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.

Dosimetric evaluation of vaginal cuff brachytherapy planning in cervical and endometrial cancer patients.

PURPOSE: The aim of the study was to perform a prospective analysis of dosimetric consequences of rectal enema administration before vaginal cuff brachytherapy (VCB), the dose distribution in organs at risk (OARs), and the presence of air gaps (AGs) in patients with cervical or endometrial cancer. MATERIAL AND METHODS: In total, 75 patients treated in 2019 were randomly divided into two groups including 38 patients with and 37 without an enema before VCB. All patients received post-operative high-dose-rate (HDR). Single-channel vaginal cylinders with active length of 2.75 cm were used. Prescription dose was 7 Gy at 5 mm depth from the applicator surface in all directions. Treatment plans were based on computed tomography (CT). RESULTS: Enema performed before cylinder insertion had no effect on rectosigmoid Dmax or D2cm3. Rectosigmoid median V100 was 0.5 cm3 (range, 0-2.7 cm3). V100 ≥ 1 cm3 in 22 and ≥ 2 cm3 in 6 patients, with Dmax up to 19.7 Gy (282%) were observed. No effect of bladder volume in the range of 27-256 cm3 on Dmax or D2cm3 was found. The median bladder V100 was 0.1 cm3 (range, 0-1.4 cm3). There were 62 (83%) patients with AGs, with 24% at the top of the vagina and 75% on the remaining length of the vagina. Most of the AGs were small (≤ 3 mm), but in 5 (8%) cases, they were bigger than 5 mm. CONCLUSIONS: VCB planning with the use of CT is essential. CT can facilitate the selection of optimal cylinder size to reduce the occurrence of large AGs. A few percent of plans require correction of dose distribution because of hot spots in OARs and the presence of AGs. Enema before cylinder insertion does not influence rectosigmoid Dmax and D2cm3. The analysis revealed no bladder volume effect on bladder doses Dmax and D2cm3.

Image-guided high-dose-rate brachytherapy for prostate cancer patients with previous rectal resection and pelvic irradiation: feasibility study.

PURPOSE: The aim of this study was to describe treatment procedure and early clinical outcomes of high-dose-rate (HDR) interstitial brachytherapy (BT) in clinically localized prostate cancer patients previously treated for rectal cancer with abdominoperineal rectal resection and external beam radiation therapy (EBRT). MATERIAL AND METHODS: Between February and July 2015, two patients with clinically localized prostate cancer without rectal access were treated in our brachytherapy department. HDR interstitial brachytherapy was conducted with the guidance of fluoroscopy and computed tomography (CT) imaging. Brachytherapy was combined with hormonal therapy. RESULTS: Follow-up lasted for 34 and 39 months for patient 1 and 2, respectively. Both patients remained free from biochemical recurrence according to the Phoenix definition. No severe G3/G4 late toxicity was observed, and neither patient experienced any gastrointestinal morbidity. Acute and late urinary toxicities were at an acceptance level, and were scored G1 and G2 for patient 1, and G3 and G1 for patient 2, respectively. CONCLUSIONS: Fluoroscopy and 3D CT image-guided interstitial brachytherapy is feasible and appears to be a suitable treatment technique for patients with clinically localized prostate cancer after previous rectal resection and external beam radiation therapy.

Analysis of the long-term stability of the output of electron beams generated by the Novac11™ IORT accelerator.

AIM: The aim of the study was to analyze the long-term stability of electron beams generated by the Novac11™ IORT accelerator. BACKGROUND: Novac11™ (NRT®) is a mobile electron accelerator designed to irradiate small areas of tissue, up to 10 cm in diameter, with electron beams during surgical procedures. It is characterized by a great mobility guaranteed by a number of degrees of freedom enabling irradiation in the conditions of an operating theatre. MATERIALS AND METHODS: Over the period of January 2013 and September 2016, the measurement sessions of the output of clinically used beam qualities (6, 8 and 10 MeV) were carried out 41 times. Because of the unsatisfactory long-term stability, an extra procedure of tuning of the magnetron, suggested by the manufacturer, was introduced in October 2015, 15 measurements were performed since then. The output of the Novac11™ accelerator was measured in the reference conditions recommended by the IAEA Report 398, the measurements of the charge in the ionization chamber at the reference depth were carried out with a Dose1™ electrometer and a plane-parallel chamber PPC05™ from IBA®. RESULTS: The introduction of the tuning of the magnetron procedure resulted in satisfactory long-term stability of the measured outputs below 2%. CONCLUSIONS: After the introduction of the STV parameter tuning procedure, the long-term stability of the Novac11™ output increased considerably and is within the values declared by the manufacturer.

Comparison of computed tomography with magnetic resonance imaging for imaging-based clinical target volume contours in cervical cancer brachytherapy.

PURPOSE: To compare CT- and MRI-based brachytherapy (BT) target volumes for patients with advanced cervical cancer so as to identify those who benefit most from MRI-based planning. We also studied how the natural mobility of the organ at risks (OARs) affects the given doses. METHODS AND MATERIALS: Subjects were 60 patients with International Federation of Gynecology and Obstetrics (FIGO) Stage IB-IVA cervical cancer. The CT high-risk clinical target volume (HR-CTV) was first delineated, then the MRI HR-CTV, with volume discrepancies calculated by subtraction. The DICE coefficient (DC) of similarity was calculated from a superimposition of the volumes. Maximum doses delivered to D2cc of OARs in CT and MRI plans were compared; the effect of time on the natural mobility was analyzed. RESULTS: The mean HR-CTVs and the maximum doses given to OARs in CT- and MRI-based planes were similar. Multivariate analysis showed that deep infiltration affecting the uterine corpus and bowel loops adjacent to the cervix were the factors significantly impacting on the volume discrepancy between CT and MRI HR-CTV (p = 0.001, p = 0.045) and on the DC (p = 0.005, p = 0.028). Univariate analysis demonstrated that the FIGO stage had a significant impact on DC (p = 0.022). Patients with bowel loops adjacent to the cervix had lower body mass indices (p = 0.003). The median difference between the doses given in CT- and MRI-based plans, caused by mobility, were 0.5 Gy, 0.3 Gy, and 0.45 Gy per fraction for the rectum, bladder and sigmoid, respectively. No correlation of observed uncertainties and time between image acquisitions was detected. CONCLUSIONS: CT- or MRI-based scans at BT are adequate for OAR dose-volume histograms analysis. Cervical cancer patients with deep infiltration affecting the uterine corpus, a low body mass index with bowel loops adjacent to the cervix and an FIGO Stage III-IVA benefit most from MRI-based planning of BT.

Computed Tomography-Planned High-Dose-Rate Brachytherapy for Treating Uterine Cervical Cancer.

PURPOSE: To evaluate the long-term results of computed tomography (CT)-planned high-dose-rate (HDR) brachytherapy (BT) for treating cervical cancer patients. METHODS AND MATERIALS: CT-planned HDR BT was performed according to the adapted Group European de Curietherapie-European Society for Therapeutic Radiology and Oncology (GEC-ESTRO) recommendations in 216 consecutive patients with locally advanced cervical cancer, International Federation of Gynecology and Obstetrics (FIGO) stage IB to IVA, who were treated with conformal external beam radiation therapy and concomitant chemotherapy. We analyzed outcomes and late side effects evaluated according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer and Subjective, Objective, Management, Analysis evaluation scoring system and compared them with the results from a historical group. RESULTS: The median age was 56 years (range, 32-83 years). The median follow-up time for living patients was 52 months (range 37-63 months). The 5-year cumulative incidence function for the local recurrence rate for patients with FIGO II and III was 5.5% and 20%, respectively (P=.001). The 5-year rates of overall survival (OS) and disease-free survival (DFS) were 66.4% and 58.5%, respectively. The relative risk of failure for OS and DFS for FIGO III in relation to FIGO II was 2.24 (P=.003) and 2.6 (P=.000) and for lymph node enlargement was 2.3 (P=.002) and 2 (P=.006), respectively. In 2 patients, rectovaginal fistula occurred, and in 1 patient, vesicovaginal fistula occurred without local progression. Comparison of late adverse effects in patients treated according to the GEC-ESTRO recommendations and in the historical group revealed a reduction in fistula formation of 59% and also a reduction in rectal grade 3 to 4 late toxicity of >59%. CONCLUSIONS: This is the largest report with mature data of CT-planned BT HDR for the treatment of cervical cancer with good local control and acceptable toxicity. In comparison with the historical series, there is a substantial benefit in terms of severe late effects. FIGO III and enlarged lymph nodes in positron emission tomography-CT/CT are negative prognostic factors, both with a relative risk of failure of approximately 2.

Brachytherapy for vaginal intraepithelial neoplasia.

OBJECTIVE: To retrospectively evaluate the efficacy of high-dose-rate brachytherapy of vaginal intraepithelial neoplasia with a special focus on analysis of toxicity. STUDY DESIGN: Twenty consecutive patients were irradiated with brachytherapy of vaginal intraepithelial neoplasia with component ca in situ (N=3). Late complications of the vagina graded using the CTCAE v.3.0. General assessment three-step scale was introduced for simplicity of analysis. RESULTS: The median age was 57 years (range: 28-80 years). The median follow-up time was 39 months (range: 14-115 months). Vaginal intraepithelial neoplasia recurrence was observed in 1 patient. The 3-year disease free survival rate was 90% (95% confidence interval [CI]: 71-100%). Observed late side effects: libido grades 1-2 in 15 (75%), vaginal discharge grade 2 (pad use indicated) in 2 (10%), dryness grade 2 (dyspareunia) in 7 (35%), mucositis grades 2-3 in 6 (30%), stenosis grades 2-3 in 7 (35%) and vaginitis grades 2-3 in 4 (20%) cases. General assessment was good in 9 (45%), average in 2 (10%), and bad in 9 (45%) patients. Treatment dose affected the toxicity (p=0.05). In groups of patients irradiated with biologically equivalent dose (assuming α/ß=3Gy) of 47.3-63Gy and ≥70Gy, the risk of poor or moderate toxicity amounted to 16.7% (95% CI: 0-47%) and 71.4% (95% CI: 48-95%), respectively. CONCLUSION: Brachytherapy revealed to be effective method of vaginal intraepithelial neoplasia treatment, but applying EQD2≥70Gy into vagina generates unacceptable toxicity.

HDR brachytherapy as a solution in recurrences of locally advanced prostate cancer.

PURPOSE: The object of this study was to analyze the outcome of salvage HDR brachytherapy treatment after local failure, for patients with prostate specific antigen (PSA) failure without distant metastasis, after external beam radiation and HDR brachytherapy treatment, or after radical prostatectomy, with or without hormonal therapy. MATERIAL AND METHODS: The group of 115 patients, without distant metastasis, after local failure and external beam radiation, followed by HDR brachytherapy treatment, or after radical prostatectomy, with hormonal therapy and without, have been enrolled to salvage HDR brachytherapy (SBR). All patients had minimum 3 months androgen deprivation therapy before salvage brachytherapy, which was continued until the next 9 months after SBR. Brachytherapy was administered in three 10 Gy fractions with 3 weeks gap between them. Each session of SBR was supported by trans-rectal USG real time pictures. The treatment planning was done on the base of Abacus system from Sauerwein® or with SWIFT system from Nucletron®. The following data were collected: Gleason score, clinical staging, the volume of the prostate, PSA before and after the initial treatment and periodically during the follow-up period. Also the time during which the PSA stays at the nadir level, patient's age and toxicity of treatments were taken into consideration. RESULTS: Doses from external radiotherapy or from HDR brachytherapy were recalculated to equivalent biological dose (EBD). The independence from biochemical progression in our group of patients after retreatment was 46% for patients with PSA ≤ 6 and 18% for patients with PSA > 6. Overall survival for patients with PSA ≤ 6 was 86% and 48% for patients with PSA > 6, respectively. CONCLUSIONS: Salvage prostate brachytherapy (SBR) can be safely performed with acceptable biochemical control and toxicity.