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.

Efficacy of a hydrogel spacer for improving quality of life in patients with prostate cancer undergoing low-dose-rate brachytherapy alone or in combination with intensity-modulated radiotherapy: An observational study using propensity score matching.

BACKGROUND: It is unclear whether a hydrogel spacer can improve quality of life (QOL) in patients undergoing low-dose-rate brachytherapy (LDR-BT) alone or in combination with intensity-modulated radiotherapy (IMRT). METHODS: We enrolled patients with prostate cancer who underwent LDR-BT alone with (n = 186) or without (n = 348) a hydrogel spacer, or underwent LDR-BT in combination with IMRT with (n = 70) or without (n = 217) a hydrogel spacer. QOL was evaluated using Expanded Prostate Cancer Index Composite (EPIC) questionnaires at baseline and 1, 3, 6, 12, and 24 months after implantation. The groups were compared using propensity score matching analysis. RESULTS: Among patients who underwent LDR-BT alone, there were no differences regarding changes in urinary, bowel, sexual, or hormonal domain scores between the spacer and no-spacer groups; however, the dose at the bowel was significantly lower in the spacer group than in the no-spacer group. Among patients who underwent LDR-BT in combination with IMRT, there were no differences regarding changes in urinary, sexual, or hormonal domain scores between the spacer and no-spacer groups. However, the changes in the bowel domain score were significantly lower in the spacer group than in the no-spacer group (p < 0.001). CONCLUSIONS: A hydrogel spacer may not improve impaired urinary, bowel, or sexual QOL in patients undergoing LDR-BT alone. However, in patients undergoing LDR-BT in combination with IMRT, a hydrogel spacer can improve impaired bowel QOL but not sexual or urinary QOL.

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.

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.

Analysis of operative duration of image-guided brachytherapy for cervical cancer.

PURPOSE: The present study aimed to analyze the operative duration of image-guided brachytherapy (IGBT) for cervical cancer performed at our institution. METHODS: We enrolled cervical cancer patients who had undergone tandem and ovoid-based intracavitary brachytherapy (ICBT) or intracavitary and interstitial brachytherapy (IC/ISBT) between 2020 and 2024. Cone beam computed tomography (CBCT), CT, or CT + MRI were used for IGBT. For each IGBT session, we retrospectively reviewed the following: application time (AT-defined as the duration from entry into the operating room to the initial image acquisition); planning time (PT-defined as the duration from the initial image acquisition to the start of irradiation); and total operation time (TOT- defined as the duration from entry to exit of the operating room). RESULTS: We analyzed a total of 126 sessions in 36 patients, consisting of 99 ICBT-only sessions and 27 IC/ISBT sessions. The IC/ISBT sessions had a significantly longer mean operative duration than the ICBT-only sessions. The IC/ISBT sessions with three or more interstitial needles had significantly longer AT and TOT. However, the IC/ISBT sessions with one needle showed no significant difference in operative duration compared to ICBT-only sessions. CBCT, CT, and CT + MRI were used in 42, 76, and 8 sessions, respectively. In the ICBT patients, CT + MRI had the longest PT. However, there was no significant differences in TOT among CBCT, CT, and CT + MRI. CONCLUSIONS: IC/ISBT sessions with one needle had no significant difference in operative duration compared to ICBT-only sessions. There was no significant difference in TOT between CT + MRI-based IGBT and CT-based IGBT.

Protocol-based CT-guided brachytherapy for patients with prostate cancer and previous rectal extirpation-a curative approach.

OBJECTIVE: There are numerous curative treatment possibilities for prostate cancer. In patients who have undergone rectal extirpation for rectal cancer treatment, curative options are limited due to anatomic changes and previous irradiation of the pelvis. In this analysis, we validate the feasibility of CT-guided transperineal interstitial brachytherapy for this specific scenario. PATIENTS AND METHODS: We analyzed the treatment procedures and outcomes of 5 patients with metachronic nonmetastatic prostate cancer. Ultrasound-guided brachytherapy was not possible in any of the patients. Of these 5 patients, 3 were treated for prostate cancer using temporary brachytherapy with Ir-192 only, and 2 were treated with external-beam radiation therapy and temporary brachytherapy as a boost. CT-guided brachytherapy was performed in all patients. We analyzed the feasibility, efficacy, treatment-related toxicity, and quality of life (EORTC-30, IEFF, IPSS, and ICIQ questionnaires) of the treatments. RESULTS: Median follow-up was 35 months. Two out of five patients received boost irradiation (HDR 2â€¯× 9 Gy, PDR 30 Gy). Three out of five patients were treated with PDR brachytherapy in two sessions up to a total dose of 60 Gy. Dosimetric parameters were documented as median values as follows: V100 94.7% (94.5-98.4%), D2bladder 64.3% (50.9-78.3%), D10urethra 131.05% (123.2%-141.2%), and D30urethra 122.45% (116.2%-129.5%). At the time of analysis, no biochemical recurrence had been documented. Furthermore, neither early nor late side effects exceeding CTCAE grade 2 were documented. CONCLUSION: CT-guided transperineal brachytherapy of the prostate in patients with previous rectal surgery and radiation therapy is safe and represents a possible curative treatment option. Brachytherapy can be considered for patients with metachronic prostate cancer in this specific scenario, albeit preferably in experienced high-volume centers.

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.

Radiochemotherapy and interstitial brachytherapy for cervical cancer: clinical results and patient-reported outcome measures.

OBJECTIVE: To evaluate clinical results and long-term patient-reported outcome measures (PROMs) on quality of life in cervical cancer patients following radiochemotherapy (RCT) and brachytherapy (BT) as definitive treatment. MATERIALS AND METHODS: Between 2003 and 2023, a total of 132 patients with advanced cervical cancer were evaluated for possible treatment. Patients treated by postoperative RCT, palliative radiotherapy, and those treated for recurrent disease were excluded. Thus, 46 patients receiving standard RCT and BT as their curative treatment were included in this study. PROMs were assessed prospectively by patients' self-completion of the EORTC-QLQ-C30 and EORTC-QLQ-CX24 questionnaires. RESULTS: Five-year overall survival (OS), distant metastases-free survival (DMFS), and pelvic tumor-free survival rates (PTFS) were 53%, 54%, and 83%, respectively. A significant impact on OS was seen for FIGO (International Federation of Gynecologic Oncology) stage (IIB-IIIA: 79% vs. IIIB-IVA: 33%, p = 0.015), for overall treatment time (OTT; 50-65 d: 64% vs. > 65 d: 38%, p = 0.004), and for rectal D2cc (≤ 73 Gy: 50% vs. > 73 Gy: 38%, p = 0.046). The identical parameters were significantly associated with DMFS (FIGO stage: p = 0.012, OTT: p = 0.008, D2cc: p = 0.024). No parameters with a significant influence on PTFS were seen. In multivariate analysis, an impact of FIGO stage on OS (p = 0.05) and DMFS (p = 0.014) was detected, and of rectal D2cc on DMFS (p = 0.031). The overall QoL score was 63/100. Cognitive function was the least impaired (84/100), while role functioning was the worst (67/100). On the symptom scale, insomnia (46/100), fatigue (41/100), dyspnea (32/100), pain (26/100), and financial difficulties (25/100) were scored the worst. According to EORTC-QLQ-CX24, peripheral neuropathy (36/100) and lymphedema (32/100) occurred most frequently. Impaired sexual/vaginal functioning (32/100) and body image (22/100) were also frequently recorded. CONCLUSION: In patients with advanced cervical cancer, a combination of RCT and BT remains an excellent treatment option. In terms of patient-reported long-term quality of life, specific support is needed to alleviate symptoms including lymphedema, peripheral neuropathy, and impaired sexual activity.

Transrectal ultrasound for intraoperative interstitial needle guidance in cervical cancer brachytherapy.

OBJECTIVE: This study aimed to prospectively assess the visibility of interstitial needles on transrectal ultrasound (TRUS) in cervical cancer brachytherapy patients and evaluate its impact on implant and treatment plan quality. MATERIAL AND METHODS: TRUS was utilized during and after applicator insertion, with each needle's visibility documented through axial images at the high-risk clinical target volume's largest diameter. Needle visibility on TRUS was scored from 0 (no visibility) to 3 (excellent discrimination, margins distinct). Quantitative assessment involved measuring the distance between tandem and each needle on TRUS and comparing it to respective magnetic resonance imaging (MRI) measurements. Expected treatment plan quality based on TRUS images was rated from 1 (meeting all planning objectives) to 4 (violation of High-risk clinical target volume (CTVHR) and/or organ at risk (OAR) hard constraints) and compared to the final MRI-based plan. RESULTS: Analysis included 23 patients with local FIGO stage IB2-IVA, comprising 41 applications with a total of 230 needles. A high visibility rate of 99.1% (228/230 needles) was observed, with a mean visibility score of 2.5 ±â€¯0.7 for visible needles. The maximum and mean difference between MRI and TRUS measurements were 8 mm and -0.1 ±â€¯1.6 mm, respectively, with > 3 mm discrepancies in 3.5% of needles. Expected treatment plan quality after TRUS assessment exactly aligned with the final MRI plan in 28 out of 41 applications with only minor deviations in all other cases. CONCLUSION: Real-time TRUS-guided interstitial needle placement yielded high-quality implants, thanks to excellent needle visibility during insertion. This supports the potential of TRUS-guided brachytherapy as a promising modality for gynecological indications.

Initial needle tracking with the first standalone combined infrared camera - CT system for brachytherapy-analysis of tracking accuracy and uncertainties.

PURPOSE: A prototype infrared camera - cone-beam computed tomography (CBCT) system for tracking in brachytherapy has recently been developed. We evaluated for the first time the corresponding tracking accuracy and uncertainties, and implemented a tracking-based prediction of needles on CBCT scans. METHODS: A marker tool rigidly attached to needles was 3D printed. The precision and accuracy of tool tracking was then evaluated for both static and dynamic scenarios. Euclidean distances between the tracked and CBCT-derived markers were assessed as well. To implement needle tracking, ground truth models of the tool attached to 200 mm and 160 mm needles were matched to the tracked positions in order to project the needles into CBCT scans. Deviations between projected and actual needle tips were measured. Finally, we put our results into perspective with simulations of the system's tracking uncertainties. RESULTS: For the stationary scenario and dynamic movements, we achieved tool-tracking precision and accuracy of 0.04 ± 0.06 mm and 0.16 ± 0.18 mm, respectively. The tracked marker positions differed by 0.52 ± 0.18 mm from the positions determined via CBCT. In addition, the predicted needle tips in air deviated from the actual tip positions by only 1.62 ± 0.68 mm (200 mm needle) and 1.49 ± 0.62 mm (160 mm needle). The simulated tracking uncertainties resulted in tip variations of 1.58 ± 0.91 mm and 1.31 ± 0.69 mm for the 200 mm and 160 mm needles, respectively. CONCLUSION: With the innovative system it was possible to achieve a high tracking and prediction accuracy of marker tool and needles. The system shows high potential for applicator tracking in brachytherapy.

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.

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.

A dosimetric comparison of brachytherapy sources for endometrial cancer: an electronic brachytherapy and an iridium-192 source with multichannel cylinders and a three-dimensional technique.

BACKGROUND AND PURPOSE: Ir192 vaginal brachytherapy (IBT) is commonly used for patients with postoperative endometrial cancer (EC). We devised a novel multichannel vaginal applicator that could be equipped with an electronic brachytherapy (EBT) device. We aimed to explore the differences in physical parameters between the EBT and IBT. MATERIALS AND METHODS: This retrospective study included 20 EC patients who received adjuvant IBT from March 1, 2023, to May 1, 2023. Multichannel vaginal cylinders were used, and three-dimensional plans were generated. We designed an electronic multichannel vaginal applicator model and simulated a three-dimensional EBT plan. In order to ensure comparability, D90 of the CTV for the EBT plan was normalized to be equivalent to that of the IBT plan for the same patient. RESULTS: Twenty EBT plans were compared with 20 IBT plans. Results showed, the mean D90 value of clinical target volume (CTV) was 536.1 cGy for both treatment plans. For the mean dose of CTV, the EBT was significantly greater (738.3 vs. 684.3 cGy, p = 0.000). There was no significant difference in CTV coverage between the EBT and IBT plans. For high-dose areas (V200% and V150%), the EBTs were significantly greater. There were no significant differences in the maximum doses to the vaginal mucosa between the EBT and IBT, whether at the apex or in the middle segment. For the bladder and rectum, both the low-dose area and high-dose area were significantly lower in the EBT plans. For the conformity index, there was no significant difference between the EBT and IBT plans. For the dose homogeneity index, the EBT value was lower. CONCLUSION: In conclusion, under the premise of a three-dimensional brachytherapy plan, for patients receiving multichannel vaginal applicator brachytherapy, compared with IBT, EBT could reduce the dose to the surrounding organs at risk while maintaining the dose in the target area.

Salvage radiotherapy for locally recurrent cervical and endometrial carcinoma: clinical outcomes and toxicities.

BACKGROUND: The management of locally recurrent gynecological carcinoma remains a challenge due to the limited availability of data. This study aims to share our institutional experience in using definitive radiotherapy (RT) for the treatment of locally recurrent cervical and endometrial carcinoma. METHODS: The study retrospectively reviewed 20 patients in our hospital completing salvage 3D image-based HDR brachytherapy, with or without EBRT, for locally recurrent cervical and endometrial carcinoma after surgery. The Kaplan-Meier method was applied to estimate the disease-free survival (DFS) and overall survival (OS). The toxicities were assessed by CTCAEv5. RESULTS: During a median observation period of 21 months, the study reported a tumor objective response rate of 95%. The 3-year DFS and OS rates were 89.4% and 90.9%, respectively. The EBRT combined with brachytherapy achieved a median cumulative dose of 88 Gy to CTV D90. 14 patients received concurrent and/or systemic chemotherapy. Two patients suffered locoregional recurrence after salvage treatment, one of whom only received salvage brachytherapy for prior RT history. The analysis identified significant predictors for DFS, including tumor histology and FIGO stage. 5 patients observed acute grade 1-2 rectal (15%) or genitourinary (10%) toxicities. Late toxicities including grade 1-2 rectal bleeding (10%) and grade 2 pelvic fracture (5%) were seen in 3 patients. CONCLUSIONS: 3D image-guided brachytherapy combined with EBRT shows effective tumor control and acceptable toxicity profile for women with locally recurrent gynecologic cancer. The success in managing vaginal recurrence is notably influenced by histologic subtype and FIGO staging.

Dose-response relationship between volume base dose and tumor local control in definitive radiotherapy for vaginal cancer.

OBJECTIVE: This study aimed to establish the dose-response relationship between volume base dose and tumor local control for vaginal cancer, including primary vaginal cancer and recurrent gynecologic malignancies in the vagina. MATERIALS AND METHODS: We identified studies that reported volume base dose and local control by searching the PubMed, the Web of Science, and the Cochrane Library Database through August 12, 2023. The regression analyses were performed using probit model between volume based dose versus clinical outcomes. Subgroup analyses were performed according to stratification: publication year, country, inclusion time of patients, patients with prior radiotherapy, age, primaries or recurrent, tumor size, concurrent chemoradiotherapy proportion, dose rate, image modality for planning, and interstitial proportion. RESULTS: A total of 879 patients with vaginal cancer were identified from 18 studies. Among them, 293 cases were primary vaginal cancer, 573 cases were recurrent cancer in the vagina, and 13 cases were unknown. The probit model showed a significant relationship between the HR-CTV (or CTV) D90 versus the 2-year and 3-year local control, P values were 0.013 and 0.014, respectively. The D90 corresponding to probabilities of 90% 2-year local control were 79.0 GyEQD2,10 (95% CI: 75.3-96.6 GyEQD2,10). CONCLUSIONS: A significant dependence of 2-year or 3-year local control on HR-CTV (or CTV) D90 was found. Our research findings encourage further validation of the dose-response relationship of radical radiotherapy for vaginal cancer through protocol based multicenter clinical trials.

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.

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 of brachytherapy versus radical prostatectomy for localized prostate cancer-propensity score-matched comparison.

OBJECTIVE: The brachytherapy (BT) and radical prostatectomy (RP) are two methods recommended in current guidelines for the treatment of localized prostate cancer (PCa). It is difficult to compare the oncological results of these two treatments because of differences in baseline characteristics and treatment selection.we sought to compare the efficacy of BT and RP after propensity score matching(PSM)analysis. METHODS: Between January 2009 and December 2021, our institution treated 657 patients with localized PCa (BT: n = 198; RP: n = 459)and followed up for > 2 years. Biochemical recurrence was defined as prostate-specific antigen (PSA) levels of nadir plus 2 ng/ml or higher (Phoenix definition) for BT, and as PSA0.2 ng/ml or greater for RP. PSM was applied based on the age, body mass index, PSA, prostate volume, clinical T-stage, Gleason grade, percentage of positive puncture needles ≥ 1/2, maximum tumor diameter ≥ 5 mm, and follow-up period. RESULTS: Median follow-up was 63 months for BT and 52 months for RP. After propensity score adjustment, a total of 294 (147 each) patients remained for further analysis.Kaplan-Meier curves showed no statistically significant difference in clinical relapse-free survivals (cRFS) (p = 0.637),overall survival (OS) (p = 0.726),and cancer-specific survival (CSS) (p = 0.505).BT was associated with improved biochemical relapse-free survivals (bRFS) compared to RP (p = 0.022), Logistic multivariate analysis based on the whole cohort revealed that clinical T stage ≥ T2b (p = 0.043) and tumor maximum diameter ≥ 5 mm (p = 0.044) were associated with significantly bRFS. CONCLUSION: The BT and RP group patients exhibited similar cRFS, OS, and CSS. However, patients in the BT groups exhibited better bRFS than those in the RP group.Clinical T stage ≥ T2b and a maximum tumor diameter ≥ 5 mm were independent prognostic factors.

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.