Stereotactic ablative brachytherapy versus percutaneous microwave ablation as salvage treatments for lung oligometastasis from colorectal cancer.

BACKGROUND: The treatment for lung oligometastasis from colorectal cancer (CRC) remains challenging. This retrospective study aimed to compare the local tumor control, survival and procedure-related complications in CRC patients undergoing low-dose rate stereotactic ablative brachytherapy (L-SABT) versus percutaneous microwave ablation (MWA) for lung oligometastasis. METHODS: Patients between November 2017 and December 2020 were retrospectively analyzed. Local tumor progression-free survival (LTPFS) and overall survival (OS) were analyzed in the entire cohort as well as by stratified analysis based on the minimal ablation margin (MAM) around the tumor. RESULTS: The final analysis included 122 patients: 74 and 48 in the brachytherapy and MWA groups, respectively, with a median follow-up of 30.5 and 35.3 months. The 1- and 3-year LTPFS rate was 54.1% and 40.5% in the brachytherapy group versus 58.3% and 41.7% in the MWA group (P = 0.524 and 0.889, respectively). The 1- and 3-year OS rate was 75.7% and 48.6% versus 75.0% and 50.0% (P = 0.775 and 0.918, respectively). Neither LTPFS nor OS differed significantly between the patients with MAM of 5-10 mm versus > 10 mm. Pulmonary complication rate did not differ in the overall analysis, but was significantly higher in the MWA group in the subgroup analysis that only included patients with lesion within 10 mm from the key structures (P = 0.005). The increased complications was primarily bronchopleural fistula. CONCLUSIONS: Considering the caveats associated with radioisotope use in L-SABT, MWA is generally preferable. In patients with lesion within 10 mm from the key pulmonary structures, however, L-SABT could be considered as an alternative due to lower risk of bronchopleural fistula.

Efficacy of radioactive 125I seed implantation in treating inoperable or refused operation head and neck cancers.

PURPOSE: This study aims to observe the curative effect of radioactive 125I seed implantation in treating inoperable or refused operation head and neck cancer. METHODS: Data from 132 patients with head and neck malignant tumors underwent computed tomography-guided radioactive 125I seed implantation from April 2004 to August 2020 were analyzed retrospectively. The Kaplan-Meier method was used to calculate the local control and survival rates. The logarithmic rank test and the Cox proportional risk model were used for univariate and multivariate analysis, respectively. RESULTS: A total of 132 patients were enrolled. All tumors were confirmed to be malignant through pathological analysis. Herein, we revealed that the seeds were implanted at the primary tumor site (23 cases, representing 17.4%), recurrent (9 cases, representing 6.8%), or metastatic lymph nodes (100 cases, representing 75.8%). Three months after the operation, 96 patients were evaluated as effective, whereas 36 patients were considered ineffective. The median local control time was 16 months; the local rates at 6, 12, 18, and 24 months were observed to be 75%, 47%, 35%, and 22%, respectively. The study reports a median survival period (OS) of 15 months. Additionally, the survival rates at 6, 12, 18, and 24 months were 61%, 42%, 31%, and 27%, respectively. Regarding side effects, skin or mucosal toxicity occurred in 14 patients. Grade I skin toxicity occurred in seven cases (5.3%), grade IV skin toxicity in one case (0.8%), grade I mucosal ulcer in four cases (3.0%), and grade I dry mouth in four cases (3.0%). The multivariate analysis showed that short-term efficacy and tumor site were independent prognostic factors (P < 0.001, 0.006, respectively). Additionally, the multivariate analysis showed that the independent OS influencing factors included D90, the longest tumor diameter, and short-term efficacy (P = 0.017, 0.001, <0.001). CONCLUSION: Radioactive 125I seed implantation is a safe and effective salvage therapy for patients with inoperable or refused operation head and neck cancer.

Treatment of malignant airway obstruction with Y-shape sigma stent loaded with I125 seeds installed via rigid bronchoscopy.

PURPOSE: To summarize and analyze the safety and efficacy of a Y-shape Sigma stent loaded with I125 in patients with inoperable malignant main airway obstruction. METHODS: This study was approved by the Institutional Ethics Committee, and a written informed consent was obtained from each participant. A Y-shape Sigma stent loaded with I125 was placed under vision from rigid bronchoscopy. The primary endpoint was alleviation of symptoms and improvement of Karnofsky Performance Status (KPS) score, and the secondary endpoint was complications and technical success. RESULTS: From November 2018 through June 2023, total 33 patients with malignant airway obstruction were palliatively treated by installing Y-shape Sigma stents loaded with I125. The airway lumen was immediately restored and the average airway opening significantly increased to 70 ± 9.4% after the procedure from baseline 30.2 ± 10.5% (p < 0.05). Average KPS score was improved from baseline 30.0 ± 10.0 to 70.0 ± 10.0 (p < 0.05) as well as PaO2 from baseline 50.1 ± 15.4 mmHg to 89.3 ± 8.6 mmHg (p < 0.05). The technical success rate of placing the stent in this study was 73%, and adverse events or complications including bleeding, I125 loss, and airway infection occurred during or after the procedure. CONCLUSION: Placement of Y-shape Sigma stents under vision from rigid bronchoscopy in the patients with malignant airway obstruction is feasible and it immediately alleviates dyspnea and significantly improves quality of life.

Clinical characteristics and radiation therapy modality of younger patients with early-stage endometrial cancer, a multicenter study in China's real world.

BACKGROUND: Endometrial cancer is a prevalent gynecologic malignancy found in postmenopausal women. However, in the last two decades, the incidence of early-stage has doubled in women under 40 years old. This study aimed to investigate the clinical and pathological characteristics and adjuvant therapeutic modalities of both young and not -young patients with early-stage endometrial cancer in China's real world. METHODS: This retrospective study analyzed patients with early-stage endometrial cancer at 13 medical institutions in China from 1999 to 2015. The patients were divided into two groups: young (≤ 45 years old) and non-young (> 45 years old). Statistical comparisons were conducted between the two groups for clinical characteristics, pathological features, and survival. The study also identified factors that affect local recurrence-free survival (LRFS) using Cox proportional risk regression analysis. Propensity score matching (1:1) was used to compare the effects of local control between vaginal brachytherapy (VBT) alone and pelvic external beam radiotherapy (EBRT) ± VBT. RESULTS: The study involved 1,280 patients, 150 of whom were 45 years old or younger. The young group exhibited a significantly higher proportion of stage II, low-risk, lower uterine segment infiltration (LUSI), and cervical invasion compared to the non-young group. Additionally, the young patients had significantly larger maximum tumor diameters. The young group also had a significantly higher five-year overall survival (OS) and a five-year LRFS. Age is an independent risk factor for LRFS. There was no significant difference in LRFS between young patients with intermediate- to high-risk early-stage endometrial cancer who received EBRT ± VBT and those who received VBT alone. CONCLUSIONS: In the present study, young patients had better characteristics than the non-young group, while they exhibited higher levels of aggressiveness in certain aspects. The LRFS and OS outcomes were better in young patients. Age is an independent risk factor for LRFS. Additionally, VBT alone may be a suitable option for patients under 45 years of age with intermediate- to high-risk early-stage endometrial cancer, as it reduces the risk of toxic reactions and future second cancers while maintaining similar local control as EBRT.

Long-term results of intraoperative multicatheter breast implant (IOMBI) for accelerated partial breast irradiation (APBI) on early breast cancer patients.

BACKGROUND AND PURPOSE: Multicatheter breast brachytherapy is a standard technique for accelerated partial breast irradiation (APBI) in early breast cancer patients. Intraoperative multicatheter breast implant (IOMBI) followed by perioperative high-dose-rate brachytherapy (PHDRBT) offers a novel and advantageous approach. We present long-term oncological, toxicity, and cosmesis outcomes for a well-experienced single institution. MATERIALS AND METHODS: Eligible women aged ≥ 40 years with clinically and radiologically confirmed unifocal invasive or in situ ≤ 3 cm breast tumors underwent IOMBI during breast-conserving surgery. Patients meeting APBI criteria by definitive pathologic results received 3.4 Gy × 10fx with PHDRBT. Patients not suitable for APBI received PHDRBT-boost followed by WBRT. RESULTS: A total of 171 patients underwent IOMBI during BCS, 120 patients (70.1 %) were suitable for APBI and 51 (29.8 %) for anticipated PHDRBT-boost. The median age was 61 years (range: 40-78), the median tumor size was 1.1 cm (range: 0.2-3.5), with a histological diagnosis of invasive ductal carcinoma in 78.9 % and ductal in situ in 21.1 %. A median of 9 catheters (range: 4-14) were used. For APBI, the median CTV and V100 were 40.8 cc (range: 8.6-99) and 35.4 cc (range: 7.2-94). The median of healthy breast tissue irradiated represents 7.2 % (range: 2.3-28 %) and the median local treatment duration was 10 days (range: 7-16). With a median follow-up of 8.8 years (range: 0.3-16.25), the 8-year local, locoregional, and distant control rates were 99 %, 98.1 %, and 100 %. G1-G2 late-toxicity rate was 53.4 %. Long-term cosmetic evaluation was excellent-good in 90.8 %. CONCLUSION: IOMBI&PHDRBT program reports excellent long-term oncological outcomes, with a reduction from unnecessary irradiation exposure which translates into low long-term toxicity and good cosmesis outcomes, especially on well-selected APBI patients.

Less than whole uterus irradiation for patients with locally advanced cervical cancer.

INTRODUCTION: Current consensus guidelines for definitive cervical cancer intensity modulated radiation therapy (IMRT) recommend inclusion of the entire uterus within the clinical target volume, however this is debated. We aimed to evaluate outcomes of patients with cervical cancer who were treated with less than whole uterus irradiation. METHODS: We identified 109 patients with FIGO Stage IB-IVA cervical cancer treated definitively with concurrent chemoradiation, including IMRT and brachytherapy, from 2010 to 2022 at a single institution where the practice was to include the gross cervix tumor with an internal target volume with differences in bladder filing accounted for, plus additional 5 mm planning target volume (PTV) margin. Local, regional, and distant recurrences were analyzed using competing risk methods, and a Wilcoxon rank sum test was performed to assess differences in dose to organs at risk based on the proportion of the uterus included in the PTV, with the median proportion of the uterus included (75 %) used as the cut-point. RESULTS: The median follow-up time was 65 months (range 3-352 months). The 2-year cumulative incidence of LR for the entire cohort was 4.2 % (95 % confidence interval [CI] 1.3-9.7). Compared with patients who had ≥ 75 % of the uterus included in the PTV, patients who had < 75 % of the uterus included in the PTV had significantly lower bowel D200cc (p = 0.02). The cumulative incidence of local failure (LR) was not significantly different between the two groups. CONCLUSIONS: Including less than the whole uterus for definitive cervix cancer IMRT does not seem to compromise local control. Less than whole uterus irradiation could be considered for carefully selected cervix cancer patients to decrease bowel dose and possible treatment-related toxicity.

Stereotactic ablative brachytherapy versus percutaneous microwave ablation for early-stage non-small cell lung cancer: a multicenter retrospective study.

BACKGROUND: To analyze the efficacy of stereotactic ablative brachytherapy (SABT) and percutaneous microwave ablation (MWA) for the treatment of early-stage non-small cell lung cancer (NSCLC). METHODS: Patients with early-stage (T1-T2aN0M0) NSCLC who underwent CT-guided SABT or MWA between October 2014 and March 2017 at four medical centers were retrospectively analyzed. Survival, treatment response, and procedure-related complications were assessed. RESULTS: A total of 83 patients were included in this study. The median follow-up time was 55.2 months (range 7.2-76.8 months). The 1-, 3-, and 5-year overall survival (OS) rates were 96.4%, 82.3%, and 68.4% for the SABT group (n = 28), and 96.4%, 79.7%, and 63.2% for MWA group (n = 55), respectively. The 1-, 3-, and 5-year disease-free survival (DFS) rates were 92.9%, 74.6%, and 54.1% for SABT, and 92.7%, 70.5%, and 50.5% for MWA, respectively. There were no significant differences between SABT and MWA in terms of OS (p = 0.631) or DFS (p = 0.836). The recurrence rate was also similar between the two groups (p = 0.809). No procedure-related deaths occurred. Pneumothorax was the most common adverse event in the two groups, with no significant difference. No radiation pneumonia was found in the SABT group. CONCLUSIONS: SABT provided similar efficacy to MWA for the treatment of stage I NSCLC. SABT may be a treatment option for unresectable early-stage NSCLC. However, future prospective randomized studies are required to verify these results.

Brachyterapy: The radiation oncologist opinion.

The role of the radiation oncologist in the management of patients affected by prostate cancer is increasingly considered thanks to important technological innovations that have marked the radiotherapeutic approach in its three main fields: external beam radiotherapy (EB-RT), brachytherapy (interventional radiotherapy, I-RT), and metabolic radiotherapy (M-RT) through the use of new radiopharmaceuticals. Regarding the modern brachytherapy, the introduction of intensity-modulated techniques (IM-IRT), thanks to the implementation of HDR remote-after loading machines, and image-guided techniques (IG-IRT), has led to advantages in optimizing dose distribution after implantation with the possibility of modulating the dose according to the intraprostatic dominant lesions, limiting the dose to the surrounding tissues with improvement in local control and a significant reduction in side effects. I-RT today represents a safe, scientifically established, effective and well-tolerated treatment for patients affected by prostate cancer. Like most special techniques, in order to obtain the best results, it must be performed in centers with a high volume of activity and consolidated experience with an interdisciplinary approach.

Effective Differences between 2D and 3D Planned Brachytherapy in Lung Cancer: An Institutional Retrospective Study.

Background and Objectives: Advanced lung cancer is usually manifested by endoluminal tumor propagation, resulting in central airway obstruction. The objective of this study is to compare the high dose rate brachytherapy treatment outcomes in non-small-cell lung cancer (NSCLC) depending on the treatment planning pattern-two-dimension (2D) or three-dimension (3D) treatment planning. Materials and Methods: The study was retrospective and two groups of patients were compared in it (a group of 101 patients who underwent 2D planned high-dose-rate endobronchial brachytherapy (HDR-EBBT) in 2017/18 and a group of 83 patients who underwent 3D planned HDR-EBBT between January 2021 and June 2023). Results: In the group of 3D planned brachytherapy patients, there was a significant improvement in terms of loss of symptoms of bronchial obstruction (p = 0.038), but no improvement in terms of ECOG PS (European Cooperative Oncology Group Performance Status) of the patient (p = 0.847) and loss of lung atelectasis (if there was any at the beginning of the disease) (p = 0.781). Two-year overall survival and time-to-progression periods were similar for both groups of patients (p = 0.110 and 0.154). Fewer treatment complications were observed, and 91.4% were in 3D planned brachytherapy (BT) patients. Conclusions: Three-dimensionally planned HDR-EBBT is a suggestive, effective palliative method for the disobstruction of large airways caused by endobronchial lung tumor growth. Independent or more often combined with other types of specific oncological treatment, it certainly leads to the loss of symptoms caused by bronchial obstruction and the improvement of the quality of life of patients with advanced NSCLC. Complications of the procedure with 3D planning are less compared to 2D planned HDR-EBBT.

Very accelerated partial breast irradiation in 1 or 2 days: Late toxicity and early oncological outcome of the GEC-ESTRO VAPBI cohort.

PURPOSE: To analyze late toxicity after very accelerated partial breast irradiation (VAPBI) for low-risk breast cancer. MATERIALS: Methods: In this retrospective, observational, international multicenter study (HDH F20220713143949), patients with low-risk breast cancer underwent lumpectomy + vAPBI (high-dose rate multicatheter interstitial brachytherapy-MIBT). VAPBI was performed with 4(4x6.2 Gy/2d), 3(3x7.45 Gy/2d) or 1 fraction (1x16Gy or 1x18Gy/1d). Primary endpoint was late toxicity. Secondary endpoints were cumulative incidence of breast cancer local relapse (LR) and distant metastatic relapse (DMR) and specific (SS) and overall (OS) survivals. Prognostic factors for late toxicity were analyzed. RESULTS: From 01/2012 to 06/2022, 516 pts with early breast cancer were enrolled. Median follow-up was 44 months [95 %CI 39-46]. Median age was 71 years [40-100]. Median tumor size was 12 mm [1-35]. VAPBI delivered 1, 3 and 4 fractions for 205pts (39.7 %), 167pts (32.4 %) and 144pts (28 %) respectively. 221 late toxicity events were observed in 168pts (32.6 %) (Fibrosis, dyschromia, pain and telangiectasia). Grade 2 and 3 late toxicities were observed in 7.2 and 0.6 % respectively (no G4) with no difference between 1 and ≥ 2 treatment days. CTV > 50 cc (p = 0.007) and V150 > 40 % (p = 0.027) were prognostic factors for G ≥ 2 late toxicity. Four-year cumulative incidence rates of LR and DMR were 2 % [95 %CI 0-3] and 1 % [95 %CI 0-2] respectively. CONCLUSIONS: VAPBI based on 1 or ≥ 2 days of MIBT represents an attractive de-escalation of irradiation approach for low-risk breast cancer. Late toxicity profile appears acceptable while early oncological outcome shows encouraging local control. Longer follow-up is warranted in order to confirm these preliminary results.

CT-guided radioactive 125I seeds brachytherapy for lung oligometastases from colorectal cancer: initial results.

OBJECTIVES: To evaluate the safety and effectiveness of computed tomography (CT)-guided radioactive 125I seeds brachytherapy (RISB) for lung oligometastases (LO) from colorectal cancer (CRC). METHODS: Data for 144 LOs from 70 CRC patients who underwent CT-guided RISB were retrospectively analyzed. The primary endpoints were progression-free survival (PFS) and overall survival (OS), and the secondary endpoints were technical success, local control rate (LCR), and complications. Kaplan-Meier method was used for survival analysis. Cox model was used to identify the independent predictors of poor prognosis. RESULTS: The RISB procedures were successfully performed in all patients, and the success rate was 100%. The median follow-up was 27.8 months. The median PFS was 10.0 months (95% CI: 8.9-11.1) and the 1- and 2-year PFS rates were 32.9% and 5.9%, respectively. On multivariate analysis, serum carcinoembryonic antigen (CEA) ≤ 15 ng/ml (P = 0.048), middle-high differentiated pathological classification (P = 0.015), primary TNM stages I-III (P = 0.001), LO number ≤ 2 (P < 0.001) and cumulative gross tumor volume (GTV) ≤ 40 cm3 (P < 0.001) showed superior PFS. The median OS was 30.8 months (95% CI: 27.1-34.4) and the 1-, 2-, and 3-year OS rates were 95.7%, 67.4%, and 42.5%, respectively. On multivariate analysis, serum CEA ≤ 15 ng/ml (P = 0.004), middle-high differentiated pathological classification (P < 0.001), primary TNM stages I-III (P < 0.001), LO number ≤ 2 (P < 0.001), cumulative GTV ≤ 40 cm3 (P < 0.001) and system treatments combined with chemotherapy and target therapy (P < 0.001) showed superior OS. The LCR for 3, 6, and 12 months was 97.9%, 91.0%, and 83.6%, respectively. There were 4 cases of pneumothorax at 5.7% that required drainage. CONCLUSIONS: RISB for LO from CRC is safe and effective, and serum CEA, TNM stage, LO number, cumulative GTV, and system treatments should be emphasized for long OS.

Efficacy and Safety of Brachytherapy for Localized Prostate Cancer in Renal Transplant Recipients.

BACKGROUND: Prostate cancer is common among male renal transplant recipients and can present challenges for medical management and patient survival. It is imperative to have a comprehensive understanding of available treatment options in this population to determine the most effective and safe therapies. Brachytherapy, a safe and effective treatment for localized prostate cancer, has not been sufficiently studied in this patient population. Therefore, this study aimed to evaluate the safety and effectiveness of brachytherapy in treating prostate cancer in renal transplant recipients. METHODS: We retrospectively reviewed our brachytherapy database to identify patients with a previous history of renal transplantation who underwent seed implantation for localized prostate cancer. Long-term prostate-specific antigen control and treatment-related toxicity, including graft dysfunction and urinary and rectal complications, were assessed and compared with published outcomes. Results were analyzed to evaluate the efficacy and safety of seed implantation in this patient population. RESULTS: We identified 2 patients with previous renal transplantation who underwent permanent seed implantation for localized prostate cancer. Follow-ups ranged from 53 to 57 months, and both patients remained free of prostate-specific antigen progression with normal graft function. No acute and late complications occurred. CONCLUSION: Brachytherapy is a safe and effective treatment option for post-renal transplant prostate cancer. Given the paucity of reports on brachytherapy in this population, the findings of this study, despite a small sample size, contribute to the increasing body of evidence supporting the use of brachytherapy in this patient population.

Preliminary report on ultrashort perioperative partial-breast irradiation with multicatheter interstitial brachytherapy for early-stage breast cancer.

PURPOSE: Perioperative partial-breast irradiation (PBI) with multicatheter interstitial brachytherapy (MIB) is less invasive and more convenient than postoperative one. This study aimed to compare ultrashort perioperative MIB-PBI (uPBI) and conventional perioperative MIB-PBI (cPBI) performed during the same period of time. METHODS: Inclusion criteria of the study were patients aged ≥ 40 years and those with T0-2 (≤ 3 cm), N0-mi, and negative margins on mammography. The locoregional recurrence (LRR) and toxicity rates were compared between uPBI at a dose of 25.2 Gy in four fractions and cPBI at a dose of 32 Gy in eight fractions. RESULTS: In total, 198 patients (151 with uPBI and 47 with cPBI) were evaluated. At a median follow-up of 20.1 months, one (0.66%) patient in the uPBI group had LRR. The 2-year ipsilateral breast tumor recurrence-free survival rates of the uPBI and cPBI groups were 98.7% and 100%, respectively. The highest toxicity grades were grade 1 in 23 (15.2%) and grade 2 in 2 (1.3%) patients in the uPBI group, and grade 1 in 8 (17.0%) and grade 2 in 1 (2.1%) patient in the cPBI group. None of the patients in the two groups presented with grade 3 and higher toxicities. The toxicity rates between the two groups did not significantly differ. Further, 22 (14.6%) patients in the uPBI group and 8 (17.0%) in the cPBI group, and 3 (2.0%) patients in the uPBI group and 1 (2.1%) in the cPBI had acute and late toxicities, respectively. The timing of toxicity development between the two groups did not significantly differ. CONCLUSIONS: Although this preliminary report included a small sample size and had a short follow-up period, the local control and toxicity rates were similar between the uPBI and cPBI groups. Further research is warranted to investigate the ideal dose schedule of MIB-PBI.

Retrospective Analysis of All Types of Adjuvant Radiotherapy in Endometrial Cancer: Single-Center Experiences in a Middle-Income Country.

OBJECTIVE: We retrospectively analyzed the efficacy, focusing on overall survival (OS) and the patterns of failure, along with the toxicities of adjuvant radiotherapy (RT) in endometrial cancer patients. METHODS: Two-hundred and nineteen patients with endometrial cancer patients who received adjuvant radiotherapy ± adjuvant chemotherapy (ACT) from January 2014 to December 2018 were investigated for overall survival (OS), local recurrence-free survival rate (LRFS), regional recurrence-free survival rate (RRFS), and distant metastasis-free survival rate (DMFS). RESULT: Two-hundred and fourteen patients were evaluated. The numbers of VBT alone, EBRT plus VBT, and adjuvant chemotherapy (ACT) plus EBRT plus VBT were 65 (30.4%), 80 (37.4%), and 69 (32.2%) patients, respectively. Stage I (107 patients) was the most common followed by stage III (87 patients). With a median follow-up time of 67 months (IQR 56-78), the 5-year overall survival rates for VBT alone, EBRT plus VBT, and EBRT plus VBT plus ACT were 84.4%, 65%, and 57.4%, respectively. The most common severe (grade 3-4) acute toxicity was neutropenia (4.6%), followed by diarrhea (3.7%). Grade 3-4 late proctitis was found in only 1.9%. On multivariate analysis, advanced age (HR 6.15, p: 0.015), lymph node involvement (HR 6.66, p: 0.039), cervical involvement (HR 10.60, p: 0.029), and substantial LVSI (HR 21.46, p: 0.005) were associated with a higher risk of death. CONCLUSION: Advanced age (>65), substantial LVSI, lymph node involvement, and cervical stromal involvement were associated with poor overall survival. These findings here will help identifying high-risk patients and would make it possible to avoid unnecessary adjuvant treatment among patients with a good prognosis.

Brachytherapy for high grade prostate cancer induces distinct changes in circulating CD4 and CD8 T cells - Implications for systemic control.

This exploratory study is a follow up to our previous investigation of immune response in the circulation of high-grade Gleason 9 prostate cancer patients treated with EBRT + BT compared to EBRT alone. Notably, EBRT + BT demonstrates the potential to elicit an effect on CD4/CD8 ratio which may have attributed to improved clinical response to therapy. Our findings show promise for leveraging circulating immune cells as predictive biomarkers for radiotherapy response.

Effectiveness and toxicity of five-fraction prone accelerated partial breast irradiation.

PURPOSE: Our institution was an early adopter of 5-fraction accelerated partial breast irradiation (ABPI) to treat women with early-stage breast cancer. This study reports long-term oncologic and cosmetic outcomes. METHODS: We included patients receiving APBI 600 cGy × 5 fx delivered every other day or every day between 2010 and 2022. Logistic regression models were used to identify factors associated with development of late toxicities, clinician, and patient-rated cosmesis. Kaplan-Meier methodology was used to calculate overall survival (OS), disease-free survival (DFS), and locoregional recurrence-free survival (LR-RFS). RESULTS: 442 patients received APBI either daily (56%) or every other day (44%) in the prone position (92%). At a median follow-up of 48 months (range: 5.96-155 months), 12 (2.7%) patients developed a local recurrence (LR). Out of 258 patients with > 3-month toxicity data available, the most common late grade ≥ 2 adverse event was breast fibrosis (6.2%). On multivariate analysis, daily APBI treatment (vs every other day) did not correlate with an increased risk of any late grade ≥ 2 toxicity though it did correlate with a lower risk of any late grade ≥ 2 fibrosis. Overall, at a median follow-up of 80 months, the rates of good-excellent physician and patient-rated cosmesis were 95% and 85%, respectively, with no difference between patients treated on consecutive vs. every other day. On multivariate analysis, patients who did not receive any adjuvant therapy were at increased risk of developing a LR. Five-year OS, LRFS, and DFS were 97.2%, 97.7%, and 89.5%, respectively. CONCLUSIONS: Five-fraction APBI delivered primarily in the prone position either daily or every other day was effective with low rates of local recurrence, minimal toxicity, and excellent cosmesis at long-term follow-up.

Intraoperative Radiation Therapy Delivered by Brachytherapy in Breast Cancer: An Interim Analysis of a Phase 2 Trial.

PURPOSE: Intraoperative breast cancer radiotherapy (IORT) offers an alternative to external beam radiotherapy (EBRT) after breast-conserving surgery (BCS). The Intraoperative brachytherapy (IOBT) trial applies high dose rate (HDR) brachytherapy with a new applicator prototype as IORT after BCS. In this interim analysis of the IOBT trial, we present the oncological safety and toxicity of the method METHODS: Eligible patients were women, ≥ 50 years old with an unifocal nonlobular, estrogen-receptor-positive, HER2-negative breast cancer, cN0, ≤ 3 cm, treated with BCS and sentinel node biopsy (SNB). Toxicity was registered according to the LENT-SOMA scale. Cumulative incidence of local (LR) and regional recurrence (RR) were calculated through cumulative incidence function whereas overall survival (OS) was illustrated through Kaplan-Meier curve. RESULTS: Until February 2023, 155 women (median age 68 years) were included in the trial. Twenty-nine women (18.7%) received supplemental EBRT, mostly due to positive SNB. Three-year cumulative incidence of LR and RR were 1.0% (CI 95 % 0.1%-2.3%) and 2.1% (CI 95% 0.8%-4.2%) respectively. Five- year cumulative incidence of LR and RR were 3.9% (CI 95% 1.8%-6.4%) and 2.1% (CI 95% 0.8%-4.2%) respectively. Five-year OS was 96.3% (CI 95% 93.6%-98.4%). Side effects were limited, low grade, and transient. CONCLUSION: Acknowledging the short median follow-up time at interim analysis, our initial results indicate that delivering IORT through HDR brachytherapy in carefully selected breast cancer patients is feasible and oncological safe so far. A long-term follow-up is essential to confirm the initial results.

High-Dose Rate Brachytherapy Combined with PD-1 Blockade as a Treatment for Metastatic Adrenocortical Carcinoma - A Single Center Case Series.

The response rate of advanced adrenocortical carcinoma (ACC) to standard chemotherapy with mitotane and etoposide/doxorubicin/cisplatin (EDP-M) is unsatisfactory, and benefit is frequently short lived. Immune checkpoint inhibitors (CPI) have been examined in patient's refractory to EDP-M, but objective response rates are only approximately 15%. High-dose rate brachytherapy (HDR-BT) is a catheter-based internal radiotherapy and expected to favorably combine with immunotherapies. Here we describe three cases of patients with advanced ACC who were treated with HDR-BT and the CPI pembrolizumab. None of the tumors were positive for established response markers to CPI. All patients were female, had progressed on EDP-M and received external beam radiation therapy for metastatic ACC. Pembrolizumab was initiated 7 or 23 months after brachytherapy in two cases and prior to brachytherapy in one case. Best response of lesions treated with brachytherapy was complete (n=2) or partial response (n=1) that was ongoing at last follow up after 23, 45 and 4 months, respectively. Considering all sites of tumor, response was complete and partial remission in the two patients with brachytherapy prior to pembrolizumab. The third patient developed progressive disease with severe Cushing's syndrome and died due to COVID-19. Immune-related adverse events of colitis (grade 3), gastroduodenitis (grade 3), pneumonitis (grade 2) and thyroiditis (grade 1) occurred in the two patients with systemic response. HDR-BT controlled metastases locally. Sequential combination with CPI therapy may enhance an abscopal antitumoral effect in non-irradiated metastases in ACC. Systematic studies are required to confirm this preliminary experience and to understand underlying mechanisms.

Dose and fractionation regimen for brachytherapy boost in cervical cancer in the US.

PURPOSE: Curative-intent radiotherapy for locally advanced and select early stage cervical cancer in the US includes external beam radiotherapy (EBRT) with brachytherapy. Although there are guidelines for brachytherapy dose and fractionation regimens, there are limited data on practice patterns. This study aims to evaluate the contemporary utilization of cervical cancer brachytherapy in the US and its association with patient demographics and facility characteristics. METHODS: We retrospectively analyzed clinical covariates of cervical cancer patients diagnosed and treated in 2018-2020 with curative-intent radiotherapy from the 2020 National Cancer Database. Associations between patient and institutional factors with the number of brachytherapy fractions were identified with logistic regression. Factors with association (p < 0.10) were then included in a multivariable logistic regression model. All tests were two-sided with significance <0.05 unless specified otherwise. RESULTS: Among the eligible 2517 patients, 97.3% received HDR or LDR and is further analyzed. More patients received HDR than LDR brachytherapy (98.9% vs 1.1%) and intracavitary than interstitial brachytherapy (86.4% vs 13.6%). The most common number of HDR fractions prescribed were 5 (51.0%), 4 (32.9%), and 3 (8.6%). After adjusting for the other variables in the model, ethnicity, private insurance status, overall insurance status, and facility type were the only factors that were significantly associated with the number of brachytherapy factions (p < 0.0001, p = 0.028, p = 0.001, and p < 0.0001, respectively, n = 2184). CONCLUSIONS: In the US, various HDR brachytherapy regimens are utilized depending on patient and institutional factors. Future research may optimize cervical cancer brachytherapy by correlating specific dose and fractionation regimens with patient outcomes.