Primary breast irradiation in large-breasted or heavy women: analysis of cosmetic outcome

Comparison of dose distributions and organs at risk (OAR) doses in conventional tangential technique (CTT) and IMRT plans with different numbers of beam in left-sided breast cancer

AIM

Our aim was to improve dose distribution to the left breast and to determine the dose received by the ipsilateral lung, heart, contralateral lung and contralateral breast during primary left-sided breast irradiation by using intensity modulated radiotherapy (IMRT) techniques compared to conventional tangential techniques (CTT). At the same time, different beams of IMRT plans were compared to each other in respect to CI, HI and organs at risk (OAR) dose.

BACKGROUND

Conventional early breast cancer treatment consists of lumpectomy followed by whole breast radiation therapy. CTT is a traditional method used for whole breast radiotherapy and includes standard wedged tangents (two opposed wedged tangential photon beams). The IMRT technique has been widely used for many treatment sites, allowing both improved sparing of normal tissues and more conformal dose distributions. IMRT is a new technique for whole breast radiotherapy. IMRT is used to improve conformity and homogeneity and used to reduce OAR doses.

MATERIALS AND METHODS

Thirty patients with left-sided breast carcinoma were treated between 2005 and 2008 using 6, 18 or mixed 6/18 MV photons for primary breast irradiation following breast conserving surgery (BCS). The clinical target volume [CTV] was contoured as a target volume and the contralateral breast, ipsilateral lung, contralateral lung and heart tissues as organs at risk (OAR). IMRT with seven beams (IMRT7), nine beams (IMRT9) and 11 beams (IMRT11) plans were developed and compared with CTT and among each other. The conformity index (CI), homogeneity index (HI), and doses to OAR were compared to each other.

RESULTS

ALL OF IMRT PLANS SIGNIFICANTLY IMPROVED CI (CTT: 0.76; IMRT7: 0.84; IMRT9: 0.84; IMRT11: 0.85), HI (CTT: 1.16; IMRT7: 1.12; IMRT9: 1.11; IMRT11: 1.11), volume of the ipsilateral lung receiving more than 20 Gy (>V20 Gy) (CTT: 14.6; IMRT7: 9.08; IMRT9: 8.10; IMRT11: 8.60), and volume of the heart receiving more than 30 Gy (>V30 Gy) (CTT: 6.7; IMRT7: 4.04; IMRT9: 2.80; IMRT11: 2.98) compared to CTT. All IMRT plans were found to significantly decrease >V20 Gy and >V30 Gy volumes compared to conformal plans. But IMRT plans increased the volume of OAR receiving low dose radiotherapy: volume of contralateral lung receiving 5 and 10 Gy (CTT: 0.0-0.0; IMRT7: 19.0-0.7; IMRT9: 17.2-0.66; IMRT11: 18.7-0.58, respectively) and volume of contralateral breast receiving 10 Gy (CTT: 0.03; IMRT7: 0.38; IMRT9: 0.60; IMRT11: 0.68). The differences among IMRT plans with increased number of beams were not statistically significant.

CONCLUSION

IMRT significantly improved conformity and homogeneity index for plans. Heart and lung volumes receiving high doses were decreased, but OAR receiving low doses was increased.

Breast reduction in the irradiated breast: evidence for the role of breast reduction at the time of lumpectomy

Given the high incidence of breast cancer in our society, it is common to encounter patients with macromastia who desire breast reduction after breast-conserving therapy by lumpectomy and radiation. We hypothesize that radiation leads to a significant increase in postoperative complications after breast reduction. All patients with a history of unilateral breast lumpectomy and radiation who subsequently underwent bilateral breast reduction by a single surgeon from 2004 to 2008 were retrospectively reviewed. Outcomes including cellulitis, wound breakdown, seroma, and need for repeat operations were compared between the radiated and nonradiated breast. The Fisher's exact test was used for statistical analysis. Twelve patients (mean age, 57 years) underwent bilateral breast reduction a mean of 86 months after unilateral lumpectomy and radiation. The nonradiated breasts had no complications postoperatively. The radiated breasts had a significant increase in complications with a total of five breasts (42%, p<0.04) having postoperative complications including cellulitis in two breasts, seroma requiring drainage in five breasts, two cases of fat necrosis, and one case of wound dehiscence. This resulted in two admissions for intravenous antibiotics and two repeat operative procedures. Additionally, three patients had significant breast asymmetry or contour deformities after reduction requiring operative revisions. Breast reduction after radiation leads to a significant increase in complications. Given this data, patients with macromastia undergoing breast conservation therapy for cancer should be considered for reduction at the time of lumpectomy and prior to radiation.

Partial-volume segmentation for dose optimization in whole-breast radiotherapy: a comparative dosimetric and clinical analysis

PURPOSE

: To analyze the dosimetric and clinical benefit of a forward planned technique to optimize dose distribution in whole-breast irradation (WBI) using additional partial-volume segments (PVSeg).

PATIENTS AND METHODS

: In two separate treatment periods, 265 breast cancer patients received tangential-field WBI and were retrospectively analyzed. Between 02/2004 and 03/2006, 96 patients were treated with one to two additional low-weighted PVSeg to reduce dose peaks within the target volume. 169 patients treated between 01/2000 and 12/2001 before implementation of this PVSeg technique served as comparison group. Total dose was 50-50.4 Gy (single dose, 1.8-2 Gy). The planning target volume (PTV) receiving at least 95%, 105% and 110% of the reference dose (V(95-110%)) and frequency of moist skin desquamation during radiotherapy were compared uni- and multivariately with patient- and treatment-related variables.

RESULTS

: The mean PTV was 1,144 ml (range, 235-2,365 ml). Moist skin desquamations developed in 16 patients (17%) with PVSeg compared to 30 patients (18%) without PVSeg (p = 0.482). In breast volumes > 1,100 ml, the corresponding figures were 19% versus 29% (p = 0.133). V(105%) was significantly reduced by the use of PVSeg (82 +/- 51 ml vs. 143 +/- 129 ml; p < 0.0001). In univariate analysis, the following variables had significant influence on the development of moist skin desquamation: V(95%) (p < 0.0001), V(105%) (p < 0.001), V(110%) (p = 0.012) adjuvant chemotherapy (p = 0.02), and single dose (p = 0.009). In multivariate analysis, only V(95%) (p = 0.002) remained significant.

CONCLUSION

: The use of PVSeg in WBI reduced dose peaks within the PTV while breast volumes > 1,100 ml benefited most. V(95%) was strongly correlated to the risk of developing moist skin desquamations.

Irregular surface compensation for radiotherapy of the breast: correlating depth of the compensation surface with breast size and resultant dose distribution

Irregular surface compensation uses dynamic multileaf collimators to modify the fluence to an irregular surface along the cranio-caudal axis. The depth of the compensation surface can be varied by specifying a user-defined parameter called the transmission penetration depth (TPD). In our institution, a review has been carried out of 60 breast patients treated using irregular surface compensation of the tangent fields. The effect of changes in the TPD on the dose distribution was investigated, and the optimum TPD was correlated with the maximum field separation (S(max)) along the posterior border. Reducing the TPD below 50% pushes the dose towards the front of the breast. This reduces hot spots at the medial and lateral regions next to the posterior border of the tangential fields, particularly for patients with large separation. In 23/60 patients, with a mean S(max) of 23.9 +/- 1.6 cm, a TPD between 35% and 45% was used to reduce the proportion of the planning target volume receiving more than 107% of the prescribed dose by 3.4% +/- 2.8%. Our department protocol states that, subject to an acceptable dose distribution, a TPD of 40% is used if S(max) is greater than 24 cm; for smaller separations, a TPD of 50% is used.

The potential of proton beam radiation therapy in breast cancer

A group of Swedish oncologists and hospital physicists have estimated the number of patients in Sweden suitable for proton beam therapy. The estimations have been based on current statistics of tumour incidence, number of patients potentially eligible for radiation treatment, scientific support from clinical trials and model dose planning studies and knowledge of the dose-response relations of different tumours and normal tissues. In primary breast cancer, it is estimated that about 300 of the annually 3 425 irradiated patients can potentially be candidates for proton beam therapy to reduce late toxicity, mainly from the heart and lungs.

Oncoplastic breast surgery: a review and systematic approach

Oncoplastic breast surgery (OBS) is relatively new, but has made rapid progress from its tentative steps of infancy in the 1990s. The recent Milanese Consensus Conference on Breast Conservation concluded that, firstly, oncoplastic techniques are warranted to allow wide excision and clear margins without compromising cosmesis. Secondly, such surgery is ideally performed at the same time as oncological excision. Whilst technically more challenging than standard breast conserving therapy (BCT), OBS is well proven, if not yet widely practised, both oncologically and aesthetically and a review of the available techniques is perhaps timely. The roots of breast conserving therapy can be traced to the 1930s, actually due to advances made in radiotherapy, and the last 20 years have seen it become firmly established. This review aims to summarise the key historical developments and latest innovations in OBS. Not only are our patients, who expect not only safe cancer treatment but a satisfactory aesthetic outcome, increasingly informed and demanding, but longer follow up has stimulated surgeons to improve outcomes. In many cases, particularly with ptosis and macromastia, the cancer can be treated, usually with wider excision margins, simultaneously improving the aesthetic appearance. Present at the birth of OBS, the Institut Curie has continued to introduce innovative techniques over the last two decades and a systematic approach, comprising nine basic techniques, has evolved to allow high quality treatment of any and all breast cancers suitable for OBS.

Variability of target and normal structure delineation for breast cancer radiotherapy: an RTOG Multi-Institutional and Multiobserver Study

PURPOSE

To quantify the multi-institutional and multiobserver variability of target and organ-at-risk (OAR) delineation for breast-cancer radiotherapy (RT) and its dosimetric impact as the first step of a Radiation Therapy Oncology Group effort to establish a breast cancer atlas.

METHODS AND MATERIALS

Nine radiation oncologists specializing in breast RT from eight institutions independently delineated targets (e.g., lumpectomy cavity, boost planning target volume, breast, supraclavicular, axillary and internal mammary nodes, chest wall) and OARs (e.g., heart, lung) on the same CT images of three representative breast cancer patients. Interobserver differences in structure delineation were quantified regarding volume, distance between centers of mass, percent overlap, and average surface distance. Mean, median, and standard deviation for these quantities were calculated for all possible combinations. To assess the impact of these variations on treatment planning, representative dosimetric plans based on observer-specific contours were generated.

RESULTS

Variability in contouring the targets and OARs between the institutions and observers was substantial. Structure overlaps were as low as 10%, and volume variations had standard deviations up to 60%. The large variability was related both to differences in opinion regarding target and OAR boundaries and approach to incorporation of setup uncertainty and dosimetric limitations in target delineation. These interobserver differences result in substantial variations in dosimetric planning for breast RT.

CONCLUSIONS

Differences in target and OAR delineation for breast irradiation between institutions/observers appear to be clinically and dosimetrically significant. A systematic consensus is highly desirable, particularly in the era of intensity-modulated and image-guided RT.

The prone technique for breast irradiation - is it ready for clinical trials?

PURPOSE

Our aim was to determine whether a radiotherapy technique for treating breast cancer patients in a prone position could be developed as a means of reducing toxicity. We also aimed to consider its suitability for testing in a large randomized study.

METHODS AND MATERIALS

Based on the sparse literature and techniques currently used at other centres, we designed a simple technique for simulation and treatment in the prone position. A specialised patient positioning device was designed to allow the breast to hang vertically downwards away from the chest wall and away from the contralateral breast. Planning and treatment were performed, and clinical data on the first 40 patients treated were reviewed.

RESULTS

The reasons given by clinicians for choosing the prone technique included a large, pendulous breast shape (36 patients), an elevated risk of pneumonitis (three patients) and inability to adopt a supine position due to arthritis (one patient). The treatment was well tolerated, although 50% of the patients still developed moist desquamation. All but one patient completed their full course of radiotherapy. Dosimetric analysis revealed high levels of dose homogeneity and low doses to surrounding normal structures. With a median follow-up of 11 months, only one patient has developed metastatic disease, and one has locally recurred.

CONCLUSIONS

This study shows that prone breast irradiation for patients with large or pendulous breasts can be readily developed in radiotherapy treatment centers and could be tested for efficacy in a large, multi-centre randomized trial.

Early initiation of external beam radiotherapy (EBRT) may increase the risk of long-term toxicity in patients undergoing intraoperative radiotherapy (IORT) as a boost for breast cancer

BACKGROUND

Intraoperative radiotherapy (IORT) during breast-conserving surgery is increasingly used. We analyzed the influence of the interval between an IORT boost and external beam radiotherapy (EBRT) on late toxicity.

METHODS

Forty-eight patients received 20 Gy IORT (50 kV X-rays (Intrabeam, Carl Zeiss, Oberkochen, Germany) followed by 46-50 Gy EBRT with a median interval of 36 days (14-197). Late toxicity was assessed with the modified LENT SOMA score after a median of 36 months.

RESULTS

Twelve patients developed a higher grade fibrosis ( degrees II-III), three teleangiectases, one a breast edema grade degrees II, six retractions, four hyperpigmentations and five pain ( degrees II-III). The median interval between IORT and EBRT was significantly shorter in these patients (n=18) compared to the 30 patients without higher grade toxicity (29.5 days vs. 39.5 days, p=0.023, Mann-Whitney U-test).

CONCLUSION

Starting EBRT about 5-6 weeks after IORT appears to be associated with a decreased risk of chronic late toxicity compared with a shorter interval. The impact on local recurrence of prolonged gaps between IORT and EBRT is not known.

Breast dose heterogeneity in CT-based radiotherapy treatment planning

The aim of this study was to evaluate the breast dose heterogeneity in CT-based radiotherapy treatment planning and to correlate with breast parameters. Also, the number of slices required for treatment planning in breast cancer by tangential field technique has been assessed by comparing the treatment plans according to International Commission on Radiation Units and Measurement (ICRU) 50 guidelines (1993) for single-slice, three-slice, and multi-slice (3D) planning . Sixty women who underwent isocentric tangential field breast radiotherapy were included in this study. The plans were optimized and analyzed with dose volume histograms. Sixty-three percent of the single-slice plans and 26.7% of the three-slice plans showed poor dose homogeneity as compared to the 3D plans. Dose inhomogeneity correlated better with breast volume (r² = 0.43) than the chest wall separation (r² = 0.37) and breast area product (r² = 0.36). Similarly, breast volume correlated better with breast area product (r² = 0.80) than with chest wall separation (r² = 0.56). Breast volume can be approximated to breast area product from the relation, breast volume = [(breast area product × 8.85) − 120.05]. The results of this study showed that most of the cases require 3D planning for breast cancer. It also showed that patients with large breast are prone to have more dose inhomogeneity with standard tangential field radiotherapy. In centers where 3D planning is not possible due to lack of facilities or workload, three slices–based planning can be performed to approximate the dosimetric advantage of 3D planning.

Practical guidelines for repair of partial mastectomy defects using the breast reduction technique in patients undergoing breast conservation therapy

BACKGROUND

The authors previously compared the local tissue rearrangement, breast reduction, and latissimus dorsi flap reconstruction techniques for repairing partial mastectomy defects and showed the benefits of breast reduction.

METHODS

In this study, the authors focused solely on factors influencing outcome in 41 patients who underwent repair of a partial mastectomy defect using breast reduction.

RESULTS

Tumor location had a significant effect on the design of the parenchymal pedicle (p = 0.05). Most repairs were performed with an inferior pedicle. Fifty percent of the lower outer and central quadrant tumors required an amputative design with a free nipple graft. The complication rates for immediate and delayed repair were 24 and 50 percent, respectively. The superior pedicle was associated with the highest complication rates. Tumors in the upper outer quadrant of the breast were associated with the highest complication rate (35 percent). Ninety percent of patients with planned repairs had a viable nipple-areola complex (p = 0.05) and did not require a free nipple graft. More favorable cosmetic outcomes were achieved using an inferior pedicle; less favorable cosmetic outcomes were achieved for tumors in the upper inner quadrant of the breast. Larger defects did not result in less favorable cosmetic outcomes than smaller defects. Only 7 percent of patients had a positive tumor margin. Five percent of patients developed local breast cancer recurrence after a mean follow-up of 36 months.

CONCLUSION

The authors provide practical guidelines for repairing a partial mastectomy defect using breast reduction that should minimize the occurrence of complications and optimize the cosmetic outcome.

Intra- and interfractional variations for prone breast irradiation: an indication for image-guided radiotherapy

PURPOSE

Intra- and interfractional errors for breast cancer patients undergoing breast irradiation in the prone position were analyzed.

METHODS AND MATERIALS

To assess intrafractional error resulting from respiratory motion, four-dimensional computed tomography scans were acquired for 3 prone and 3 supine patients, and the respiratory motion was compared for the two positions. To assess the interfractional error caused by daily set-up variations, daily electronic portal images of one of the treatment beams were taken for 15 prone-positioned patients. Portal images were then overlaid with images from the planning system that included the breast contour and the isocenter, treatment beam portal, and isocenter. The shift between the planned and actual isocenter was recorded for each portal image, and descriptive statistics were collected for each patient. The margins were calculated using the 2Sigma + 0.7sigma recipe, as well as 95% confidence interval based on the pooled standard deviation of the datasets.

RESULTS

Respiratory motion of the chest wall is drastically reduced from 2.3 +/- 0.9 mm in supine position to -0.1 +/- 0.4 mm in prone position. The daily set-up errors vary in magnitude from 0.0 cm to 1.65 cm and are patient dependent. The margins were defined by considering only the standard deviation to be 1.1 cm, and 2.0 cm when the systematic errors were considered using the 2Sigma + 0.7sigma recipe.

CONCLUSIONS

Prone positioning of patients for breast irradiation significantly reduces the uncertainty introduced by intrafractional respiratory motion. The presence of large systematic error in the interfractional variations necessitates a large clinical target volume-to-planning target volume margin and indicates the importance of image guidance for partial breast irradiation in the prone position, particularly using imaging modality capable of identifying the lumpectomy cavity.

Haplotype-based analysis of genes associated with risk of adverse skin reactions after radiotherapy in breast cancer patients

PURPOSE

To identify haplotypes of single nucleotide polymorphism markers associated with the risk of early adverse skin reactions (EASRs) after radiotherapy in breast cancer patients.

METHODS AND MATERIALS

DNA was sampled from 399 Japanese breast cancer patients who qualified for breast-conserving radiotherapy. Using the National Cancer Institute-Common Toxicity Criteria scoring system, version 2, the patients were grouped according to EASRs, defined as those occurring within 3 months of starting radiotherapy (Grade 1 or less, n = 290; Grade 2 or greater, n = 109). A total of 999 single nucleotide polymorphisms from 137 candidate genes for radiation susceptibility were genotyped, and the haplotype associations between groups were assessed.

RESULTS

The global haplotype association analysis (p < 0.05 and false discovery rate < 0.05) indicated that estimated haplotypes in six loci were associated with EASR risk. A comparison of the risk haplotype with the most frequent haplotype in each locus showed haplotype GGTT in CD44 (odds ratio [OR] = 2.17; 95% confidence interval [CI], 1.07-4.43) resulted in a significantly greater EASR risk. Five haplotypes, CG in MAD2L2 (OR = 0.55; 95% CI, 0.35-0.87), GTTG in PTTG1 (OR = 0.48; 95% CI, 0.24-0.96), TCC (OR = 0.48; 95% CI, 0.26-0.89) and CCG (OR = 0.50; 95% CI, 0.27-0.92) in RAD9A, and GCT in LIG3 (OR = 0.46; 95% CI, 0.22-0.93) were associated with a reduced EASR risk. No significant risk haplotype was observed in REV3L.

CONCLUSION

Individual radiosensitivity can be partly determined by these haplotypes in multiple loci. Our findings may lead to a better understanding of the mechanisms underlying the genetic variation in radiation sensitivity and resistance among breast cancer patients.

Reliability of inferior dermoglandular pedicle reduction mammaplasty in reconstruction of partial mastectomy defects: surgical planning and outcome

The objective of this study is to describe the surgical planning of the inferior dermoglandular pedicle (IDP) technique and its outcome following partial mastectomy reconstruction. A total of 26 patients with breast cancer underwent immediate IDP reconstruction. IDP was indicated to reconstruct superior/central breast defects. Postoperative complications were evaluated and information on esthetic result and satisfaction were collected. About 57.6 percent had tumors measuring 2cm or less (T1). Immediate complications occurred in 34.2 percent with skin necrosis in 11.4 and dehiscence in 7.6 percent. Late complications were observed in 11.4 percent. The cosmetic result was considered to be good or very good in 88.4 percent and the majority of patients were satisfied. All complications were treated by conservative approach. IDP is a reliable technique and should be given consideration in cases of superior/central quadrant reconstruction. The success of the procedure depends on patient selection and careful intra-operative management.

Intensity-modulated radiotherapy results in significant decrease in clinical toxicities compared with conventional wedge-based breast radiotherapy

PURPOSE

We have previously demonstrated that intensity-modulated radiotherapy (IMRT) with a static multileaf collimator process results in a more homogenous dose distribution compared with conventional wedge-based whole breast irradiation (WBI). In the present analysis, we reviewed the acute and chronic toxicity of this IMRT approach compared with conventional wedge-based treatment.

METHODS AND MATERIALS

A total of 172 patients with Stage 0-IIB breast cancer were treated with lumpectomy followed by WBI. All patients underwent treatment planning computed tomography and received WBI (median dose, 45 Gy) followed by a boost to 61 Gy. Of the 172 patients, 93 (54%) were treated with IMRT, and the 79 patients (46%) treated with wedge-based RT in a consecutive fashion immediately before this cohort served as the control group. The median follow-up was 4.7 years.

RESULTS

A significant reduction in acute Grade 2 or worse dermatitis, edema, and hyperpigmentation was seen with IMRT compared with wedges. A trend was found toward reduced acute Grade 3 or greater dermatitis (6% vs. 1%, p = 0.09) in favor of IMRT. Chronic Grade 2 or worse breast edema was significantly reduced with IMRT compared with conventional wedges. No difference was found in cosmesis scores between the two groups. In patients with larger breasts (> or =1,600 cm(3), n = 64), IMRT resulted in reduced acute (Grade 2 or greater) breast edema (0% vs. 36%, p <0.001) and hyperpigmentation (3% vs. 41%, p = 0.001) and chronic (Grade 2 or greater) long-term edema (3% vs. 30%, p = 0.007).

CONCLUSION

The use of IMRT in the treatment of the whole breast results in a significant decrease in acute dermatitis, edema, and hyperpigmentation and a reduction in the development of chronic breast edema compared with conventional wedge-based RT.

Long-term Clinical Outcomes of Whole-Breast Irradiation Delivered in the Prone Position

PURPOSE

The aim of this study was to evaluate retrospectively the effectiveness and toxicity of post-lumpectomy whole-breast radiation therapy delivered with prone positioning.

METHODS AND MATERIALS

Between September 1992 and August 2004, 245 women with 248 early-stage invasive or in situ breast cancers were treated using a prone breast board. Photon fields treated the whole breast to 46 to 50.4 Gy with standard fractionation. The target volume was clinically palpable breast tissue; no attempt was made to irradiate chest wall lymphatics. Tumor bed boosts were delivered in 85% of cases. Adjuvant chemotherapy and hormonal therapy were administered to 42% and 62% of patients, respectively.

RESULTS

After a median follow-up of 4.9 years, the 5 year actuarial true local and elsewhere ipsilateral breast tumor recurrence rates were 4.8% and 1.3%, respectively. The 5-year actuarial rates of regional nodal recurrence and distant metastases were 1.6% and 7.4%. Actuarial disease-free, disease-specific, and overall survival rates at 5 years were 89.4%, 97.3%, and 93%, respectively. Treatment breaks were required by 2.4% of patients. Grade 3 acute dermatitis and edema were each limited to 2% of patients. Only 4.9% of patients complained of acute chest wall discomfort. Chronic Grade 2 to 3 skin and subcutaneous tissue toxicities were reported in 4.4% and 13.7% of patients, respectively.

CONCLUSIONS

Prone position breast radiation results in similar long-term disease control with a favorable toxicity profile compared with standard supine tangents. The anatomic advantages of prone positioning may contribute to improving the therapeutic ratio of post-lumpectomy radiation by improving dose homogeneity and minimizing incidental cardiac and lung dose.

Direct aperture optimization–based intensity-modulated radiotherapy for whole breast irradiation

PURPOSE

To investigate the technical and dosimetric advantages and the efficacy of direct aperture optimized intensity-modulated radiation therapy (DAO-IMRT) over standard (e.g., beamlet optimized) IMRT and conventional three-dimensional conformal radiotherapy (3D-CRT) for whole breast irradiation in supine and prone positions.

METHODS AND MATERIALS

We retrospectively designed DAO-IMRT plans for 15 breast cancer patients in supine (10 patients) and prone (5 patients) positions with a goal of uniform dose coverage of the whole breast. These DAO-IMRT plans were compared with standard IMRT using beamlet optimization and conventional 3D-CRT plans using wedges. All plans used opposed tangential beam arrangements.

RESULTS

In all cases, the DAO-IMRT plans were equal to or better than those generated with 3D-CRT and standard beamlet-IMRT. For supine cases, DAO-IMRT provided higher uniformity index (UI, defined as the ratio of the dose to 95% of breast volume to the maximum dose) than either 3D-CRT (0.88 vs. 0.82; p = 0.026) or beamlet-IMRT (0.89 vs. 0.85; p = 0.003). Direct aperture optimized IMRT also gave lower lung doses than either 3D-CRT (V20 = 7.9% vs. 8.6%; p = 0.024) or beamlet-IMRT (V20 = 8.4% vs. 9.7%; p = 0.0008) for supine patients. For prone patients, DAO-IMRT provided higher UI than either 3D-CRT (0.89 vs. 0.83; p = 0.027) or beamlet-IMRT (0.89 vs. 0.85; p = 0.003). The planning time for DAO-IMRT was approximately 75% less than that of 3D-CRT. The monitor units for DAO-IMRT were approximately 60% less than those of beamlet-IMRT.

CONCLUSION

Direct aperture optimized IMRT improved the overall quality of dose distributions as well as the planning and delivery efficiency for treating whole breast in both supine and prone positions.

Prone breast irradiation for pendulous breasts

The purpose of this study was to quantify the differences in doses in the organs at risk and to compare the PTV coverage and dose homogeneity of patients with pendulous breasts between prone and supine position. In 10 patients a CT-based treatment plan was made in prone and supine position. Data about dose homogeneity and doses to organs at risk were collected. Dose homogeneity turned out to be better in prone position and doses in organs at risk were lower, but with the current technique, this occurred at the cost of a reduced PTV coverage.

Obesity Alters Rat Abdominal Flap Survival

Obesity presents a risk factor for flap-related complications in autologous tissue breast reconstruction. In this study, an animal model was developed to examine this phenomenon. Abdominal flaps based on a superficial inferior epigastric pedicle were elevated in an experimental group of obese Zucker (fa/fa) rats (n = 8; mean weight, 413 g) and in their lean littermates (n = 9; mean weight, 276 g). Flap tissue was harvested from a subset of both groups for baseline characterization, including histology, and assays for ATP and oxidative phosphorylation uncoupler, UCP-2. Flaps were then evaluated for survival by planimetry at 4 and 7 days postprocedure. Flap survival 7 days postoperatively was reduced in obese (42.0% ± 8.6%) versus lean (70.3% ± 6.7%) rats ( P < 0.05). At baseline, flap tissue of obese animals had decreased ATP content relative to lean counterparts (0.12 ± 0.12 nM/μg vs 0.36 ± 0.23 nM/μg protein, P < 0.05), whereas UCP2 mRNA was higher in obese flap tissue versus lean. Reduced viability of obese flaps may be attributable to decreased baseline energy stores due to oxidative phosphorylation uncoupling by UCP-2. This study is the first to introduce a promising animal model for examining the effect of obesity on increased flap-related complications in breast reconstruction using autologous tissue.

Analysis of non-genetic risk factors for adverse skin reactions to radiotherapy among 284 Breast Cancer patients

OBJECTIVES

We analyzed non-genetic risk factors for adverse skin reactions to irradiation at 4 collaborating Japanese institutions, to design future investigation into genetic risk factors for adverse skin reactions to irradiation in a multicenter setting.

METHODS

From April 2001, 284 breast cancer patients, who underwent radiotherapy with breast-conserving surgery, were enrolled from 4 collaborating institutions in Japan. We graded skin reactions according to international scoring systems. Clinical factors were tested against adverse effects.

RESULTS

Grade 1+ skin reactions were observed in 261 (92%) of the patients in less than 3 months, 118 (42%) at 3 months, and 29 (10%) at 6 months in the late phase. Univariate analysis of treatment risk factors (such as the use of a multi-leaf colimeter, wedge-filter, or immobilization device) for skin reactions revealed a significant association (p< 0.0001). After a variable selection procedure with logistic regression, the institution, operative procedure, and magnitude of photon energy remained significantly associated with acute skin reactions. Only the institution was an explanatory variable for skin reactions at 3 and 6 months in the final logistic model.

CONCLUSION

After stratification, substantial remaining variations in the occurrence of skin reactions of a given level suggested that individual genetic factors contribute markedly to individual radiosensitivity. Analysis of genetic factors associated with adverse effects would be possible by stratifying patients according to institution. Selection of eligible institutions, where appropriate treatment modalities could be performed, would also be possible when planning such a study.

Breast reduction as an alternative treatment option for early breast cancer in women with macromastia

Macromastia has been considered a relative contraindication to breast conservation therapy because of difficulties with postoperative radiation therapy and cosmesis. This study evaluates the feasibility of the inferior pedicle reduction mammaplasty as a component of breast conservation therapy for patients with early breast cancer. A retrospective review identified 6 patients with macromastia receiving oncologic treatment of breast cancer and simultaneous breast reduction. Mean age was 43.5 +/- 8.7 (mean +/- SD) years, and all breast cancers were stage I or II, averaging 2.3 +/- 1.5 cm in size. All patients underwent a Wise-pattern inferior pedicle breast reduction after cancer extirpation and received postoperative radiation as part of their treatment. They were evaluated for postoperative complications, esthetic outcome of the breasts, and local recurrence. Patients in this series were followed for an average of 30.3 months, with no significant postoperative complications and recurrences. Breast reduction incisions healed primarily and adjuvant radiation was completed without a delay. All patients were pleased with the esthetic result and had improvement of their symptoms related to macromastia. Thus, we believe that breast reduction is a reasonable and safe option for early breast cancer patients with macromastia who desire breast conservation therapy. Our combined oncologic and reconstructive approach may improve the outcome of this group of patients with early breast cancers.

Cosmetic outcome of breast conservative treatment for early stage breast cancer

PURPOSE

To evaluate the cosmetic outcome of breast conservative therapy and to examine the degree of agreement between the patients' and oncologists' ratings. We also analyze the influence of several factors on cosmesis.

METHODS AND MATERIALS

We retrospectively evaluated 145 patients with primary breast cancer treated by local excision and radiotherapy between January 2000 and May 2001. Cosmetic outcome was evaluated by doctors and patients and was scored as excellent, good, fair or poor.

RESULTS

73% of patients rated cosmesis as excellent or good while the percentage was 71% when rated by radiation oncologists. The degree of cosmesis concordance evaluated by oncologists and patients was low (kappa = 0.3). In our study the variables which significantly influence on the cosmetic outcome were concomitant adjuvant chemotherapy (p = 0.04) and radiation therapy boost, either by electron beam or brachytherapy (p = 0.013).

CONCLUSION

The cosmetic outcome of breast conserving therapy was good. There was a similar rating by the patient and radiation oncologist, but the level of concordance between patients and doctors was low. Factors that significantly influence the cosmesis appear to be concomitant adjuvant chemotherapy and radiation therapy boost.

Determining the optimal approach to breast reconstruction after partial mastectomy

BACKGROUND

Unfortunately, patients who desire repair of contour deformities after partial mastectomy usually present after radiation therapy, which may increase the risk of complications and result in a poor aesthetic outcome. The authors reviewed their experience with repair of partial mastectomy defects to determine the optimal approach to breast reconstruction after partial mastectomy.

METHODS

Sixty-nine patients who underwent repair of a partial mastectomy defect and received radiation therapy were included in this analysis. The reconstructive techniques were categorized as local tissue rearrangement (LTR), breast reduction, or use of a latissimus dorsi myocutaneous flap or thoracoepigastric skin flap (hereafter referred to as "flap").

RESULTS

Fifty patients underwent immediate reconstruction before radiation therapy, and 19 underwent delayed reconstruction after radiation therapy. The reconstructive techniques in patients with immediate reconstruction were local tissue rearrangement in 28 percent, breast reduction in 66 percent, and flaps in 6 percent. In patients with delayed reconstruction, 32 percent had local tissue rearrangement, 42 percent had breast reduction, and 26 percent had flaps. The complication rates for immediate and delayed reconstruction were 26 percent and 42 percent, respectively. Overall, and in the setting of immediate reconstruction, the flap technique was associated with a higher complication rate than local tissue rearrangement and breast reduction. However, in the setting of delayed reconstruction, the flap technique was associated with a lower complication rate than the other two techniques. Fifty-seven percent of the immediate reconstructions performed with the local tissue rearrangement or breast reduction technique, but only 33 percent of the immediate reconstructions performed with the flap technique, were associated with an excellent or good aesthetic outcome.

CONCLUSION

Immediate repair of partial mastectomy defects with local tissues results in a lower risk of complications and better aesthetic outcomes than immediate repair of partial mastectomy defects with a latissimus dorsi flap.

Planning and use of therapeutic mammoplasty--Nottingham approach

Therapeutic mammaplasty, the use of reduction mammaplasty and radiotherapy to surgically treat breast cancer, is an established technique for selected breast cancers and can extend the role of breast conserving surgery. Most frequently described is the use of a wise pattern reduction for tumours that lie within the expected mammaplasty excision. However, mammaplasty techniques can be safely adapted to treat patients with cancers in all areas of the breast. An approach to selection and planning surgery is presented which has evolved from the experience of other units and our first 50 clinical cases over a 3-year period. The outcomes of these 50 cases are found in the accompanying article. Technique will vary depending upon the tumour position. Breast cancers may lie within the normal excision site of a recognised mammaplasty method (scenario A) or outside of the expected excision sites (scenario B). In scenario A, a range of recognised techniques can be performed without adaptation to widely excise the tumour and re-shape the breasts. In scenario B the techniques need to be adapted. Three decisions are needed for planning in scenario B; the skin incision, the nipple-aereola complex (NAC) pedicle orientation and finally the method of filling the cancer defect. The latter can be achieved by either extending the nipple pedicle or by creating a secondary pedicle within the breast dissection. Either method will move tissue that is normally excised into the cancer defect. For central tumours an inferior pedicle is usually used to both fill the defect and re-create the nipple.

A cosmetic evaluation of breast cancer treatment: A randomized study of radiotherapy boost technique

PURPOSE

To compare cosmetic results of two different radiotherapy (RT) boost techniques used in the treatment of breast cancer after whole breast radiotherapy and to identify factors affecting cosmetic outcomes.

METHODS AND MATERIALS

Between 1996 and 1998, 142 patients with Stage I and II breast cancer were treated with breast conservative surgery and adjuvant RT. Patients were then randomly assigned to receive a boost dose of 15 Gy delivered to the tumor bed either by iridium 192, or a combination of photons and electrons. Cosmetic evaluations were done on a 6-month basis, with a final evaluation at 36 months after RT. The evaluations were done using a panel of global and specific subjective scores, a digitized scoring system using the breast retraction assessment (BRA) measurement, and a patient's self-assessment evaluation. As cosmetic results were graded according to severity, the comparison of boost techniques was done using the ordinal logistic regression model. Adjusted odds ratios (OR) and their 95% confidence intervals (CI) are presented.

RESULTS

At 36 months of follow-up, there was no significant difference between the two groups with respect to the global subjective cosmetic outcome (OR = 1.40; 95%CI = 0.69-2.85, p = 0.35). Good to excellent scores were observed in 65% of implant patients and 62% of photon/electron patients. At 24 months and beyond, telangiectasia was more severe in the implant group with an OR of 9.64 (95%CI = 4.05-22.92, p < 0.0001) at 36 months. The only variable associated with a worse global cosmetic outcome was the presence of concomitant chemotherapy (OR = 3.87; 95%CI = 1.74-8.62). The BRA value once adjusted for age, concomitant chemotherapy, and boost volume showed a positive association with the boost technique. The BRA value was significantly greater in the implant group (p = 0.03). There was no difference in the patient's final self-assessment score between the two groups. Three variables were statistically associated with an adverse self-evaluation: an inferior quadrant tumor localization, postoperative hematoma, and concomitant chemotherapy.

CONCLUSIONS

Although this trial showed that at 36 months of follow-up, there were no significant differences in the overall global cosmetic scores between the implant boost group and the photon/electron boost group, telangiectasia was more severe and the BRA value was greater in the implant group.

Cosmesis with bilateral mammoreduction for conservative breast cancer treatment

Over 7 years, 57 women with breast cancer underwent lumpectomy and bilateral mammoreduction. Physical complaints about large or lax breast shape were the predominate rationale. Two patients were immediately lost to follow-up, 55 patients remained and were followed every 3 months for an average of 1.6 years. This is the largest series traceable by computer and literature search. Chart review and patient examination in this retrospective review were utilized as the basis for data within the article. Collated notes from patients' doctors were assessed, as well as documented patient responses to the procedure. Pictures without head/face for identifiers were taken of the patients. Chart data were collected by clinicians, but were reviewed blindly by a statistician. The overall control and cosmesis rates as well as alleviation of heavy breast problems were noted. Only 6% of women had fair to poor cosmetic results; the majority (82%) had excellent to good results. Women with very large breasts or markedly relaxed breast tissue of concern to the patients proved optimal candidates for lumpectomy of cancer and bilateral mammoreduction in the conservative treatment of these cancers. There was a significant reduction in the physical complaints of the patients as well. For women with very pendulous or extremely large breasts, lumpectomy and bilateral mammoreduction may prove to be the optimal course of action.

Comparative study of surgical margins in oncoplastic surgery and quadrantectomy in breast cancer

BACKGROUND

Oncoplastic surgery for breast cancer is a novel concept that combines a plastic surgical procedure with breast-conserving treatment to improve the final cosmetic results. The aim of this study was to evaluate the oncological safety of oncoplastic procedures by studying the status of the surgical margins of the excised tumor specimen in comparison with standard quadrantectomies.

METHODS

Thirty consecutive breast cancer patients undergoing oncoplastic surgery (group 1) and 30 patients undergoing standard quadrantectomy (group 2) were prospectively studied with regard to the stage of breast cancer, the surgical procedures performed, the volume of breast tissue excised, and the histopathology of the tumor specimen, with specific details on surgical margins.

RESULTS

Patients who underwent oncoplastic surgery (group 1) were younger (mean age, 48.73 years) than patients who had a classic quadrantectomy (group 2; mean age, 55.76 years; P = .022). The mean volume of the excised specimen in group 1 was 200.18 cm(3), compared with 117.55 cm(3) in group 2 (P = .016). Surgical margins were negative in 25 cases out of 30 in group 1 and 17 out of 30 in group 2 (P = .05). The average length of the surgical margin was 8.5 mm in group 1 and 6.5 mm in group 2, but the difference was not statistically significant (P = .074).

CONCLUSIONS

Oncoplastic surgery adds to the oncological safety of breast-conserving treatment because a larger volume of breast tissue can be excised and a wider negative margin can be obtained. It is especially indicated for large tumors, for which standard breast-conserving treatment has a high probability of leaving positive margins.

Support of large breasts during tangential irradiation using a micro-shell and minimizing the skin dose—a pilot study

Tangential radiotherapy delivered to women with large breasts can be problematic due to the excessive skin folds and the way that the breast falls into the axilla. This may necessitate excessive lung irradiation to cover the posterior part of the breast volume adequately. Conventional breast rings used to move the breast anteriorly can be very difficult to reproduce and may substantially increase the skin dose and hence skin toxicity due to the bolus effect. An in-house designed microshell device was constructed to improve setup reproducibility and minimize skin dose. Dose comparisons using a phantom were made between this device and 2 other commonly used devices. The microshell successfully reduced the surface dose compared to the other breast rings tested. This device was then investigated on 8 patients under clinical conditions. Skin doses measured on the trial patients were within acceptable limits. During this small pilot study, no patients suffered excessive skin toxicity or required treatment breaks. Due to the microshell's expandable nature, ease of application, which increases patient comfort compared to other breast rings, and the lower surface dose, the microshell is the preferred breast stabilization device for this department when treating patients with large pendulous breasts. We encourage other departments to consider their current method of breast stabilization and compare them to our results.

Applying Innovations in Surgical and Radiation Oncology to Breast Conservation Therapy

A paradigm shift is occurring in the radiotherapeutic management of early breast carcinoma. The current change includes technological advances in radiation therapy delivery to limit toxicity by minimizing patient treatment. These treatments include improved techniques for whole-breast irradiation, for example, hypofractionation and intensity modulated radiation therapy, and those for irradiating a smaller portion of the breast in a shorter period of time, specifically, accelerated partial breast irradiation. This article also addresses interesting research on delivering radiation therapy intraoperatively and looks ahead toward applications aimed at minimizing the physical, biological, and psychosocial impact of breast conservation therapy.

Dosimetric analysis of a simplified intensity modulation technique for prone breast radiotherapy

PURPOSE

Prone-position breast radiotherapy (RT) has been described as an alternative technique to improve dose homogeneity for women with large, pendulous breasts. We report the feasibility and dosimetric analysis of a simplified intensity-modulated RT (IMRT) technique, previously reported for women in the supine treatment position, to plan prone-position RT to the intact breast.

METHODS AND MATERIALS

Twenty patients with clinical Stage TisN0-T1bN1 breast cancer undergoing breast-conserving therapy underwent whole breast RT using a prone position technique. The treatment plans were developed using both conventional tangents and a simplified intensity-modulated tangential beam technique based on optimization of the intensity distributions across the breast. The plans were compared with regard to the dose-volume parameters.

RESULTS

Dose heterogeneity within the breast planning target volume was significantly greater for the conventional tangent plans. Of 20 patients, 16 (80%) received maximal doses of > or =110% using the conventional tangents vs. only 1 (5%) using the IMRT plan. The isodose level encompassing 5% of the planning target volume was reduced from an average of 110% with conventional tangents to 105% with IMRT. The maximal dose within the planning target volume was reduced from an average of 114% with conventional tangents to 107% with IMRT. The greatest improvement was seen in the patients with the most pendulous breasts.

CONCLUSION

An IMRT planning approach is feasible for prone-position breast RT and improves dose homogeneity, particularly in women with larger, pendulous breasts. Additional follow-up is necessary to determine whether the improvements in dose homogeneity impact acute toxicity and cosmetic outcome in this cohort of women who have historically suffered from poor cosmesis after breast-conserving therapy.

Reduction mammaplasty in conjunction with breast conservation

Breast conservation therapy, consisting of lumpectomy or segmental mastectomy with negative margins followed by breast irradiation, has become a standard and safe alternative to mastectomy in selected patients with early-stage breast cancer. As the inclusion criteria for breast conservation therapy have continued to evolve to include lower quadrant tumors, very large breasts, and central tumors, the potential for significant disfigurement after breast conservation therapy has increased. Bilateral reduction mammaplasty in conjunction with tumor-directed partial mastectomy is a surgical approach that can benefit these patients by creating symmetric, aesthetically pleasing breasts in a single-stage operation.

Personal characteristics, therapy modalities and individual DNA repair capacity as predictive factors of acute skin toxicity in an unselected cohort of breast cancer patients receiving radiotherapy

BACKGROUND AND PURPOSE

Intrinsic and extrinsic factors can affect the occurrence of side effects of radiotherapy. The influence of therapy modalities, personal characteristics and individual DNA repair capacity on the risk of acute skin toxicity was thus evaluated.

MATERIALS AND METHODS

In a prospective study of 478 female breast cancer patients receiving adjuvant radiotherapy of the breast after breast-conserving surgery, acute skin toxicity was documented systematically using a modified version of the common toxicity criteria. Prognostic personal and treatment characteristics were identified for the entire cohort. Individual DNA repair capacity was determined in a subgroup of 113 patients with alkaline comet assay using phytohemagglutinin stimulated lymphocytes. Using proportional hazards analysis to account for cumulative biologically effective radiation dose, the hazard for the development of acute skin reactions (moist desquamation) associated with DNA repair capacity was modeled.

RESULTS

Of the 478 participants, 84 presented with acute reactions by the end of treatment. Higher body mass index was significantly associated with an increased risk for acute reactions (hazard ratio=1.09 per 1 kg/m(2)), adjusted for treating hospital and photon beam quality. The comet assay parameters examined, including background DNA damage in non-irradiated cells, DNA damage induced by 5 Gy, and DNA repair capacity, were not significantly associated with risk of acute skin toxicity.

CONCLUSIONS

Higher BMI is predictive of acute skin toxicity, however, individual repair parameters as determined by the alkaline comet assay are not informative enough. More comprehensive analyses including late effects of radiotherapy and repair kinetics optimized for different radiation-induced DNA lesions are warranted.

Advances in Radiation Treatments of Breast Cancer

During the past decade, improvements in treatment-planning tools, computer and imaging technologies, and new therapeutic modalities have allowed radiation to be delivered in a conformal fashion while minimizing treatment toxicity. It is important that physicians involved in breast cancer treatment recognize the numerous advances that have occurred in the delivery of radiation therapy. Changes in 3 specific areas in treatment planning and delivery have revolutionized the way we approach breast cancer treatment: the design of radiation fields using computed tomography (CT) data sets, the development of 3-dimensional dose-calculation algorithms, and the development of new methods to modulate the delivery of radiation dose. With the advent of CT simulators, individual patient anatomy and pathology can be readily visualized and reconstructed in axial, coronal, and sagittal views. With an improved anatomic delineation between the target volumes and critical organ structures, the treatment fields can be designed to be more congruous to the areas at highest risk. In the past few years, new 3-dimensional dose-calculation algorithms have been generated that more accurately calculate dose distributions throughout the treatment-planning volume. Finally, modern linear accelerators allow for modulation of the dose intensity of the radiation beam, which may lead to improved aesthetics and decreased side effects while ensuring that the volumes at high risk receive the prescribed dose. Radiation therapy can be delivered safely and effectively to patients with breast cancer.

Three-dimensional conformal breast irradiation in the prone position

The prone position can be used for the planning of adjuvant radiotherapy after conservative breast surgery in order to deliver less irradiation to lung and cardiac tissue. In the present study, we compared the results of three-dimensional conformal radiotherapy planning for five patients irradiated in the supine and prone position. Tumor stage was T1N0M0 in four patients and T1N1M0 in one. All patients had been previously submitted to conservative breast surgery. Breast size was large in three patients and moderate in the other two. Irradiation in the prone position was performed using an immobilization foam pad with a hole cut into it to accommodate the breast so that it would hang down away from the chest wall. Dose-volume histograms showed that mean irradiation doses reaching the ipsilateral lung were 8.3+/-3.6 Gy with the patient in the supine position and 1.4+/-1.0 Gy with the patient in the prone position (P = 0.043). The values for the contralateral lung were 1.3+/-0.7 and 0.3+/-0.1 Gy (P = 0.043) and the values for cardiac tissue were 4.6+/-1.6 and 3.0+/-1.7 Gy (P = 0.079), respectively. Thus, the dose-volume histograms demonstrated that lung tissue irradiation was significantly lower with the patient in the prone position than in the supine position. Large-breasted women appeared to benefit most from irradiation in the prone position. Prone position breast irradiation appears to be a simple and effective alternative to the conventional supine position for patients with large breasts, since they are subjected to lower pulmonary doses which may cause less pulmonary side effects in the future.

Breast conservation therapy with concomitant breast reduction in large-breasted women

Cosmetic results from radiation following breast-conserving surgery and radiation therapy are generally poorer in women with large or heavy breasts. Breast reduction carried out at the time of definitive surgery allows this group of women to undergo breast-conserving surgery and radiation with excellent cosmetic results. Four cases are presented in which partial mastectomy was carried out in conjunction with immediate bilateral breast reduction. All patients had clear margins and all had excellent cosmetic results following radiation therapy. Immediate breast reduction should be considered in women with large or heavy breasts who otherwise qualify for breast-conserving surgery.

A comparison in cosmetic outcome between per-operative interstitial breast implants and delayed interstitial breast implants after external beam radiotherapy

BACKGROUND AND PURPOSE

Interstitial implants for brachytherapy boost in the breast conserving therapy of breast cancer can be performed in two ways; implants during the tumor excision (per-operative implants) or after the external beam therapy (delayed interstitial implants). Differences in cosmetic outcome were investigated.

PATIENTS AND METHODS

Cosmetic results in 47 patients having a per-operative implant were compared to 123 patients having a delayed interstitial implant in a matched case-control study. Cosmesis was scored on a four-point-scale varying from 0 (excellent) to 3 (poor).

RESULTS

After mean follow-up of 63 months, three observers found no difference in cosmetic outcome between the two groups after adjustment for variables found to be related with cosmesis (difference in mean score 0.50, P=0.26). Implant volume at 100% isodose was not found to differ (P=0.084) between the per-operative group (mean 102 cm3, S.D. 34 cm3) and the delayed group (mean 93 cm3, S.D. 29 cm3).

CONCLUSIONS

Performing per-operative implants has not led to smaller implants. The method of performing brachytherapy does not result in marked differences in cosmetic outcome.

Factors influencing outcomes for breast conservation therapy of mammographically detected malignancies

OBJECTIVE

To evaluate the importance of surgeon caseload, lesion type, and biopsy type on outcomes in breast conservation therapy (BCT).

BACKGROUND

Breast conservation therapy has low rates of morbidity and mortality and is being performed with increasing frequency. Its primary advantage is cosmetic, and the amount of breast tissue resected is the main determinant of cosmetic outcomes.

STUDY DESIGN

Two hundred seventeen consecutive patients undergoing breast conservation therapy at Northwestern Memorial Hospital for mammographically detected breast cancer were evaluated. The volume of tissue excised was compared with the volume of the tumor as a ratio. Univariate and multivariate analyses of the relationships between the specimen-to-tumor-volume ratio (STVR) and histologic diagnosis, biopsy type, surgeon caseload, and lesion type were examined.

RESULTS

The mean (log scale) STVR was significantly lower when the mammographic lesion was identified as a mass or architectural distortion versus calcifications (p < 0.001 in multivariate analysis). Mean log (STVR) was also decreased for higher-caseload surgeons (p = 0.02). Core biopsy before lumpectomy was associated with significantly increased mean log (STVR) (83 versus 50, p = 0.05) without significantly increasing the rate of negative margins.

CONCLUSIONS

Mammographic lesion type and biopsy method were associated with the amount of tissue excised relative to tumor size as measured by STVR. In addition, surgeons with higher caseloads were better able to perform needle localization lumpectomy to negative margins while limiting the volume of normal breast tissue excised.