Interstitial Brachytherapy Techniques Research Articles

Post- versus intra-operative implant for breast cancer interstitial brachytherapy: How to choose?

Breast brachytherapy (BB) represents an important radiation therapy modality in modern breast cancer treatments. Currently, BB is mainly used for accelerated partial breast irradiation (APBI), local boost after whole breast radiation therapy (WBRT), and as salvage re-irradiation after second lumpectomy (APBrl). Two multi-catheter interstitial brachytherapy (MIB) techniques can be offered: intra-operative (IOB) and post-operative (POB) brachytherapy. The aim of this article was to summarize current available data on these two different brachytherapy approaches for breast cancer. A literature search was performed, and different experiences published by BB expert teams were analyzed and compared. These two different brachytherapy approaches for breast cancer have also been presented and discussed during meetings of the GEC-ESTRO BCWG. In addition, expert recommendations were defined. A comprehensive description and practical comparison of both the techniques, i.e., IOB and POB, considering the latest available published data were presented. Different technical, logistic, and clinical aspects of both the methods were thoroughly examined and analyzed. This detailed comparison of the two breast brachytherapy techniques was supported by scientific data from extensive experience of experts, facilitating an objective analysis that, to our knowledge, has not been previously published. Based on the comprehensive analysis of both the brachytherapy techniques available, this article serves as a valuable resource to guide breast teams in selecting the optimal BB technique (POB or IOB), considering hospital environment, multi-disciplinary collaboration, and patient logistics.

In-silico calculations of DNA damage induced by [formula omitted]-particles in the 224Ra DaRT decay chain for a better understanding of the radiobiological effectiveness of this treatment

Diffusing alpha-emitters radiation Therapy (DaRT) is an interstitial brachytherapy technique using 224Ra seeds. For accurate treatment planning a good understanding of the early DNA damage due to α-particles is required. Geant4-DNA was used to calculate the initial DNA damage and radiobiological effectiveness due to α-particles with linear energy transfer (LET) values in the range 57.5–225.9 keV/μm from the 224Ra decay chain. The impact of DNA base pair density on DNA damage has been modelled, as this parameter varies between human cell lines. Results show that the quantity and complexity of DNA damage changes with LET as expected. Indirect damage, due to water radical reactions with the DNA, decreases and becomes less significant at higher LET values as shown in previous studies. As expected, the yield of complex double strand breaks (DSBs), which are harder for a cell to repair, increases approximately linearly with LET. The level of complexity of DSBs and radiobiological effectiveness have been found to increase with LET as expected. The quantity of DNA damage has been shown to increase for increased DNA density in the expected base pair density range of human cells. The change in damage yield as a function of base pair density is largest for higher LET α-particles, an increase of over 50% for individual strand breaks between 62.7 and 127.4 keV/μm. This change in yield shows that the DNA base pair density is an important parameter for modelling DNA damage particularly at higher LET where the DNA damage is greatest and most complex.

Evaluation of the Dosimetric Parameters of the Interstitial HDR Liver Brachytherapy at USM

There are numerous treatment options available to treat hepatocellular carcinoma (HCC). Up to now, stereotactic body radiotherapy (SBRT) has been considered the best option to cure the HCC, however SBRT does not adequately spare the nearby organ at risk (OAR) [1]. A high dose rate interstitial brachytherapy (HDR IBT) technique for HCC is considered as an alternative to the SBRT due to accurate and precise dose delivery to the target and well spared adjacent OAR [2]. The main objective of this retrospective study was to evaluate the dosimetry tolerance for the tumour and OAR for HDRIBT technique for HCC technique using the iridium-192 (Ir-192) source.
 A computed tomography (CT) image-guided for 41 patients with 71 treatment cases in USM were used to analyse the dose distribution in tumour (HCC) and the OAR (diaphragm). The computed dosimetry data from the Oncentra treatment planning system (v.4.3) was used to analyse the relationship between the dosimetric variables, of the prescribed dose (15 Gy – 25 Gy) and fractionation used for the HDRIBT for HCC by statistical analysis.
 In this study, 95% of the gross tumour volume (GTV) of HCC adequately achieved the prescribed dose in both single and multiple fractionations. The GTV dose decreased as the GTV volume increased for all the prescribed doses. Apart from that, the prescribed doses, 20 Gy and 25 Gy, exhibited a higher diaphragm dose in single fractionation treatment compared to 15 Gy dose. Meanwhile, the multiple fractionations treatment also exhibited a remarkably high diaphragm dose compared to the single fractionation treatment.
 The minimum GTV dose recommended was based on a comparison with the RTOG 0438, liver SBRT protocol. These recommended values were applicable in both single and multiple fractionations. In addition, it is also applicable in a prescribed dose of 15y – 25 Gy. In short, the minimum recommended GTV doses were the V99% 90% of the prescribed dose, V95% 95% of the prescribed dose V90% 100% of the prescribed dose, respectively. Meanwhile, the diaphragm tolerance dose in this study was compared with RTOG 0438 protocol of ribs tolerance dose, within 54 Gy. Therefore, the diaphragm tolerance dose recommended for diaphragm volume of 0.2cm3, 0.5cm3 and 2.0cm3 (15 Gy prescribed dose) < 10 Gy, (20 Gy prescribed dose) < 15 Gy and (25 Gy prescribed dose) < 20 Gy in single fractionation respectively for all prescribed dose, whereas for the multiple fractionations < 54 Gy, regardless of the GTV volume. In conclusion, HDRIBT technique for HCC is the most promising technique by maximizing the dose to the GTV and reducing dose to the diaphragm by both single and multiple fractionations.

Toxicity Related Patients Factors and Bevasizumab Use in Patients With Locally Advanced Cervical Cancer Treated With Definitive Chemoradiation and HDR Brachytherapy Boost

The purpose of this study is to identify factors associated with severe late toxicity and prognosis in women with locally advanced cervical cancer treated with definitive chemoradiation (CRT) and high dose rate (HDR) radiation therapy boost. An increased rate of GI toxicity when Bevacizumab is administered in combination with high doses of abdominal radiation therapy such as stereotactic body radiotherapy (SBRT) has been demonstrated in other malignancies. Our aim is to compare the risk of Grade 3+ toxicity in patients who receive Bevacizumab after HDR brachytherapy in comparison with other risk factors.Patients with locally advanced cervical cancer treated with CRT from 2010-2019 in a single academic institution were included. Records were reviewed for demographic information, treatment details, toxicities, and outcomes. Patients with and those without severe late gastrointestinal (GI) toxicity and severe late genitourinary (GU) toxicity were compared. Progression free-survival (PFS) was also compared between groups. Smoking status was classified as current smokers, former smokers and non-smokers. Statistical comparisons were performed using t-tests and ANOVA tests.Of 101 patients identified, 10.9% had severe grade 3+ GI toxicity, and 9.1% had severe grade 3+ GU toxicity. Mean duration to follow up was 30 months (range 1-124 months). In patients who received Bevacizumab after completion of definitive treatment, there was a significantly higher rate of Grade 3+ GI or GU toxicity (50% versus 16%, P = 0.005). 83% of Grade 3+ toxicity in the Bevacizumab group was GI related. There was no correlation between the time interval between radiation and Bevacizumab initiation to toxicity. Age was also significantly associated with toxicity, patients 55 and younger had a 10% rate of Grade 3+ toxicity while patients older than 55 had a 28% rate (P = 0.02). Patient who received interstitial versus intracavitary brachytherapy technique also demonstrated high rates of toxicity (30% vs. 8%, P = 0.002). PFS was similar among patients with severe toxicities compared to those without toxicity. In regards to smoking status, there was no significant difference in toxicity. Risk of recurrence was higher in the current smokers and former smokers (40% and 31% respectively) but did not reach statistical significance when compared to non-smokers (25%).In patients with locally advanced cervical cancer, the use of Bevacizumab is significantly associated with increased toxicity after definitive chemoradiation. Similar data has been shown in patients who receive Bevacizumab and abdominal SBRT. Given that the addition of Bevacizumab is first-line therapy and improves survival for recurrent cervical cancer, further investigation is warranted to determine how to optimize the risk-benefit ratio.S. Azghadi: None. P.L. Beagen: None. A. Ahmed: None. R.K. Valicenti: None. R.A. Brooks: None. X. Zhao: None.

PLEN03 Presentation Time: 1:45 PM: HDR Interstitial Spine Brachytherapy Using an Intraoperative CT-Guided Surgical Navigation System Compared with Stereotactic Radiosurgery

Purpose: Stereotactic radiosurgery (SRS) has been used to treat spinal metastases. However, reirradiation to the tumor is limited by spinal cord tolerance due to dose fall off outside the target. In order to escalate dose to the target with high accuracy and precision, we have developed a novel high-dose-rate (HDR) interstitial brachytherapy (IS-BT) technique using an intraoperative mobile 3D CT-guided surgical navigation system and compared dosimetry with SRS.

HDR brachytherapy using cylinder, tandem-ovoid (T&O) and interstitial implant with prognosis

Purpose: Among the therapeutic modalities available for the treatment of cervical cancer, irradiation is regarded to be the standerd treatment for all tumor stages, which includes external beam radiation therapy and HDR brachytherapy or a combination of these two. This modality of cancer, needless to say, is prevalent in Bangladesh as the women are coming forward for its detection. Dramatic advances have been made in brachytherapy for cervical cancer. Radiation treatment planning has evolved from two-dimensional to three-dimensional, incorporating magnetic resonance imaging and/or computed tomography into the treatment paradigm. This allows for better delineation and coverage of the tumor, as well as improved avoidance of surrounding organs. Brachytherapy applications are not restricted to one method only; any method could be combined with another, as well as other radiotherapy techniques. In cervical cancer, intracavitary brachytherapy (ICBT) has been used for practical reasons. Lately though, combination of ICBT and interstitial brachytherapy (ISBT) techniques are being evaluated in deference to feasibility, practicality and reproducibility. Advanced brachytherapy can achieve very high rates of local control with a reduction in morbidity, compared with historic approaches. This study provides an overview of state-of-the-art gynecologic brachytherapy, with a focus on recent advances and their implications for women with cervical cancer.Materials and Methods: Three patients were selected on different staging. Three different types of applicator (Cylinder, Tandem and Ovoid and Interstitial Implant) were inserted according to the patient’s anatomy and staging. Prescribed dose were different for the implant technique.Result: Progress from 2D- to 3D-based imaging and treatment planning for cervical cancer brachytherapy has improved local control, reduced toxicity, and improved overall survival for women.Conclusion: The result of our study indicates that a precise delivery of treatment by applying a appropriate applicator and the choice of treatment planning technique is more important for a better outcome.

Metal tube combined with ultrasound-guided accurate interstitial brachytherapy for postoperative pelvic side-wall recurrences of cervical cancers: Technique and outcome

Objective: Our goal was to describe and evaluate the metal tube-assisted ultrasound-guided accurate interstitial brachytherapy technique (TUG-ISBT) and the clinical outcome of a transvaginal treatment without anesthesia modality for the treatment of women with postoperative pelvic sidewall recurrences of cervical cancer.

Iodine-125 interstitial brachytherapy for malignant lacrimal sac tumours: an innovative technique

ObjectivesPrimary malignant tumours of the lacrimal sac are rare, surgery and radiotherapy may induce substantial side effects for patients. Here, this article reports an innovative technique of interstitial brachytherapy developed for the treatment of malignant lacrimal sac tumours.Patients and methodsFour patients (male 3, female 1), with an average age of 52.7 years (range 41–72 years), were individually diagnosed with squamous cell carcinoma, adenocarcinoma, adenoid cystic carcinoma and lymphoma. All patients received Iodine-125 interstitial brachytherapy after surgical resection for malignant lacrimal sac tumours. Visual function examination (vision, intraocular tension, fundus photography, fluorescein angiography, and optical coherence tomography) and CT/MRI/PET-MRI were performed to look for signs of recurrent tumours or metastasis.ResultsFour patients were followed for an average of 28 months (range, 23–37 months). All patients were free from local disease. Their visual function was normal, and CT/MRI did not reveal any tumour recurrence.ConclusionsIodine-125 interstitial brachytherapy can be used as an alternative to wide excision or exenteration of these tumours. There was good local control, reasonable maintenance of vision, and good cosmesis.

Analysis of clinical utilization of ring applicator for combined intracavitary/interstitial image-guided brachytherapy treatment in Chinese patients with locally advanced cervical cancer.

PurposeTo analyze the results of clinical utilization of ring applicator for combined intracavitary (IC)/interstitial (IS) image-guided brachytherapy (BT) technique in locally advanced cervical cancer (LACC), and to explore the application conditions of IC/IS BT approach with this applicator for Chinese patients.Material and methodsIC/IS BT was performed in total of 95 LACC patients, who already received external beam radiotherapy. In forty-three of these patients, utilization of ring applicator in brachytherapy was done, including IC/IS BT approach with ring applicator for 65 fractions. Clinically optimized IC/IS BT plan with ring applicator (IC/IS treatment) and additionally generated optimized plan without needle use (IC research) were designed, respectively. Dosage differences in target regions and organs at risk (OARs) were analyzed between both the plans. Four planes were selected in the longitudinal direction of uterine cervix and divided the 360° area around the tandem into eight equal sectors. Tumor target features and prescription dose distributions on different planes were described.ResultsThe usage rate of ring applicator with most suitable ring diameter of 26 mm was 45.3% in Chinese cervical cancer patients. The high-risk clinical target volume (HR-CTV) D90/D98 and intermediate-risk CTV (IR-CTV) D90/D98 in IC/IS treatment were significantly higher than IC research. As compared with IC research plan, the D2.0 cm3 of bladder and rectum in IC/IS treatment were significantly lower (p < 0.05). There was no significant difference in D2.0 cm3 of sigmoid and small bowel between two plans. When the target volume was larger than 36 cm3, IC alone had an inadequate coverage of target.ConclusionsNearly half of Chinese patients with LACC could be treated with the ring applicator. The application conditions of IC/IS BT approach with ring applicator for Chinese patients were achieved. Combined IC/IS image-guided BT based on magnetic resonance imaging (MRI) planning is clinically feasible in Chinese patients.

A hybrid technique of intracavitary and interstitial brachytherapy for locally advanced cervical cancer: initial outcomes of a single-institute experience

BackgroundLocally advanced uterine cervical cancer (LAUCC) with lateral tumor extension may not always be covered adequately by conventional intracavitary brachytherapy (ICBT). Hybrid intracavitary and interstitial brachytherapy (HBT) seems to be an effective alternative by improving anatomy-oriented dose optimisation. The purpose of this study was to report initial clinical result for LAUCC treated by HBT.MethodsBetween January 2012 and November 2015, 42 patients with LAUCC (T1b2-4a) were treated with primary radiation therapy including HBT. Patients with distant metastasis other than para-aortic lymph node spread were excluded from this study. A retrospective analysis was performed for toxicity evaluation and oncological outcome calculation.ResultsMedian follow-up was 23.2 months (range 13.2–71.4). Two-year overall survival, progression free survival, and local control rate were 81.6, 54.4, and 80.2%, respectively. Seven patients experienced local recurrence (16.6%). Of those, five were confined to the uterus and two at the parametria. Late adverse events ≥ grade 3 were seen in 3 patients.ConclusionsHBT can generate favorable local control in tumors which cannot be adequately covered by ICBT.

Parametrial Boost (PMB) in the Era of Image-Guided Brachytherapy (IGBT) for Cervical Cancer

Historically, PMB was standard practice in locally advanced cervical cancers to provide sufficient dose to involved parametria. Modern 3D imaging, as well as high-dose rate (HDR) and interstitial (IS) brachytherapy techniques have improved the delineation and coverage of a high-risk clinical target volume (HRCTV) while allowing for higher dose delivery. PMB has become increasingly controversial in the era of IGBT. Due to the lack of data on safety of omitting PMB, patterns of failure with and without use of PMB were explored. Women with locally advanced (FIGO Stage IIB-IVA or with PM invasion identified on imaging) cervical cancer diagnosed between 2001-2016 were identified. All patients received external beam radiotherapy (EBRT) and brachytherapy boost (BT) using either low-dose rate (LDR) or HDR sources (prescribed to point A and HRCTV, respectively). HRCTV was contoured using MRI guidance (either diagnostic or with apparatus in place). PMB was delivered to achieve a cumulative dose of 56-60 Gy to the lateral parametria. Demographic, treatment era (pre and post 2009), pre-treatment imaging modality, FIGO stage, lymph node status, PMB, BT modality (IS vs. tandem & ovoid, T&O), dose rate, and patterns of failure were collected. Cramer’s V and chi-squared tests were used to assess strength of association between variables. The log-rank test was used for univariate analysis (UVA) and a Cox proportional hazards model was created for multivariable analysis (MVA). Overall survival (OS) was estimated using Kaplan-Meier analysis A total of 71 women were identified with median follow up of 25 months. 36 women received PMB. Median doses were as follows: EBRT 45 Gy, PMB 4.5 Gy, HDR BT 29.5 Gy, and LDR 40 Gy. 37 women received HDR and 34 received LDR BT. Six patients who did not receive PMB had PM involvement only on imaging. PMB patients were less likely to have received diagnostic MRI, PET, or IS and more likely to receive LDR. The use of PET, dose rate, and treatment era were highly correlated with one another (Cramer’s V 0.7-0.9, p<0.001). 2-year OS was 74%. On UVA, treatment year, use of PET, use of MRI, and dose rate were associated with OS (all p<0.05). In an MVA including PMB, age, race, nodal status, FIGO stage, and PET, para-aortic nodal involvement (HR= 4.33, 95% CI 1.01-10.7, p=0.049) and use of PET (HR=0.22, 95% CI 0.1-0.7, p=0.007) were associated with OS. PMB was associated with higher crude rates of local (22% vs. 6%, p=0.049), locoregional (30% vs. 6%, p=0.01), and distant failure (28% vs. 9%, p=0.04). In this retrospective study, the omission of PMB did not compromise local control or impact OS in the setting of IGBT. At our institution, PMB treatment has gradually been eliminated in cervical cancer treatment. Adaptive IGBT provides accurate identification and dose shaping of HRCTV previously unachievable in the 2D era, allowing for targeting of gross parametrial involvement.

Impact of adjuvant systemic chemotherapy on wound healing and cosmetic outcome in 224 women treated with accelerated partial breast irradiation using interstitial brachytherapy

PurposeTo evaluate the impact of timing of adjuvant chemotherapy on wound healing and cosmetic outcome in women treated with accelerated partial breast irradiation (APBI). Methods and MaterialsBetween August 2000 to December 2011, 224 women were treated with APBI using multicatheter interstitial high-dose-rate brachytherapy. Patients were treated to a dose of 34 Gy/10#/5–7 days with bid regimen. Systemic chemotherapy was administered as per the standard guidelines. ResultsMulticatheter interstitial brachytherapy technique was open cavity in 136 (60%) and closed cavity in 88 (40%). Adjuvant chemotherapy was given in 117 (52%). Wound complications (WCs) were observed in 24 patients (11%), which included wound infections (WIs) in 20 and wound dehiscence in 14. The median gap between chemotherapy and APBI was 13 days in women who developed WCs, 20 days for prechemo, and 32 days for postchemo APBI in its absence. On multivariate analysis, gap between APBI and chemotherapy of ≤3 weeks was the only significant factor (p = 0.03) affecting WCs. Acute WI (p = 0.01) and two-dimensional planning (p = 0.04) had significant impact on cosmesis resulting in fair to poor cosmetic outcome. ConclusionsGap of ≤3 weeks between APBI and chemotherapy resulted in increased WCs. WI and two-dimensional planning resulted in poorer cosmetic outcome. We recommend gap of at least 3 weeks for optimal outcome.

Interstitial brachytherapy for orbital soft tissue sarcoma: an innovative technique.

PurposeTo report an innovative technique of interstitial brachytherapy developed for treatment of orbital soft tissue tumors.Material and methodsA 4-month-old child diagnosed with rhabdomyosarcoma of orbit was treated with multiagent chemotherapy (CTh) and brachytherapy. Pre-planning computed tomography (CT) images were obtained and clinical target volume (CTV) was defined using the pre-treatment magnetic resonance imaging (MRI). Brachytherapy plan was generated for deciding optimal catheter placement. With the child under general anesthesia, catheter entry points were extrapolated and marked on the skin as determined from the pre-planning CT scan. Implantation of catheters was performed as per pre-determined catheter position and depths. Brachytherapy plan was generated and evaluated using dose volume histograms (DVH). A comparative external beam radiotherapy (EBRT) plan using RapidArc was also generated for the CTV with a 3 mm margin as the planning target volume (PTV).ResultsThe mean CTV dose with brachytherapy was 158% compared to 101% with RapidArc. The CTV V100 was 90% for brachytherapy vs. 95% for RapidArc. The mean dose to Lt Lens were 51% and 60%, respectively for brachytherapy and RapidArc, while the corresponding mean doses to the bony orbit were 39% and 68%, respectively. Follow-up MRI at 3 months showed complete response of the tumor.ConclusionsInterstitial brachytherapy for orbit using this innovative technique is a safe and effective modality of local treatment for appropriately selected orbital soft tissue tumors. Brachytherapy resulted in excellent disease control with significant reduction of dose to surrounding ocular structures compared to EBRT.

Rationale, indications, techniques and applications of interstitial brachytherapy for carcinoma cervix

AbstractWith evolution of different newer radiotherapy techniques, still the role of brachytherapy in different gynecological malignancies has not sublimed. Most commonly used form of brachytherapy in carcinoma cervix patients is intracavitary brachytherapy. However, all the patients do not qualify for the treatment with intracavitary brachytherapy due to certain clinicopathological conditions. This warrants use of interstitial brachytherapy technique for treatment. For getting good results from interstitial brachytherapy, a good expertise and a proper infrastructure are needed. For perineal interstitial brachytherapy, different templates have been designed, used, and published by authors in different literature over the period. Among all these different templates, Martinez Universal Perineal Interstitial Template (MUPIT) has been used in gynecological, urological, and anorectal malignancies. In this literature review, we have discussed mainly MUPIT.

Interstitial High Dose Rate (HDR) Brachytherapy with Open Laparotomy for Locally Advanced Primary or Recurrent Gynaecological Cancer: Peter MacCallum Cancer Centre Experience

To report the technique and treatment outcomes of open interstitial brachytherapy performed at the Peter MacCallum Cancer Centre between 2007- 2013. Between June 2007 and December 2013, 11 patients were treated with curative intent using open interstitial implants as a radiotherapy boost (in combination with external beam radiotherapy (EBRT) and weekly platinum chemotherapy. Patients had no evidence of nodal or distant metastasis, and were receiving either upfront treatment for carcinoma of the vagina (n=2) or cervix stump (n=1) or isolated vault recurrence following primary surgery (cervix- 4; endometrium - 3; vagina-1). The main rationale for laparotomy was to minimise toxicity to bowel by allowing 1) placement of a spacer between interstitial needles and the bowel 2) adhesion lysis, if required 3) direct visualization of needle placement. RT planning was performed using MRI and CT. With a minimum follow up of 2 years, 10 of 11 patients were alive and 6 patients were disease-free and remained asymptomatic. These patients were either receiving primary treatment or had a prolonged disease-free interval between their initial primary treatment and presentation with recurrent disease. Of the remaining 5 patients, all had either persistent disease or relapsed at primary site. 1 of them developed distant metastasis and died of disease. 2 of these patients progressed in the inguinal nodes. 4 patients were alive with disease at 12 months, 3.5 years, 3 years and 2 years from the date of implant. Open Interstitial Implant is feasible and tolerated with acceptable toxicity. However, patient selection and adequate expertise are of utmost importance.

Long-term Results of Multicatheter Accelerated Partial-Breast Irradiation

Adjuvant radiation therapy has been shown to increase local control when delivered as a part of breast conservation surgery for patients with early stage disease. In an effort to expedite radiation therapy a variety of accelerated partial breast irradiation (APBI) techniques have been developed, yet there are few reports of long term outcomes. To partially address this we reviewed our experience with APBI via a multi-catheter interstitial brachytherapy (ISI) technique for patients treated before 2005. APBI began at our institution in 2003 and for several years was exclusively done via ISI. Patients treated in our clinic from February 2003 - March 2005 were reviewed. This date range was selected to allow for a minimum potential follow up period of ten years. Selection criteria for APBI at our institution predated the ASTRO consensus statement and, as such, included patients with age greater than 40 years at diagnosis, Tis-T2 (< 3cm) disease, no nodal involvement, no metastatic disease, negative surgical margins, and who underwent breast conservation surgery. We report patient and treatment characteristics as well as local-regional control and survival. One hundred consecutive patients were identified. Median age at diagnosis was 61 years. Median follow-up was 9.9 years. Tumor stages were 22 Tis, 72 T1, and 6 T2. All patients with invasive disease were N0. Invasive breast cancer subtypes were 62 ER/PR+ Her2 -, 7 ER/PR+ Her2 amplified, 1 ER/PR- Her2 amplified, 7 ER/PR/Her2-. By ASTRO APBI consensus categories: 41 were Suitable, 40 Cautionary, and 19 Unsuitable. Most patients in the Cautionary category were there due to age and/or DCIS histology while most patients in the Unsuitable category were there due to age < 50 years. ISI was performed via a free hand technique either in the operating room or via ultrasound guidance. The goal of the ISI was to encompass the surgical cavity plus a 2 cm margin. This approach used 22 catheters on average and treated a mean PTV volume of 163 dL. Mean coverage by the prescription dose of 34 Gy/10 fractions/twice daily was 95% with mean values for 1 - V150/V100 = 0.78, V150 = 53 mL, and V200 = 18 mL. Overall survival at ten years was 88% and actuarial ten-year local-regional control was 92%. There were 6 ipsilateral breast recurrences (IBR), 1 regional node recurrence (LN), 1 simultaneous IBR-LN recurrence, 1 LN and distant recurrence, and 1 distant recurrence. Fat necrosis was identified as a symptomatic event in 7 patients and as a mammogram-only finding in 13 patients. Fat necrosis was managed conservatively in 6 of the 7 symptomatic patients. Our results suggest that APBI via a multi-catheter technique in a population of predominantly Cautionary and Unsuitable patients provides durable local-regional control with limited late toxicity.

Outpatient combined intracavitary and interstitial cervical brachytherapy: barriers and solutions to implementation of a successful programme - a single institutional experience.

Involvement of parametrial disease in locally advanced cervical patients poses a challenge for women undergoing brachytherapy. Current use of the Fletcher suit applicator may not adequately cover the high risk clinical target volume (HR CTV), especially in the parametrial region due to the physical qualities of brachytherapy from the inverse square law and the need to respect organs at risk (OAR) constraints, and leads to lower local control rates. Combined intracavitary and interstitial brachytherapy with the use of 1 or 2 interstitial needles allows adequate coverage of the HR CTV and the clinical evidence have demonstrated a correlation with better clinical results. This procedure is often resource intensive, requiring inpatient stay and magnetic resonance imaging (MRI) planning. In departments where such resources are limited, there is a poor uptake of interstitial brachytherapy. This article discusses the technique of combined intracavitary and interstitial brachytherapy in an outpatient setting, and explores the issues and barriers for implementation and suggestions to overcome such barriers.

Interstitial brachytherapy technique for chest wall refractory recurrence of breast cancer

PurposeTo report the treatment effect of interstitial brachytherapy for chest wall locoregional recurrence of breast cancer.Material and methodsThis 44-year-old female presented with chest wall recurrence seven years after modified radical mastectomy for stage II breast cancer. Despite external beam radiation and chemotherapy, the lesion expanded as 5.3 × 5.1 × 3.0 cm3, and 8.0 × 5.1 × 4.0 cm3. The locoregional recurrent tumor was treated with interstitial brachytherapy under ultrasound guidance. The brachytherapy dose was 30 Gy in 6 fractions of 5 Gy each.ResultsRemoval of the recurrent tumor was securely achieved by interstitial brachytherapy guided with ultrasound scanning. The refractory tumor in patient healed uneventfully after interstitial brachytherapy without recurrence during the 7 months of follow-up.ConclusionsThe ultrasound-guided interstitial brachytherapy may be effective for refractory recurrence of breast cancer.

MR-Guided Interstitial Brachytherapy Using Customized Vaginal Applicator: An Innovative Yet Cautious Step to Personalized Medicine

In gynaecological cancer, BT is typically administered using a cylindrical applicator with a single line source. Interstitial brachytherapy (IB) can improve local control by tailoring the dose to the anatomy compared with standard intracavitary brachytherapy. IB can be delivered using intra-vaginal applicator or gynaecological perineal templates. Institutions employ imaging fluoroscopy or ultra-sound to further guide interstitial needle (IN) placement. This presentation demonstrates case studies and our process in delivering a MR-guided IB technique using a customized vaginal applicator (CVA) to treat endometrial carcinoma recurrences in the vagina.

Customized Vaginal Vault Brachytherapy With CT Imaging-derived Applicator Prototyping

Conventional cylindrical intracavitary brachytherapy applicators do not conform to individual vaginal conformation. Irregular, fibrotic, or tethered tissue result in suboptimal dosimetry when treated with standard applictors5. The technique presented here enables the physical creation of a patient specific applicator with embedded optimized catheter trajectories. The curved catheter trajectories employed cannot be created and optimized using any other standard manufacturing process available today. In this example case, this design effectively treat a wide irregular vaginal apex, while simultaneously achieving relatively narrow dose distribution in the anterior/posterior directions, directly translating to relative rectal and bladder sparing. Clinically, early vaginal edema may occur after the first fraction, therefore an allowance for tissue expansion was recognized in adapting the 3-D model to the physical applicator. Rapid-prototyping offers a feasible alternative to inflatable intracavitary applicators6 or interstitial brachytherapy techniques. The design of applicators is no longer constrained by standard 2D manufacturing process, and can eliminate the need for mould room resources.