Journal of Contemporary Brachytherapy最新文献

Purpose: To determine the dosimetric impact of brachytherapy applicator displacement during intracavitary (IC) and combined intracavitary/interstitial (IC/IS) high-dose-rate brachytherapy in the treatment of cervical cancer.

Material and methods: Data from 27 consecutively treated patients undergoing IC or IC/IS high-dose-rate brachytherapy with tandem and ovoid-based applicators at a single academic medical center were analyzed. Virtual applicator displacements (a single shift of whole applicator with tandem/ovoid/associated needles) of 0 (clinical position), 2, 5, 7, and 10 mm in the inferior direction were modeled on treatment planning CT or MRI scans, with maintaining the same dwell times. Radiation dose to target volumes (D₉₀ of high-risk clinical target volume) and organs at risk (OARs) (D_0.1cc, D_1cc, and D_2cc of bladder, rectum, and sigmoid) were calculated for each virtual applicator shift, and significance of displacements was assessed using general linear model and Kruskal-Wallis test.

Results: Mean dose to high-risk clinical target volume (HR-CTV) D₉₀ was 95.7%, 88.9%, 84.6%, and 77.1% of the prescribed dose in clinical position with displacements of 2, 5, 7, and 10 mm, respectively. Rectal D_2cc significantly increased by 28% and 44% at displacement of 7 mm and 10 mm, respectively. IC/IS cases showed relatively greater dosimetric differences than IC cases, with HR-CTV D₉₀ doses of 94.4%, 85.8%, 80.4%, and 72.4% at virtual displacements of 2, 5, 7, and 10 mm, respectively.

Conclusions: Applicator displacements of 5 mm or greater result in statistically significant and clinically meaningful decreases in radiation dose to HR-CTV during 3-dimensional high-dose-rate brachytherapy treatment planning, with corresponding increase in radiation dose to the rectum. IC/IS applicator displacements lead to relatively greater differences than those of IC applicators.

Purpose: Rectal complications in radiotherapy for cervical cancer can highly affect quality of life and correlate with rectal dose. Vaginal gauze packing (VP) and rectal retraction (RR) are widely used for rectal dose reduction in high-dose-rate brachytherapy. We aimed to perform a dosimetric comparison of these two methods for three-dimensional image-guided adaptive brachytherapy.

Material and methods: We retrospectively examined 50 patients with cervical cancer treated with definitive radiotherapy, including intra-cavitary brachytherapy, performed with VP and RR. We extracted two fractions for each patient: one fraction with VP and the next fraction with RR, and then compared dose-volume parameters. In total, 50 fractions each were analyzed in VP and RR groups. Dose to 90% (D₉₀) of high-risk clinical target volume (HR-CTV), and minimum dose to most exposed 2.0 cm³ of other organs at risk (D_2cm³) for the rectum and bladder were determined from planning computed tomography.

Results: There were no significant differences between VP and RR in D₉₀ of HR-CTV (mean: 7.479 Gy and 7.652 Gy, respectively, p = 0.172). The D_2cm³ values for the rectum (mean: 4.234 Gy vs. 4.627 Gy, p = 0.008) and bladder (mean: 5.959 Gy vs. 6.690 Gy, p < 0.001) were significantly lower with VP compared with RR.

Conclusions: VP reduced the dose to the rectum and bladder when compared with RR without impairing the dose to CTV.

Simulators have revolutionized medical education and training across various disciplines, offering unique advantages in skill acquisition and performance improvement. In the context of interventional radiation therapy (IRT), simulators have emerged as valuable tools for training healthcare professionals in these complex procedures. This narrative review summarized the available evidence on the use of simulators in IRT training, highlighting their impact on proficiency, engagement, and self-confidence as well as their benefits for medical physicists and radiation therapists. A systematic search was conducted in PubMed, resulting in inclusion of 10 papers published since 2009, with 5 of them published since 2020. Publications originated from centers in USA, Ireland, Switzerland, Canada, and Japan, covering a range of IRT settings, including general, prostate, and cervical IRT. The review demonstrated that simulators provide a controlled and realistic environment for skill acquisition, allowing healthcare professionals to practice procedures, optimize image quality, and enhance technical proficiency. The use of simulators addressed the barriers associated with limited caseload and procedural complexity, ultimately contributing to improved education and IRT training. While cost considerations may exist, simulators offer long-term cost-effective solutions, balancing the potential benefits in improving educational outcomes and patient care. Overall, simulators play a crucial role in IRT training, enhancing the skills and competence of healthcare providers and improving access to quality IRT care worldwide. Future research should focus on evaluating the long-term impact of simulation-based training on clinical outcomes and patient satisfaction, exploring different simulation models and training approaches, and addressing region-specific barriers to optimize the utilization of IRT.

Purpose: Delineation is a critical and challenging step in radiotherapy planning. Differences in delineation among observers are common, despite the presence of contouring guidelines. This study aimed to identify the inter-observer variability in the target volume delineation of computed tomography (CT)-guided brachytherapy for cervical cancer.

Material and methods: Four radiation oncologists (ROs) with different expertise levels delineated high-risk (HR) and intermediate-risk (IR) clinical target volume (CTV) according to GYN GEC-ESTRO recommendations, in a blinded manner on every CT set of ten locally advanced cervical cancer cases. The most experienced RO's contours were determined as the index and used for comparison. Dice similarity coefficient (DSC) and pairwise Hausdorff distance (HD) metrics were applied to compare the overlap and gross deviations of all contours.

Results: Median DSC for HR-CTV and IR-CTV were 0.73 and 0.76, respectively, and a good concordance was achieved for both in majority of contours. While there was no difference in DSC measurements for HR-CTV among the three ROs, RO-3 provided improved DSC values for IR-CTV (p = 0.01). Median HD95 was 5.02 mm and 6.83 mm, and median HDave was 1.69 mm and 2.21 mm for HR-CTV and IR-CTV, respectively. There was no significant difference among ROs in HR-CTV for HD95 or HDave; however, IR-CTV value was significantly improved according to RO-3 (p = 0.01). Case-by-case HD analysis showed no significant inter-observer variations, except for two cases.

Conclusions: The inter-observer agreement is generally high for target volumes in CT-guided brachytherapy for cervical cancer. The agreement is lower for IR-CTV than HR-CTV. The individual characteristics of each case and different expertise levels of the ROs may have caused the differences. Despite the good concordance for delineation, dosimetric consequences can still be clinically significant.

Purpose: Interstitial brachytherapy (ISBT) is indicated for intact cervical carcinoma (IN-CC) if intracavitary brachytherapy (ICRT) is not feasible and also in vault carcinoma (VA-C). We aimed to evaluate the doses to pelvic lymph node regions in IN-CC and VA-C treated with ISBT.

Material and methods: Ten patients (6 IN-CC, 4 VA-C) were chosen for this dosimetric study. IN-CC had a central tandem in addition to the needles. External iliac (EI-N), internal iliac (II-N), obturator (OB-N) and sacral (SA-N) groups of lymph nodes were delineated. A dose of 10 grays (Gy) and 8 Gy each × 2 fractions was prescribed to the target in IN-CC and VA-C respectively. Doses received by 100%, 90% and 50% volume (D₁₀₀, D₉₀, D₅₀) and D_2cc, D_1cc, D_0.1cc were evaluated. Doses to lymph nodal groups in IN-CC vs. VA-C were compared using Student's t-test.

Results: For 20 implants, the median number of needles was 18 (range, 16-20). Mean D₉₀ and D_2cc of the combined bilateral OB-N, II-N, EI-N and SA-N groups were 33.62 ±3.46% and 102.94 ±10.71%, 6.98 ±0.65% and 39.69 ±3.64%, 5.1 ±0.51% and 15.4 ±0.8%, 7.76 ±0.95% and 15.36 ±1.09% of the prescribed doses respectively. Patients with a central tandem (IN-CC) received significantly higher doses to external, internal iliac and sacral group of lymph nodes (p < 0.001) as compared to VA-C.

Conclusions: In patients with cervical carcinoma treated with ISBT, pelvic lymph node groups received significant doses. The dose contribution to pelvic lymph nodes is higher in patients with intact cervical cancer where a central tandem is used as compared to post-operative patients.

Purpose: To report outcomes of using image-guided hybrid intra-cavitary/interstitial applicators under moderate sedation for locally advanced cervical cancer patients in our institution.

Material and methods: A total of 69 fractions of brachytherapy with hybrid applicators were performed in 33 patients from January 2017 to April 2021. All patients underwent MRI pelvis 1 week pre-brachytherapy to determine suitability for interstitial brachytherapy and pre-plan needle placement. All insertion of applicators were performed under moderate sedation with midazolam and/or fentanyl. Fifty-eight (84.1%) fractions were planned with CT alone. Clinical outcomes, dose volume parameters, and toxicities were analyzed.

Results: The median follow-up was 28 months. A total of 320 needles (median, 5 needles per fraction) were implanted, with a median insertion depth of 3 cm (range, 1.5-4 cm). The median high-risk clinical target volume (HR-CTV) during initial brachytherapy was 34.5 cc (range, 17.8-74.7 cc). The median total EQD₂ D_2cc of the rectum, bladder, sigmoid, and small intestine colon was 71.8 Gy, 81.5 Gy, 69 Gy, and 58.3 Gy, respectively. The 2-year local control and overall survival were 80.7% and 77.7%, respectively. Larger volume HR-CTV was significantly associated with worse local control (HR = 1.08, p = 0.005) and overall survival (HR = 1.04, p = 0.015). None of the patients required in-patient admission or blood transfusion post-procedure. Late grade 3 gastrointestinal and genitourinary toxicities were observed in 4 patients (12.2%).

Conclusions: Hybrid applicators inserted under moderate sedation are feasible and safe. Image-guided interstitial brachytherapy with CT planning aided by MRI performed 1 week pre-brachytherapy is associated with favorable outcomes and modest toxicities.

Purpose: The prevalence of non-melanoma skin cancer (NMSC) increases, especially in older adults with comorbidities, narrowing radical treatment options. About 5% of skin cancer patients are diagnosed with an advanced stage, which impairs daily functioning. The study was to present a retrospective summary of elderly patients unfit for surgery and treated with various brachytherapy (BT) techniques tailored individually for locally advanced NMSCs in a reference BT department. Clinical case presentations supported the findings.

Material and methods: Inoperable patients older than 75 years presenting with advanced pathologically confirmed NMSCs were retrospectively identified. All cases were individually assessed, and the best suiting radical treatment option was chosen, including contact, interstitial, or hybrid high-dose-rate (HDR) or pulsed-dose-rate (PDR) BT. Doses ranging from 45 to 60 Gy were administered to clinical target volume (CTV) in different time schedules. All patients were closely followed-up until complete remission.

Results: Ten elderly patients (mean age, 84 years) with differently located locally advanced NMSCs (all staged T3) were treated between 2007 and 2022. Six basal and four squamous cell carcinoma cases showed most painful symptoms as well as bleeding and exudation. Six patients underwent HDR-BT and four PDR-BT. Six patients had superficial, and four interstitial or hybrid applications. All patients completed the intended protocols. Median follow-up was 8.5 months (range, 3-35 months). Six out of ten patients died from other reasons before analysis. All case data were presented in the text and respective figures.

Conclusions: Advanced NMSCs in elderly patients are challenging in terms of cure. Inoperable cases may be referred for feasible and locally effective interventional radiotherapy (BT). Individually tailored BT leads to an excellent disease control, function sparing, symptoms release, and quality of life improvement. Large treated volumes are related to prolonged healing. BT should be discussed in a multidisciplinary tumor board regarding older patients with symptomatic functions affecting advanced NMSCs.

Purpose: Cervical stump cancer is a carcinoma that grows on the cervical stump after a sub-total hysterectomy. There have been no studies on the application of 3D brachytherapy in cervical stump cancer. In the present study, we aimed to compare the curative effects, toxicity, and dosimetry of 3D and 2D brachytherapy in cervical stump cancer.

Material and methods: Thirty-one patients admitted between 2012 and 2021, who were concurrently treated with intensity-modulated radiation therapy and brachytherapy for cervical stump cancer were divided into three groups according to the brachytherapy techniques: 2D brachytherapy, 3D image-guided brachytherapy (3D-IGBT), and 2D + 3D. For patients undergoing 2D brachytherapy and 3D-IGBT, data on survival, complications, and dose to target area or organs at risk (OARs) were collected and compared. Furthermore, dosimetry difference was investigated by reconstructing the 2D plan into a 3D plan.

Results: The median follow-up duration of all patients was 58 months. The overall 5-year progression-free survival, overall survival, and local control rates were 69.6%, 90.2%, and 78.2%, respectively. Late complications in the rectum, sigmoid colon, and bladder were milder in 3D brachytherapy than in 2D brachytherapy. Concerning the D₉₀ value of clinical target volume (CTV) and D_2cm³ value of OARs in EQD₂, the 3D brachytherapy provided a lower dose to CTV (76.5 Gy vs. 95.9 Gy, on average) and OARs compared with 2D brachytherapy.

Conclusions: Despite lacking statistical significance, 3D brachytherapy showed better outcomes regarding late toxicity than 2D brachytherapy, owing to the lower dose coverage in the bladder, rectum, sigmoid colon, and small intestine.

Few cases of patients with Cheng's type III portal vein tumor thrombus (PVTT) have been reported to achieve radical cure without recurrence over time. In this study, we reported on a 55-year-old male patient with a diagnosis of stage IIIa China liver cancer staging (CNLC), PVTT Cheng's type III, mild cirrhosis, and chronic viral hepatitis B. TACE combined with radioactive iodine-125 (¹²⁵I) particle implantation was applied to achieve radical treatment with sequential oral anlotinib hydrochloride capsules. This case might serve as a reference for the treatment of this disease.