibrosis of grade 2 or higher. CONCLUSION: APBI in Japanese women provides satisfactory clinical results except for cosmetic outcomes. There is some difficulty with the assessment of fibrosis and cosmetic outcomes, especially in patients with small breasts. CLINICAL TRIAL REGISTRATION NUMBER: UMIN000001677.

Reirradiation for recurrent head and neck cancers using charged particle or photon radiotherapy.

OBJECTIVE: To examine the outcomes of reirradiation for recurrent head and neck cancers using different modalities. METHODS: This retrospective study included 26 patients who received charged particle radiotherapy (CP) and 150 who received photon radiotherapy (117 CyberKnife radiotherapy [CK] and 36 intensity-modulated radiotherapy [IMRT]). Inverse probability of treatment weighting (IPTW) involving propensity scores was used to reduce background selection bias. RESULTS: Higher prescribed doses were used in CP than photon radiotherapy. The 1­year overall survival (OS) rates were 67.9% for CP and 54.1% for photon radiotherapy (p = 0.15; 55% for CK and 51% for IMRT). In multivariate Cox regression, the significant prognostic factors for better survival were nasopharyngeal cancer, higher prescribed dose, and lower tumor volume. IPTW showed a statistically significant difference between CP and photon radiotherapy (p = 0.04). The local control rates for patients treated with CP and photon radiotherapy at 1 year were 66.9% (range 46.3-87.5%) and 67.1% (range 58.3-75.9%), respectively. A total of 48 patients (27%) experienced toxicity grade ≥3 (24% in the photon radiotherapy group and 46% in the CP group), including 17 patients with grade 5 toxicity. Multivariate analysis revealed that younger age and a larger planning target volume (PTV) were significant risk factors for grade 3 or worse toxicity. CONCLUSION: CP provided superior survival outcome compared to photon radiotherapy. Tumor volume, primary site (nasopharyngeal), and prescribed dose were identified as survival factors. Younger patients with a larger PTV experienced toxicity grade ≥3.

Nationwide, Multicenter, Retrospective Study on High-Dose-Rate Brachytherapy as Monotherapy for Prostate Cancer.

PURPOSE: To present, analyze, and discuss results of a nationwide, multicenter, retrospective study on high-dose-rate brachytherapy (HDR-BT) as monotherapy for low-, intermediate-, and high-risk prostate cancer. METHODS AND MATERIALS: From 1995 through 2013, 524 patients, 73 (14%) with low-risk, 207 (40%) with intermediate-risk, and 244 (47%) with high-risk prostate cancer, were treated with HDR-BT as monotherapy at 5 institutions in Japan. Dose fractionations were 27 Gy/2 fractions for 69 patients (13%), 45.5 Gy/7 fractions for 168 (32%), 49 Gy/7 fractions for 149 (28%), 54 Gy/9 fractions for 130 (25%), and others for 8 (2%). Of these patients, 156 (30%) did not receive androgen deprivation therapy, and 202 patients (39%) did receive androgen deprivation therapy <1 year, 112 (21%) for 1-3 years, and 54 (10%) for >3 years. Median follow-up time was 5.9 years (range, 0.4-18.1 years), with a minimum of 2 years for surviving patients. RESULTS: After 5 years, respective actuarial rates of no biochemical evidence of disease, overall survival, cause-specific survival, and metastasis-free survival for all patients were 92%, 97%, 99%, and 94%. For low/intermediate/high-risk patients, the 5-year no biochemical evidence of disease rates were 95%/94%/89%, the 5-year overall survival rates were 98%/98%/94%, the 5-year cause-specific survival rates were 98%/100%/98%, and the 5-year metastasis-free survival rates were 98%/95%/90%, respectively. The cumulative incidence of late grade 2 to 3 genitourinary toxicity at 5 years was 19%, and that of late grade 3 was 1%. The corresponding incidences of gastrointestinal toxicity were 3% and 0% (0.2%). No grade 4 or 5 of either type of toxicity was detected. CONCLUSIONS: The findings of this nationwide, multicenter, retrospective study demonstrate that HDR-BT as monotherapy was safe and effective for all patients with low-, intermediate-, and high-risk prostate cancer.