A prospective study of conservative surgery alone in the treatment of selected patients with stage I breast cancer

Male breast cancer: a multicenter study to provide a guide for proper management

INTRODUCTION

To offer an extensive retrospective experience on the management of male breast cancer.

METHODS

A multicenter retrospective observational cohort study was conducted, including male patients diagnosed with breast cancer (invasive or in situ) in 12 Italian breast units from January 1975 to December 2019. Patients aged 18 years or older were assessed for eligibility. Exclusion criteria were metastatic cancer at diagnosis, previous cancer(s), received neoadjuvant treatment, incomplete data on (neo) adjuvant treatment(s), and/or follow-up data. Data on radiological examinations, demographic characteristics, risk factors, histological features, receptor status, treatments, and follow-up were collected.

RESULTS

In a series of 671 male patients with breast cancer assessed for eligibility, 403 (28 in situ and 375 invasive neoplasms) were included in the study. All included patients underwent surgery. The median age at surgery was 63.8 years (IQR 56.1-72.1). In 68% of cases, patients underwent echography, and in 55.1%, a mammography. Most patients were ER and PR positive (63.8%), HER2 negative (80.4%), with high (≥ 20%) Ki67 values (61.3%), and luminal B subtype (51.1%). The 10-year overall survival was 73.6% (95% CI 67.0-79.1) for invasive breast cancer and 90% (95% CI 65.6-97.4) for in situ breast cancer. In patients with invasive breast cancer, at univariable analysis, having a G3 tumor (vs. G1), pT2/3/4 (vs. pT1), pN2/3 (vs. pN0), luminal B subtype with Ki67 ≥ 20% (vs. Luminal A), were significantly associated with a higher risk of death. In multivariable analyses, pT2/3/4 (vs. pT1) remained significantly associated with a higher risk of death (HR 3.14, 95% CI 1.83-5.39), and having a HER2 positive or a triple-negative subtype (vs. Luminal A) was also significantly associated with a higher risk of mortality (HR 4.76, 95% CI 1.26-18.1).

CONCLUSION

Male breast cancer is a rare disease, the better understanding of which is necessary for a more effective diagnostic and therapeutic approach.

Incorporating Tumor Biology to Select Patients for the Omission of Radiation Therapy

Although adjuvant breast radiotherapy has long been a universal component of breast conservation therapy (BCT), it is now clear that "breast cancer" is a broad class of many disparate diseases with varying natural histories and risk profiles. In turn, some breast conservation patients enjoy exceedingly favorable outcomes following surgery alone. Ongoing trials seek to identify such low-risk patient populations, hypothesizing that some may safely forego radiotherapy. Whereas prior-generation trials focused on clinicopathologic features for risk stratification, contemporary studies are employing molecular biomarkers to identify those patients who are unlikely to benefit significantly from radiotherapy.

Inter-fractional variations in the dosimetric parameters of accelerated partial breast irradiation using a strut-adjusted volume implant

The aim of the study was to evaluate inter-fractional dosimetric variations for high-dose rate breast brachytherapy using a strut-adjusted volume implant (SAVI). For the nine patients included, dosimetric constraints for treatment were as follows: for the planning target volume for evaluation (PTV_Eval), the volume receiving 90, 150 and 200% of the prescribed dose (V90%,150%,200%) should be >90%, ≤50 cm3 and ≤20 cm3, respectively; the dose covering 1 cm3 (D1cc) of the organs at risk should be ≤110% of the prescribed dose; and the air volume should be ≤10% of PTV_Eval. Differences in V90%,150%,200%, D1cc and air volume ($\Delta V$ and $\Delta D$) as inter-fractional dosimetric variations and SAVI displacements were measured with pretreatment and planning computed tomography (CT) images. Inter-fractional dosimetric variations were analyzed for correlations with the SAVI displacements. The patients were divided into two groups based on the distance of the SAVI from the surface skin to assess the relationship between the insertion position of the SAVI and dosimetric parameters. The median ΔV90%,150%,200% for the PTV_Eval in all patients was -0.3%, 0.2 cm3 and 0.2 cm3, respectively. The median (range) ΔD1cc for the chest wall and surface skin was -0.8% (-18.9 to 9.4%) and 0.3% (-7.6 to 5.3%), respectively. SAVI displacement did not correlate with inter-fractional dosimetric variations. In conclusion, the dose constraints were satisfied in most cases. However, there were inter-fractional dosimetric changes due to SAVI displacement.

Contemporary Issues in Breast Cancer Radiotherapy

A series of landmark studies have increasingly emphasized the role of adjuvant radiotherapy for the definitive management of breast cancer. Although regional nodal irradiation, including the internal mammary nodes, was typically reserved for high-risk patients, there is now evidence of benefit to this approach even for those with a limited nodal disease burden. Similarly, low-risk disease has historically been treated with whole-breast tangents, although contemporary studies now support accelerated partial breast irradiation or the omission of radiotherapy in select cases. This article presents recent data informing these contemporary developments in the radiotherapeutic management of breast cancer.

No breast cancer subgroup can be spared postoperative radiotherapy after breast-conserving surgery. Fifteen-year results from the Swedish Breast Cancer Group randomised trial, SweBCG 91 RT

BACKGROUND

Breast-conserving surgery (BCS) followed by radiotherapy (RT) is an established treatment for women with T1-2N0 breast cancers. Since subgroups of patients have low ipsilateral breast tumour recurrence (IBTR) rates, it is important to study whether RT is necessary for all patients.

PATIENTS AND METHODS

A total of 1187 women with primary T1-2N0M0 breast cancer were randomised, after standardised sector resection, to postoperative whole breast RT or no local treatment. Adjuvant systemic therapy was offered to patients with stage II cancers. Patients were followed with clinical examinations and annual mammography for 10 years and thereafter referred to the Swedish mammography screening program.

RESULTS

After 15 years of follow-up, a higher cumulative incidence of IBTR was observed in control patients, 23.9%, versus irradiated patients, 11.5%, P<0.001. Recurrence-free survival was inferior, 51.7% versus 60.4%, P=0.0013. The main effect of RT was seen during the first 5 years. However, overall survival was not significantly lower 68.4% versus 71.1%, P=0.68, nor was breast cancer-specific mortality significantly higher.

CONCLUSIONS

RT after BCS significantly reduced the incidence of IBTR at 15 years of follow-up. We were unable to identify subgroups which could be spared RT. Breast cancer mortality was not significantly reduced after RT. Good predictive markers for radiation sensitivity and improved adjuvant systemic therapy are needed to omit RT after BCS.

Patients' perceptions of health-related quality of life during and after adjuvant radiotherapy for T1N0M0 breast cancer

AIMS

The effects of radiotherapy on health-related quality of life (HRQOL) may influence decisions about adjuvant radiotherapy after breast-conserving surgery. We sought women's ratings of HRQOL during and after radiotherapy.

MATERIALS AND METHODS

Women completed HRQOL measures before, during and after adjuvant radiotherapy for node-negative, hormone receptor-positive breast cancers that were less than 2 cm in size. Acute and late toxicities were rated by clinicians.

RESULTS

There were 161 participants with a median age of 58 years (range 34-82). Mean scores for most aspects of HRQOL worsened only slightly during radiotherapy and improved to baseline levels or better within a few months. The symptoms rated as most distressing were: difficulty sleeping (29%), fatigue (23%), breast discolouration (21%), uncertainty about the future (18%), feeling sad or depressed (18%), feeling anxious or worried (19%). Most rated their experience as better (39%) or much better (28%) than expected. Grade 3 toxicities were rare (5% acute, 1% late) with no grade 4 toxicities.

CONCLUSIONS

Radiotherapy was associated with transient and generally mild impairments in a few aspects of HRQOL. Concerns about adverse effects on HRQOL should not weigh heavily on decisions about adjuvant breast radiotherapy.

Partial breast irradiation: targeting volume or breast molecular subtypes?

The eligibility criteria for partial breast irradiation (APBI) are mainly based on histopathological factors, which not always explain the clinical behaviour of breast cancers. International guidelines represent useful platform to collect data for continued refinement of patient selection, but the clinical applicability to APBI series showed some limitations, particularly among the intermediate and high-risk groups. The heterogeneity of APBI techniques, along with the heterogeneity of breast cancer, generates clinical results, where the predictive value of the histopathological factors can assume different weight. There is a need of further refinement and implementation of risk factors. Currently, the impact of breast cancer subtype on local control is matter of investigation, and treatment decision about radiotherapy is generally made without regard to the breast cancer subtype. However, receptor status information is easily available and some histopathological factors have not a definite role, there is no uniform interpretation. As molecular classification becomes more feasible in the clinical practice, it will provide added value to conventional clinical tumour characteristics in predicting local recurrence in breast cancer and may play an important role as predictor of eventual patient outcomes.

Breast-conservative surgery with and without radiotherapy in patients aged 55-75 years with early-stage breast cancer: a prospective, randomized, multicenter trial analysis after 108 months of median follow-up

OBJECTIVES

Breast-conserving therapy (BCT), including postoperative whole breast irradiation (WBI), is generally accepted as the treatment of choice for most patients with early-stage breast cancer. The question whether WBI is mandatory in all patients remains one of the most controversial issues in BCT. To answer this question, a randomized, prospective, multicentre study was launched in January 2001. Primary endpoints of the study were to assess the cumulative incidence of in-breast-recurrences (IBR) and overall survival (OAS) after conservative surgery (BCS) with or without WBI.

METHODS

From January 2001 until December 2005, 749 patients with unifocal infiltrating breast cancer up to 25 mm, 0-3 positive axillary lymph nodes, no extensive intraductal component or lymphvascular invasion from 11 centres in Italy, were randomly assigned to BCS+WBI (arm 1:373 patients) or BCS alone (arm 2:376 patients). Treatment arms were well balanced in terms of baseline characteristics. Systemic adjuvant therapy was administered according to the institutional policies. Kaplan-Meier method was used for survival analysis and log-rank test to evaluate the difference between the two arms. RESULTS (Last analysis 31.12.2012): After median follow-up of 108 months, 12 (3.4%) IBR were observed in arm 1 and 16 (4.4%) in arm 2. OAS was 81.4% in arm 1 and 83.7% in arm 2. There was no statistically significant difference regarding IBR and death in the two treatment groups.

CONCLUSIONS

These data are promising and suggest that WBI after BCS can be omitted in selected patients with early stage breast cancer without exposing them to an increased risk of local recurrence and death. Longer follow-up is needed to further consolidate these results.

Radiotherapy or tamoxifen after conserving surgery for breast cancers of excellent prognosis: British Association of Surgical Oncology (BASO) II trial

BACKGROUND

The incidence of local recurrence (LR) after conservative surgery for early breast cancer without adjuvant therapy is unacceptably high even with favourable tumours. The aim of this study was to examine the effect of adjuvant therapies in tumours with excellent prognostic features.

METHODS

Patients with primary invasive breast cancer <2 cm diameter, grade 1 or good prognosis special type, and node negative, treated by wide local excision (WLE) with clear margins were randomised into a 2 × 2 clinical trial of factorial design with or without radiotherapy and with or without tamoxifen. Trial entry was allowed to either comparison or both.

FINDINGS

The actuarial breast cancer specific survival in 1135 randomised patients at 10 years was 96%. Analysis by intention to treat showed that LR after WLE was reduced in patients randomised to radiotherapy (RT) (HR 0.37, CI 0.22-0.61 p<0.001) and to tamoxifen (HR 0.33, CI 0.15 - 0.70 p<0.004). Actuarial analysis of patients entered into the four-way randomisation showed that LR after WLE alone was 1.9% per annum (PA) versus 0.7% with RT alone and 0.8% with tamoxifen alone. No patient randomised to both adjuvant treatments developed LR. Analysis by treatment received showed LR at 2.2%PA for surgery alone versus 0.8% for either adjuvant radiotherapy or tamoxifen and 0.2% for both treatments.

CONCLUSIONS

Even in these patients with tumours of excellent prognosis, LR after conservative surgery without adjuvant therapy was still very high. This was reduced to a similar extent by either radiotherapy or tamoxifen but to a greater extent by the receipt of both treatments.

Multidisciplinary care of patients with early-stage breast cancer

There is a compelling need for close coordination and integration of multiple specialties in the management of patients with early-stage breast cancer. Optimal patient care and outcomes depend on the sequential and often simultaneous participation and dialogue between specialists in imaging, pathologic and molecular diagnostic and prognostic stratification, and the therapeutic specialties of surgery, radiation oncology, and medical oncology. These are but a few of the various disciplines needed to provide modern, sophisticated management. The essential role for coordinated involvement of the entire health care team in optimal management of patients with early-stage breast cancer is likely to increase further.

Hypofractionated radiation therapy in the treatment of early-stage breast cancer

Hypofractionated radiation refers to the use of fewer, larger-dose radiation treatments that are usually given over a shorter time period compared to conventional radiation fraction sizes. Randomized trials of hypofractionated whole breast irradiation (WBI) have demonstrated comparable outcomes as conventional fractionation. For a higher-risk population for local recurrence, a phase 3 trial by the Radiation Therapy Oncology Group (RTOG) is currently studying hypofractionated WBI with a concurrent tumor bed boost over 3 weeks. Accelerated partial breast irradiation limits radiation to the region of the tumor bed for 1-3 weeks and is the subject of an ongoing randomized trial by the National Surgical Breast and Bowel Project and RTOG. Questions remain for hypofractionation about optimal patient selection, radiation techniques, and the risk of late toxicity. But results from current trials could make hypofractionation more widely accepted for patients with early-stage breast cancer.

Basal subtype of invasive breast cancer is associated with a higher risk of true recurrence after conventional breast-conserving therapy

PURPOSE

To determine whether breast cancer subtype is associated with patterns of ipsilateral breast tumor recurrence (IBTR), either true recurrence (TR) or elsewhere local recurrence (ELR), among women with pT1-T2 invasive breast cancer (IBC) who receive breast-conserving therapy (BCT).

METHODS AND MATERIALS

From Jan 1998 to Dec 2003, 1,223 women with pT1-T2N0-3 IBC were treated with BCT (lumpectomy plus whole-breast radiation). Ninety percent of patients received adjuvant systemic therapy, but none received trastuzumab. Biologic cancer subtypes were approximated by determining estrogen receptor-positive (ER+), progesterone receptor-positive (PR+), and human epidermal growth factor receptor-2-positive (HER-2+) expression, classified as luminal A (ER+ or PR+ and HER-2 negative [HER-2-]), luminal B (ER+ or PR+ and HER-2+), HER-2 (ER- and PR- and HER-2+), and basal (ER- and PR- and HER-2- ) subtypes. Imaging, pathology, and operative reports were reviewed by two physicians independently, including an attending breast radiologist. Readers were blinded to subtype and outcome. TR was defined as IBTR within the same quadrant and within 3 cm of the primary tumor. All others were defined as ELR.

RESULTS

At a median follow-up of 70 months, 24 patients developed IBTR (5-year cumulative incidence of 1.6%), including 15 TR and 9 ELR patients. At 5 years, basal (4.4%) and HER-2 (9%) subtypes had a significantly higher incidence of TR than luminal B (1.2%) and luminal A (0.2%) subtypes (p < 0.0001). On multivariate analysis, basal subtype (hazard ratio [HR], 4.8, p = 0.01), younger age at diagnosis (HR, 0.97; p = 0.05), and increasing tumor size (HR, 2.1; p = 0.04) were independent predictors of TR. Only younger age (HR, 0.95; p = 0.01) significantly predicted for ELR.

CONCLUSIONS

Basal and HER-2 subtypes are significantly associated with higher rates of TR among women with pT1-T2 IBC after BCT. Younger age predicts for both TR and ELR. Strategies to reduce TR in basal breast cancers, such as increased boost doses, concomitant radiation and chemotherapy, or targeted therapy agents, should be explored.

A primary experience of conventional fractionated three-dimensional conformal partial breast irradiation for early-stage breast cancer

Recently, a number of clinical trials assessing partial breast irradiation (PBI), in particular accelerated partial breast irradiation, have been conducted in patients with early-stage breast cancer after breast-conserving surgery (BCS) in Europe and the US. By contrast, PBI is rarely performed in Eastern countries. In general, there are many physiological differences between Eastern and Western populations, and whether PBI is suitable for Eastern populations remains uncertain. Moreover, PBI is still in the stage of clinical research, and numerous questions have yet to be resolved. Thus, we designed a PBI trial to explore its feasibility and effectiveness for Eastern patients. According to the study criteria, 12 patients were enrolled between June 2003 and March 2007. Using three-dimensional conformal partial breast irradiation, they received a conventional fraction of 2 Gy/fraction/day, 5 fractions/week, DT60 Gy. According to follow-up data collected in August 2010, the rates of local recurrence and distant metastasis were 0%. The most common adverse reactions included grade 2 radioactive erythema in 2 (17%) cases and pigment deposition in 10 (83%). The results revealed that the patients exhibited good local tumor control, with minor adverse reactions and satisfactory cosmetic results. More samples and long-term observations are required to further assess the validity and feasibility of PBI.

Accelerated partial breast irradiation as part of breast conserving therapy of early breast carcinoma: a systematic review

New strategies for adjuvant radiotherapy of early breast cancer are being investigated in several phase III randomised trials at the present time. Accelerated partial breast irradiation (APBI) is a way to offer an early breast cancer patient, who has had breast conservative surgery, an adjuvant radiotherapy of short duration aimed at the tumour bed with a certain margin. The rationale of this strategy is that most local recurrences appear close to the tumorectomy cavity and a wish to spare the patient late radiation morbidity. This review discusses the background for APBI, the different techniques, and we highlight possible pitfalls using these techniques. A systematic overview of all phase I and II studies is provided. Patient selection for this therapy is pivotal and based on evidence from previous studies on patient/tumour characteristics and pattern of local recurrences we propose inclusion criteria for patients in APBI protocols.

Local relapse rates are falling after breast conserving surgery and systemic therapy for early breast cancer: can radiotherapy ever be safely withheld?

Rates of local tumour relapse after breast conservation treatment in women with early breast cancer are falling. Explanations for this decline are considered in this review including advances in breast cancer management and aging of the breast cancer population. Breast surgery has become more standardised following publication of practice guidelines and is mostly carried out by specialist surgeons. Systemic therapies (hormonal therapy and chemotherapy) are now more effective and are recommended to a higher proportion of patients than ever before. Radiotherapy techniques have also improved. The contributions of each factor are difficult to quantify precisely, but all are likely to be relevant. In order to identify a subgroup of women that might safely be spared radiotherapy, several factors are analysed, including the prognostic significance for local relapse of tumour characteristics (pathologic data, gene-expression profiles), patient characteristics and life expectancy (age and comorbidities).

Common Gynecologic Problems in Geriatric-aged Women

Gynecologic concerns in postmenopausal women are common. Although various conditions may affect all women in this age group, the prevalence of certain disorders, and also diagnostic approaches and treatment options, may vary significantly when considering very elderly women compared with those early in the sixth decade. The focus of this chapter is to address several commonly encountered gynecologic issues in postmenopausal women, with particular attention given to aspects that must be considered when caring for women in the geriatric age group.

Variability Among Breast Radiation Oncologists in Delineation of the Postsurgical Lumpectomy Cavity

PURPOSE

Partial breast irradiation (PBI) is becoming more widely used. Accurate determination of the surgical lumpectomy cavity volume is more critical with PBI than with whole breast radiation therapy. We examined the interobserver variability in delineation of the lumpectomy cavity among four academic radiation oncologists who specialize in the treatment of breast cancer.

METHODS AND MATERIALS

Thirty-four lumpectomy cavities in 33 consecutive patients were evaluated. Each physician contoured the cavity and a 1.5-cm margin was added to define the planning target volume (PTV). A cavity visualization score (CVS) was assigned (1-5). To eliminate bias, the physician of record was eliminated from the analysis in all cases. Three measures of variability of the PTV were developed: average shift of the center of mass (COM), average percent overlap between the PTV of two physicians (PVO), and standard deviation of the PTV.

RESULTS

Of variables examined, pathologic resection volume was significantly correlated with CVS, with larger volumes more easily visualized. Shift of the COM decreased and PVO increased significantly as CVS increased. For CVS 4 and 5 cases, the average COM shift was 3 mm and 2 mm, respectively, and PVO was 77% and 87%, respectively. In multiple linear regression, pathologic diameter >4 cm and CVS > or =3 were significantly associated with smaller COM shift. When CVS was omitted from analysis, PVO was significantly larger with pathologic diameter > or =5 cm, days to planning <36, and older age.

CONCLUSIONS

Even among radiation oncologists who specialize in breast radiotherapy, there can be substantial differences in delineation of the postsurgical radiotherapy target volume. Large treatment margins may be prudent if the cavity is not clearly defined.

Locoregional therapy of breast cancer: maximizing control, minimizing morbidity

The goal of locoregional therapy in breast cancer has remained unchanged for a century: the eradication of all malignant cells from the breast and draining lymph nodes, hopefully prior to them having spread to distant organs. However, how we accomplish this goal has changed dramatically over this time period and our success in achieving this goal has been greatly enhanced by improvements in breast imaging and systemic therapies. The therapeutic importance of surgery and radiation has been underestimated in recent years and is thought to have minimal impact on long-term outcome. More recent data have reputed this contention and the relationship between local control and survival in breast cancer is becoming increasingly apparent. This article will review the importance of attaining optimum local control with minimum morbidity and examine where the future of locoregional therapy of breast cancer may lie.

A Clinical Oncology Perspective on the Use of Breast MR

MR imaging of the breast detects additional carcinoma in as many as 30% of women thought to have localized disease by clinical examination and mammography. This has led some to advocate its routine use in the preoperative evaluation of breast cancer patients. However, local failure rates in patients selected for breast conservation by conventional methods are less than 5% at 10 years, suggesting that he majority of this disease is controlled with radiotherapy. The potential role of MR in the preoperative evaluation and postoperative follow-up of patients with early-stage breast cancer is discussed.

Breast surgery: minimally invasive diagnosis and treatment

The increasingly large proportion of elderly women in the United States population carries a disproportionate burden of breast cancer. The advent of minimally invasive surgical techniques applicable to breast disease has brought new opportunities to diagnose and treat breast cancer in the older population. This article reviews issues important to the evolving field of breast cancer management in older women: cancer risk and screening considerations, diagnosis and biopsy approaches, and surgical treatment options based on current studies and recommendations.

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.

When May Adjuvant Radiotherapy be Avoided in Operable Breast Cancer?

Randomised trials in which the omission of radiotherapy has been tested after breast-conserving surgery, with or without adjuvant systemic therapy, show a significant four- to five-fold reduction in local recurrence. As yet, no subgroup of women managed by breast-conserving surgery has been identified from whom radiotherapy can be withheld. Few randomised data have been published on the effect of omission of radiotherapy on local control, quality of life and costs, particularly in older women for whom the risk of local recurrence is generally lower. Ongoing trials are evaluating the role of radiotherapy in this population of low risk, older women. Adjuvant radiotherapy after breast-conserving surgery or mastectomy significantly reduces the incidence of local recurrence. In women who have had a mastectomy at high risk of recurrence (> 20% risk of recurrence at 10 years), adjuvant radiotherapy improves survival if combined with adjuvant systemic therapy. Among women with T3 tumours, and those with four or more involved axillary nodes treated by mastectomy, postoperative radiotherapy is the standard of care. For women at intermediate risk of recurrence (i.e. <15% 10-year risk of recurrence after surgery and systemic therapy alone), with one to three involved nodes or node negative with other risk factors, the role of radiotherapy is unclear. Clinical trials to assess the role of postmastectomy radiotherapy (PMRT) in this setting are needed. For pT1-2, pNO tumours without other risk factors, there is no evidence at present that PMRT is needed.

Radiation Therapy for Breast Cancer

Over the past five decades, radiotherapy (RT) has become an integral part in the combined modality management of breast cancer. Although its significant effect on local control has been long demonstrated, only recently has adjuvant RT been shown to have a significant effect on breast cancer mortality and overall survival. This article summarizes the adjuvant role of RT after mastectomy and lumpectomy, as well as the rationale and techniques for partial-breast irradiation.

Tubular Carcinoma of the Breast: a Retrospective Analysis and Review of the Literature

BACKGROUND

The favorable prognosis associated with tubular carcinoma of the breast has led some studies to propose less aggressive treatments for patients with this disease. This study aims to address the extent of therapy needed for tubular patients.

METHODS

A retrospective review identified 73 cases of tubular carcinoma treated at the Massachusetts General Hospital between 1980 and 2002. Primary treatment was conservative surgery (CS) plus radiation therapy (RT) in 67%, CS without RT in 18%, and mastectomy in 15%. Median follow-up time was 90.5 months. The published literature of 529 conservatively treated tubular carcinomas was reviewed along with the 62 conservative cases from this series. : No patients developed distant metastasis or died from this disease. Local failure occurred in three (4%) of the cases, after 13, 84 and 121 months. All three had initially been treated with CS + RT. Five cases were node-positive, three of which were associated with a primary tumor smaller than 1 cm. Thirteen women, with a median age of 74, were treated by CS without RT and none recurred. A literature review showed that adjuvant RT reduces local failure following CS for tubular carcinoma.

CONCLUSIONS

Tubular carcinoma is associated with an excellent prognosis, but long-term follow-up is essential for detecting local failures and a small primary tumor size does not preclude nodal involvement. Adjuvant RT reduces the incidence of local failure following CS for tubular carcinoma, however, elderly women treated by CS may have a very low risk of local recurrence without adjuvant RT.

T1 G1 NO ER positive breast cancer--adjuvant therapy is needed

AIMS

To assess the outcome of treating patients with excellent prognosis (T1 G1 N0 ER +ve) breast cancers with breast conserving surgery alone.

METHODS

One hundred and twenty-one women with grade 1, node negative, ER+ tumours, smaller than 20 mm who were treated by breast conserving surgery alone between 1991 and 2000. Margin width was always at least 5 mm. The following were recorded: local recurrence (LR), distant recurrence, new contra-lateral primaries and death. Recurrence rates were then compared to those in the largest series.

RESULTS

One hundred and twenty-one women were followed up for a median of 68 months. Fourteen developed further breast cancer in the same side and eight new cancers in the contra-lateral breast. There was one case of distant metastasis and no deaths. Local recurrence rate was significantly higher than other studies (p=0.006).

CONCLUSIONS

Although there is no detrimental effect on survival after this length of follow-up, the omission of radiotherapy and tamoxifen appears to increase the probability of LR. Patients with T1 G1 N0 ER+ breast cancer treated by breast conserving surgery should be offered both radiotherapy and tamoxifen.

Predictors of local recurrence after breast-conservation therapy

Breast-conserving therapy (BCT) is a proven local treatment option for select patients with early-stage breast cancer. This paper reviews pathologic, clinical, and treatment-related features that have been identified as known or potential predictors for ipsilateral breast tumor recurrence in patients treated with BCT. Pathologic risk factors such as the final pathologic margin status of the excised specimen after BCT, the extent of margin involvement, the interaction of margin status with other adverse features, the role of biomarkers, and the presence of an extensive intraductal component or lobular carcinoma in situ all impact the likelihood of ipsilateral breast tumor recurrence. Predictors of positive repeat excision findings after conservative surgery include young age, presence of an extensive intraductal component, and close or positive margins in prior excision. Finally, treatment-related factors predicting ipsilateral breast tumor recurrence include extent of breast radiation therapy, use of a boost to the lumpectomy cavity, use of tamoxifen or chemotherapeutic agents, and timing of systemic therapy with irradiation. The ability to predict for an increased risk of ipsilateral breast tumor recurrence enhances the ability to select optimal local treatment strategies for women considering BCT.

Pattern of local recurrence after conservative surgery and whole-breast irradiation

PURPOSE

Most recurrences in the breast after conservative surgery and whole-breast irradiation have been reported to occur within the same quadrant as the initial primary tumor. We analyzed the long-term risk of recurrence by area of the breast after whole-breast irradiation.

MATERIALS AND METHODS

In all, 1,990 women with Stage 0-II breast cancer were treated with conservative surgery and whole-breast irradiation from 1970-1998. Stage was ductal carcinoma in situ in 237, T1 in 1273, and T2 in 480 patients. Of 120 local recurrences, 71 were classified as true local (confined to the original quadrant) and 49 as elsewhere (involving outside the original quadrant). Kaplan-Meier methodology was used to calculate 5-year, 10-year, and 15-year rates of recurrence (95% confidence intervals in parentheses). The median follow-up is 80 months.

RESULTS

There was no apparent difference in the 15-year rate of true local vs. elsewhere recurrence, but the time to recurrence was different. The rate of true local recurrence was 2%, 5%, and 7% (5-9%) at 5, 10, and 15 years, respectively. The recurrences elsewhere in the breast were rare at 5 (1%) and 10 (2%) years, but increased to 6 (3-9%) at 15 years. This 15-year rate of elsewhere recurrence was half the rate of contralateral breast cancers of 13% (10-16%).

CONCLUSIONS

Recurrence elsewhere in the breast is rare for the first 10 years, but by 15 years is nearly equal to true local recurrence even after whole-breast irradiation. The 15-year rate of elsewhere recurrence was half the rate of contralateral breast cancers. This may indicate a therapeutic effect of whole-breast radiation for other areas of the breast. Very long follow-up will be needed for partial breast irradiation with or without tamoxifen to show that the risk of elsewhere recurrence is not significantly different than after whole-breast irradiation.

Breast brachytherapy: North American experience

Accelerated partial breast irradiation (APBI) has been investigated for over a decade as a potential alternative adjuvant treatment approach after lumpectomy for women with early-stage breast cancer. The rationale for APBI is based on pathologic data regarding the spread of cancer within the breast and study of the patterns of in-breast recurrence after breast-conserving therapy performed with or without whole-breast irradiation. This report reviews the North American experience using interstitial brachytherapy for APBI. Studies achieving low failure rates have universally been distinguished from those with high failure rates by requiring documented microscopically negative surgical margins, using a target definition consisting of the lumpectomy cavity plus a 1- to 2-cm margin, and having a rigorous quality assurance program to assure target coverage. We conclude that APBI brachytherapy programs that include all of these components have great potential to overcome many of the barriers that have prevented women from pursuing standard breast-conserving therapy.

Brachytherapy for partial breast irradiation: The European experience

There has been great interest in Europe in treating selected patients with early-stage breast cancer with accelerated partial breast irradiation (APBI) using interstitial brachytherapy. We review the results of these studies. Five early studies had local recurrence rates of 6% to 37%, reflecting suboptimal patient selection, target definition, and quality assurance procedures. Five more recent studies performed using much more stringent approaches have had recurrence rates of 0% to 7% with 84% to 92% of patients having excellent or good cosmetic results. The 3-year results of a single-institution phase III trial suggest that partial-breast brachytherapy performed in this manner yields local control that is very similar to that of whole-breast irradiation. Recently, a phase III multicenter protocol comparing these 2 modalities has been activated in Europe by the Breast Cancer Working Group of the Groupe Europeen de Curietherapie-European Society for Therapeutic Radiology and Oncology. As data from this and other trials mature, they will address and refine issues of patient selection, target volume definition, total dose, and fractionation and hopefully support the implementation of APBI into routine clinical practice.

Lessons of studies of breast-conserving therapy with and without whole-breast irradiation for patient selection for partial-breast irradiation

Partial-breast irradiation is a promising approach for treating patients with early-stage invasive breast cancer. There are still few studies of partial-breast irradiation that address critical issues, such as criteria for patient selection. However, an enormous body of experience has been accumulated regarding the results in patients treated with "conventional" breast-conserving therapy using whole-breast irradiation and for patients treated with conservative surgery without radiotherapy of any kind. This article will therefore review portions of this existing experience that may aid the development of partial-breast irradiation and give perspective on the overall role that partial-breast irradiation may ultimately play in our therapeutic armamentarium.

High-dose-rate brachytherapy alone versus whole breast radiotherapy with or without tumor bed boost after breast-conserving surgery: Seven-year results of a comparative study

PURPOSE

To report the 7-year results of a prospective study of accelerated partial breast irradiation (APBI) using interstitial high-dose-rate brachytherapy and compare the treatment results with those achieved by standard, whole breast radiotherapy (WBRT), with or without a tumor bed boost (TBB).

METHODS AND MATERIALS

Between 1996 and 1998, 45 prospectively selected patients with T1N0-N1mi (single nodal micrometastasis), nonlobular breast cancer without the presence of an extensive intraductal component and with negative surgical margins were treated with APBI using interstitial high-dose-rate implants. A total dose of 30.3 Gy (n = 8) and 36.4 Gy (n = 37) in seven fractions within 4 days was delivered to the tumor bed plus a 1-2-cm margin. During the same period, 80 patients, who met the eligibility criteria for APBI but who were treated with 50 Gy WBRT with (n = 36) or without (n = 44) a 10-16-Gy TBB, were selected as controls. The median follow-up for the APBI and control groups was 81 and 83 months, respectively. Local control, relapse-free survival, cancer-specific survival, late side effects, and cosmetic results were assessed.

RESULTS

The crude rate of total ipsilateral breast failure was 6.7% (3 of 45), 11.4% (5 of 44), and 8.3% (3 of 36) for patients treated with APBI, WBRT, and WBRT + TBB, respectively. The differences in the 5- and 7-year actuarial rates of ipsilateral breast recurrence were not statistically significant among patients treated with APBI (4.4% and 9.0%), WBRT (4.7% and 14.8%), and WBRT + TBB (5.7% and 9.5%). No statistically significant difference in either the 7-year probability of relapse-free survival (79.8%, 73.5%, and 77.7% for APBI, WBRT, and WBRT + TBB, respectively) or cancer-specific survival (93.3%, 92.9%, and 93.9% for APBI, WBRT, and WBRT + TBB, respectively) was found. The 7-year actuarial elsewhere breast failure rate was 9.0% in the APBI group and 8.3% in the control group (p = 0.80). The rate of excellent/good cosmetic results was 84.4% in the APBI group and 68.3% in the control group (p = 0.04). The corresponding rates of asymptomatic fat necrosis were 20.0% and 20.6%. Symptomatic fat necrosis occurred in 1 patient (2.2%) treated with APBI. The incidence of Grade 2 or worse late radiation side effects was similar for both groups (26.7% vs. 28.6%).

CONCLUSION

Accelerated partial breast irradiation using interstitial high-dose-rate implants, with proper patient selection and quality assurance, yields similar 7-year results to those achieved with standard breast-conserving therapy. APBI does not increase the risk of elsewhere breast failures.

Breast cancer in the elderly: the role of adjuvant radiation therapy

PURPOSE

To evaluate available data on breast conserving surgery (BCS) with or without radiation therapy (RT), and alternative options (e.g. Tamoxifen alone) (Tam), focusing specifically on the older patients.

METHODS AND MATERIALS

The MEDLINE was searched for the terms elderly, BCS, adjuvant/postoperative RT, Tamoxifen, and randomized trials from 1992 to 2002.

RESULTS

Authors reviewed papers of general interest on the elderly and breast cancer (BC), meta-analysis, randomized trials on BCS+/-RT and Tam+/-surgery without RT, retrospective non-randomized trials, and reported on prognostic factors for local recurrence in BCS alone, including biomarkers, attempts made to define a low-risk group, and methods of modification of the current, protracted standard adjuvant RT course.

CONCLUSIONS

Postoperative RT after BCS has a firm rationale; in current clinical practice, if the BCS+RT is medically appropriate and the patient shares the choice, after a full information of the available options and their implications, it is clinically sound to propose this approach. However, there is controversy whether a subgroup of elderly patients could be safely spared: in this setting a randomized trial is clearly warranted.

Management of T1a Breast Cancer

Identification of early-stage breast cancers has increased over the past 2 decades primarily because of mammographic screening. The general guidelines to management of breast cancer may not apply to the smallest of these tumors, as their metastatic potential may be smaller than larger tumors. Tumors < 5 mm (T1a) carry an excellent prognosis, despite a variety of treatment approaches. However, some patients' cancer returns. There appear to be some histologic features that can predict a higher risk of axillary metastases, and therefore, a higher risk of distant metastases. Controversy exists over the extent of treatment, as to whether less than conventional treatment, such as mastectomy, axillary evaluation, and breast-conserving surgery and radiation, can be done. T1a lesions associated with extensive ductal carcinoma in situ and T1a lesions in young patients should be treated with caution if less than conventional breast treatment is to be considered. In older patients with good histologic features, axillary assessment may not be necessary. Very wide excision alone may be appropriate for some patients, but partial breast irradiation is under study and may provide a reasonable compromise. Systemic therapy for node-negative patients is not recommended. Recurrences within the breast occur later in early-stage breast cancers than with extensive-stage breast cancers, requiring annual imaging and evaluation for many years.

Novel approaches to postoperative radiation therapy as part of breast-conserving therapy for early-stage breast cancer

Breast-conserving therapy (BCT) consists of segmental mastectomy followed by postoperative radiation therapy (RT) to the whole breast. At least 6 prospective randomized trials have proven the equivalence of BCT to mastectomy. However, BCT remains underused and, most importantly, a sizable proportion of patients with invasive breast cancer fail to complete the recommended protocol of breast preservation by omitting postoperative RT. The inconvenience of complying with the standard 6-week radiation regimen, which includes approximately 30 daily visits, at least partially explains this lack of adherence. New clinical studies have generated preliminary evidence that more convenient, shorter radiation regimens might reveal equivalence to the current standard. Moreover, the availability of modern technology to deliver and target ionizing radiation by improving homogeneity of radiation dose has made it possible to safely explore the use of greater radiation doses per fraction. Finally, currently ongoing research trials will enable the identification of specific subsets of patients who are likely to be safely treated by partial-breast radiation (instead of radiation to the whole breast) with more accelerated regimens. This article reviews the available data and the current ongoing research on novel RT techniques and fractionation schedules in BCT for early-stage breast cancer.

Adjuvant Radiation Therapy After Breast-Conserving Surgery in Elderly Women with Early-Stage Breast Cancer: Controversy or Consensus?

Breast-conservation therapy (BCT), which consists of breast-conserving surgery (BCS) and postoperative radiation therapy (RT), provides similar levels of local control and survival compared with mastectomy. Although the incidence of breast cancer increases with age and the proportion of elderly women in the population continues to increase, clinical trials of BCT have included few women aged > or = 65 years, limiting the ability to establish clear consensus regarding optimal therapy in this population. This article examines the literature on BCT in elderly women with early-stage breast cancer. A systematic search of the Medline and CancerLit databases was conducted to identify articles specifically addressing BCT in elderly women. The outcomes evaluated were local control, disease-free survival, overall survival, and treatment-related toxicities. The lack of consensus in breast-conservation management in elderly patients is highlighted by a paucity of prospective data and numerous retrospective series reporting diverse treatment approaches with conflicting results. The available evidence from BCT trials with and without age subgroup analyses support BCS with postoperative RT as the standard approach associated with the most favorable local control outcomes. A low-risk subset of patients in whom RT may be omitted without compromising local control remains to be defined. Despite these findings, the use of standard therapy significantly decreases with advancing patient age. Although data specifically addressing BCT in elderly patients are limited, age should not preclude consideration of standard treatment strategies to optimize local disease control. Modern clinical trials with representative samples of elderly patients evaluating cancer recurrence and survival as well as functional and quality-of-life outcomes are needed to define optimal breast-conservation management for this important patient population.

Limited-field radiation therapy in the management of early-stage breast cancer

BACKGROUND

Several phase III trials have demonstrated equivalent long-term survival between breast conserving surgery plus radiation therapy and mastectomy in patients with early-stage breast cancer but have not provided information on the optimal volume of breast tissue requiring post-lumpectomy radiation therapy. Therefore, we examined the 5-year results of a single institution's experience with radiation therapy limited to the region of the tumor bed (i.e., limited-field radiation therapy) in selected patients treated with breast-conserving therapy and compared them with results of matched breast-conserving therapy patients who underwent whole-breast radiation therapy.

METHODS

A total of 199 patients with early-stage breast cancer were treated prospectively with breast-conserving therapy and limited-field radiation therapy using interstitial brachytherapy. To compare potential differences in local recurrence rates based on the volume of breast tissue irradiated, patients in the limited-field radiation therapy group were matched with 199 patients treated with whole-breast radiation therapy. Match criteria included tumor size, lymph-node status, patient age, margins of excision, estrogen receptor status, and use of adjuvant tamoxifen therapy. Local-regional control and disease-free and overall survival were analyzed using the Kaplan-Meier method, and the statistical significance of differences between treatment groups was calculated using the log-rank test. All statistical tests were two-sided.

RESULTS

Median follow-up for surviving patients was 65 months (range = 12-115 months). Five ipsilateral breast failures (i.e., recurrences) were observed in patients treated with limited-field radiation therapy. The cumulative incidence of local recurrence was 1% (95% confidence interval [CI] = 0% to 2.8%). On matched-pair analysis, the rate of local recurrence was not statistically significantly different between the patient groups (1% [95% CI = 0% to 2.4%] for the whole-breast radiation therapy patients versus 1% [95% CI = 0% to 2.8%] for the limited-field radiation therapy patients; P =.65).

CONCLUSIONS

Limited-field radiation therapy administered to the region of the tumor bed has comparable 5-year local control rates to whole-breast radiation therapy in selected patients.

Breast conservation surgery, with and without radiotherapy, in women with lymph node-negative breast cancer: a randomised clinical trial in a population with access to public mammography screening

The effect of postoperative radiotherapy after sector resection for stage I-II lymph node-negative breast cancer was evaluated in a patient population with access to public mammographical screening. 1187 women were randomised to no further treatment or postoperative radiotherapy following a standardised sector resection and axillary dissection. Radiation was administered to a dose of 48-54 Gy. Median age was 60 years, and median size of the detected tumours was 12 mm. Of the women 65% had their tumours detected by mammographical screening. The relative risk (RR) of ipsilateral breast recurrence was significantly higher in the non-irradiated patients compared with the irradiated patients, RR=3.33 (95% Confidence Interval (CI) 2.13-5.19, P<0.001). The corresponding cumulative incidence at 5 years was 14% versus 4%, respectively. Overall survival (OS) was similar, RR=1.16 (95% CI 0.81-1.65, P=0.41), with 5 year probabilities of 93 and 94%, respectively. Recurrence-free survival (RFS) at 5 years was significantly lower in the non-irradiated women, 77% versus 88% (P<0.001). Although women above 49 years of age, whose tumours were detected with mammographical screening, had the lowest rate of ipsilateral breast recurrence in this study, the cumulative incidence of such event amounted to 10% at 5 years if radiotherapy was not given. Such a recurrence rate has been considered as unacceptably high, but is, however, in the same range as that reported after lumpectomy and postoperative radiotherapy in published series.

Breast conserving treatment without radiotherapy

Radiotherapy (RT) is not always necessary for the prevention of ipsilateral breast recurrence in cases where cancer is not detected in the remaining breast tissue after breast conserving surgery. In addition, under these circumstances, the rate of a second primary cancer of the remaining breast is theoretically equal to the rate of contralateral breast cancer. In performing breast conserving treatment (BCT) at our institution we do not treat with RT if a strict serial pathological examination of the specimen (every 5 mm) reveals that the case has been safely resected (negative surgical margins). From 1986 to 1998, 827 patients (157 were ductal carcinoma in situ, and 670 were invasive) underwent BCT without RT at the Cancer Institute Hospital. Ipsilateral breast cancer was observed in 46 cases or 5.6% (0.85% annually) during a median observation period of 67 months. Of these 46 cases, 19 (2.3%) were diagnosed as a recurrence and 27 cases (3.3%) were second primary cancers. This recurrence rate is equivalent to the rate observed in 406 cases of BCT (1.7%) that were treated with RT. Most of these cases had shown positive surgical margins. Furthermore, the rate of occurrence of second cancers is not significantly different from the rate of occurrence of contralateral breast cancers. These results suggest that, by selecting irradiation cases based on careful pathological examinations, BCT can be safely performed.

Adjuvant radiotherapy after conservative surgery for breast cancer: is it always necessary?

Breast irradiation is used to reduce the risk of within-breast recurrence following conservative surgery. This review examines factors--particularly patient age--that may be used to select patients at low risk of local failure where radiotherapy may not be necessary.

The appropriate rate of breast conserving surgery: an evidence-based estimate

PURPOSE

The objective of the present study was to estimate the proportion of incident cases of breast cancer that should receive breast conserving surgery (BCS), using an evidence-based approach.

METHODS

An extensive search of the literature was undertaken to identify eligibility criteria for BCS. The eligibility criteria for BCS were combined with the information about case mix and patient preference to estimate the need for BCS. An epidemiological approach was then used to estimate the incidence of each eligibility criterion for BCS in a typical North American population of breast cancer patients. The effect of sampling error on the estimated appropriate rate of BCS was calculated, and the effect of systematic error using alternative sources of information, was estimated by sensitivity analysis.

RESULTS

The analysis showed that 69.6% of breast cancer cases are eligible for BCS, and that 48.0 +/- 6.0% of breast cancer patients are both eligible for BCS and prefer it to mastectomy. Based on sensitivity analysis, the plausible range of the appropriate rate was 42.1% to 49.43%. The proportion of breast cancer cases in which BCS was appropriate was stage dependent; 63.0 +/- 11.5% in ductal carcinoma in-situ; 57.0 +/- 9.9% in stage I; 52.2 +/- 9.4% in stage II, and 27.2 +/- 5.2% in stage III.

CONCLUSIONS

This model suggests that BCS is appropriate in 48% of all breast cancer patients. This information may be useful in auditing surgical practice, and may serve as a basis for planning of ancillary services, including radiotherapy.

Uncontrolled local disease after salvage treatment for ipsilateral breast tumour recurrence

AIM

Uncontrolled local disease (ULD) following breast conservation constitutes a clinical problem with a major impact on quality of life. The current study analysed the outcome following treatment of ipsilateral breast tumour recurrence (IBTR) and the risk for ULD with the aim to identify risk factors for ULD.

METHODS

In a cohort of 5502 patients treated for invasive breast cancer Stage I-II with breast-conserving surgery 1976-1998 in Stockholm, 307 patients with subsequent IBTR were identified. The majority (n = 219) had received postoperative radiotherapy. Twenty-six per cent of the patients received adjuvant tamoxifen, for 2 or 5 years, and 9% received adjuvant polychemotherapy. Median follow-up time was 11(2-23) years. 50/307 patients developed ULD, defined as the appearance of clinically manifest invasive adenocarcinoma in the remaining breast or on the ipsilateral chest wall which could not be eradicated within 3 months of detection. Multivariate linear logistic regression was used in the statistical analysis to identify prognostic factors for ULD.

RESULTS

Five years following the diagnosis of IBTR the cumulative incidence of ULD was 13%. Five independent risk factors for ULD were identified; non-surgical treatment of IBTR, disseminated disease concurrent with IBTR, axillary lymph node metastases (at primary breast conservation), time < 3 years between breast conservation and IBTR, no adjuvant endocrine therapy. Eighty-eight per cent of the patients were treated with salvage mastectomy (n = 207) or re-excision (n = 62). The cumulative incidence at 5 years of ULD following salvage mastectomy and salvage re-excision were 10% and 16% respectively compared to 32% among patients treated non-surgically. Following IBTR, the 5-year overall survival among patients with local control was 78% in contrast to 21% among patients with ULD.

CONCLUSION

Uncontrolled local disease is an infrequent but important outcome following breast-conserving surgery. Primary postoperative radiotherapy reduces the risk for IBTR and is therefore recommended as part of the primary treatment to avoid both IBTR and ULD. In addition to radiotherapy, adjuvant therapy reduces the risk for IBTR and thereby the risk for subsequent ULD. Patients with IBTR, independent of concurrent distant metastases, should when feasible be recommended for salvage surgery as it provides superior local control compared to salvage systemic therapy alone.

Accelerated partial breast irradiation using 3D conformal radiation therapy (3D-CRT)

PURPOSE

We present a novel three-dimensional conformal radiation therapy (3D-CRT) technique to treat the lumpectomy cavity, plus a 1.5-cm margin, in patients with early-stage breast cancer and study its clinical feasibility.

METHODS AND MATERIALS

A 3D-CRT technique for partial-breast irradiation was developed using archived CT scans from 7 patients who underwent an active breathing control study. The clinical feasibility of this technique was then assessed in 9 patients who were prospectively enrolled on an Investigational Review Board-approved protocol of partial-breast irradiation. The prescribed dose was 34 Gy in 5 patients and 38.5 Gy in 4 patients, delivered in 10 fractions twice daily over 5 consecutive days. The impact of both breathing motion and patient setup uncertainty on clinical target volume (CTV) coverage was studied, and an appropriate CTV-to-PTV (planning target volume) margin was calculated.

RESULTS

By adding a CTV-to-PTV "breathing-only" margin of 5 mm, 98%-100% of the CTV remained covered by the 95% isodose surface at the extremes of normal inhalation and normal exhalation. The "total" CTV-to-PTV margin employed to accommodate organ motion and setup error (10 mm) was found to be sufficient to accommodate the observed uncertainty in the delivery precision. Patient tolerance was excellent, and acute toxicity was minimal. No skin changes were noted during treatment, and at the initial 4-8-week follow-up visit, only mild localized hyperpigmentation and/or erythema was observed. No instances of symptomatic radiation pneumonitis have occurred.

CONCLUSIONS

Accelerated partial-breast irradiation using 3D-CRT is technically feasible, and acute toxicity to date has been minimal. A CTV-to-PTV margin of 10 mm seems to provide coverage for most patients. However, more patients and additional studies will be needed to validate the accuracy of this margin, and longer follow-up will be needed to assess acute and chronic toxicity, tumor control, and cosmetic results.