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.

The influence of Gleason score ≤ 6 histology on the outcome of high-risk localized prostate cancer after modern radiotherapy.

We aimed to retrospectively review outcomes in patients with high-risk prostate cancer and a Gleason score ≤ 6 following modern radiotherapy. We analyzed the outcomes of 1374 patients who had undergone modern radiotherapy, comprising a high-risk low grade [HRLG] group (Gleason score ≤ 6; n = 94) and a high-risk high grade [HRHG] group (Gleason score ≥ 7, n = 1125). We included 955 patients who received brachytherapy with or without external beam radio-therapy (EBRT) and 264 who received modern EBRT (intensity-modulated radiotherapy [IMRT] or stereotactic body radiotherapy [SBRT]). At a median follow-up of 60 (2-177) months, actuarial 5-year biochemical failure-free survival rates were 97.8 and 91.8% (p = 0.017), respectively. The frequency of clinical failure in the HRLG group was less than that in the HRHG group (0% vs 5.4%, p = 0.012). The HRLG group had a better 5-year distant metastasis-free survival than the HRHG group (100% vs 96.0%, p = 0.035). As the HRLG group exhibited no clinical failure and better outcomes than the HRHG group, the HRLG group might potentially be classified as a lower-risk group.

Hands-on-training tailored in response to pre-questionnaire-based survey on image-guided brachytherapy effectively reduces anxiety about its implementation.

This study assessed the significance of hands-on-training (HoT) and questionnaire-based surveys on 3D image-guided brachytherapy (3D-IGBT) and a combination of intracavitary and interstitial brachytherapy, the so-called 'hybrid' BT (HBT), in uterine cervical cancer. In October 2023, 29 radiation oncologists, nurses, radiologic technologists and medical physicists from 10 Japanese facilities participated in an HoT on 3D-IGBT and HBT. Questionnaires were distributed to each participant before and after the HoT, and feedback was obtained through online channels. The questionnaire response rate was 83% (24/29), with at least one participant responding from each facility. 'Insertion of applicators and needles', 'human resource shortage' and 'pain relief and sedation' were the primary concerns of radiation oncologists. 'Applicator reconstruction', ' optimization of dwell positions', ' treatment planning' and ' human resource shortages ' were the primary concerns of radiological technologists and medical physicists. The HoT content was adjusted according to the results of preliminary surveys. The concerns expressed by the participants were addressed during the lectures and practical training. Significant reductions in anxiety were observed toward all items of the 10-point self-assessment after the HoT, regardless of the profession. The average score on satisfaction with the HoT (on a 10-point scale) was 9.52 (minimum of 8 and maximum of 10). In conclusion, HoT tailored in response to a pre-questionnaire-based survey effectively reduced participants' anxiety regarding the implementation of 3D-IGBT and HBT.

Novel image-guided marker aimed at organ-preserving therapies for prostate cancer.

OBJECTIVE: We developed fiducial imaging-guidance markers for the prostate with less imaging artifacts than currently commercially available markers. The aim of this study was to evaluate the imaging artifacts and potential usefulness and safety of these novel fiducial imaging markers in preclinical experiments. METHODS: We selected specific metal materials and a shape that can minimize artifacts in line with a license we obtained for a metal with a gold-platinum (Au-Pt) alloy composition that maximized artifact-free MRI images. Both phantom and canine prostate tests were conducted in order to evaluate the imaging artifacts for three imaging modalities, MRI, CT and ultrasound, and the risk of migration of the markers from the site of insertion to elsewhere, as well as crushing. RESULTS: The newly developed Au-Pt material had less imaging artifacts in the MRI, CT and ultrasound imaging modalities in comparison with current commercially available fiducial markers made from gold materials only. The Au-Pt markers had sufficient strength and durability and were considered to be potentially clinically useful and safe markers. CONCLUSION: The developed Au-Pt markers could be potential tools for accurate lesion-targeted, organ-preserving therapies such as lesion-targeted focal therapy and active surveillance in addition to conventional radiation therapies.

Patterns of care for brachytherapy in Japan.

This study aimed to assess the current state of brachytherapy (BT) resources, practices and resident education in Japan. A nationwide survey was undertaken encompassing 177 establishments facilitating BT in 2022. Questionnaires were disseminated to each BT center, and feedback through online channels or postal correspondence was obtained. The questionnaire response rate was 90% (159/177), and every prefecture had a response in at least one center. The number of centers in each prefecture ranged from 0.6 to 3.6 (median: 1.3) per million population. The annual number of patients in each center ranged from 0 to 272 (median: 31). While most prefectures provided intracavitary (IC) BT for gynecological cancers and interstitial (IS) BT for prostate cancer, only one-third of the prefectures provided IS BT for cancer sites other than the prostate. The institutional image-guided BT implementation rate was 71%. IC and IS BT was performed for 15.4% of IC BT cases of gynecological cancer. Only 47% of the BT training centers answered that they could provide adequate training in BT for residents. The most common reason for this finding was the insufficient number of patients in each center. The results show that, although BT has achieved uniformity in terms of facility penetration, new technologies are not yet widespread enough. Furthermore, IS BT, which requires advanced skills, is limited to a few BT centers, and considerable number of BT training centers do not have sufficient caseloads to provide the necessary experience for their residents.

Ultra-High Prostate-Specific Antigen Level: A Potential Very-High-Risk Factor for Localized High-Risk Prostate Cancer.

To examine the impact of ultra-high iPSA levels of >50 ng/mL (uhPSA) after modern radiotherapy, we compared outcomes of 214 patients with uhPSA levels to 1161 other high-risk patients. Radiotherapy included brachytherapy ± external beam radiotherapy (EBRT) and EBRT alone (intensity-modulated radiotherapy or stereotactic body radiotherapy). The biochemical disease-free survival rate (bDFS), the distant metastasis-free survival rate (DMFS), local control, and pelvic lymph node control were analyzed. Patients with uhPSA levels had an inferior bDFS (84.8% at 5 years) and DMFS (93.9% at 5 years) compared to other high-risk patients (92.7% and 97.2%, both p < 0.001). The uhPSA group showed more distant metastases than the non-uhPSA group; however, the frequencies of local failure and pelvic lymph node recurrence were similar. The uhPSA group demonstrated hazard ratios (HRs) of 2.74 for bDFS and 2.71 for DMFS, similar to those of T3b-4 (HR 2.805 and 2.678 for bDFS and DMFS) and GS 9-10 (HR 2.280 and 2.743 for bDFS and DMFS). An uhPSA level could be a candidate for a single VHR factor to identify high-risk patients who require intensified treatment.

The Feasibility of Omitting Postoperative Radiotherapy in Japanese Patients With Ductal Carcinoma In Situ of Breast Treated With Breast-Conserving Surgery.

Background To analyze the feasibility of omitting postoperative radiotherapy (PORT) after breast-conserving surgery (BCS) in Japanese patients with ductal carcinoma in situ (DCIS). Materials and methods We retrospectively analyzed 88 patients with small pure DCIS (median diameter 1.1 cm, ≤ 4 cm) who underwent BCS with (n = 39) or without (n = 49) PORT. The primary and secondary endpoints were ipsilateral breast tumor recurrence (IBTR) and overall survival (OS), respectively, between the groups that received PORT and those that did not. Results The PORT group included a high number of margin-positive cases. The incidence of IBTR was 2.4% (95% confidence interval (CI), 0.3-15.7%) and 2.8% (95% CI, 0.4-18.2%) at five years and 5.5% (95% CI, 1.4-20.6%) and 2.8% (95% CI, 0.4-18.2%) at 10 years in patients without and with PORT, respectively (p = 0.686). In the margin-negative group, only one patient showed IBTR without RT (2.3%), whereas no patient with PORT experienced IBTR (0%). To date, there have been no regional or distant metastases; therefore, no patient has experienced breast cancer-related deaths. The OS rates were 97.7% (95% CI, 84.9-99.6%) and 100% at 10 years in patients without and with PORT, respectively (p = 0.372). Conclusion This study suggests that the omission of PORT after BCS could be a feasible option for selected Japanese patients but requires further investigation to identify the low-risk factor in patients who can omit PORT.

The prognosis of patients with prostate cancer receiving permanent seed implantation stratified by prostate volume: Should we be reluctant to treat with brachytherapy because of a very small prostate (<15 cc)?

PURPOSE: We evaluated the treatment outcomes of different prostate volumes (PVs), <15 cc, 15-20 cc, and > 20 cc, in patients with prostate cancer who underwent permanent seed implantation (PI) ± external beam radiation therapy ± hormone therapy in a national Japanese prospective cohort study (J-POPS). METHODS AND MATERIALS: Of the 6721 patients in J-POPS from 2005 to 2011, 6652 were included in the analysis population. We categorized the patients into the following three PV groups: <15 cc, 15-20 cc, and > 20 cc. We evaluated the effect of PV on biochemical freedom from failure (bFFF), prostate cancer-specific mortality (PCSM), and all-cause mortality (ACM) using the Phoenix definition and Cox proportional hazard models. RESULTS: The median follow-up period was 60.0 months. Patients in each PV group was 491 (7.4%), 1118 (16.8%), and 5043 (75.8%), respectively. No difference was observed in bFFF (94.7%, 96.2%, and 95.7%, p = 0.407), PCSM (99.8%, 99.7%, and 99.8%, p = 0.682), and ACM (98.2%, 96.7%, and 97.2%, p = 0.119) at 5 years for each PV group. In univariate and multivariate analyses, PV was not associated with bFFF, PCSM, ACM, or grade 2 toxicity. The percentage of positive biopsies was the single most significant predictor for all treatment outcomes. CONCLUSIONS: Our results obtained by analyzing a very large Japanese prospective database showed no difference in treatment outcomes according to PV (<15 cc, 15-20 cc, and ˃20 cc). Our study confirmed that PI in small prostates (even < 15 cc) remains an effective treatment option.

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.

Hands-on seminar for image-guided adaptive brachytherapy and intracavitary/interstitial brachytherapy for uterine cervical cancer.

OBJECTIVE: Compared with the implementation speed of image-guided adaptive brachytherapy for uterine cervical cancer, that of intracavitary and interstitial brachytherapy is slow, possible because it requires more invasive procedure of inserting needles directly into tumours. To accelerate the implementation speed of intracavitary and interstitial brachytherapy, a first hands-on seminar for image-guided adaptive brachytherapy and intracavitary and interstitial brachytherapy for uterine cervical cancer was held on 26 November 2022, supported by Japanese Society for Radiology and Oncology. This article deals with this hands-on seminar and difference of degree of confidence of participants in starting intracavitary and interstitial brachytherapy before and after the seminar. METHODS: The seminar consisted of lectures regarding intracavitary and interstitial brachytherapy in the morning and hands-on practice of needle insertion and contouring, as well as dose calculation practice using the radiation treatment system in the evening. Prior to and following the seminar, participants completed a questionnaire asking about their level of confidence in performing intracavitary and interstitial brachytherapy, expressed between 0 and 10 (the higher the number, the stronger the confidence). RESULTS: A total of 15 physicians, six medical physicists and eight radiation technologists from 11 institutions attended the meeting. The median level of confidence before and after the seminar was 3 (range, 0-6) and 5.5 (range, 3-7), respectively, and a statistically significant improvement was observed (P<0.001). CONCLUSION: It was suggested that the hands-on seminar on intracavitary and interstitial brachytherapy for locally advanced uterine cervical cancer improved the level of confidence of the attendees and propelled their motivation, through which it is expected that the implementation of intracavitary and interstitial brachytherapy will be accelerated.

Biochemical outcomes and toxicities in young men with prostate cancer after permanent iodine-125 seed implantation: Prospective cohort study in 6662 patients.

PURPOSE: We evaluated the effect of age, <60 and ≥60 years, on biochemical outcomes and toxicities in patients with prostate cancer who underwent permanent seed implantation (PI) ± external beam radiation therapy ± hormone therapy in a national Japanese prospective cohort study (J-POPS). METHODS AND MATERIALS: The safety and efficacy analyses included 6721 and 6662 patients, respectively. We categorized patients into two age groups: <60 (n = 716) and ≥60 (n = 6,005) years. We used propensity score matching (PSM) to estimate the marginal effect of age on biochemical freedom from failure (bFFF) using a Phoenix definition and Cox proportional hazard models. RESULTS: The median followup period was 60.0 months. Without PSM, men <60 years demonstrated similar 5-year bFFF (96.3%) compared with men ≥60 years (95.6%; p = 0.576); percent positive biopsies, biologically effective dose, Gleason score, risk classification, and supplemental external beam radiation therapy (p <0.001, <0.001, <0.001, 0.008, and <0.001) were significantly associated with bFFF while age was not (p = 0.576). With PSM, bFFF was not significantly different between age groups (p = 0.664); however, men <60 years showed a significantly lower incidence of declining erectile function, grade ≥2 all urinary toxicities, urinary frequency/urgency, and rectal bleeding (p <0.001, 0.024, 0.031, and 0.010) than men ≥60 years. CONCLUSIONS: After PI, men <60 years achieved a comparable 5-year biochemical control rate and showed a lower incidence of several toxicities compared to men ≥60 years. This suggests that PI should be an excellent treatment option for men <60 years with prostate cancer.

The combination of volumetric arc radiation therapy and boost high-dose rate interstitial brachytherapy for T3N2c tongue cancer: a technical report.

Currently, tongue cancers are primarily managed by surgery, and interstitial brachytherapy is only recommended for a selected group of early state T1-2N0 patients who refuse surgery or are medically inoperable. In this report, a case with T3N2cM0 tongue cancer who has been effectively treated by the combination of concurrent chemoradiotherapy involving volumetric arc therapy and boost high-dose rate interstitial brachytherapy is presented. Of course, surgery remains the main treatment strategy for tongue cancer patients; however, the authors believe that if volumetric arc therapy is carefully planned to reduce the mandible dose as much as possible and high-dose rate interstitial brachytherapy with a mouthpiece that protects the mandible is combined, it is possible to treat T3N2 disease, and this can be considered for patients who want to preserve organ function.

Chemoradiation versus surgery for superficial esophageal squamous cell carcinoma after noncurative endoscopic submucosal dissection: comparison of long-term oncologic outcomes.

BACKGROUND: Esophagectomy is the standard adjuvant treatment for superficial esophageal squamous cell carcinoma (SESCC) following noncurative endoscopic submucosal dissection (ESD). However, recent reports have also shown that ESD with adjuvant chemoradiotherapy (CRT) has promising results. This retrospective study aimed to elucidate the efficacy of CRT compared to surgery in patients with SESCC after noncurative ESD. METHODS: This study retrospectively compared the long-term outcomes of patients who received adjuvant treatment with surgery or CRT after noncurative ESD for SESCC. RESULTS: Data were collected from 60 patients who developed SESCC after noncurative ESD, 34 of whom received adjuvant chemoradiotherapy (CRT) and 26 underwent esophagectomy. The median follow-up periods were 46 and 56 months in the CRT and esophagectomy groups, respectively. The median patient age was significantly higher in the CRT group than in the esophagectomy group (69 vs. 65 years, p = 0.0054). CRT was completed in all patients, and the incidence of grade ≥ 3 nonhematologic adverse events was 6%. The overall and disease-free survival did not significantly differ between the two groups. CONCLUSIONS: CRT following ESD seems a promising nonsurgical strategy for optimizing the selection of therapies for high-risk SESCC and warrant further investigation.

Palliative Radiation Therapy for Intramedullary Spinal Cord Metastasis.

BACKGROUND/AIM: The purpose of this study was to retrospectively review the outcomes of intramedullary spinal cord metastasis (ISCM) and identify predictors for ambulation after radiotherapy (RT). PATIENTS AND METHODS: We analyzed 16 lesions in 15 patients treated with RT for ISCM at our clinic from October 2009 to April 2020 to evaluate predictors for improved ambulation following RT. RESULTS: The primary diseases included nine cases of lung cancer, two cases of breast cancer, and several others. The RT schedule was primarily 30 Gy/10 fractions in seven cases, while others were applied to nine cases. The median overall survival time was 99 days. After RT, all seven patients who could walk prior to RT were still able to walk (100%), whereas only two of nine patients who could not walk prior to RT were able to walk (22%, p=0.004). CONCLUSION: Ambulation prior to RT was a significant predictor of ambulation ability after RT.

＜Editors' Choice＞ Elective nodal irradiation versus involved field radiotherapy for limited disease small cell lung cancer: a single-institution experience.

Elective nodal irradiation (ENI) and involved field radiotherapy (IFRT) are definitive radiotherapeutic approaches used to treat patients with limited-disease small cell lung cancer (LD-SCLC). However, no solid consensus exists on their optimal target volume. The current study aimed to assess the clinical outcomes of patients with LD-SCLC who received definitive ENI or IFRT. A retrospective single-institution study of patients who received definitive radiotherapy between 2008 and 2020 was performed. All patients underwent whole-body positron emission tomography/computed tomography before three-dimensional conformal radiotherapy. Among the 37 patients analyzed, 22 and 15 received ENI and IFRT, respectively. The thoracic radiotherapy dose was mostly either 60 Gy in 30 fractions delivered in 2-Gy fractions once daily or 45 Gy in 30 fractions delivered in 1.5-Gy fractions twice daily. The median follow-up period was 21.4 months. A total of 12 patients (32%) experienced locoregional relapse: 10 within and 2 outside the irradiation fields. One patient in the IFRT group experienced isolated nodal failure. Differences in locoregional relapse-free, progression-free, and overall survival rates between ENI and IFRT were not significant. Overall, IFRT did not promote a significant increase in locoregional recurrence compared to ENI. Our findings suggested the utility of IFRT in standard clinical practice and support its use for patients with LD-SCLC.

Role of Brachytherapy Boost in Clinically Localized Intermediate and High-Risk Prostate Cancer: Lack of Benefit in Patients with Very High-Risk Factors T3b-4 and/or Gleason 9-10.

This study examined the role of brachytherapy boost (BT-boost) and external beam radiotherapy (EBRT) in intermediate- to high-risk prostate cancer, especially in patients with very high-risk factors (VHR: T3b-4 or Gleason score 9-10) as patients with double very high-risk factors (VHR-2: T3b-4 and Gleason score 9-10) previously showed worst prognosis in localized prostate cancer. We retrospectively reviewed multi-institutional data of 1961 patients that were administered radiotherapy (1091 BT-boost and 872 EBRT: 593 conventional-dose RT (Conv RT: equivalent to doses of 2 Gy per fraction = EQD2 ≤ 72 Gy) and 216 dose-escalating RT (DeRT = EQD2 ≥ 74 Gy). We found that BT-boost improved PSA control and provided an equivalent overall survival rate in the intermediate- and high-risk groups, except for patients within the VHR factor group. In the VHR-1 group (single VHR), BT-boost showed a superior biochemical control rate to the Conv RT group but not to the DeRT group. In the VHR-2 group, BT-boost did not improve outcomes of either Conv RT or DeRT groups. In conclusion, BT-boost showed no benefit to modern DeRT in the patients with VHR; therefore, they are not good candidates for BT-boost to improve outcome and may be amenable to clinical trials using multimodal intensified systemic treatments.

Comparison of toxicities between ultrahypofractionated radiotherapy versus brachytherapy with or without external beam radiotherapy for clinically localized prostate cancer.

To compare gastrointestinal (GI) and genitourinary (GU) toxicities in patients with localized prostate cancer treated with ultrahypofractionated radiotherapy (UHF) or brachytherapy [BT; low dose rate, LDR or high dose rate (HDR) with or without external beam radiotherapy (EBRT)]. We compared 253 UHF and 1664 BT ± EBRT groups. The main outcomes were the incidence and severity of acute and late GU and GI toxicities. The secondary endpoint was biochemical control rate. Cumulative late actuarial GU toxicity did not differ for grade ≥ 2 (8.6% at 5-years in UHF and 13.3% in BT ± EBRT, hazard ratio [HR], 0.7066; 95% CI, 0.4093-1.22, p = 0.2127). Actuarial grade ≥ 2 late GI toxicity was higher in UHF (5.8% at 5-years, HR: 3.619; 95% CI, 1.774-7.383, p < 0.001) than in BT ± EBRT (1.1%). In detailed subgroup analyses, the high-dose UHF group (H-UHF) using BED ≥ 226 Gy1.5, showed higher GI toxicity profiles than the other subgroups (HDR + EBRT, LDR + EBRT, and LDR monotherapy, and L-UHF BED < 226 Gy1.5) with equivalent GU toxicity to other modalities. With a median follow-up period of 32 months and 75 months, the actuarial biochemical control rates were equivalent between the UHF and BT ± EBRT groups. UHF showed equivalent efficacy, higher GI and equivalent GU accumulated toxicity to BT ± EBRT, and the toxicity of UHF was largely dependent on the UHF schedule.

3D-Image-Guided Multi-Catheter Interstitial Brachytherapy for Bulky and High-Risk Stage IIB-IVB Cervical Cancer.

This study aimed to evaluate the efficacy and safety of computed tomography-magnetic resonance imaging (CT-MRI)-guided multi-catheter interstitial brachytherapy for patients with bulky (≥4 cm) and high-risk, stage IIB-IVB advanced cervical cancer. Eighteen patients who underwent concurrent chemoradiotherapy with multi-catheter interstitial brachytherapy between September 2014 and August 2020 were enrolled. The prescribed dose of external beam radiotherapy was 45-50.4 Gy, and the brachytherapy high-dose-rate aim was 25-30 Gy per 5 fractions. The endpoints were four-year local and pelvic control rates, four-year disease-free and overall survival rates, and the adverse events rate. The median follow-up period was 48.4 months (9.1-87.5 months). Fifteen patients received concurrent cisplatin therapy (40 mg/m2, q1week). Four (22.2%), seven (38.9%), and seven (38.9%) patients had stage II, III, and IV cervical cancer, respectively. Pelvic and para-aortic lymph node metastases were observed in 11 (61.1%) and 2 (11.1%) patients, respectively. The median pre-treatment volume was 87.5 cm3. The four-year local control, pelvic control, disease-free survival, and overall survival rates were 100%, 100%, 81.6%, and 87.8%, respectively. Three (16.7%) patients experienced grade 3 adverse events, and none experienced grade 4-5 adverse events. CT-MRI-guided multi-catheter interstitial brachytherapy could be a promising treatment strategy for locally advanced cervical cancer.