The MammoSite breast brachytherapy applicator: a review of technique and outcomes

Breastdosimetry of 99mTc-balloon in complementary radiotherapy

Dose reinforcement in primary tumor cavity can complement conventional radiotherapy in patients with early breast cancer. In this study, a dosimetric analysis was conducted by pertechnetate-^99mTc-filled balloon brachytherapy (TBB).

METHODS

Dosimetry based on radiochromic films and on a computational voxel thorax model was performed. Calibration protocol achieved a mathematical relationship between dose and optical density in films placed on the surface at a distance of 0-9cm, 1cm between them, in which dose values were provided by MCNP® code. Moreover, experimental spatial dose distribution was prepared. A female thorax voxel model was developed in the SISCODES®/MCNP® codes. Additionally, experimental and computational doses at 8-10mm from balloon surface were compared.

RESULTS

Dose from ^99mTc-balloon, with 16mm diameter, 32.22GBq activity, and 24h exposure time, achieved 8.08±0.42 (Ue) and 8.82±1.76 (Ue) Gy, at a distance of 10mm from the balloon surface for the experimental data and computational modeling, respectively, thus showing nonsignificant difference. The spatial dose distribution in the chest wall, glandular tissue, breast skin, and lung was presented. The dosimetric findings supported the TBB modality presenting a suitable spatial dose distribution in the tumor bed and preserving the adjacent health tissues.

CONCLUSION

TBB is a viable adjuvant brachytherapy modality for breast cancer in patients who have an appropriate indication.

Balloon-based adjuvant radiotherapy in breast cancer: comparison between (99m)Tc and HDR (192)Ir

OBJECTIVE

To perform a comparative dosimetric analysis, based on computer simulations, of temporary balloon implants with (99m)Tc and balloon brachytherapy with high-dose-rate (HDR) (192)Ir, as boosts to radiotherapy. We hypothesized that the two techniques would produce equivalent doses under pre-established conditions of activity and exposure time.

MATERIALS AND METHODS

Simulations of implants with (99m)Tc-filled and HDR (192)Ir-filled balloons were performed with the Siscodes/MCNP5, modeling in voxels a magnetic resonance imaging set related to a young female. Spatial dose rate distributions were determined. In the dosimetric analysis of the protocols, the exposure time and the level of activity required were specified.

RESULTS

The (99m)Tc balloon presented a weighted dose rate in the tumor bed of 0.428 cGy.h(-1).mCi(-1) and 0.190 cGyh(-1).mCi(-1) at the balloon surface and at 8-10 mm from the surface, respectively, compared with 0.499 and 0.150 cGyh(-1).mCi(-1), respectively, for the HDR (192)Ir balloon. An exposure time of 24 hours was required for the (99m)Tc balloon to produce a boost of 10.14 Gy with 1.0 Ci, whereas only 24 minutes with 10.0 Ci segments were required for the HDR (192)Ir balloon to produce a boost of 5.14 Gy at the same reference point, or 10.28 Gy in two 24-minutes fractions.

CONCLUSION

Temporary (99m)Tc balloon implantation is an attractive option for adjuvant radiotherapy in breast cancer, because of its availability, economic viability, and similar dosimetry in comparison with the use of HDR (192)Ir balloon implantation, which is the current standard in clinical practice.

WBRT vs. APBI: an interim report of patient satisfaction and outcomes

PURPOSE

To determine differences in patient's reported quality of life and self-reported breast cosmesis between whole breast radiation therapy (WBRT) and accelerated partial breast irradiation (APBI) via single and multi-lumen high-dose-rate (HDR) brachytherapy for women with early stage breast cancer.

MATERIAL AND METHODS

Patient information was retrospectively reviewed and survey data were prospectively collected for women treated between 2004 to 2014 (APBI) and 2012 to 2014 (WBRT). Criteria for APBI treatments were ER+ (after 2010), N0 (after 2010), T < 3 cm, and post-menopausal. All patients were given a survey with modified FACIT (Functional Assessment of Chronic Illness Therapy) breast quality of life questions to rate their amount of pain, self-consciousness, low energy, presence of lymphedema, and breast cosmesis.

RESULTS

242 APBI patients and 59 WBRT patients were identified. In the WBRT cohort, 34 women met departmental criteria for APBI treatment (WBRT who were APBI eligible). The FACIT survey was completed by 80 women treated with APBI (33%; mean follow-up time of 14 months), and 26 women treated with WBRT who were APBI eligible (76%; mean follow-up time of 26 months). During the first year post-treatment, low energy (p = 0.009), self-consciousness (p = 0.0004), and lymphedema (p = 0.0002) scores were significantly lower in the APBI cohort when compared to women treated with WBRT who were APBI eligible. During the second year post-treatment, women treated with APBI reported significantly better breast cosmesis (p = 0.04). The single-lumen balloon (score = 6.3/10) was found to be associated with worse cosmesis compared to the multi-lumen balloons (Mammosite ML and Contura; score = 8.2/10; p = 0.002). There were no significant differences in rates of recurrence between balloons or treatments (p > 0.05).

CONCLUSIONS

APBI treated patients reported higher cosmetic satisfaction than patients in the matched WBRT cohort. Quality of life scores tended to improve over time. Multi-lumen catheters provided superior cosmetic results compared to single-lumen catheters.

Trends in Local Therapy Utilization and Cost for Early-Stage Breast Cancer in Older Women: Implications for Payment and Policy Reform

PURPOSE

Older women with early-stage disease constitute the most rapidly growing breast cancer demographic, yet it is not known which local therapy strategies are most favored by this population in the current era. Understanding utilization trends and cost of local therapy is important for informing the design of bundled payment models as payers migrate away from fee-for-service models. We therefore used the Surveillance, Epidemiology, and End Results Medicare database to determine patterns of care and costs for local therapy among older women with breast cancer.

METHODS AND MATERIALS

Treatment strategy and covariables were determined in 55,327 women age ≥66 with Tis-T2N0-1M0 breast cancer who underwent local therapy between 2000 and 2008. Trends in local therapy were characterized using Joinpoint. Polychotomous logistic regression determined predictors of local therapy. The median aggregate cost over the first 24 months after diagnosis was determined from Medicare claims through 2010 and reported in 2014 dollars.

RESULTS

The median age was 75. Local therapy distribution was as follows: 27,896 (50.3%) lumpectomy with external beam radiation, 18,356 (33.1%) mastectomy alone, 6159 (11.1%) lumpectomy alone, 1488 (2.7%) mastectomy with reconstruction, and 1455 (2.6%) lumpectomy with brachytherapy. Mastectomy alone declined from 39.0% in 2000 to 28.2% in 2008, and the use of breast conserving local therapies rose from 58.7% to 68.2%. Mastectomy with reconstruction was more common among the youngest, healthiest patients, whereas mastectomy alone was more common among patients living in rural low-income regions. By 2008, the costs were $36,749 for lumpectomy with brachytherapy, $35,030 for mastectomy with reconstruction, $31,388 for lumpectomy with external beam radiation, $21,993 for mastectomy alone, and $19,287 for lumpectomy alone.

CONCLUSIONS

The use of mastectomy alone in older women declined in favor of breast conserving strategies between 2000 and 2008. Using these cost estimates, price points for local therapy bundles can be constructed to incentivize the treatment strategies that confer the highest value.

Partial–breast irradiation: towards a replacement for whole–breast irradiation?

Largely thanks to all of the investigators and patients who have participated in randomized breast-conservation trials, many women facing a diagnosis of breast cancer today can conserve their breast with the help of adjuvant radiation therapy. A standard course of radiation consists of 5-7 weeks of daily radiation treatments delivered to the whole breast. The success of this treatment has led investigators to attempt to determine whether the same control can be achieved while decreasing the volume of breast tissue irradiated, thus allowing treatment to be delivered in a shorter period of time. This approach could alleviate time and logistical problems faced by patients during their course of treatment as well as improving overall cost-effectiveness. It can also allow complete avoidance of the adjacent heart and lung tissue in the radiation treatment portal. Partial-breast irradiation (the delivery of radiation to the resection cavity, plus a safety margin) delivered in just hours or days, is currently under investigation. Although relatively new, its use is growing rapidly and many institutional and cooperative group trials are quickly enlisting patients, while physicians are gaining experience in a variety of partial-breast irradiation techniques.

Trial Watch: Anticancer radioimmunotherapy

Radiotherapy has extensively been employed as a curative or palliative intervention against cancer throughout the last century, with a varying degree of success. For a long time, the antineoplastic activity of X- and γ-rays was entirely ascribed to their capacity of damaging macromolecules, in particular DNA, and hence triggering the (apoptotic) demise of malignant cells. However, accumulating evidence indicates that (at least part of) the clinical potential of radiotherapy stems from cancer cell-extrinsic mechanisms, including the normalization of tumor vasculature as well as short- and long-range bystander effects. Local bystander effects involve either the direct transmission of lethal signals between cells connected by gap junctions or the production of diffusible cytotoxic mediators, including reactive oxygen species, nitric oxide and cytokines. Conversely, long-range bystander effects, also known as out-of-field or abscopal effects, presumably reflect the elicitation of tumor-specific adaptive immune responses. Ionizing rays have indeed been shown to promote the immunogenic demise of malignant cells, a process that relies on the spatiotemporally defined emanation of specific damage-associated molecular patterns (DAMPs). Thus, irradiation reportedly improves the clinical efficacy of other treatment modalities such as surgery (both in neo-adjuvant and adjuvant settings) or chemotherapy. Moreover, at least under some circumstances, radiotherapy may potentiate anticancer immune responses as elicited by various immunotherapeutic agents, including (but presumably not limited to) immunomodulatory monoclonal antibodies, cancer-specific vaccines, dendritic cell-based interventions and Toll-like receptor agonists. Here, we review the rationale of using radiotherapy, alone or combined with immunomodulatory agents, as a means to elicit or boost anticancer immune responses, and present recent clinical trials investigating the therapeutic potential of this approach in cancer patients.

Breast conservation therapy utilizing partial breast brachytherapy for early-stage cancer of the breast: a retrospective review from the Saint Luke's Cancer Institute

BACKGROUND

Accelerated partial breast irradiation (APBI) is a convenient alternative to whole-breast irradiation, as less overall time is needed for completion. The use of APBI outside the framework of large prospective clinical trials has markedly increased. To our knowledge, no high-volume, community-based breast program has published their experience with APBI.

METHODS

The records of 93 consecutive patients who underwent APBI utilizing Mammosite Radiation Therapy System from 2005 to 2010 at Saint Luke's Cancer Institute in Kansas City, MO, were retrospectively reviewed. The Kaplan-Meier method was used to estimate the ipsilateral breast recurrence rate and recurrence-free survival.

RESULTS

Median age at diagnosis was 63 years (range, 45 to 86 y) and mean follow-up was 29 months. Patient stratification ASTRO consensus classifications for APBI was 37% suitable, 57% cautionary, and 6% unsuitable. The 3-year breast control rate was 98.7%. Three-year overall recurrence-free survival was 94.4%, and 3-year mastectomy-free survival was 97.4%. Using univariate analysis, no tumor or patient factors were associated with ipsilateral breast recurrence. However, tumor grade (P<0.05), stage (P=0.04), estrogen receptor status (P<0.001), progesterone receptor status (P<0.001), tumor size (P<0.001), and ASTRO suitability criteria (P=0.027) were associated with overall recurrence-free survival. No differences were observed when outcomes of patients with ductal carcinoma in situ were compared with those with invasive disease.

CONCLUSIONS

In our high-volume community-based program, APBI outcomes are comparable with those reported from large academic institutions. We also found relationships between tumor stage, grade, negative estrogen receptor status, and ASTRO suitability criteria with overall recurrence rates. The continued careful application of APBI in appropriately selected patients appears warranted until phase III trials comparing this modality to whole-breast irradiation have matured.

Brachytherapy in accelerated partial breast irradiation (APBI) - review of treatment methods

Breast conserving surgery (BCS) with following radiotherapy (EBRT) of the conserved breast became widely accepted in the last decades as the treatment of early invasive breast cancer. In an early stage of breast cancer, research has shown that the area requiring radiation treatment to prevent cancer from local recurrence is the breast tissue that surrounds the area where the initial cancer was removed. Accelerated partial breast irradiation (APBI) is an approach that treats only the lumpectomy bed with 1-2 cm margin, rather than the whole breast and as a result allows accelerated delivery of the radiation dose in four to five days. Published results of APBI are very promising. It is evident that APBI will play a role in the management of a selected group of early breast cancer. We discuss current status, indications, technical aspects and recently published results of APBI using different brachytherapy techniques.

A comprehensive analysis of cardiac dose in balloon-based high-dose-rate brachytherapy for left-sided breast cancer

PURPOSE

To investigate radiation dose to the heart in 60 patients with left-sided breast cancer who were treated with balloon-based high-dose-rate brachytherapy using MammoSite or Contura applicators.

METHODS AND MATERIALS

We studied 60 consecutive women with breast cancer who were treated with 34 Gy in 10 twice-daily fractions using MammoSite (n = 37) or Contura (n = 23) applicators. The whole heart and the left and right ventricles were retrospectively delineated, and dose-volume histograms were analyzed. Multiple dosimetrics were reported, such as mean dose (D(mean)); relative volume receiving 1.7, 5, 10, and 20 Gy (V1.7, V5, V10, and V20, respectively); dose to 1 cc (D(1cc)); and maximum point dose (D(max)). Biologic metrics, biologically effective dose and generalized equivalent uniform dose were computed. The impact of lumpectomy cavity location on cardiac dose was investigated.

RESULTS

The average ± standard deviation of D(mean) was 2.45 ± 0.94 Gy (range, 0.56-4.68) and 3.29 ± 1.28 Gy (range, 0.77-6.35) for the heart and the ventricles, respectively. The average whole heart V5 and V10 values were 10.2% and 1.3%, respectively, and the heart D(max) was >20 Gy in 7 of 60 (11.7%) patients and >25 Gy in 3 of 60 (5%) patients. No cardiac tissue received ≥30 Gy. The V1.7, V5, V10, V20, and D(mean) values were all higher for the ventricles than for the whole heart. For balloons located in the upper inner quadrant of the breast, the average whole heart D(mean) was highest. The D(mean), biologically effective dose, and generalized equivalent uniform dose values for heart and ventricles decreased with increasing minimal distance from the surface of the balloon.

CONCLUSIONS

On the basis of these comprehensive cardiac dosimetric data, we recommend that cardiac dose be routinely reported and kept as low as possible in balloon-based high-dose-rate brachytherapy treatment planning for patients with left-sided breast cancer so the correlation with future cardiac toxicity data can be investigated.

Accelerated partial breast irradiation using the strut-adjusted volume implant single-entry hybrid catheter in brachytherapy for breast cancer in the setting of breast augmentation

PURPOSE

Accelerated partial breast irradiation (APBI) has gained popularity as an alternative to adjuvant whole breast irradiation; however, owing to limitations of delivery devices for brachytherapy, APBI has not been a suitable option for all the patients. This report evaluates APBI using the strut-adjusted volume implant (SAVI) single-entry catheter to deliver brachytherapy for breast cancer in the setting of an augmented breast.

METHODS AND MATERIALS

The patient previously had placed bilateral subpectoral saline implants; stereotactic core biopsy revealed estrogen receptor- and progesterone receptor-positive ductal carcinoma in situ of intermediate nuclear grade. The patient underwent needle-localized segmental mastectomy of her left breast; pathologic specimen revealed no residual malignancy. An SAVI 8-1 device was placed within the segmental resection cavity. Treatment consisted of 3.4 Gy delivered twice a day for 5 days for a total dose of 34 Gy. Treatments were delivered with a high-dose-rate (192)Ir remote afterloader.

RESULTS

Conformance of the device to the lumpectomy cavity was excellent at 99.2%. Dosimetric values of percentage of the planning target volume for evaluation receiving 90% of the prescribed dose, percentage of the planning target volume for evaluation receiving 95% of the prescribed dose, volume receiving 150% of the prescribed dose, and volume receiving 200% of the prescribed dose were 97.1%, 94.6%, 22.7 cc, and 11.6 cc, respectively. Maximum skin dose was 115% of the prescribed dose. The patient tolerated treatment well with excellent cosmetic results, and limited acute and late toxicity at 8 weeks and 6 months, respectively.

CONCLUSIONS

Breast augmentation should not be an exclusion criterion for the option of APBI. The SAVI single-entry catheter is another option to successfully complete APBI using brachytherapy for breast cancer in the setting of an augmented breast.

Comparison of single and multiple dwell position methods in MammoSite high dose rate (HDR) brachytherapy planning

The purpose of this study is to dosimetrically compare two plans generated using single dwell position method (SDPM) and multiple dwell position methods (MDPM) in MammoSite high dose rate (HDR) brachytherapy planning for 19 breast cancer patients. In computed tomography (CT) image-based HDR planning, a surface optimization technique was used in both methods. Following dosimetric parameters were compared for fraction 1 plans: %PTV_EVAL (planning target volume for plan evaluation) coverage, dose homogeneity index (DHI), dose con-formal index (COIN), maximum dose to skin and ipsilateral lung, and breast tissue volume receiving 150% (V150[cc]) and 200% (V200[cc]) of the prescribed dose. In addition, a plan was retrospectively generated for each fraction 2-10 to simulate the clinical situation where the fraction 1 plan was used for fractions 2-10 without modification. In order to create nine derived plans for each method and for each of the 19 patients, the catheter location and contours of target and critical structures were defined on the CT images acquired prior to each fraction 2-10, while using the same dwell-time distribution as used for fraction 1 (original plan). Interfraction dose variations were evaluated for 19 patients by comparing the derived nine plans (each for fractions 2-10) with the original plan (fraction 1) using the same dosimetric parameters used for fraction 1 plan comparison. For the fraction 1 plan comparison, the MDPM resulted in slightly increased %PTV_EVAL coverage, COIN, V150[cc] and V200[cc] values by an average of 1.2%, 0.025, 0.5 cc and 0.7cc, respectively, while slightly decreased DHI, maximum skin and ipsilateral lung dose by an average of 0.003, 3.2 cGy and 5.8 cGy, respectively. For the inter-fraction dose variation comparison, the SDPM resulted in slightly smaller variations in %PTV_EVAL coverage, DHI, maximum skin dose and V150[cc] values by an average of 0.4%, 0.0005, 0.5 cGy and 0.2 cc, respectively, while slightly higher average variations in COIN, maximum ipsilateral lung dose and V200[cc] values by 0.0028, 0.2 cGy and 0.2 cc, respectively. All differences were too small to be clinically significant. Compared to the MDPM, the SDPM combined with a surface optimization technique can generate a clinically comparable fraction 1 treatment plan with a similar interfraction dose variation if a single source is carefully positioned at the center of the balloon catheter.

Dose volume histogram analysis of normal structures associated with accelerated partial breast irradiation delivered by high dose rate brachytherapy and comparison with whole breast external beam radiotherapy fields

PURPOSE

To assess the radiation dose delivered to the heart and ipsilateral lung during accelerated partial breast brachytherapy using a MammoSite applicator and compare to those produced by whole breast external beam radiotherapy (WBRT).

MATERIALS AND METHODS

Dosimetric analysis was conducted on patients receiving MammoSite breast brachytherapy following conservative surgery for invasive ductal carcinoma. Cardiac dose was evaluated for patients with left breast tumors with a CT scan encompassing the entire heart. Lung dose was evaluated for patients in whom the entire lung was scanned. The prescription dose of 3400 cGy was 1 cm from the balloon surface. MammoSite dosimetry was compared to simulated WBRT fields with and without radiobiological correction for the effects of dose and fractionation. Dose parameters such as the volume of the structure receiving 10 Gy or more (V10) and the dose received by 20 cc of the structure (D20), were calculated as well as the maximum and mean doses received.

RESULTS

Fifteen patients were studied, five had complete lung data and six had left-sided tumors with complete cardiac data. Ipsilateral lung volumes ranged from 925-1380 cc. Cardiac volumes ranged from 337-551 cc. MammoSite resulted in a significantly lower percentage lung V30 and lung and cardiac V20 than the WBRT fields, with and without radiobiological correction.

CONCLUSION

This study gives low values for incidental radiation received by the heart and ipsilateral lung using the MammoSite applicator. The volume of heart and lung irradiated to clinically significant levels was significantly lower with the MammoSite applicator than using simulated WBRT fields of the same CT data sets.

A Phase II trial of brachytherapy alone after lumpectomy for select breast cancer: tumor control and survival outcomes of RTOG 95-17

PURPOSE

Radiation Therapy Oncology Group 95-17 is a prospective Phase II cooperative group trial of accelerated partial breast irradiation (APBI) alone using multicatheter brachytherapy after lumpectomy in select early-stage breast cancers. Tumor control and survival outcomes are reported.

METHODS AND MATERIALS

Eligibility criteria included Stage I/II breast carcinoma confirmed to be <3 cm, unifocal, invasive nonlobular histology with zero to three positive axillary nodes without extracapsular extension. APBI treatment was delivered with either low-dose-rate (LDR) (45 Gy in 3.5-5 days) or high-dose-rate (HDR) brachytherapy (34 Gy in 10 twice-daily fractions over 5 days). End points evaluated included in-breast control, regional control, mastectomy-free rate, mastectomy-free survival, disease-free survival, and overall survival. The study was designed to analyze the HDR and LDR groups separately and without comparison.

RESULTS

Between 1997 and 2000, 100 patients were accrued and 99 were eligible; 66 treated with HDR brachytherapy and 33 treated with LDR brachytherapy. Eighty-seven patients had T1 lesions and 12 had T2 lesions. Seventy-nine were pathologically N0 and 20 were N1. Median follow-up in the HDR group is 6.14 years with the 5-year estimates of in-breast, regional, and contralateral failure rates of 3%, 5%, and 2%, respectively. The LDR group experienced similar results with a median follow-up of 6.22 years. The 5-year estimates of in-breast, regional, and contralateral failure rates of 6%, 0%, and 6%, respectively.

CONCLUSION

Patients treated with multicatheter partial breast brachytherapy in this trial experienced excellent in-breast control rates and overall outcome that compare with reports from APBI studies with similar extended follow-up.

Clinical and dosimetric experience with MammoSite-based brachytherapy under the RTOG 0413 protocol

MammoSite balloon brachytherapy is a relatively new technique for partial breast irradiation. The present paper focuses on the treatment planning, dosimetry, and quality assurance aspects of that treatment, based on the Radiation Therapy Oncology Group 0413 randomized prospective trial (RTOG 0413) protocol. We investigate the usefulness of evaluating implants for treatment appropriateness according to the full set of RTOG criteria as compared with the manufacturer's guidelines. We describe our methods to improve MammoSite balloon implants that would otherwise not comply with the protocol. The initially acquired computed tomography (CT) images are evaluated for tissue conformance, balloon surface-to-skin distance, and balloon symmetry. If the implant fails to meet the foregoing criteria, corrective action such as delay in the CT scan, balloon manipulation, or fluid volume adjustment is taken, and the patient is re-scanned. If the corrective action appears to be successful, three dimensional treatment planning and dose-volume histogram analysis is performed to evaluate the geometric and dosimetric parameters with regard to the RTOG 0413 protocol. The evaluated parameters include, volume ratio of the lumpectomy cavity to the ipsilateral breast, target volume coverage, tissue-balloon conformance, balloon symmetry, minimal balloon surface-to-skin distance, maximum skin dose, and normal breast tissue dose-volume parameters V150 and V200. Among our implants, 21.7% did not initially meet the RTOG 0413 acceptance criteria. Asymmetry and poor conformance values reduce the target volume coverage, and so an implant with moderate conformance and asymmetry can be within the manufacturer's guidelines, but still not meet the RTOG criteria. Our intervention corrected all but one of the implants that failed to meet the criteria. Manipulating the cavity and adjusting the balloon volume may salvage an implant and meet the strict geometric and dosimetric criteria imposed by the RTOG 0413 protocol.

Target Volume Delineation for Partial Breast Radiotherapy Planning: Clinical Characteristics Associated with Low Interobserver Concordance

PURPOSE

To examine variability in target volume delineation for partial breast radiotherapy planning and evaluate characteristics associated with low interobserver concordance.

METHODS AND MATERIALS

Thirty patients who underwent planning CT for adjuvant breast radiotherapy formed the study cohort. Using a standardized scale to score seroma clarity and consensus contouring guidelines, three radiation oncologists independently graded seroma clarity and delineated seroma volumes for each case. Seroma geometric center coordinates, maximum diameters in three axes, and volumes were recorded. Conformity index (CI), the ratio of overlapping volume and encompassing delineated volume, was calculated for each case. Cases with CI </=0.50 were analyzed to identify features associated with low concordance.

RESULTS

The median time from surgery to CT was 42.5 days. For geometric center coordinates, variations from the mean were 0.5-1.1 mm and standard deviations (SDs) were 0.5-1.8 mm. For maximum seroma dimensions, variations from the mean and SDs were predominantly <5 mm, with the largest SDs observed in the medial-lateral axis. The mean CI was 0.61 (range, 0.27-0.84). Five cases had CI </=0.50. Conformity index was significantly associated with seroma clarity (p < 0.001) and seroma volume (p < 0.002). Features associated with reduced concordance included tissue stranding from the surgical cavity, proximity to muscle, dense breast parenchyma, and benign calcifications that may be mistaken for surgical clips.

CONCLUSION

Variability in seroma contouring occurred in three dimensions, with the largest variations in the medial-lateral axis. Awareness of clinical features associated with reduced concordance may be applied toward training staff and refining contouring guidelines for partial breast radiotherapy trials.

Biocompatibility evaluation of crosslinked chitosan hydrogels after subcutaneous and intraperitoneal implantation in the rat

The aim of the present study was to evaluate the toxicity of biodegradable hydrogels in the rat with a future aim of utilizing this hydrogel as a vehicle for brachytherapy delivery in cancer patients. Two types of chitosan hydrogels: fast degrading and slow degrading; were prepared and surgically implanted in rats. The adjacent tissue response to the gels after subcutaneous and intraperitoneal implantation was examined histologically and found to be identical to typical foreign body response and was milder than the response to absorbable surgical sutures (Vicril). Neither tissue damage nor gel fragments could be detected in distant organs (brain, heart, lungs, liver, spleen, kidney, and sternal bone marrow) after implantation of the hydrogels. The degradation mechanism of the gels was studied in vivo, and it was deduced that an oxidative process degraded the chitosan. Loading the hydrogels with a radioisotope (131I-norcholesterol) caused a severe tissue response and necrosis in adjacent tissues only at a distance of several microns. It is concluded that crosslinked chitosan implants could serve as alternative, biocompatible, and safe biodegradable devices for radioisotope delivery in brachytherapy for cancer.

The emergence of advanced brachytherapy techniques for common malignancies

The recent advent and integration of sophisticated radiation planning and imaging modalities has improved the quality of brachytherapy treatments, allowing for more conformal radiation delivery. Further investigation and follow-up are necessary to demonstrate improvements in outcome and morbidity with these refined approaches.

Image-guided breast brachytherapy: an alternative to whole-breast radiotherapy

Lumpectomy and whole-breast radiotherapy (ie, breast-conservation treatment) are accepted as viable alternatives to mastectomy in locoregional management of breast cancer. These techniques are used to keep morbidity to a minimum, optimise cosmesis, and maintain treatment outcomes. Pathological and clinical data suggest that most recurrences of cancer in the ipsilateral breast are in the vicinity of the index lesion, and that remote recurrences are uncommon, whether or not whole-breast radiotherapy is delivered. These data lend support to the idea of partial-breast radiotherapy. Such a restricted treatment volume allows safe delivery of an accelerated hypofractionated regimen over a shortened course of 1 week. This technique differs from that of standard whole-breast tangential external-beam radiotherapy and necessitates investigation of accelerated partial-breast irradiation (APBI). Several techniques of APBI are being investigated; however, most experience, and the most favourable early outcomes, has been obtained with image-guided breast brachytherapy. This review highlights the rationale and outcomes of brachytherapy techniques.

Breast imaging: a surgeon's prospective

Mammography, ultrasound, magnetic resonance imaging, positron emission tomography, gamma camera and intraoperative gamma detection, and computed tomography are employed in the diagnosis and treatment of breast cancer. This paper summarizes the role of each modality from the perspective of the physician responsible for management of the patient's care. An understanding of an imaging modality's current role can provide insights into the design of new applications and diagnostic agents. Moreover, knowledge of the mechanism by which each modality provides clinical information can guide the design of new imaging methods that complement and add certainty to the patient's management. The reader should note the lack of molecular information provided by the current imaging methods. The perspective concludes with a request for an imaging technique that can measure the biologic aggressiveness of a woman's cancer. The surgeon notes that basing the formation of an image on a molecular process would be compatible with current medical practice, which utilizes molecular concepts to base medical decisions. In addition, molecular imaging will enable rapid translation between basic science and medical practice.

A new option for early breast cancer patients previously irradiated for Hodgkin's disease: intraoperative radiotherapy with electrons (ELIOT)

Introduction

Patients who have undergone mantle radiotherapy for Hodgkin's disease (HD) are at increased risk of developing breast cancer. In such patients, breast conserving surgery (BCS) followed by breast irradiation is generally considered contraindicated owing to the high cumulative radiation dose. Mastectomy is therefore recommended as the first option treatment in these women.

Methods

Six patients affected by early breast cancer previously treated with mantle radiation for HD underwent BCS associated with full-dose intraoperative radiotherapy with electrons (ELIOT).

Results

A total dose of 21 Gy (prescribed at 90% isodose) in five cases and 17 Gy (at 100% isodose) in one case were delivered directly to the mammary gland without acute complications and with good cosmetic results. After an average of 30.8 months of follow up, no late sequelae were observed and the patients are free of disease.

Conclusion

In patients previously irradiated for HD, ELIOT can avoid repeat irradiation of the whole breast, permit BCS and decrease the number of avoidable mastectomies.