Brachytherapy: An overview for clinicians.

Brachytherapy is a specific form of radiotherapy consisting of the precise placement of radioactive sources directly into or next to the tumor. This technique is indicated for patients affected by various types of cancers. It is an optimal tool for delivering very high doses to the tumor focally while minimizing the probability of normal tissue complications. Physicians from a wide range of specialties may be involved in either the referral to or the placement of brachytherapy. Many patients require brachytherapy as either primary treatment or as part of their oncologic care. On the basis of high-level evidence from randomized controlled trials, brachytherapy is mainly indicated: 1) as standard in combination with chemoradiation in patients with locally advanced cervical cancer; 2) in surgically treated patients with uterine endometrial cancer for decreasing the risk of vaginal vault recurrence; 3) in patients with high-risk prostate cancer to perform dose escalation and improve progression-free survival; and 4) in patients with breast cancer as adjuvant, accelerated partial breast irradiation or to boost the tumor bed. In this review, the authors discuss the clinical relevance of brachytherapy with a focus on indications, levels of evidence, and results in the overall context of radiation use for patients with cancer.

International multidisciplinary consensus on the integration of radiotherapy with new systemic treatments for breast cancer: European Society for Radiotherapy and Oncology (ESTRO)-endorsed recommendations.

Novel systemic therapies for breast cancer are being rapidly implemented into clinical practice. These drugs often have different mechanisms of action and side-effect profiles compared with traditional chemotherapy. Underpinning practice-changing clinical trials focused on the systemic therapies under investigation, thus there are sparse data available on radiotherapy. Integration of these new systemic therapies with radiotherapy is therefore challenging. Given this rapid, transformative change in breast cancer multimodal management, the multidisciplinary community must unite to ensure optimal, safe, and equitable treatment for all patients. The aim of this collaborative group of radiation, clinical, and medical oncologists, basic and translational scientists, and patient advocates was to: scope, synthesise, and summarise the literature on integrating novel drugs with radiotherapy for breast cancer; produce consensus statements on drug-radiotherapy integration, where specific evidence is lacking; and make best-practice recommendations for recording of radiotherapy data and quality assurance for subsequent studies testing novel drugs.

Anticancer actions of carnosine in cellular models of prostate cancer.

Treatments for organ-confined prostate cancer include external beam radiation therapy, radical prostatectomy, radiotherapy/brachytherapy, cryoablation and high-intensity focused ultrasound. None of these are cancer-specific and are commonly accompanied by side effects, including urinary incontinence and erectile dysfunction. Moreover, subsequent surgical treatments following biochemical recurrence after these interventions are either limited or affected by the scarring present in the surrounding tissue. Carnosine (ß-alanyl-L-histidine) is a histidine-containing naturally occurring dipeptide which has been shown to have an anti-tumorigenic role without any detrimental effect on healthy cells; however, its effect on prostate cancer cells has never been investigated. In this study, we investigated the effect of carnosine on cell proliferation and metabolism in both a primary cultured androgen-resistant human prostate cancer cell line, PC346Flu1 and murine TRAMP-C1 cells. Our results show that carnosine has a significant dose-dependent inhibitory effect in vitro on the proliferation of both human (PC346Flu1) and murine (TRAMP-C1) prostate cancer cells, which was confirmed in 3D-models of the same cells. Carnosine was also shown to decrease adenosine triphosphate content and reactive species which might have been caused in part by the increase in SIRT3 also shown after carnosine treatment. These encouraging results support the need for further human in vivo work to determine the potential use of carnosine, either alone or, most likely, as an adjunct therapy to surgical or other conventional treatments.

Fewer systematic prostate core biopsies in clinical stage T1c prostate cancer leads to biochemical recurrence after brachytherapy as monotherapy.

BACKGROUND: After brachytherapy, fewer prostate biopsy cores at diagnosis can underestimate the pathological characteristics of prostate cancer (PCa) with lower concordance, resulting in improper treatment, particularly in patients with low-risk nonpalpable cT1c PCa. The aim of this study was to assess the relationship between the number of biopsy cores at diagnosis and long-term clinical outcomes after brachytherapy for cT1c PCa. METHODS: We reviewed 516 patients with localized cT1c PCa with Gleason scores of 3 + 3 = 6 or 3 + 4 = 7 who underwent brachytherapy as monotherapy without hormonal therapy between January 2005 and September 2014 at our institution. Clinical staging was based on the American Joint Committee on Cancer manual for staging. Thus, the cT1c category is based solely on digital rectal examination. The primary outcome was biochemical recurrence (BCR). Based on the optimized cutoff value for biopsy core number obtained from receiver operating characteristic analysis, patients were divided into the biopsy cores ≤8 (N = 123) and ≥9 (N = 393) groups. The BCR-free survival rate was compared between the groups. Prognostic factors for BCR were evaluated, including age, initial prostate-specific antigen (PSA) level, Gleason score, positive core rate, PSA density, prostate magnetic resonance imaging findings, and biopsy core number. RESULTS: The median patient age was 66.0 years (interquartile range [IQR]: 61.0-71.0 years), and the median follow-up time was 11.1 years (IQR: 9.5-13.3 years). The median number of core biopsies was 12 (IQR: 9-12). The area under the curve was 0.637 (95% confidence interval [CI]: 0.53-0.75), and the optimal biopsy core cutoff value for BCR prediction was 8.5 (sensitivity = 43.5%, specificity = 77.1%). Although fewer patients had Gleason scores of 3 + 4 = 7 (19/123 [15%] vs. 125/393 [32%], p < 0.02) in the biopsy cores ≤8 group, the 10-year BCR-free survival rate was significantly lower in the biopsy cores ≤8 group than in the biopsy cores ≥9 group (93.8% vs. 96.3%, p < 0.05). Multivariate analysis revealed that a lower biopsy core number (hazard ratio: 0.828, 95% CI: 0.71-0.97, p < 0.03) and a Gleason score of 3 + 4 = 7 (hazard ratio: 3.26, 95% CI: 1.37-7.73, p < 0.01) significantly predicted BCR. CONCLUSIONS: A low number of prostate core biopsies results in worse BCR-free survival after brachytherapy as monotherapy in patients with cT1c PCa.

Comparison of partial-breast irradiation and intraoperative radiation to whole-breast irradiation in early-stage breast cancer patients: a Kaplan-Meier-derived patient data meta-analysis.

PURPOSE: Partial breast irradiation (PBI) and intraoperative radiation (IORT) represent alternatives to whole breast irradiation (WBI) following breast conserving surgery. However, data is mixed regarding outcomes. We therefore performed a pooled analysis of Kaplan-Meier-derived patient data from randomized trials to evaluate the hypothesis that PBI and IORT have comparable long-term rates of ipsilateral breast tumor recurrence as WBI. METHODS: In February, 2023, PubMed, EMBASE and Cochrane Central were systematically searched for randomized phase 3 trials of early-stage breast cancer patients undergoing breast-conserving surgery with PBI or IORT as compared to WBI. Time-to-event outcomes of interest included ipsilateral breast tumor recurrence (IBTR), overall survival (OS) and distant disease-free survival (DDFS). Statistical analysis was performed with R Statistical Software. RESULTS: Eleven randomized trials comprising 15,460 patients were included; 7,675 (49.6%) patients were treated with standard or moderately hypofractionated WBI, 5,413 (35%) with PBI and 2,372 (15.3%) with IORT. Median follow-up was 9 years. PBI demonstrated comparable IBTR risk compared with WBI (HR 1.20; 95% CI 0.95-1.52; p = 0.12) with no differences in OS (HR 1.02; 95% CI 0.90-1.16; p = 0.70) or DDFS (HR 1.15; 95% CI 0.81-1.64; p = 0.43). In contrast, patients treated with IORT had a higher IBTR risk (HR 1.46; 95% CI 1.23-1.72; p < 0.01) compared with WBI with no difference in OS (HR 0.98; 95% CI 0.84-1.14; p = 0.81) or DDFS (HR 0.91; 95% CI 0.76-1.09; p = 0.31). CONCLUSION: For patients with early-stage breast cancer following breast-conserving surgery, PBI demonstrated no difference in IBTR as compared to WBI while IORT was inferior to WBI with respect to IBTR.

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.

CT-guided High-Dose-Rate Brachytherapy versus Transarterial Chemoembolization in Patients with Unresectable Hepatocellular Carcinoma.

Background CT-guided high-dose-rate (HDR) brachytherapy (hereafter, HDR brachytherapy) has been shown to be safe and effective for patients with unresectable hepatocellular carcinoma (HCC), but studies comparing this therapy with other local-regional therapies are scarce. Purpose To compare patient outcomes of HDR brachytherapy and transarterial chemoembolization (TACE) in patients with unresectable HCC. Materials and Methods This multi-institutional retrospective study included consecutive treatment-naive adult patients with unresectable HCC who underwent either HDR brachytherapy or TACE between January 2010 and December 2022. Overall survival (OS) and progression-free survival (PFS) were compared between patients matched for clinical and tumor characteristics by propensity score matching. Not all patients who underwent TACE had PFS available; thus, a different set of patients was used for PFS and OS analysis for this treatment. Hazard ratios (HRs) were calculated from Kaplan-Meier survival curves. Results After propensity matching, 150 patients who underwent HDR brachytherapy (median age, 71 years [IQR, 63-77 years]; 117 males) and 150 patients who underwent TACE (OS analysis median age, 70 years [IQR, 63-77 years]; 119 male; PFS analysis median age, 68 years [IQR: 63-76 years]; 119 male) were analyzed. Hazard of death was higher in the TACE versus HDR brachytherapy group (HR, 4.04; P < .001). Median estimated PFS was 32.8 months (95% CI: 12.5, 58.7) in the HDR brachytherapy group and 11.6 months (95% CI: 4.9, 22.7) in the TACE group. Hazard of disease progression was higher in the TACE versus HDR brachytherapy group (HR, 2.23; P < .001). Conclusion In selected treatment-naive patients with unresectable HCC, treatment with CT-guided HDR brachytherapy led to improved OS and PFS compared with TACE. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Chapiro in this issue.

Long-Term Second Malignancies in Prostate Cancer Patients Treated With Low-Dose-Rate Brachytherapy and Radical Prostatectomy.

PURPOSE: Second malignancy is a rare but potentially lethal event after prostate brachytherapy, but data remain scarce on its long-term risk. The objective of this study is to estimate the number of pelvic second malignancies following brachytherapy compared to radical prostatectomy (RP). MATERIALS AND METHODS: We retrospectively reviewed patients treated with low-dose 125I brachytherapy and RP in British Columbia from 1999 to 2010. Kaplan-Meier estimates for pelvic (bladder and rectum), invasive pelvic, any second malignancy, and death from any second malignancy were assessed. Cox multivariable analyses were performed adjusting for initial treatment type, age, post-RP adjuvant/salvage external beam radiation therapy status, and smoking history. RESULTS: Two thousand three hundred seventy-eight brachytherapy and 9089 RP patients were included. Median age was 66 years (interquartile range [IQR] 61-71) and 63 years (IQR 58-67), respectively. Median follow-up time to event or censured was 14 years (IQR 11.5-17.3). The Kaplan-Meier estimates for pelvic second malignancy at 15 and 20 years were 6.4% and 9.8%, respectively, after brachytherapy, and 3.2% and 4.2% after RP. Time to any second malignancy and time to death from any second malignancy were not significantly different (P > .05). On Cox multivariable analysis, brachytherapy, compared to surgery, was an independent factor for pelvic (hazard ratio [HR] 1.81 [95% CI 1.45-2.26], P < .001) and invasive pelvic second malignancy (HR 2.13 [95% CI 1.61-2.83], P < .001). Increased age and smoking were also associated with higher estimates of events (P < .001). CONCLUSIONS: After adjustment for age, post-RP adjuvant/salvage external beam radiation therapy status, and smoking status, numerically higher long-term HRs of pelvic and invasive pelvic second malignancy in patients treated with brachytherapy compared to RP were noted.

Cost-benefit ratio of modern medical education using micro-costing: a model calculation using the example of an innovative breast brachytherapy workshop.

BACKGROUND AND PURPOSE: Radiation oncology is an essential component of therapeutic oncology and necessitates well-trained personnel. Multicatheter brachytherapy (MCBT) is one radiotherapeutic option for early-stage breast cancer treatment. However, specialized hands-on training for MCBT is not currently included in the curriculum for residents. A recently developed hands-on brachytherapy workshop has demonstrated promising results in enhancing knowledge and practical skills. Nevertheless, these simulation-based teaching formats necessitate more time and financial resources. Our analyses include computational models for the implementation and delivery of this workshop and can serve as a basis for similar educational initiatives. METHODS: This study aimed to assess the cost-effectiveness of a previously developed and evaluated breast brachytherapy simulation workshop. Using a micro-costing approach, we estimated costs at a detailed level by considering supplies, soft- and hardware, and personnel time for each task. This method also allows for a comprehensive evaluation of the costs associated with implementing new medical techniques. The workshop costs were divided into two categories: development and workshop execution. The cost analysis was conducted on a per-participant basis, and the impact on knowledge improvement was measured using a questionnaire. RESULTS: The total workshop costs were determined by considering the initial workshop setup expenses including the development and conceptualization of the course with all involved collaborators, as well as the costs incurred for each individual course. The workshop was found to be financially efficient, with a per-participant cost of €â€¯39, considering the industrial sponsorship provided for brachytherapy equipment. In addition, we assessed the workshop's efficacy by analyzing participant feedback using Likert scale evaluations. The findings indicated a notable enhancement in both theoretical and practical skills among the participants. Moreover, the cost-to-benefit ratio (CBFR) analysis demonstrated a CBFR of €â€¯13.53 for each Likert point increment. CONCLUSION: The hands-on brachytherapy workshop proved to be a valuable and approximately cost-effective educational program, leading to a significant enhancement in the knowledge and skills of the participants. Without the support of industrial sponsorship, the costs would have been unattainable.

Can interventional radiotherapy (brachytherapy) be an alternative to surgery in early-stage oral cavity cancer? A systematic review.

PURPOSE: Brachytherapy (BT), also known as interventional radiotherapy (IRT), has proven its utility in the treatment of localized tumors. The aim of this review was to examine the efficacy of modern BT in early-stage oral cavity cancer (OCC) in terms of local control (LC), overall survival (OS), disease-free survival (DFS), cancer-specific survival (CSS), and safety. METHODS: The SPIDER framework was used, with sample (S), phenomena of interest (PI), design (D), evaluation (E), and research type (R) corresponding to early-stage oral cavity cancer (S); BT (PI); named types of qualitative data collection and analysis (D); LC, OS, DFS, CSS, and toxicity (E); qualitative method (R). Systematic research using PubMed and Scopus was performed to identify full articles evaluating the efficacy of BT in patients with early-stage OCC. The studies were identified using medical subject headings (MeSH). We also performed a PubMed search with the keywords "brachytherapy oral cavity cancer, surgery." The search was restricted to the English language. The timeframe 2002-2022 as year of publication was considered. We analyzed clinical studies of patients with OCC treated with BT alone only as full text; conference papers, surveys, letters, editorials, book chapters, and reviews were excluded. RESULTS: The literature search resulted in 517 articles. After the selection process, 7 studies fulfilled the inclusion criteria and were included in this review, totaling 456 patients with early-stage node-negative OCC who were treated with BT alone (304 patients). Five-year LC, DFS, and OS for the BT group were 60-100%, 82-91%, and 50-84%, respectively. CONCLUSION: In conclusion, our review suggests that BT is effective in the treatment of early-stage OCC, particularly for T1N0 of the lip, mobile tongue, and buccal mucosa cancers, with good functional and toxicity profiles.

Investigating the impact of breast positioning control on physical treatment parameters in multi-catheter breast brachytherapy.

PURPOSE: To assess the effects of a workflow for reproducible patient and breast positioning on implant stability during high-dose-rate multi-catheter breast brachytherapy. METHODS: Thirty patients were treated with our new positioning control workflow. Implant stability was evaluated based on a comparison of planning-CTs to control-CTs acquired halfway through the treatment. To assess geometric stability, button-button distance variations as well as Euclidean dwell position deviations were evaluated. The latter were also quantified within various separated regions within the breast to investigate the location-dependency of implant alterations. Furthermore, dosimetric variations to target volume and organs at risk (ribs, skin) as well as isodose volume changes were analyzed. Results were compared to a previously treated cohort of 100 patients. RESULTS: With the introduced workflow, the patient fraction affected by button-button distance variations > 5 mm and by dwell position deviations > 7 mm were reduced from 37% to 10% and from 30% to 6.6%, respectively. Implant stability improved the most in the lateral to medial breast regions. Only small stability enhancements were observed regarding target volume dosimetry, but the stability of organ at risk exposure became substantially higher. D0.2ccm skin dose variations > 12.4% and D0.1ccm rib dose variations > 6.7% were reduced from 11% to 0% and from 16% to 3.3% of all patients, respectively. CONCLUSION: Breast positioning control improved geometric and dosimetric implant stability for individual patients, and thus enhanced physical plan validity in these cases.

Tracing the Evolution of Prostate Brachytherapy in the 20th Century.

BACKGROUND: Prostate brachytherapy (BT) techniques have evolved over the past century. This paper aimed to preserve our collective memory of history and the early development of its technique. We searched articles in PubMed and Google Scholar using keywords referring to authors, dates, and BT technical details, including different radioactive sources and country-specific publications. We reviewed the work published by Holm and Aronowitz. The digital library Internet Archives was used to retrieve original journal articles, science newspaper printings, and government reports, which allowed us to situate the development of BT in its sociopolitical context in Europe and the USA. Our search was conducted in English, French, and German languages. SUMMARY: Early BT methods were developed by European physicians with early access to radium. Technical advancements were made by HH Young, who brought this practice to the USA, where Barringer pioneered the use of radon seeds and low-dose interstitial brachytherapy. While centralized radiotherapy centers, such as Memorial Hospital in New York, emerged for training and research, the high cost of radium and opposing interests made brachytherapy harder to implement in Germany. After World War II, the introduction of man-made radioisotopes allowed experiments with colloidal solutions and new seeds, including I-125. In the 1980s, transrectal ultrasound allowed for more accurate radioactive seed insertion and replaced the transrectal finger guidance.

Brachytherapy at the nanoscale with protein functionalized and intrinsically radiolabeled [169Yb]Yb2O3 nanoseeds.

PURPOSE: Classical brachytherapy of solid malignant tumors is an invasive procedure which often results in an uneven dose distribution, while requiring surgical removal of sealed radioactive seed sources after a certain period of time. To circumvent these issues, we report the synthesis of intrinsically radiolabeled and gum Arabic glycoprotein functionalized [169Yb]Yb2O3 nanoseeds as a novel nanoscale brachytherapy agent, which could directly be administered via intratumoral injection for tumor therapy. METHODS: 169Yb (T½ = 32 days) was produced by neutron irradiation of enriched (15.2% in 168Yb) Yb2O3 target in a nuclear reactor, radiochemically converted to [169Yb]YbCl3 and used for nanoparticle (NP) synthesis. Intrinsically radiolabeled NP were synthesized by controlled hydrolysis of Yb3+ ions in gum Arabic glycoprotein medium. In vivo SPECT/CT imaging, autoradiography, and biodistribution studies were performed after intratumoral injection of radiolabeled NP in B16F10 tumor bearing C57BL/6 mice. Systematic tumor regression studies and histopathological analyses were performed to demonstrate therapeutic efficacy in the same mice model. RESULTS: The nanoformulation was a clear solution having high colloidal and radiochemical stability. Uniform distribution and retention of the radiolabeled nanoformulation in the tumor mass were observed via SPECT/CT imaging and autoradiography studies. In a tumor regression study, tumor growth was significantly arrested with different doses of radiolabeled NP compared to the control and the best treatment effect was observed with ~ 27.8 MBq dose. In histopathological analysis, loss of mitotic cells was apparent in tumor tissue of treated groups, whereas no significant damage in kidney, lungs, and liver tissue morphology was observed. CONCLUSIONS: These results hold promise for nanoscale brachytherapy to become a clinically practical treatment modality for unresectable solid cancers.

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.

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.

Brachytherapy in craniopharyngiomas: a systematic review and meta-analysis of long-term follow-up.

OBJECTIVE: Brachytherapy has been indicated as an alternative option for treating cystic craniopharyngiomas (CPs). The potential benefits of brachytherapy for CPs have not yet been clarified. The purpose of this work was to conduct a meta-analysis to analyze the long-term efficacy and adverse reactions profile of brachytherapy for CPs. MATERIALS AND METHODS: The relevant databases were searched to collect the clinical trials on brachytherapy in patients with CPs. Included studies were limited to publications in full manuscript form with at least 5-year median follow-up, and adequate reporting of treatment outcomes and adverse reactions data. Stata 12.0 was used for data analysis. RESULTS: According to the inclusion and exclusion criteria, a total of 6 clinical trials involving 266 patients with CPs were included in this meta-analysis. The minimum average follow-up was 5 years. The results of the meta-analysis showed that 1-year, 2-3 years and 5 years progression free survival rates (PFS) are 75% (95%CI: 66-84%), 62% (95%CI: 52-72%) and 57% (95%CI: 22-92%), respectively. At the last follow-up, less than 16% of patients with visual outcomes worser than baseline in all included studies. While, for endocrine outcomes, less than 32% of patients worser than baseline level. CONCLUSION: In general, based on the above results, brachytherapy should be considered as a good choice for the treatment of CP.

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.

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.

Image-guided high-dose-rate brachytherapy as the method of choice in medically inoperable early-stage endometrial cancer patients.

PURPOSE: About 3-9% of patients with endometrial cancer are unable to undergo surgery due to medical comorbidities, including morbid obesity, or age-related frailty syndrome. An alternative curative option is irradiation. The aim of this prospective study was to evaluate clinical outcomes of high-dose-rate intracavitary brachytherapy (HDR-ICBT) treatment in such patients. MATERIALS AND METHODS: Seventy-eight patients with FIGO stage I-II endometrial cancer disqualified from surgery were treated with HDR-ICBT with 45-52,5 Gy prescribed to high-risk clinical target volume (HR-CTV) in 5-9 fractions given once a week. All fractions were planned using computed tomography (CT) scans. RESULTS: The median follow-up time was 67 months. Median age was 79 years (range: 42-93 years). Median body mass index (BMI) was 39,1 kg/m2 (range: 24,2-68 kg/m2). We observed no statistically significant impact of BMI ≥ 40 on overall survival (OS) or prgression free survival (PFS). The 3- and 5-year OS for the whole population were 69% and 55%, respectively. The impact of high risk features (FIGO II, grade 3 or type 2 cancer) on OS was significant (p = 0,049). The 5-year cumulative incidence of local failure, distant metastases and non-cancer death were 12,9% [95% CI: 5,4%-20,5%], 6,4% [95% CI: 0,9%-11,9%], 33,1% [95% CI: 22,3%-43,9%], respectively. The 5-year risk of cancer and non-cancer death were 9% (95% CI: 3%-16%) and 36% (95% CI: 25%-47%), respectively. We observed G1 vaginal apex stenosis only. CONCLUSIONS: CT-guided HDR-ICBT is a feasible and safe management of FIGO stage I endometrial cancer in obese and elderly patients. The survival outcome of the treated group is influenced more by associated comorbidities than by the progression of endometrial cancer.

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.