Purpose/Objective(s)Post-mastectomy radiation in the reconstructed breast cancer patient has been associated with an increased risk of complications including loss of the tissue expander/implant. One factor contributing to this risk is the use of bolus, which increases the surface/skin dose. Modern treatment planning systems do not provide an accurate estimation of skin dose. Detectors such as OSLDs or film may be used to measure this dose, however, these devices give the dose at the point at which they are placed, and not an overall picture of the surface dose, and thus hot and cold spots may go undetected. Monte Carlo simulation (MC) can provide an accurate calculation of the dose delivered to the patient, including the skin dose.Materials/MethodsPatients who had mastectomy with immediate reconstruction receive radiation to the reconstructed breast with the use of custom shape-conforming bolus, usually used every other day. Surface dose measurements are obtained at 5 points on the reconstructed breast using OSLDs on the bolus day and film on the non-bolus day. These measurements influence the total number of bolus fractions. A previously determined phase-space description of our linear accelerator and a previously delivered patient treatment plan were employed to give an accurate characterization of the dose delivered using MC. The location of the OSLDs and film were assessed from patient images and transferred to the dose map. The mean and standard deviation of the dose in the voxels in these areas were compared with measurement for both bolus and non-bolus treatments.ResultsThe dose near the surface of a water-equivalent plastic phantom calculated with MC compared within 2-3% with dose measured with OSLD, film, and a Markus chamber in the build-up region. The dose distribution on the surface of breast cancer patients was successfully simulated and displayed in a 2-D map. There was significant voxel-to-voxel dose variation in the calculated surface dose distributions due to variations in particle fluence, the relative proportion of skin and air in the surface voxel, and noise in the CT. Thus, an area of 5x4 voxels was averaged to estimate the dose at the position of each detector. The dose calculated by MC in the regions where the detectors had been placed on the breast agreed within two-sigma of the measurements for the first water-filled voxel. As expected, the calculated dose was higher and the variation in the dose was lower for the deeper voxels.ConclusionsWe have demonstrated the ability to accurately simulate the surface dose for breast cancer patients. This presents us with the possibility of using MC to design precision custom bolus for reconstructed mastectomy patients to improve surface dose uniformity and potentially decrease the risk of complications. Purpose/Objective(s)Post-mastectomy radiation in the reconstructed breast cancer patient has been associated with an increased risk of complications including loss of the tissue expander/implant. One factor contributing to this risk is the use of bolus, which increases the surface/skin dose. Modern treatment planning systems do not provide an accurate estimation of skin dose. Detectors such as OSLDs or film may be used to measure this dose, however, these devices give the dose at the point at which they are placed, and not an overall picture of the surface dose, and thus hot and cold spots may go undetected. Monte Carlo simulation (MC) can provide an accurate calculation of the dose delivered to the patient, including the skin dose. Post-mastectomy radiation in the reconstructed breast cancer patient has been associated with an increased risk of complications including loss of the tissue expander/implant. One factor contributing to this risk is the use of bolus, which increases the surface/skin dose. Modern treatment planning systems do not provide an accurate estimation of skin dose. Detectors such as OSLDs or film may be used to measure this dose, however, these devices give the dose at the point at which they are placed, and not an overall picture of the surface dose, and thus hot and cold spots may go undetected. Monte Carlo simulation (MC) can provide an accurate calculation of the dose delivered to the patient, including the skin dose. Materials/MethodsPatients who had mastectomy with immediate reconstruction receive radiation to the reconstructed breast with the use of custom shape-conforming bolus, usually used every other day. Surface dose measurements are obtained at 5 points on the reconstructed breast using OSLDs on the bolus day and film on the non-bolus day. These measurements influence the total number of bolus fractions. A previously determined phase-space description of our linear accelerator and a previously delivered patient treatment plan were employed to give an accurate characterization of the dose delivered using MC. The location of the OSLDs and film were assessed from patient images and transferred to the dose map. The mean and standard deviation of the dose in the voxels in these areas were compared with measurement for both bolus and non-bolus treatments. Patients who had mastectomy with immediate reconstruction receive radiation to the reconstructed breast with the use of custom shape-conforming bolus, usually used every other day. Surface dose measurements are obtained at 5 points on the reconstructed breast using OSLDs on the bolus day and film on the non-bolus day. These measurements influence the total number of bolus fractions. A previously determined phase-space description of our linear accelerator and a previously delivered patient treatment plan were employed to give an accurate characterization of the dose delivered using MC. The location of the OSLDs and film were assessed from patient images and transferred to the dose map. The mean and standard deviation of the dose in the voxels in these areas were compared with measurement for both bolus and non-bolus treatments. ResultsThe dose near the surface of a water-equivalent plastic phantom calculated with MC compared within 2-3% with dose measured with OSLD, film, and a Markus chamber in the build-up region. The dose distribution on the surface of breast cancer patients was successfully simulated and displayed in a 2-D map. There was significant voxel-to-voxel dose variation in the calculated surface dose distributions due to variations in particle fluence, the relative proportion of skin and air in the surface voxel, and noise in the CT. Thus, an area of 5x4 voxels was averaged to estimate the dose at the position of each detector. The dose calculated by MC in the regions where the detectors had been placed on the breast agreed within two-sigma of the measurements for the first water-filled voxel. As expected, the calculated dose was higher and the variation in the dose was lower for the deeper voxels. The dose near the surface of a water-equivalent plastic phantom calculated with MC compared within 2-3% with dose measured with OSLD, film, and a Markus chamber in the build-up region. The dose distribution on the surface of breast cancer patients was successfully simulated and displayed in a 2-D map. There was significant voxel-to-voxel dose variation in the calculated surface dose distributions due to variations in particle fluence, the relative proportion of skin and air in the surface voxel, and noise in the CT. Thus, an area of 5x4 voxels was averaged to estimate the dose at the position of each detector. The dose calculated by MC in the regions where the detectors had been placed on the breast agreed within two-sigma of the measurements for the first water-filled voxel. As expected, the calculated dose was higher and the variation in the dose was lower for the deeper voxels. ConclusionsWe have demonstrated the ability to accurately simulate the surface dose for breast cancer patients. This presents us with the possibility of using MC to design precision custom bolus for reconstructed mastectomy patients to improve surface dose uniformity and potentially decrease the risk of complications. We have demonstrated the ability to accurately simulate the surface dose for breast cancer patients. This presents us with the possibility of using MC to design precision custom bolus for reconstructed mastectomy patients to improve surface dose uniformity and potentially decrease the risk of complications.

Purpose/Objective(s)The treatment volume for post-mastectomy breast cancer patients treated with radiation therapy includes the entire breast, and in particular the skin. In patients with larger breasts, high energy photons are often used achieve desired levels of dose homogeneity. However, this may result in reduced dose to the more superficial aspects of the breast (i.e., the subcutaneous tissue) if a beam spoiler is not used. This study was performed to evaluate the effects of photon energy on superficial dose in breast cancer patients treated with external beam radiation.Materials/MethodsAn anthropomorphic phantom was irradiated using CT planned tangent fields containing varying amounts of 6 MV and 18 MV photon beams. The plans used a "field in field" technique to maximize coverage and target uniformity without the use of wedges. The plan prescriptions were adjusted so that for all plans 95% of the volume defined by the 90% isodose line in the all 6 MV plan received the prescription dose (200 cGy). The phantom had a 3 mm thick layer of bolus covering the breast, under which were placed 4 MOSFET detectors used to measure dose. Measured dose values were also compared with values predicted by the treatment planning system (Pinnacle3 v8.0, Phillips Healthcare, Cleveland, OH). In vivo measurements were also performed on breast cancer patients treated in our clinic.ResultsOn the lateral and medial sides of the breast, the phantom dose measured 3 mm below the surface decreased with increasing use of high energy (18 MV) photons. However, no clear trend in dose reduction was seen for measurements on the superior and inferior aspects. For a plan containing 60% 18 MV beams, the lateral and medial dose was 6-7% lower than for the plan using 100% 6 MV beams, resulting in doses 7-12% below the prescription dose. A subset of the measurements were also compared with Pinnacle3 calculations and found to agree within approximately 5%. In vivo measurements also showed that increased use of 18 MV photons resulted in lower superficial dose.ConclusionsExcessive use of high energy photons may result in decreased superficial dose to the breast. Therefore, we recommend that the use of high energy photons be limited whenever possible, particularly for post-mastectomy patients with reconstructed breasts. Purpose/Objective(s)The treatment volume for post-mastectomy breast cancer patients treated with radiation therapy includes the entire breast, and in particular the skin. In patients with larger breasts, high energy photons are often used achieve desired levels of dose homogeneity. However, this may result in reduced dose to the more superficial aspects of the breast (i.e., the subcutaneous tissue) if a beam spoiler is not used. This study was performed to evaluate the effects of photon energy on superficial dose in breast cancer patients treated with external beam radiation. The treatment volume for post-mastectomy breast cancer patients treated with radiation therapy includes the entire breast, and in particular the skin. In patients with larger breasts, high energy photons are often used achieve desired levels of dose homogeneity. However, this may result in reduced dose to the more superficial aspects of the breast (i.e., the subcutaneous tissue) if a beam spoiler is not used. This study was performed to evaluate the effects of photon energy on superficial dose in breast cancer patients treated with external beam radiation. Materials/MethodsAn anthropomorphic phantom was irradiated using CT planned tangent fields containing varying amounts of 6 MV and 18 MV photon beams. The plans used a "field in field" technique to maximize coverage and target uniformity without the use of wedges. The plan prescriptions were adjusted so that for all plans 95% of the volume defined by the 90% isodose line in the all 6 MV plan received the prescription dose (200 cGy). The phantom had a 3 mm thick layer of bolus covering the breast, under which were placed 4 MOSFET detectors used to measure dose. Measured dose values were also compared with values predicted by the treatment planning system (Pinnacle3 v8.0, Phillips Healthcare, Cleveland, OH). In vivo measurements were also performed on breast cancer patients treated in our clinic. An anthropomorphic phantom was irradiated using CT planned tangent fields containing varying amounts of 6 MV and 18 MV photon beams. The plans used a "field in field" technique to maximize coverage and target uniformity without the use of wedges. The plan prescriptions were adjusted so that for all plans 95% of the volume defined by the 90% isodose line in the all 6 MV plan received the prescription dose (200 cGy). The phantom had a 3 mm thick layer of bolus covering the breast, under which were placed 4 MOSFET detectors used to measure dose. Measured dose values were also compared with values predicted by the treatment planning system (Pinnacle3 v8.0, Phillips Healthcare, Cleveland, OH). In vivo measurements were also performed on breast cancer patients treated in our clinic. ResultsOn the lateral and medial sides of the breast, the phantom dose measured 3 mm below the surface decreased with increasing use of high energy (18 MV) photons. However, no clear trend in dose reduction was seen for measurements on the superior and inferior aspects. For a plan containing 60% 18 MV beams, the lateral and medial dose was 6-7% lower than for the plan using 100% 6 MV beams, resulting in doses 7-12% below the prescription dose. A subset of the measurements were also compared with Pinnacle3 calculations and found to agree within approximately 5%. In vivo measurements also showed that increased use of 18 MV photons resulted in lower superficial dose. On the lateral and medial sides of the breast, the phantom dose measured 3 mm below the surface decreased with increasing use of high energy (18 MV) photons. However, no clear trend in dose reduction was seen for measurements on the superior and inferior aspects. For a plan containing 60% 18 MV beams, the lateral and medial dose was 6-7% lower than for the plan using 100% 6 MV beams, resulting in doses 7-12% below the prescription dose. A subset of the measurements were also compared with Pinnacle3 calculations and found to agree within approximately 5%. In vivo measurements also showed that increased use of 18 MV photons resulted in lower superficial dose. ConclusionsExcessive use of high energy photons may result in decreased superficial dose to the breast. Therefore, we recommend that the use of high energy photons be limited whenever possible, particularly for post-mastectomy patients with reconstructed breasts. Excessive use of high energy photons may result in decreased superficial dose to the breast. Therefore, we recommend that the use of high energy photons be limited whenever possible, particularly for post-mastectomy patients with reconstructed breasts.

PURPOSE To quantify the extent of neuronal cell loss imparted to the brain by means of radiation therapy through the decline of the amino acid derivative N-acetylaspartate (NAA) by using proton (hydrogen 1) magnetic resonance (MR) spectroscopy. MATERIALS AND METHODS Proton MR spectroscopy in a clinical MR imager was used to ascertain the amount of whole-brain NAA before and immediately after whole-brain radiation therapy 3-4 weeks later. Eight patients (four women, four men; median age, 55 years; age range, 39-70 years) were studied. All subjects had lung cancer (non-small cell lung cancer [n = 5], small-cell lung cancer [n = 3]) and received either palliative or prophylactic whole-brain radiation therapy. Six of them also underwent a Mini-Mental Status Examination (MMSE) for correlation with the whole-brain NAA. Two-tailed Student t tests were used to evaluate the data. RESULTS A significant (P = .042) average decline in whole-brain NAA of -0.91 mmol per person was observed in the cohort. No corresponding changes occurred in MMSE scores. There was no significant difference in whole-brain NAA decline between prophylactic and therapeutic whole-brain radiation therapy. CONCLUSION Since whole-brain NAA loss was detected even when MMSE scores were unchanged, the former seems to be a more sensitive measure of radiation therapy injury than is the latter.

Approximately 10% to 15% of patients with stage I/II invasive breast cancer will develop a clinically isolated local recurrence. The standard management of an ipsilateral breast tumor recurrence following breast-conserving surgery and radiation is salvage mastectomy, while local excision and radiation are optimal treatment of a chest wall recurrence following initial mastectomy. Although there are few data regarding the efficacy of systemic therapy after isolated local relapse, chemotherapy and/or hormonal therapy should be considered for most patients because of the high risk of subsequent distant relapse. However, local relapse does not always herald distant metastases. A prolonged interval between initial treatment and local recurrence is the most important prognostic factor for subsequent outcome, and when combined with other favorable characteristics, can predict 5-year survival rates of 70% or higher.

PURPOSE:To assess patterns of failure and how selected prognostic and treatment factors affect the risks of locoregional failure (LRF) after mastectomy in breast cancer patients with histologically involved axillary nodes treated with chemotherapy with or without tamoxifen without irradiation.PATIENTS AND METHODS:The study population consisted of 2,016 patients entered onto four randomized trials conducted by the Eastern Cooperative Oncology Group. The median follow-up time for patients without recurrence was 12.1 years (range, 0.07 to 19.1 years).RESULTS:A total of 1,099 patients (55%) experienced disease recurrence. The first sites of failure were as follows: isolated LRF, 254 (13%); LRF with simultaneous distant failure (DF), 166 (8%); and distant only, 679 (34%). The risk of LRF with or without simultaneous DF at 10 years was 12.9% in patients with one to three positive nodes and 28.7% for patients with four or more positive nodes. Multivariate analysis showed that increasing tumor size, increasing numbers of involved nodes, negative estrogen receptor protein status, and decreasing number of nodes examined were significant for increasing the rate of LRF with or without simultaneous DF.CONCLUSION:LRF after mastectomy is a substantial clinical problem, despite the use of chemotherapy with or without tamoxifen. Prospective randomized trials will be necessary to estimate accurately the potential disease-free and overall survival benefits of postmastectomy radiotherapy for patients in particular prognostic subgroups treated with presently used and future systemic therapy regimens.

PURPOSEDuctal carcinoma in situ (DCIS) is increasingly detected as a nonpalpable lesion on mammographic screening performed for the early detection of breast cancer. Because of the growing incidence of mammographically detected DCIS, the present study was undertaken to determine the outcome of treatment of nonpalpable, mammographically detected intraductal carcinoma of the breast using breast-conserving surgery and definitive breast irradiation.MATERIALS AND METHODSAn analysis was performed of 110 women who presented with unilateral, nonpalpable, mammographically detected intraductal carcinoma of the breast and who were treated with breast-conserving surgery and definitive breast irradiation at 10 institutions in Europe and the United States. In all patients, complete gross excision of the primary tumor was performed, and breast irradiation was delivered with definitive intent. When performed, pathologic axillary lymph node staging was node negative (n=29). The median follow-up time was 9.3 years.RESULTSThe 10-year actuarial overall survival rate was 93%, and the 10-year actuarial cause-specific survival rate was 96%. The 10-year actuarial rate of freedom from distant metastases was 96%. There were 15 local recurrences in the treated breast. The actuarial rate of local failure was 7% at 5 years and 14% at 10 years. The histology of the local recurrence was intraductal carcinoma in 9 cases and invasive ductal carcinoma (with or without associated intraductal carcinoma) in 6 cases. The median time to local recurrence was 5.0 years (mean, 5.4; range, 2.1-15.2). With a median follow-up time of 4.4 years after salvage treatment, 14 of the 15 patients with local recurrence were alive without evidence of disease at the time of last follow-up examination. The crude incidence of local recurrence was 7% (3/42) when the final pathology margin of tumor excision was negative, 29% (5/17) when the margin was close or positive, and 14% (7/51) when the margin was unknown. There was no difference in the rate of local recurrence based on pathologic characteristics of the primary tumor.DISCUSSIONResults from the present study demonstrate high rates of overall survival, cause-specific survival, and freedom from distant metastases at 10 years following the treatment of nonpalpable, mammographically detected DCIS of the breast using breast-conserving surgery and definitive breast irradiation. Local recurrences within the treated breast were detected early and were treated with salvage for cure. These results support the initial treatment of nonpalpable, mammographically detected DCIS of the breast using breast-conserving surgery and definitive breast irradiation. Improvements in patient selection have the potential to reduce the risk of local recurrence.

PURPOSE: To investigate the effect of contrast material-enhanced magnetic resonance (MR) imaging on staging of breast cancer in patients with mammographically or clinically suspected tumor. MATERIALS AND METHODS: One hundred seventy-six patients underwent breast MR imaging at 1.5 T before excisional biopsy of a suspicious mammographic or palpable abnormality. Diagnostic imaging studies in patients with biopsy-proved or presumed breast carcinoma were reviewed. RESULTS: Sixty-four patients met the study criteria. MR imaging enabled detection of all 57 invasive breast cancers and nine of 15 in situ cancers. In 22 patients (34%), MR imaging depicted one or more cancers not visible at mammography, 13 (20%) of which were unsuspected multifocal or diffuse disease. As a result of the increased sensitivity of MR imaging compared with that of mammography, clinical staging and subsequent treatment were altered in seven patients (11%). CONCLUSION: MR imaging allows detection of mammographically and clinically occult foci of carcinoma in patients with suspected breast cancer.

Purpose: To determine the accuracy of using the lumpectomy scar, specifically the midpoint or center of the scar, to define the tumor bed in the electron beam boost for the treatment of early stage breast carcinoma.Methods and Materials: Electron boost simulation films from 316 cases of early breast carcinoma treated with lumpectomy and radiotherapy were reviewed. For each case which had surgically placed lumpectomy bed clips (N = 316), four clinical set-up methods (''hypothetical fields'') of several field sizes were compared to the actual location of the tumor bed (as defined by the surgical clips). Each method was based on using the center of the scar as the center of the field and is described as follows: Method 1 uses a standard circular cone of a given diameter; method 2 also uses circular cones, but the diameter is based on the scar length; method 3 uses an oval field in which a constant margin is kept around the scar; method 4 results in an oblong field in which a 2 cm margin is placed on the lateral edge of the scar, but a larger margin around the tenter of the scar. The adequacy of each of these popular clinical set-up techniques was then analyzed for the population as a whole. ''Inadequate'' coverage was defined as any portion of the field edge coming within 1 cm of at least one surgical clip.Results: (1) Method 1: Inadequate coverage was found in 43%, 26%, and 17% of cases, using 7, 8, and 9 cm canes, respectively. (2) Method 2: Inadequate coverage was found in 88%, 61%, 36% and 20% of cases,,vith field size = star length + 0, 2, 3, and 4 cm, respectively. (3) Method 3: Inadequate coverage was found in 34%, 17%, and 10% of cases, using 3, 3.5, and 4 cm margins, respectively. (4) Method 4: Inadequate coverage was found in 36% and 24% of cases using 3.5 and 4 cm margins around the scar center, respectively. Inadequate coverage was found in 51% and 42% of cases using margins equal to one-half the scar length or one-half the scar length + 1 cm, respectively.Conclusion: We conclude that the lumpectomy scar is often a poor indicator of the location of the underlying tumor bed as defined by surgical clips. We recommend the use of clip placement and simulation of the electron boost to maximize target definition.

Ipsilateral breast tumor recurrence occurs in approximately 10% to 15% of patients undergoing conservative surgery and definitive radiation therapy. Mammography alone detects one third of breast recurrences. Most recurrences are invasive, few demonstrate simultaneous distant metastasis, and approximately 40% have axillary lymph node involvement. Mastectomy is the standard salvage procedure. Axillary lymph node dissection may help guide adjuvant treatment as well as reduce the risk of a subsequent regional recurrence. The decision of whether to use adjuvant therapy should be based on tumor size, lymph node status, receptor status, DNA index, S-phase fraction, and disease-free interval. Ipsilateral recurrence may be an independent prognostic factor for distant metastasis.

PURPOSE Limited information is available regarding factors that predispose to complications following postoperative pelvic radiotherapy (RT) for endometrial cancer. To address this issue, patients with clinically staged I/II endometrial cancer who received postoperative RT following total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH/BSO) with or without lymph node sampling (LNS) were studied. PATIENTS AND METHODS From 1960 through 1990, 235 patients with adenocarcinoma of the endometrium received postoperative RT after surgical staging. Multiple factors were evaluated to determine associations with severe complications. Pretreatment factors included age, stage, comorbidities. Treatment-related factors consisted of LNS, total RT dose, volume of RT fields, dose per fraction, total number of RT fields, number of RT fields treated per day, machine energy, and addition of vaginal implant. RESULTS The 5-year actuarial risk of a severe complication was 5.5%. Factors associated with an increased risk of complications in univariate analysis included age more than 65 years (11% v 2%), use of only one portal per day (40% v 3%), use of anteroposterior/posteroanterior fields (23% v 4%), total dose > or = 50 Gy (8% v 2%), and LNS (11% v 3%). In a multivariate analysis, only older age, LNS, and the use of one field per day were significant. Increased risks associated with a total dose > or 50 Gy and the anteroposterior/posteroanterior technique were entirely attributable to the use of one field per day. A subanalysis among patients who had adequate RT techniques (eg, multiple fields treated per day) showed a significant increase in complications (7% v 1%) for those with and without LNS, respectively. CONCLUSIONS Severe complications associated with adjuvant RT for endometrial cancer were increased among patients who were older or underwent LNS or received suboptimal RT technique. Pelvic RT using proper methods can be delivered with acceptable risks.