Brachytherapy Catheters Research Articles

Three-year clinical outcome using the Contura multilumen balloon breast brachytherapy catheter to deliver accelerated partial breast irradiation (APBI): Improving radiation standards for the optimal application of APBI

PurposeWe reviewed our institution’s 3-year clinical experience in treating patients with the Contura multilumen balloon (SenoRx, Inc., Aliso Viejo, CA) breast brachytherapy catheter to deliver accelerated partial breast irradiation (APBI). Methods and MaterialsForty-six patients treated with breast-conserving therapy received adjuvant radiation using the Contura catheter (34Gy in 3.4Gy fractions). Fourteen patients had Stage 0, 24 had Stage I, and 8 had Stage II breast cancer. Median follow-up was 36 months (range, 1–44 months). ResultsOnly one local recurrence developed (2%). The rate of persistent seroma formation at latest reported follow-up was 4.3% (2 patients) and the incidence of any clinically detectable telengiectasias was 2.2%. No major toxicities (0% Grade III) have occurred. The median skin dose (% of the prescribed dose) was 99.7. The median dose to 95% of the planning target volume for evaluation was 98.8%. The percentage of patients with excellent/good cosmetic results at 24 (n=23) and 36 (n=22) months was 100% and 97%, respectively. ConclusionAdjuvant APBI using the Contura multilumen balloon catheter exhibited similar locoregional control, cosmesis, and toxicities to other forms of APBI with similar lengths of follow-up. In addition, improved radiation standards for the delivery of APBI were demonstrated.

In vivo assessment of catheter positioning accuracy and prolonged irradiation time on liver tolerance dose after single-fraction 192Ir high-dose-rate brachytherapy

BackgroundTo assess brachytherapy catheter positioning accuracy and to evaluate the effects of prolonged irradiation time on the tolerance dose of normal liver parenchyma following single-fraction irradiation with 192 Ir.Materials and methodsFifty patients with 76 malignant liver tumors treated by computed tomography (CT)-guided high-dose-rate brachytherapy (HDR-BT) were included in the study. The prescribed radiation dose was delivered by 1 - 11 catheters with exposure times in the range of 844 - 4432 seconds. Magnetic resonance imaging (MRI) datasets for assessing irradiation effects on normal liver tissue, edema, and hepatocyte dysfunction, obtained 6 and 12 weeks after HDR-BT, were merged with 3D dosimetry data. The isodose of the treatment plan covering the same volume as the irradiation effect was taken as a surrogate for the liver tissue tolerance dose. Catheter positioning accuracy was assessed by calculating the shift between the 3D center coordinates of the irradiation effect volume and the tolerance dose volume for 38 irradiation effects in 30 patients induced by catheters implanted in nearly parallel arrangement. Effects of prolonged irradiation were assessed in areas where the irradiation effect volume and tolerance dose volume did not overlap (mismatch areas) by using a catheter contribution index. This index was calculated for 48 irradiation effects induced by at least two catheters in 44 patients.ResultsPositioning accuracy of the brachytherapy catheters was 5-6 mm. The orthogonal and axial shifts between the center coordinates of the irradiation effect volume and the tolerance dose volume in relation to the direction vector of catheter implantation were highly correlated and in first approximation identically in the T1-w and T2-w MRI sequences (p = 0.003 and p < 0.001, respectively), as were the shifts between 6 and 12 weeks examinations (p = 0.001 and p = 0.004, respectively). There was a significant shift of the irradiation effect towards the catheter entry site compared with the planned dose distribution (p < 0.005). Prolonged treatment time increases the normal tissue tolerance dose. Here, the catheter contribution indices indicated a lower tolerance dose of the liver parenchyma in areas with prolonged irradiation (p < 0.005).ConclusionsPositioning accuracy of brachytherapy catheters is sufficient for clinical practice. Reduced tolerance dose in areas exposed to prolonged irradiation is contradictory to results published in the current literature. Effects of prolonged dose administration on the liver tolerance dose for treatment times of up to 60 minutes per HDR-BT session are not pronounced compared to effects of positioning accuracy of the brachytherapy catheters and are therefore of minor importance in treatment planning.

Prostate HDR brachytherapy catheter displacement between planning and treatment delivery

Background and purposeHDR brachytherapy is used as a conformal boost for treating prostate cancer. Given the large doses delivered, it is critical that the volume treated matches that planned. Our outpatient protocol comprises two 9Gy fractions, two weeks apart. We prospectively assessed catheter displacement between CT planning and treatment delivery. Materials and methodsThree fiducial markers and the catheters were implanted under transrectal ultrasound guidance. Metal marker wires were inserted into 4 reference catheters before CT; marker positions relative to each other and to the marker wires were measured from the CT scout. Measurements were repeated immediately prior to treatment delivery using pelvic X-ray with marker wires in the same reference catheters. Measurements from CT scout and film were compared. For displacements of 5mm or more, indexer positions were adjusted prior to treatment delivery. ResultsResults are based on 48 implants, in 25 patients. Median time from planning CT to treatment delivery was 254min (range 81–367min). Median catheter displacement was 7.5mm (range −2.9–23.9mm), 67% of implants had displacement of 5mm or greater. Displacements were predominantly caudal. ConclusionsCatheter displacement can occur in the 1–3h between the planning CT scan and treatment. It is recommended that departments performing HDR prostate brachytherapy verify catheter positions immediately prior to treatment delivery.

Interfraction accumulation of seroma during accelerated partial breast irradiation: Preliminary results of a prospective study

PurposeTo quantify and characterize the process of seroma accumulation during accelerated partial breast irradiation using multicatheter balloon brachytherapy. Materials and MethodsTwenty-two patients were treated using the Contura Multilumen brachytherapy catheter to a dose of 34Gy in 10 fractions over 5 treatment days. Serial aspirations of the vacuum port of the catheter were performed at the time of CT simulation and before each treatment. Volume and characteristics of fluid drawn were recorded. Univariate analysis was performed to evaluate various factors predictive of seroma formation. ResultsMedian patient age was 59.5 years, body mass index was 31, and volume of surgical specimen was 62.4cm3. Median time from breast conservation surgery to placement of Contura catheter was 18.5 days. Pericatheter seroma, typically scant with a median volume of 0.75mL, was noted in 91% of patients at CT simulation. A total of 203 aspirations were performed with a median-aspirated seroma volume of 4.05mL. There was no significant correlation between the volume of seroma and histology (invasive vs. in situ), quadrant of location, body mass index, reexcision or reoperation, days from breast conservation surgery to balloon placement, or the volume of specimen removed. Radiation treatment factors, including balloon volume, balloon to skin distance, and planning target volume evaluation, also did not correlate with aspirated seroma. ConclusionsInterfraction seroma accumulation has a variable pattern of development with no discernible predictors of occurrence. Routine pretreatment aspirations via vacuum port may potentially improve dosimetric reproducibility for a minority of patients.

A Single-Institution Review of Accelerated Partial Breast Irradiation in Patients Considered “Cautionary” by the American Society for Radiation Oncology

The American Society for Radiation Oncology (ASTRO) issued a consensus statement in 2009 regarding patient selection for accelerated partial breast irradiation (APBI) following breast-conserving surgery (BCS) for breast cancer (BC). We reviewed our single-institution experience with APBI in patients considered "cautionary" by ASTRO to determine patterns of recurrence. An institutional review board-approved, retrospective chart review was conducted from January 2004 to November 2009. We identified 106 "cautionary" patients with 109 BC. All patients were treated with BCS followed by APBI via balloon catheter brachytherapy. "Cautionary" criteria include patients aged 50-59 years, tumor size 2.1-3.0 cm, close margins (<2 mm), focal lymphovascular invasion, estrogen receptor (ER)-negative tumors, invasive lobular carcinoma, or ductal carcinoma in situ (DCIS) ≤ 3 cm. Rates of recurrence at any site were evaluated. Median follow-up was 3 years. There were 3 IBTR (2.8%) at a median of 3.2 years. The 3-year actuarial IBTR rate was 1.8%. Patients with ER-negative invasive cancers had a higher IBTR rate compared with ER-positive patients (11.8% vs. 2.2%), although this did not reach statistical significance (P = 0.18). There were no IBTR in 46 patients with DCIS. On univariate analysis, there was no association between "cautionary" criteria and risk of local, regional, or distant recurrence. Patients considered "cautionary" for APBI based on ASTRO guidelines had low rates of IBTR. ER-negative patients trended toward a higher IBTR rate with APBI compared with ER-positive patients. Longer follow-up is needed to establish the safety of APBI in "cautionary" patients.

Ongoing Consideration of Cavity Evaluation Devices in the Treatment of Breast Cancer

The growing popularity of brachytherapy has greatly increased the use of single-entry balloon catheter devices for delivery of accelerated partial breast radiotherapy (APBI). To facilitate delayed, postoperative, percutaneous insertion of single-entry brachytherapy catheters, many surgeons elect to place temporary, expandable cavity evaluation devices (CED) at the time of lumpectomy to preserve the surgical cavity and maintain a tract between the skin and surgical cavity. At the time of brachytherapy catheter placement, the CED may be deflated, withdrawn from the cavity, and easily replaced by a single-entry brachytherapy catheter inserted through the very same tract. In their article, ‘‘Spacer Balloons prior to Partial Breast Irradiation: Helpful or Hurtful?’’, Drs. Kuske and Zannis provide an excellent summary of the potential limitations and challenges associated with CED usage. While they have raised several important concerns, the authors’ emphasis on the potential negative aspects of CED placement misses the opportunity to provide sufficient guidance on how and when they may be properly used. Among the important concerns raised by the authors is the tendency of some surgeons to obtain multidisciplinary consultation only after CED placement. Preoperative discussion of the patient’s treatment options in a multidisciplinary setting or referring the patient to a radiation oncologist prior to surgery will provide the best opportunity for the patient and her oncologists to identify and fully discuss the options of lumpectomy, APBI, CED usage, and the implications of unsuitable pathology. This process not only helps to identify patients who are suboptimal candidates for APBI, but also allows coordination of surgery, catheter exchange, and radiation therapy planning to avoid the significant delays in the initiation of APBI that the authors identify as being contributory to devicerelated infections. Preoperative consultation also gives the patient the opportunity to discuss their potential participation in clinical trials that might be impacted by CED placement. Another compelling issue raised by the authors is the higher incidence of wound infection associated with intraoperative placement of a brachytherapy catheter (the open-cavity technique) compared with postoperative, percutaneous brachytherapy catheter placement (the closedcavity technique). However, the association between CED placement and infection is far from clear. In referencing the 2-year outcome data of the MammoSite Registry, the authors acknowledge that CED usage was not specifically addressed in the publication. Although it is reasonable for the authors to infer that intraoperative placement of a CED is analogous to open-cavity placement of a brachytherapy catheter in terms of its risk of infection, the results of the MammoSite Registry are confounded by the lack of clear guidelines regarding the use of antibiotics. In fact, only 71% of MammoSite Registry participants received antibiotics. Perhaps patients who had catheters placed intraoperatively were less likely to be prescribed oral antibiotics because they were routinely given a single dose of intravenous antibiotics preoperatively. Alternatively, it could be that patients who had catheters placed postoperatively were more likely to be prescribed postprocedural oral antibiotics because they did not receive the benefit of preprocedural intravenous antibiotics? The MammoSite Registry update does not elucidate these factors. Furthermore, since there is a finite risk (1–4%) of surgical-site infection after breast-conserving surgery, to what degree does the higher incidence of infection after the open-cavity technique reflect the combined result of postlumpectomy infection and catheter-related infection. Interestingly, the Society of Surgical Oncology 2011

Multi-lumen Breast Brachytherapy in Patients With 5 mm or Less Balloon Surface-Skin Distance (BSD) Using the Contura™ Brachytherapy Catheter

Purpose: To evaluate the toxicity of multi-lumen breast brachytherapy in patients with 5 mm or less balloon surface-skin distance (BSD) treated with the Contura™ catheter. Materials and Methods: From September, 2008 through February, 2010 a total of 411 patients with early stage breast cancer (stages 0, I, IIA) were treated with multi-lumen HDR brachytherapy for definitive APBI using the Contura™ brachytherapy catheter. Of those patients 92 had a balloon surface-skin distance (BSD) of 5 mm or less, and had at least 6 months clinical followup. All patients were status post breast conserving surgery and met the ABS APBI guidelines for treatment eligibility. All patients received 34 Gy in ten fractions bid over 5 days, with the maximum skin dose restricted to 145% of the prescribed dose or less. Varian Brachyvision was used for 3-D conformal HDR treatment planning. CT image evaluation and DVH analyses was performed to investigate and compare the PTV_EVAL (cc) defined as a 1 cm expansion from the anterior surface of the device modified to 5 mm from the skin surface and not extending into the chest wall; BSD (mm) defined as the distance from the closest point on the balloon to the closet point on the skin surface; maximum skin dose (% and cGy); the volume of breast tissue (cc) receiving 150% and 200% of the prescription dose (V150, V200). Patient toxicity was evaluated at one week, one month and 6 months following brachytherapy including; skin reaction (RTOG Acute Radiation Morbidity Scoring Criteria), pigmentation, telangiectasia, pain, fat necrosis, symptomatic seroma. Results: The mean BSD was 3.7 mm, with a range of 1–5 mm. The mean maximum skin dose was 4508 cGy. The mean V150 was 21 cc and the V200 was 4.7 cc. The mean PTV_EVAL V90 was 93.7 %. 49 % of patients had skin reaction, including at 1 week; 47 % Grade 1, 0% Grade 2 or 3. At 1 month; 31% Grade 1, 14% Grade 2 and 0% Grade 3. At 6 months; 2% Grade 1, 2% Grade 2 and 0% Grade 3. 6.5 % developed pigmentation changes (hypo or hyper). 5.4% developed telangiectasias, 9.7% reported pain. No patients had fat necrosis, and 15.2 % had a symptomatic seroma. 1 patient had wound dehiscence (maxium skin dose 4195 cGy, 123.4% of prescribed dose) at 1 week which was healed following closure at the 1 month followup. Patients that experienced toxicity had no difference in BSD (3.6 vs 3.9 mm) or in the maximum skin dose (132.6 % vs. 132.6 %) compared to those that did not experience toxicity. Conclusions: Breast brachytherapy in patients with 5 mm or less BSD (balloon surface-skin distance) has acceptable toxicity with proper planning using the Contura™ multi-lumen catheter. Careful attention to maximum skin dose must be used, and we recommend not exceeding 145 % (4930 cGy) of the prescribed dose.

High-Dose-Rate Brachytherapy Boost for Brain Gliomas: Implementation of New Technique in a Single Institution

bile tumor) and another one cholangitis complicated by sepsis (one Klatskin III tumor), so only 20 patients underwent HDR-192Ir-ILBT. One biliary brachytherapy catheter was used in 14 patients, two catheters in 6 patients. The dose delivered was 15 Gy in 3 patients, 20 Gy in 9 patients and 25 Gy in 8 patients with daily 500 cGy per fraction. During the brachytherapy procedure, cholangitis occurred in two patients. The median followup was 42 months (range 6e76 months). Two patients developed late toxicity (1 hemobilia, 1 hepatic abscess). Subsequent bouts of cholangitis occurred in 16 patients (72,7%, median 7 months) while stent occlusion (due to biliary sludge, tumor ingrown and overgrown) was observed in 12 patients (54,5%, median 13 months). Six-month and oneyear overall survival was 77% and 59%, with a median of 13 months; sixmonth and one-year local progression (tumor ingrown and overgrown) was 82% and 72% (median not reached).

Ureteral Stent Placement During Gynecological Interstitial Brachytherapy

Purpose: We wanted to demonstrate the feasibility of ureteral stent placement during gynecologic interstitial template brachytherapy to improve dosimetry and avoid normal tissue injury. Interstitial brachytherapy has the potential to access sites of deep tissue invasion and encompass large tumor volumes, but there is also the potential to inadvertently injure normal pelvic structures. Intraoperative cystoscopy and contrast instillation into the bladder and rectum during computerized tomography (CT) simulation provide valuable information about the relationship of brachytherapy catheters to the bladder and rectum, but the course of the ureters is typically unknown.

Evaluation of minimally invasive excisional brain biopsy and intracranial brachytherapy catheter placement in dogs

To evaluate a technique for minimally invasive excisional brain biopsy and intracranial brachytherapy catheter placement in dogs. 5 healthy adult female dogs. Computed tomographic guidance was used to plan a biopsy trajectory to a selected area of brain with reference to a localizer grid. The procedure was performed through a 1-cm skin incision and 6-mm burr hole by use of a 9-gauge biopsy device. Five cylindrical samples (3 to 4 mm in diameter and 7 to 12 mm in length) were removed over 5 cycles of the vacuum-assisted tissue excision system, leaving approximately a 2-cm³ resection cavity. A balloon-tipped intracranial brachytherapy catheter was placed through the burr hole into the resection cavity, expanded with saline (0.9% NaCl) solution, and explanted 7 days later. 4 of 5 dogs survived the procedure. The fifth died because of iatrogenic brain damage. Neurologic deficits were unilateral and focal. Twenty-four hours after surgery, all surviving dogs were ambulatory, 2 dogs exhibited ipsiversive circling, 4 had contralateral proprioceptive deficits, 3 had contralateral menace response deficits, 2 had a reduced contralateral response to noxious nasal stimulation, and 1 had dull mentation with intermittent horizontal nystagmus and ventrolateral strabismus. Neurologic status improved throughout the study period. Histologic quality of biopsy specimens was excellent. This technique enabled histologic diagnosis from high-quality biopsy specimens obtained through a minimally invasive technique and has potential applications for multimodal treatment of deep brain tumors in dogs.

Evaluation of an acute focal epidural mass model to characterize the intracranial pressure-volume relationship in healthy Beagles

To characterize the intracranial pressure-volume relationship (ICPVR) in dogs by use of an acute frontal-parietal mass lesion model. 7 healthy adult female Beagles. Dogs were anesthetized with isoflurane to achieve a surgical plane of anesthesia. A fiberoptic intracranial pressure (ICP) monitor was inserted to a depth of 1 cm in the parenchyma of the right frontal-parietal region of the brain. A Foley balloon-tipped catheter was placed in the epidural space of the left frontal-parietal area through a separate 1-cm burr hole. Baseline measurements were obtained with the balloon deflated. The balloon was then inflated incrementally with 0.5 mL of 0.9% NaCl solution every 10 minutes until ICP exceeded mean arterial blood pressure. Nonlinear regression analysis with 2-factor and 3-factor exponential equations was used to characterize the ICPVR. The mean baseline ICP was 11 mm Hg, with a 95% confidence interval of 2 to 20 mm Hg. The ICPVR was well characterized by 2-factor or 3-factor exponential equations for all dogs (R² > 0.93). Balloon volumes of > 1. 2 mL were associated with ICP > 20 mm Hg. Characterization of the ICPVR may provide clinically useful information regarding the safety of obtaining CSF from the atlanto-occipital space or implantation of brachytherapy catheters and for determining the need for decompressive craniectomy in dogs with acute intracranial disease. High ICP should be suspected in dogs that have an acute frontal-parietal mass lesion estimated to exceed 2% of the brain volume.

Abstract ES5-1: Emerging Radiation Techniques — The Fast and the Furious

Abstract The equivalence of breast conserving therapy (BCT) to mastectomy in the treatment of women with early-stage breast cancer has been demonstrated in several phase III trials with over 25 years of follow-up. Despite the undisputed efficacy of this treatment approach, recent investigations have explored methods to either reduce the overall time, inconvenience or toxicity of its application. These approaches have included (1) accelerating the dose delivery scheme, (2) reducing the treatment target to less than whole breast, or (3) identifying subgroups of women in which adjuvant radiation therapy (RT) following lumpectomy can be safely omitted Accelerated partial breast irradiation (APBI) has been investigated as a possible option that incorporates both a decrease in the overall treatment time and a reduction in the amount of normal tissue irradiated. Several different treatment techniques have been developed for the delivery of APBI. Within the United States, three ‘classic’ techniques dominate and include multicatheter interstitial brachytherapy, balloon catheter brachytherapy and three-dimensional conformal external beam radiotherapy (3D-CRT). In Europe, in addition to multicatheter brachytherapy, intraoperative radiotherapy has been central to their APBI experience. The majority of results with APBI to date have provided comparable 5 and 10-year outcomes to whole breast irradiation (WBI) in highly selected, low risk patients. In recognition of the success of these single institution experiences, nine phase III studies have now been initiated or completed in the United States and Europe. Despite limited long-term clinical data, the use of APBI outside of clinical trials has increased sharply. Given these concerns, the American Society of Therapeutic Radiology and Oncology (ASTRO) Health Services Research Committee convened a Task Force of breast cancer experts to develop a consensus statement addressing patient selection criteria and best practices for the application of APBI outside of clinical trials. These recently published recommendations were based on the results of a systematic literature review of the limited APBI data and were also supplemented by the expert opinions of the Task Force members using data applying WBI to treat patients. Accelerated whole breast irradiation (AWBI) has also been explored as a potential treatment option to deliver adjuvant irradiation after lumpectomy. Similar to APBI, the goals of this treatment approach are to theoretically increase the frequency that BCT is chosen as a treatment option, provide a logistically faster, convenient and more accessible method for BCT and potentially improve overall quality-of-life for early stage breast cancer patients. The data on AWBI include several phase III trials performed in Europe and North America with some trials reporting results at 10 years. In recognition of the concerns related to appropriate selection criteria for the application of this treatment approach, the ASTRO Health Services Research Committee also convened a Task Force of breast cancer experts to develop a consensus statement addressing patient selection criteria and best practices for the application of AWBI. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr ES5-1.

Complications of Radiation Therapy to the Hand After Soft Tissue Sarcoma Surgery

Radiation has been shown to improve local control after resection of soft tissue sarcomas. However, it may also result in major complications in the hand, given the compact nature of functional tissues and limited tissue volumes in the hand. The purpose of this investigation was to describe the hand-specific complications of radiation therapy for patients with soft tissue sarcoma of the hand (STSH). We performed a retrospective chart review of 55 consecutive patients with STSH treated by a single surgeon between 1993 and 2006. We identified 26 patients who were treated with external beam radiation, brachytherapy, or both, either preoperatively or postoperatively, and reviewed their clinical course. After a median follow-up of 7 years, 29 treatment-related complications occurred in 19 patients who had received radiation, whereas 3 of the 29 patients treated with surgery alone developed complications. All patients who received brachytherapy and 14 of the 21 treated with external beam radiation alone developed complications. There were 5 early minor, 2 early major, 3 late minor, and 19 late major complications. Patients with STSH who underwent radiation therapy had a high rate of complications. The complication rate in our series was higher in patients who had brachytherapy catheters placed adjacent to finger joints. A better understanding of predictors of complications will help to determine the optimal timing and type of radiation therapy to treat patients with STSH. Therapeutic IV.

Optimal application of the Contura multilumen balloon breast brachytherapy catheter vacuum port to deliver accelerated partial breast irradiation

Purpose The impact of using the Contura multilumen balloon (MLB) (SenoRx, Inc., Irvine, CA) breast brachytherapy catheter’s vacuum port in patients treated with accelerated partial breast irradiation (APBI) was analyzed. Methods and Materials Data from 32 patients at two sites were reviewed. Variables analyzed included the seroma fluid (SF):air volume around the MLB before and after vacuum port use and on its ability to improve ( 1) the eligibility of patients for APBI and ( 2) dose coverage of the planning target volume for evaluation (PTV_EVAL) in eligible patients. Results The median SF/air volume before vacuum removal was 6.8 cc vs. 0.8 cc after vacuum removal (median reduction in SF/air volume was 90.5%). Before vacuum port use, the median SF/air volume expressed as percentage of the PTV_EVAL was 7.8% (range, 1.9–26.6) in all patients. After application of the vacuum, this was reduced to 1.2%. Before vacuum port use, 10 (31.3%) patients were not considered acceptable candidates for APBI because the SF/air volume:PTV_EVAL ratio (SF:PTV) was greater than 10% (range, 10.1–26.6%; median, 15.2%). After vacuum port use, the median SF:PTV ratio was 1.6% for a median reduction of 91.5%. In addition, the percentage of the prescribed dose covering greater than or equal to 90% of the PTV_EVAL proportionally increased a median of 8% (range, 3–10%) in eligible patients. Conclusion Use of the Contura MLB vacuum port significantly improved the conformity of the target tissue to the balloon surface, leading to reproducible dose delivery and increased target volume coverage. In addition, application of the vacuum allowed the safe treatment of unacceptable patients with APBI.

Accelerated Partial Breast Irradiation (APBI): A review of available techniques.

Breast conservation therapy (BCT) is the procedure of choice for the management of the early stage breast cancer. However, its utilization has not been maximized because of logistics issues associated with the protracted treatment involved with the radiation treatment. Accelerated Partial Breast Irradiation (APBI) is an approach that treats only the lumpectomy bed plus a 1-2 cm margin, rather than the whole breast. Hence because of the small volume of irradiation a higher dose can be delivered in a shorter period of time. There has been growing interest for APBI and various approaches have been developed under phase I-III clinical studies; these include multicatheter interstitial brachytherapy, balloon catheter brachytherapy, conformal external beam radiation therapy and intra-operative radiation therapy (IORT). Balloon-based brachytherapy approaches include Mammosite, Axxent electronic brachytherapy and Contura, Hybrid brachytherapy devices include SAVI and ClearPath. This paper reviews the different techniques, identifying the weaknesses and strength of each approach and proposes a direction for future research and development. It is evident that APBI will play a role in the management of a selected group of early breast cancer. However, the relative role of the different techniques is yet to be clearly identified.

Comparison of the Dosimetry of the New MammoSite Multi-lumen (ML) Balloon Breast Brachytherapy Catheter vs. the Single Lumen MammoSite for APBI

Comparison of the Dosimetry of the New MammoSite Multi-lumen (ML) Balloon Breast Brachytherapy Catheter vs. the Single Lumen MammoSite for APBI

Is Multi-lumen Balloon (MLB) Superior to Single-lumen Balloon (SLB) Brachytherapy Catheter for Accelerated Partial Breast Irradiation (APBI)?

Accelerated partial breast irradiation (APBI), delivering post lumpectomy radiotherapy over 1-5 days is gaining popularity due to its convenience, safety and efficacy in a well selected group of patients. However there are many techniques for delivering APBI including intra-cavitary balloon catheters. No one technique has been shown to be superior to another. The purpose of this study is to evaluate two different intracavitary balloon catheters (single-lumen balloon (SLB) (MammoSite) vs. multi-lumen balloon (MLB) (Contura) in APBI in terms of dosimetric coverage and normal tissue sparing.

Five-year Outcome of Patients Classified in the “Unsuitable” Category Using the American Society of Therapeutic Radiology and Oncology (ASTRO) Consensus Panel Guidelines for the Application of Accelerated Partial Breast Irradiation: An Analysis of Patients Treated on the American Society of Breast Surgeons MammoSite® Registry Trial

We applied the ASTRO Consensus Panel (CP) guidelines for the application of accelerated partial breast irradiation (APBI) to patients treated with this technique on the ASBS MammoSite® registry trial to determine potential differences in outcome of patients classified in the "unsuitable" category. Of 1,449 cases treated with APBI on the registry trial, 176 fit the criteria for the unsuitable category: 130 cases were <50 years of age, 13 had positive margins, 38 had positive nodes, 6 had tumors >3 cm, and 9 had an EIC >3 cm. Rates of ipsilateral breast tumor recurrence (IBTR) and regional nodal failure (RNF) were assessed. Median follow-up was 53.6 months. The 5-year actuarial rate of IBTR for unsuitable cases was 5.25% (RNF rate was 0.63%). By comparison, the 5-year actuarial IBTR rates for various subsets of patients were: all 1,449 cases, 3.89% (p = 0.2365); all 1,449 cases excluding unsuitable cases [n =1,273] (3.6%, p =0.1683); invasive only cases [n = 1,255] (3.86%, p = 0.2464); and invasive only cases excluding unsuitable invasive cases [n =1,105] (3.89%, p = 0.2396). On univariate analysis for variables potentially associated with IBTR in all 1,255 cases with invasive cancer (including age, tumor size, nodal status, overall stage, margin status, ER status, presence of an EIC, and ASTRO unsuitable category), only negative ER (-) status was associated with the 5-year rate of IBTR (p = 0002). No other variable (including unsuitable CP designation) was associated with IBTR. The ASTRO CP guideline designation of unsuitable did not differentiate a subset of patients with a significantly worse rate of IBTR when treated with the MammoSite® breast brachytherapy catheter to deliver APBI.

A dosimetric comparison of the Contura multilumen balloon breast brachytherapy catheter vs. the single-lumen MammoSite balloon device in patients treated with accelerated partial breast irradiation at a single institution

Purpose A comparison of dosimetric findings in 33 patients treated with the Contura multilumen balloon (SenoRx Inc., Irvine, CA) (C-MLB) breast brachytherapy catheter vs. 33 patients treated with the MammoSite (Hologic Inc., Bedford, MA) (MS) at a single institution to deliver accelerated partial breast irradiation (APBI) was performed. Methods and Materials CT-based 3-dimensional planning with dose optimization was completed. APBI treatment of 34 Gy in 3.4 Gy fractions was delivered. Endpoints analyzed included: ( 1) The percentage of the prescribed dose (PD) covering the planning target volume (PTV), ( 2) the maximum skin dose as a percentage of the PD, ( 3) the maximum rib dose as a percentage of the PD, and ( 4) the V150 and V200. Results The C-MLB was placed more frequently in patients with closer skin spacing (<7 mm) and rib spacing (<7 mm) than in MS patients (45.5% vs. 12.1%, p = 0.0057 and 57.6 vs. 33.3, p = 0.0131, respectively). Despite closer skin spacing, the overall median skin dose was significantly lower in C-MLB patients (112% of the PD vs. 134%, p = 0.0282). No statistically significant differences in the V150 or V200 were observed. In patients with very limited rib spacing (<4 mm), the C-MLB delivered significantly lower rib doses than the MS (144% of the PD vs. 191%, p = 0.0107). In all clinical scenarios, coverage of the PTV with the C-MLB was either equal to or significantly better than with the MS ( p = 0.0024). Conclusion The C-MLB catheter produced clinically significant improvements in dosimetric endpoints (e.g., reduced skin and rib doses and improved PTV coverage) in most clinical scenarios.

Combined radiofrequency ablation and high–dose rate brachytherapy for early-stage non–small-cell lung cancer

Purpose This retrospective analysis reports the results of patients with early-stage inoperable non–small-cell lung cancer treated with radiofrequency ablation (RFA) followed by adjuvant high–dose rate (HDR) brachytherapy. Methods and Materials Seventeen medically inoperable patients with biopsy-proven Stage I non–small-cell lung cancer were treated with RFA followed by single fraction HDR brachytherapy. Brachytherapy catheters were inserted immediately after RFA, and one fraction of HDR brachytherapy was delivered on the same day. Doses of brachytherapy ranged from 14.4 to 20 Gy (median, 18 Gy). Patients were followed clinically and radiographically to determine tumor control and toxicity profile. Results Median followup time was 22 months. Of the 17 patients, 3 patients have recurred locally. Each of the patients with local recurrences was originally treated for T2 disease. In total, three of seven cases with T2N0 disease experienced local recurrences, whereas all 9 patients with T1 disease were controlled locally. Five of the 17 patients required a chest tube posttreatment, and 1 patient developed an empyema. There were no deaths within 1 month of treatment. Conclusions RFA followed by HDR brachytherapy yields excellent local control with an acceptable toxicity profile for patients with otherwise inoperable early-stage lung cancer.