Brachytherapy For Partial Breast Irradiation Research Articles

PO-1575 CyberKnife versus interstitial brachytherapy for partial breast irradiation: dosimetrical assessment

PO-1575 CyberKnife versus interstitial brachytherapy for partial breast irradiation: dosimetrical assessment

Increased Risk for Ipsilateral Breast Tumor Recurrence in Invasive Lobular Carcinoma after Accelerated Partial Breast Irradiation Brachytherapy.

The suitability criteria for accelerated partial breast irradiation (APBI) from the American Brachytherapy Society (ABS), American Society for Radiation Oncology (ASTRO), and The Groupe Européende Curiethérapie European SocieTy for Radiotherapy & Oncology (GEC-ESTRO) have significant differences. This is a single institution retrospective review of 946 consecutive patients with invasive breast cancer who underwent lumpectomy and APBI intracavitary brachytherapy from 2003 to 2018. Overall survival (OS), breast cancer-specific survival (BCSS), relapse-free survival (RFS), and ipsilateral breast tumor recurrence (IBTR) were estimated with Kaplan-Meier method. Median follow-up time was 60.2 months. Median age was 68 years (46-94 years). The majority of patients had estrogen receptor (ER)-positive disease (94%). There were 821 (87%) cases of invasive ductal carcinoma and 68 cases (7%) of invasive lobular carcinoma (ILC). The 5-year OS, BCSS, RFS, and IBTR were 93%, 99%, 90%, and 1.5%, respectively. Upon univariate analysis, ILC (hazard ratio [HR], 4.6; p=.008) and lack of nodal evaluation (HR, 6.9; p=.01) were risk factors for IBTR. The 10-year IBTR was 2.5% for IDC and 14% for ILC. While the ABS and ASTRO criteria could not predict IBTR, the GEC-ESTRO intermediate risk group was associated with inferior IBTR (p=.04) when compared to both low risk and high risk groups. None of the suitability criteria was able to predict RFS. These results show that APBI is an effective treatment for patients with invasive breast cancer. Expansion of the current eligibility criteria should be considered, although prospective validation is needed. Caution is required when considering APBI for patients with ILC. In a large retrospective review of 946 patients with early breast cancer treated with partial mastectomy and accelerated partial breast irradiation (APBI) intracavitary brachytherapy, this study demonstrates durable local control. Patients deemed unsuitable or high risk by the American Brachytherapy Society, American Society for Radiation Oncology, and European Society for Radiotherapy and Oncology guidelines were not at increased risk for ipsilateral breast tumor recurrence (IBTR), suggesting that expansion of the current criteria should be considered. Importantly, however, these results demonstrate that caution should be taken when considering APBI for patients with invasive lobular carcinoma, as these patients had relatively high risk for IBTR (10-year IBTR, 14%).

PO-0168 External beam radiotherapy and brachytherapy for partial breast irradiation: dosimetric comparison.

PO-0168 External beam radiotherapy and brachytherapy for partial breast irradiation: dosimetric comparison.

Management of ductal carcinoma in situ with accelerated partial breast irradiation brachytherapy: Implications for guideline expansion

PurposeAccelerated partial breast irradiation (APBI) for patients with ductal carcinoma in situ (DCIS) is controversial, and the suitability criteria from the American Brachytherapy Society (ABS), American Society of Therapeutic Radiology and Oncology (ASTRO), and the European Society for Radiotherapy and Oncology (GEC-ESTRO) have important differences. Methods and MaterialsThis is a single-institution retrospective review of 169 consecutive patients with DCIS who underwent lumpectomy followed by APBI intracavitary brachytherapy from 2003 to 2018. Outcomes, including overall survival, recurrence-free survival (RFS), ipsilateral breast tumor recurrence, and distant metastasis, were estimated with the Kaplan–Meier method. ResultsThe median followup time was 62.5 months. Median age was 66 years (47–89 years). The majority of patients had estrogen receptor–positive disease (89%). Fifty patients (30%) had Grade 3 disease. Of the 142 patients with adequate pathology interpretation, 91 and 108 cases had margins ≥ 3 mm and ≥2 mm, respectively. Most patients (72%) were prescribed and started endocrine therapy. Of the patients evaluable for ABS criteria (N = 130), 97 met the suitability criteria. Of the patients evaluable for ASTRO criteria (N = 129), 42 were deemed cautionary and 33 were deemed unsuitable. Of the patients evaluable for GEC-ESTRO criteria (N = 143), 141 cases were at intermediate risk and two were at high risk. Five-year ipsilateral breast tumor recurrence, RFS, and overall survival were 0.6%, 97.7%, and 97.2%, respectively. The ABS, ASTRO, and GEC-ESTRO criteria failed to significantly predict for RFS. ConclusionsThese results, although limited by short-term followup, indicate that expansion of the eligibility criteria of APBI for patients with DCIS should be considered.

Accelerated Partial Breast Irradiation Brachytherapy as a Salvage Treatment Option for Ipsilateral Breast Tumor Recurrence

Accelerated Partial Breast Irradiation Brachytherapy as a Salvage Treatment Option for Ipsilateral Breast Tumor Recurrence

Efficiency of using the day-of-implant CT for planning of SAVI APBI

PurposeThe purpose of the study was to develop an optimized, efficient workflow for using the day-of-implant (DOI) CT for treatment planning of accelerated partial breast irradiation brachytherapy using the strut-adjusted volume implant (SAVI) device. Methods and MaterialsFor 62 consecutive SAVI patients, a DOI CT was acquired and used for treatment planning. A “verification” CT was acquired 24–72 h after implant and immediately before the first fraction, then registered to the DOI CT. If the DOI CT–based plan was no longer optimal, a replan was performed. An array of metrics describing the geometry of the device and its relative position in the patient from the DOI CTs for these patients was collected. These metrics from the DOI CT were evaluated to determine what features could predict for the need to replan before the first treatment fraction. Logistical regression analysis including χ2 tests was used to determine if different factors correlated with replanning. ResultsTwenty-two of 62 patients (35%) required replanning. Only the presence of splayed struts, where splay was toward the skin, and the use of a nine strut (“8-1”) SAVI were significantly correlated (p < 0.05) with replanning. Within these individual populations, no additional factors showed a significant statistical correlation for requiring replanning. ConclusionsFor strut-based accelerated partial breast irradiation brachytherapy, it was feasible to treat with a plan based on the DOI CT for a majority (65%) of patients. Some factors correlate to needing replanning; recognizing these could be used to optimize treatment workflow for certain patients, increasing clinical efficiency while enhancing the quality of patient care.

Significant Dose Reduction to Heart with Innovative Design of a Prone Breast Board During HDR Partial Breast Irradiation Brachytherapy

Significant Dose Reduction to Heart with Innovative Design of a Prone Breast Board During HDR Partial Breast Irradiation Brachytherapy

A Single-Site Retrospective, Nonrandomized Study of Accelerated Partial Breast Irradiation Brachytherapy for Early-Stage Breast Cancer Treatment to Evaluate Local Tumor Control, Cosmetic Outcome, and Toxicities.

To evaluate the efficacy and safety of the accelerated partial breast irradiation brachytherapy with a combination of applicators at a community hospital cancer center. Between 2005 and 2009, 120 patients with early-stage breast cancer were being followed after treatment with accelerated partial breast irradiation brachytherapy using MammoSite, single or multilumen balloon, or Contura multilumen balloon. After their lumpectomy surgery, each patient was treated with Ir-192 high-dose rate unit following radiation therapy oncology group 0413 guidelines. The patients had multiple follow-ups at 6 months, 1 year, 2 years, 3 years, or more. Based on the Harvard Breast Cosmesis Scale, 95.00% of patients described their cosmetic evaluation as the treated breast essentially the same as the opposite side (excellent) or minimal but identifiable effects were noticed from radiation (good). After a median follow-up of 36 months, the local recurrence rate was 1.66% and a disease-free survival is 98.3%. Forty-two patients reported 85 adverse events, which were fibrosis: 24.70%, hyperpigmentation: 20.00%, radiation skin reaction: 7.05%, seroma: 7.05%, breast pain: 7.05%, erythema: 5.88%, and other events were less than 5.00%. Of all the adverse events recorded, grade 1 to 3 events are 95.29% (n = 81), 2.35% (n = 2), and 2.35% (n = 2). There was no grade 4 or 5 events recorded. Our study has shown promising results for delivering radiation with MammoSite, single or multilumen balloon, or Contura multilumen balloon and has been successful in achieving local control in patients with early-stage breast cancer.

Multi-catheter interstitial brachytherapy for partial breast irradiation: an audit of implant quality based on dosimetric evaluation comparing intra-operative versus post-operative placement.

PurposeThe use of multicatheter interstitial brachytherapy (MIB) for accelerated partial breast irradiation (APBI) in early breast cancer (EBC) patients outside the trial setting has increased. Hence, there is a need to critically evaluate implant quality. Moreover, there is a scarcity of reports using an open cavity technique. We report the dosimetric indices of open and closed cavity MIB techniques.Material and methodsThe dosimetric parameters of 60 EBC patients treated with MIB (open and closed cavity) who underwent three dimensional, computerized tomography (CT) based planning for APBI from November 2011 to July 2015 were evaluated. Coverage Index (CI), Dose Homogeneity Index (DHI), Conformity Index (COIN), Plan Quality Index (PQI), and Dose Non-uniformity Index (DNR) were assessed.ResultsForty-one patients underwent open cavity and 19 patients underwent closed cavity placement of brachytherapy catheters. The median number of planes was 4 and median number of needles was 20. Median dose was 34 Gy with dose per fraction of 3.4 Gy, given twice a day, 6 hours apart. The D90 of the cavity and clinical target volume (CTV) were 105% and 89%, respectively. The median doses to the surgical clips were greater than 100%. The median CI of the cavity and CTV was 0.96 and 0.82, respectively. The DHI and COIN index of the CTV was 0.73 and 0.67. There were no significant differences in the dosimetric parameters based on whether the technique was done open or closed.ConclusionsCritical evaluation of the dosimetric parameters of MIB-APBI is important for optimal results. While the open and closed techniques have similar dosimetry, our institutional preference is for an open technique which eases the procedure due to direct visualization of the tumor cavity.

Dosimetric Comparison Between a Commercial Collapsed Cone Algorithm and the TG-43 Method for Accelerated Partial Breast Irradiation Brachytherapy

To report on the dosimetric differences between a commercial collapsed cone (CC) based brachytherapy dose calculation algorithm and the currently used TG-43 method in the setting of APBI brachytherapy.

Late toxicity and cosmetic outcomes related to interstitial multicatheter brachytherapy for partial breast irradiation

Late toxicity and cosmetic outcomes related to interstitial multicatheter brachytherapy for partial breast irradiation

Using Skin Dose Parameters Predicts Low Skin Toxicity in a Phase 2 Trial of Multiple Dwell Position Balloon-Based Brachytherapy for Partial Breast Irradiation

Purpose/Objective(s): Preliminary trials with balloon-based brachytherapy for partial breast irradiation showed a 50% rate of grade 2 or higher skin toxicity, and a substantial number of catheters had to be removed prior to treatment because of a balloon-skin distance <5 mm. These trials employed a “single dwell position” HDR technique. The objectives of this trial were: (a) to prospectively determine if a multiple dwell position dose delivery method can decrease skin dose and subsequent toxicity over an in silico modeled single dwell position technique while achieving similar or superior PTV coverage, and (b) to evaluate whether specific skin parameters could be safely used in lieu of skin-balloon distance alone for predicting toxicity and treatment eligibility. Materials/Methods: A single-arm phase II study using a Simon two-stage design was performed on 28 women with stage 0, I, or II (<3 cm) breast cancer. Each patient was treated using a multiple dwell position Ir-192 plan with a balloon-based applicator with a prescription of 3400 cGy in 10 fractions delivered BID. Initial entry required a minimum skin-balloon distance 7 mm. Plans for single dwell position treatment were also run for comparison of dosimetric parameters. The primary endpoint was grade 2 or higher skin toxicity. Acute and late toxicity was assessed during treatment and at 1, 3, 6, and 12 months. Based on the minimal toxicity seen after treating the first 16 patients, additional patients were treated irrespective of skin-balloon distance as long as the maximum dose to 1 mm thick skin tissue was <130%. Results: Compared to the phantom single dwell plans, multiple dwell position planning yielded equivalent to slightly superior PTV coverage as measured by median V90 (100% vs 97%, p < 0.001), V95 (99% vs 93%, p < 0.001), and V100 (96% vs 88%, p < 0.001) but had slightly higher median V150 (39% vs 29%, p < 0.001) and V200 (10% vs 4%, p < 0.001), as well as a lower median dose homogeneity index (0.6 vs 0.7, p Z 0.0046). Maximum point dose to skin was decreased by multiple dwell planning for all skin depths (1 mm, 2 mm, and 3 mm; p < 0.001). The most common grade 1 toxicities were erythema (16 pts), fibrosis (9 pts), fatigue (8 pts), mild pain (8 pts), hyperpigmentation (5 pts), and telangiectasias (4 pts). There have been 2 patients (7%) who developed grade 2 toxicity (both transient erythema), and no patients have experienced grade 3, 4, or 5 toxicity. Conclusions: Multiple dwell position planning for balloon-based brachytherapy results in lower skin doses with equal to superior PTV coverage and an overall low rate of skin toxicity. Our data suggest that limiting the maximum point dose to <130% to 1 mm thick skin is achievable and results in minimal toxicity independent of skin-balloon distance. This parameter may therefore be a more clinically relevant selection criterion. Author Disclosure: S.K. Nath: None. Z. Chen: None. B.P. Rowe: None. R. Blitzblau: None. S. Aneja: None. B.J. Grube: None. N. Horowitz: None. J.B. Weidhaas: None.

SU-E-T-322: A Dosimetric Comparison of PBI Brachytherapy Techniques: SAVI, Contura, and Tube and Button Applicators.

To evaluate the dosimetry of partial breast irradiation brachytherapy techniques using the Strut Adjusted Volume Implant (SAVI), Contura, and Tube and Button (T&B) applicators. A total of 51 breast-cancer patients (23 SAVI, 6 Contura, and 22 T&B) were treated. The target was delineated following NSABP B-39 guidelines. 3D plans were optimized using the Inverse Planning Simulated Annealing algorithm to deliver 3.4 Gy per fraction to the target and minimize dose to organs at risk (OARs). Graphical optimization was then used to fine tune the final dose distribution. The minimum cavity-to-skin distance was measured. Target coverage (V90 and V95) and maximum dose (D0.1cc) to the OARs were evaluated. Dose homogeneity index (DHI = 1-V150/V100) was calculated. The average cavity-to-skin distances were 4.1 mm (0.5-9.6 mm, SAVI) and 11.7 mm (7.1-15.4 mm, Contura). The target-to-skin distance for the T&B cases was 8.7 mm (5.0-13.7 mm). The average V90 and V95 to the target were 96.8% and 94.5% (SAVI), 97.0% and 93.0% (Contura), 98.6% and 97.3% (T&B). The mean D0.1cc to the skin, ribs, and lung was 91.5%, 58.8%, 44.5% (SAVI), 93.1%, 51.3%, 40.5% (Contura), 69.1%, 41.5%, and 31.9% (T&B). The average V150 and V200 to the normal breast tissue were 30.4 cc and 14.9 cc (SAVI), 29.5 cc and 7.3 cc (Contura), 18.3 cc and 7.1 cc (T&B). The average DHI for the SAVI, Contura, and T&B cases was 0.55 (0.50-0.60), 0.70 (0.63-0.78), and 0.76 (0.74-0.79). All techniques provided clinically acceptable target coverage and dose to the OARs. The SAVI device provided a lower skin dose at close cavity-to-skin distances while providing excellent target coverage. However, the T&B and Contura applicators produced more homogeneous dose distribution (higher DHI) in the target than the SAVI. The correlations between dosimetric properties and follow-up mammogram results are under investigation.

Tumor bed-to-skin distance using accelerated partial-breast irradiation with the strut-adjusted volume implant device

PurposeBecause of the risk of skin toxicity with single dwell position, single-lumen brachytherapy devices are sometimes contraindicated for tumor cavities 5–7mm from the skin surface. We discuss the use of multicatheter device to treat patients with tumor bed-to-skin distances <7mm. Methods and MaterialsWe treated 117 patients with accelerated partial-breast irradiation brachytherapy: 77 single-lumen and 40 multicatheter devices. A subset of 12 patients treated with SAVI® had bed-to-skin spacing <7mm. All patients had Tis-2N0 ductal carcinoma with negative margins. A total dose of 34.0Gy in 10 fractions was delivered twice daily. Planning target volume was created using computed tomography–based three-dimensional planning with a 1.0-cm expansion of the lumpectomy cavity. Skin dose was measured dosimetrically, with skin constraints <125% of the prescription. Toxicities were graded, and patients were assessed at various intervals. ResultsOf the patients treated with the multicatheter device, 0% (0/12) had their device pulled. At 2 weeks after treatment, fewer than 50% of the patients had skin toxicities of Grades 1–2, all of which resolved by 6 months. The cosmetic outcome was good to excellent at followup. ConclusionsMulticatheter devices permit well-tolerated accelerated partial-breast irradiation in patients with tumor cavities near the skin surface for which the single-lumen device may not be appropriate.

Dosimetry evaluation of SAVI-based HDR brachytherapy for partial breast irradiation.

Accelerated partial breast irradiation (APBI) with high dose rate (HDR) brachytherapy offers an excellent compact course of radiation due to its limited number of fractions for early-stage carcinoma of breast. One of the recent devices is SAVI (strut-adjusted volume implant), which has 6, 8 or 10 peripheral source channels with one center channel. Each channel can be differentially loaded. This paper focuses on the treatment planning, dosimetry and quality assurance aspects of HDR brachytherapy implant with GammaMed Plus HDR afterloader unit. The accelerated PBI balloon devices normally inflate above 35 cc range, and hence these balloon type devices cannot be accommodated in small lumpectomy cavity sizes. CT images were obtained and 3-D dosimetric plans were done with Brachyvision planning system. The 3-D treatment planning and dosimetric data were evaluated with planning target volume (PTV)_eval V90, V95, V150, V200 skin dose and minimum distance to skin. With the use of the SAVI 6-1 mini device, we were able to accomplish an excellent coverage — V90, V95, V150 and V200 to 98%, 95%, 37 cc (<50 cc volume) and 16 cc (<20 cc volume), respectively. Maximum skin dose was between 73% and 90%, much below the prescribed dose of 34 Gy. The minimum skin distance achieved was 5 to 11 mm. The volume that received 50% of the prescribed radiation dose was found to be lower with SAVI. The multi-channel SAVI-based implants reduced the maximum skin dose to markedly lower levels as compared to other modalities, simultaneously achieving best dose coverage to target volume. Differential-source dwell-loading allows modulation of the radiation dose distribution in symmetric or asymmetric opening of the catheter shapes and is also advantageous in cavities close to chest wall.

SU-FF-T-33: 3D Conformal Brachytherapy for Partial Breast Irradiation

Purpose: Partial‐breast brachy irradiation following the lumpectomy is effective in treatment women with early‐stage breast cancer and is being broadly implemented in clinic. However, the current popular radiation treatments are limited to treat regularly shaped, spherical or ellipsoid, targets with strictly defined skin and rib distances. In reality, many treatment targets cannot be defined perfectly spherical or ellipsoid due to the irregularly shaped lumpectomy cavity and/or skin distance or nearby critical organ limits. In such cases, the 3D conformal brachytherapy becomes necessary. Methods and Materials: Multiple channel breast brachytherapy applicator is used to replace the single channel applicator for 3D conformal brachytherapy. Patient is CT scanned with slice thickness at 1 mm. The target and critical organs are delineated by radiation oncologist and planning staff. Brachytherapy source dwell positions and dwell time are the parameters for treatment planning optimization. The inverse planning and graphic optimization of Plato treatment planning system (Nucletron, Columbia, Maryland) are utilized to achieve conformal radiation dose to the target and spare the critical organs.Treatment plans are evaluated based on the isodose curves displayed on top of CTimages, the dose conformality to the target and the dose volume histograms of target and critical organs.Results: Clinic cases with irregularly shaped targets and/or short skin distance, or closely located critical organs are planned and treated with 3D conformal brachytherapy. All the plans are achieved with satisfied dose distribution, i.e. good dose conformality to the target and sparing of critical organs. The after treatment following up demonstrates successful radiation treatment and good control of patient skin reaction. Conclusion: The 3D conformal brachytherapy for partial breast irradiation allow us to better treat the irregularly shaped targets and spare the critical organs. It also releases the restrictions of skin distance and air cavity volume in the selection of patients.

Does treatment time or source strength affect late toxicity in accelerate partial breast irradiation brachytherapy?

Does treatment time or source strength affect late toxicity in accelerate partial breast irradiation brachytherapy?

Five-year results: the initial clinical trial of Mammosite balloon brachytherapy for partial breast irradiation in early-stage breast cancer

Five-year results: the initial clinical trial of Mammosite balloon brachytherapy for partial breast irradiation in early-stage breast cancer

Consequence of varying target coverage and dose heterogeneity in accelerated partial breast irradiation brachytherapy modalities on tumor control probability

Purpose: The NSABP-B39/RTOG-0413 protocol is randomizing patients to conventional whole breast irradiation versus one of three accelerated partial breast irradiation (APBI) modalities: Mammosite brachytherapy (MB), multi-catheter brachytherapy (MCT) and 3D conformal partial breast treatment. The two brachytherapy based APBI techniques typically result in widely varying dose heterogeneity in the target (with dose heterogeneity typically larger in MB). We studied the effect of this variability in heterogeneity and minimum target dose coverage on the predicted tumor control probability (TCP) based on the linear-quadratic (LQ) model.

Preliminary results and evaluation of MammoSite balloon brachytherapy for partial breast irradiation for pure ductal carcinoma in situ: a phase II clinical study

Preliminary results and evaluation of MammoSite balloon brachytherapy for partial breast irradiation for pure ductal carcinoma in situ: a phase II clinical study