Combining Clinical and Pathologic Staging Variables Has Prognostic Value in Predicting Local-regional Recurrence Following Neoadjuvant Chemotherapy for Breast Cancer.

OBJECTIVE: The current study was undertaken to determine if the CPS+EG score could stratify patients with respect to local-regional recurrence (LRR). BACKGROUND: We previously defined and validated a novel breast cancer staging system incorporating the American Joint Committee on Cancer clinical stage (CS), final pathologic stage (PS), estrogen receptor status (E), and nuclear grade (G) (CPS+EG score). The score is associated with disease-specific survival outcomes in patients treated with neoadjuvant chemotherapy. METHODS: Patients receiving neoadjuvant chemotherapy between 1997 and 2005 were identified and clinicopathologic data were used to determine the CPS+EG score. Type of local therapy, breast-conserving therapy, mastectomy alone, or mastectomy followed by postmastectomy radiation therapy was recorded. Multivariate analysis, including CPS+EG score and local therapy, was performed to evaluate for association with LRR. RESULTS: Of 1697 patients, breast conserving therapy was performed in 656 (39%), mastectomy in 297 (17%) and mastectomy + postmastectomy radiation therapy in 744 (44%). At a median follow-up of 49 months, the crude incidence of LRR was 6.5%. Freedom from LRR at 5 years ranged from 86% to 97% by clinical stage, 86% to 97% by pathologic stage, and 71% to 99% by CPS+EG score. On multivariate analysis, CPS+EG score and surgery type were independently associated with LRR, with increased risk among patients with CPS+EG scores of 3 or greater (HR 1.94, 95% CI 1.04-3.63) or mastectomy alone (HR 2.14, 95% CI 1.26-3.63). CONCLUSIONS: The CPS+EG staging system better stratifies patients with respect to LRR after neoadjuvant chemotherapy than presenting clinical stage or final pathologic stage. For CPS+EG scores ≥3, use of postmastectomy radiation therapy decreases the likelihood of LRR after mastectomy.

Locoregional Control According to Breast Cancer Subtype and Response to Neoadjuvant Chemotherapy in Breast Cancer Patients Undergoing Breast-conserving Therapy.

BACKGROUND: Our group previously published data showing that patients could be stratified by constructed molecular subtype with respect to locoregional recurrence (LRR)-free survival after neoadjuvant chemotherapy and breast-conserving therapy (BCT). That study predated use of trastuzumab for human epidermal growth factor receptor 2 (HER2)-positive patients. The current study was undertaken to determine the impact of subtype and response to therapy in a contemporary cohort. METHODS: Clinicopathologic data from 751 breast cancer patients who received neoadjuvant chemotherapy (with trastuzumab if HER2(+)) and BCT from 2005 to 2012 were identified. Hormone receptor (HR) and HER2 status were used to construct molecular subtypes: HR(+)/HER2(-) (n = 369), HR(+)/HER2(+) (n = 105), HR(-)/HER2(+) (n = 58), and HR(-)/HER2(-) (n = 219). Actuarial rates of LRR were determined by the Kaplan-Meier method and compared by the log-rank test. Multivariate analysis was performed to determine factors associated with LRR. RESULTS: The pathologic complete response (pCR) rates by subtype were as follows: 16.5% (HR(+)/HER2(-)), 45.7% (HR(+)/HER2(+)), 72.4% (HR(-)/HER2(+)), and 42.0% (HR(-)/HER2(-)) (P < 0.001). Median follow-up was 4.6 years. The 5-year LRR-free survival rate for all patients was 95.4%. Five-year LRR-free survival rates by subtype were 97.2 % (HR(+)/HER2(-)), 96.1% (HR(+)/HER2(+)), 94.4% (HR(-)/HER2(+)), and 93.4% (HR(-)/HER2(-)) (P = 0.44). For patients with HR(-)/HER2(+) disease, the LRR-free survival rates were 97.4 and 86.7% for those who did and those who did not experience pCR, respectively. For patients with HR(-)/HER2(-) disease, the LRR-free survival rates were 98.6% (pCR) versus 89.9% (no pCR). On multivariate analysis, the HR(-)/HER2(-) subtype, clinical stage III disease, and failure to experience a pCR were associated with LRR. CONCLUSIONS: Patients undergoing BCT after neoadjuvant chemotherapy have excellent rates of 5-year LRR-free survival that are affected by molecular subtype and by response to neoadjuvant chemotherapy.

Learning anatomy changes from patient populations to create artificial CT images for voxel-level validation of deformable image registration.

The purpose of this study was to develop an approach to generate artificial computed tomography (CT) images with known deformation by learning the anatomy changes in a patient population for voxel-level validation of deformable image registration. Using a dataset of CT images representing anatomy changes during the course of radiation therapy, we selected a reference image and registered the remaining images to it, either directly or indirectly, using deformable registration. The resulting deformation vector fields (DVFs) represented the anatomy variations in that patient population. The mean deformation, computed from the DVFs, and the most prominent variations, which were captured using principal component analysis (PCA), composed an active shape model that could generate random known deformations with realistic anatomy changes based on those learned from the patient population. This approach was applied to a set of 12 head and neck patients who received intensity-modulated radiation therapy for validation. Artificial planning CT and daily CT images were generated to simulate a patient with known anatomy changes over the course of treatment and used to validate the deformable image registration between them. These artificial CT images potentially simulated the actual patients' anatomies and also showed realistic anatomy changes between different daily CT images. They were used to successfully validate deformable image registration applied to intrapatient deformation.

A method to estimate composite doses for organs at risk in prostate cancer patients treated with EBRT in combination with HDR BT.

BACKGROUND: When evaluating late toxicity after combined external beam radiation therapy (EBRT) and high-dose rate brachytherapy (HDR BT) prostate cancer treatments, it is important that the composite dose distribution is taken into account. This can be challenging if organ-at-risk (OAR) dose data are incomplete, i.e. due to a limited ultrasound imaging field-of-view in the HDR BT procedure. This work proposes a method that provides estimates of composite OAR doses for such situations. MATERIAL AND METHODS: Original EBRT, simulated HDR BT, and composite dose-volume histograms (DVHs) for 10 pelvic OARs in 30 prostate cancer cases were used for method implementation and evaluation (EBRT: 25×2.0 Gy+BT: 2×10.0 Gy). The proposed method used information from the EBRT DVH to estimate OAR BT doses (with or without fractionation correction). Coefficients of determination (R2) were calculated for linear relationships between several EBRT DVH parameters and a BT DVH parameter of interest. The largest R2 value decided the relationship that best predicted the BT DVH parameter. The composite dose value was then calculated by adding the EBRT DVH and the estimated BT DVH parameter values and was compared to the reference composite value (in 1200 OAR/patient/parameter cases). RESULTS: The linear relationships had an average R2 of 0.68 (range 0.42-0.88). Only one ninth of the 1200 estimated composite DVH values differed more than 2 Gy from their reference values. CONCLUSION: Given a successful implementation, the proposed method only requires original or simulated BT plan data for a subset of patients to estimate composite doses for large study populations in a time-efficient manner. This can assist in evaluating radiation-induced late toxicity in multimodality treatments with limited OAR dose data.

Is there an impact of heart exposure on the incidence of radiation pneumonitis? Analysis of data from a large clinical cohort.

BACKGROUND: The goal of the present study was to determine, in a large clinical cohort, whether incidental radiation exposure to the heart during definitive radiotherapy of inoperable non-small cell lung cancer (NSCLC) detectably increased the risk of radiation pneumonitis (RP) beyond that resulting from radiation exposure to lung. MATERIAL AND METHODS: Data were analyzed from all patients who received definitive three-dimensional (3D) concurrent radiotherapy or intensity-modulated radiotherapy for the treatment of NSCLC over a 10-year period at our institution, except those who had previous lung cancer or for whom radiation treatment plans were unavailable for calculation of heart and lung dose-volume histograms (DVHs). Parameters computed from heart and lung DVHs included mean lung dose (MLD), effective lung dose computed using volume parameter n = 0.5 (Deff), mean heart dose (MHD), percentage of heart receiving > 65 Gy (V65), and minimum dose to the hottest 10% of heart (D10). Univariate and multivariate normal-tissue complication probability (NTCP) models were used to analyze incidence of Grade ≥ 2 or Grade ≥ 3 RP as a function of these and other parameters. RESULTS: The study cohort included 629 patients, with crude rates of Grade ≥ 2 RP and Grade ≥ 3 RP of N = 263 (42%) and N = 124 (20%), respectively. Univariate NTCP models based on dosimetric lung parameters (MLD and Deff) fit the data better than models based on univariate heart parameters (heart D10, heart V65 or MHD). In multivariate modeling, incorporation of heart parameters did not significantly improve the fit of RP risk models based on lung parameters alone (p > 0.38 in each case). CONCLUSIONS: In this large clinical cohort, there was no evidence that incidental heart exposure during radiotherapy of NSCLC had a detectable impact on the occurrence of moderate or severe RP.

Impact of chemotherapy sequencing on local-regional failure risk in breast cancer patients undergoing breast-conserving therapy.

OBJECTIVE: This study was performed to evaluate long-term local-regional control rates after breast-conserving therapy (BCT) for patients undergoing surgery before or after neoadjuvant chemotherapy. METHODS: There were 2983 patients who underwent segmental mastectomy with whole-breast irradiation from 1987 to 2005. Clinicopathological and outcome data were reviewed, and comparisons were made between those undergoing surgery before and those undergoing surgery after neoadjuvant chemotherapy. RESULTS: There were 2331 patients (78%) who underwent surgery first and 652 (22%) received neoadjuvant chemotherapy. Patients receiving neoadjuvant chemotherapy had more advanced disease at baseline and more adverse clinicopathological features. The 5- and 10-year local-regional recurrence (LRR)-free survival rates were 97% [95% confidence interval (CI), 96-98) and 94% (95% CI, 93-95) for surgery first and 93% (95% CI, 91-95) and 90% (95% CI, 87-93) after neoadjuvant chemotherapy (P < 0.001). However, there were no differences in LRR-free survival rates when comparing the presenting clinical stage (P = NS). Of 607 patients presenting with clinical stage II/III disease, chemotherapy downstaged 313 patients (52%) to pathological stage 0/I disease; 294 (48%) had residual stage II/III disease. In multivariate analysis, an age less than 50 years, clinical stage III, grade 3, estrogen receptor (ER)-negative disease, estrogen receptor-positive disease without receipt of endocrine therapy, lymphovascular invasion, multifocal disease on pathology, and close/positive margins were associated with LRR. Use of neoadjuvant chemotherapy was not significant when added to the model. Adjusting for adverse factors, there were no differences in LRR between patients who underwent surgery before and those who underwent neoadjuvant chemotherapy after surgery. CONCLUSIONS: LRR after BCT is driven by tumor biology and disease stage. Appropriately selected patients can achieve high rates of local-regional control with BCT with either upfront surgery or surgery after neoadjuvant chemotherapy.

A technique to use CT images for in vivo detection and quantification of the spatial distribution of radiation-induced esophagitis.

The purpose of the study was to examine whether CT imaging can be used to quantify radiation-induced injury to the esophagus. Weekly CT images for 14 patients receiving proton therapy for thoracic tumors were retrospectively reviewed. The images were registered with the original treatment planning CT image using deformable registration techniques, and the esophageal contours from the treatment plan were automatically mapped to the weekly images. The relative change in the size of the esophagus was calculated for each CT slice as the ratio of the cross-sectional area of the esophagus (minus air) in the weekly CT image to the same area in the planning CT image. The maximum relative change in cross sectional area for each CT image was calculated and examined for correlation with the clinical toxicity score for all the patients. The average maximum relative expansion of the esophagus at the end of treatment was 1.41 ± 0.26, 1.68 ± 0.36, and 2.10 ± 0.18 for patients with grade 0, 2, and 3 esophagitis, respectively. An unpaired t-test, with the level of significance corrected with a Bonferroni correction, showed that the difference between grade 3 and 0 was significant, but the differences between grade 0 and 2, and 2 and 3 were not. The timing of changes in esophageal expansion closely matched that of clinically noted changes in patient symptoms. Expansion of the esophagus on CT images has potential as an objective measure of toxicity. The ability to quantify objectively the spatial distribution of radiation-induced injury will be a useful tool in understanding the impact of partial esophageal sparing on the probability of esophagitis.

Local-regional control according to surrogate markers of breast cancer subtypes and response to neoadjuvant chemotherapy in breast cancer patients undergoing breast conserving therapy.

INTRODUCTION: Breast cancers of different molecular subtypes have different survival rates. The goal of this study was to identify patients at high risk for local-regional recurrence according to response to neoadjuvant chemotherapy and surrogate markers of molecular subtypes in patients undergoing breast conserving therapy (BCT). METHODS: Clinicopathologic data from 595 breast cancer patients who received neoadjuvant chemotherapy and BCT from 1997 to 2005 were identified. Estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) expression determined by immunohistochemistry were used to construct the following subtypes: ER+ or PR+ and HER2- (hormone receptor (HR)+/HER2-; 52%), ER+ or PR+ and HER2+ (HR+/HER2+; 9%), ER- and PR- and HER2+ (HR-/HER2+; 7%) and ER- and PR- and HER2- (HR-/HER2-; 32%). Actuarial rates were calculated using the Kaplan-Meier method and compared using the log-rank test. Cox proportional hazards models were used for multivariate analysis (MVA). RESULTS: After a median follow-up of 64 months, the five-year local-regional recurrence (LRR)-free survival rate for all patients was 93.8%. The five-year LRR-free survival rates varied by subtype: HR+/HER2- 97.0%, HR+/HER2+ 95.9%, HR-/HER2+ 86.5% and HR-/HER2- 89.5% (P = 0.001). In addition to subtype, clinical stage III disease (90% vs. 95% for I/II, P = 0.05), high nuclear grade (92% vs. 97% with low/intermediate grade, P = 0.03), presence of lymphovascular invasion (LVI) (89% vs. 95% in those without LVI, P = 0.02) and four or more positive lymph nodes on pathologic examination (87% vs. 95% with zero to three positive lymph nodes, P = 0.03) were associated with lower five-year LRR-free survival on univariate analysis. On MVA, HR-/HER2+ and HR-/HER2- subtypes and disease in four or more lymph nodes were associated with decreased LRR-free survival. A pathologic complete response (pCR) was associated with improved LRR-free survival. CONCLUSIONS: Patients with HR+/HER2- and HR+/HER2+ subtypes had excellent LRR-free survival regardless of tumor response to neoadjuvant chemotherapy. Patients with HR-/HER2+ and HR-/HER2- subtypes with poor response to neoadjuvant chemotherapy had worse LRR-free survival after BCT. Additional study is needed to determine the impact of trastuzumab on local-regional control in HER2+ tumors. Our data suggest that patients with HR-/HER2- subtype tumors not achieving pCR may benefit from novel strategies to improve local-regional control.

Occult axillary lymph node metastases do not have prognostic significance in early stage breast cancer.

BACKGROUND: Axillary lymph node status is one of the most powerful prognostic indicators in patients with breast cancer and has implications for adjuvant treatment. It has been demonstrated that enhanced histologic evaluation of axillary lymph nodes, including serial sectioning of paraffin tissue blocks and immunohistochemical (IHC) staining, increases the rate of detection of occult metastases. The clinical significance of occult lymph node metastases has been the subject of debate. METHODS: In the current study, the authors identified 267 patients who underwent axillary lymph node dissection (ALND) between 1987 and 1995 and were lymph node negative according to a routine pathologic evaluation, which included the complete submission of all lymph nodes and an examination of 1 hematoxylin and eosin (H&E)-stained section per paraffin block. Patients did not receive systemic chemotherapy or hormone therapy. All of the dissected lymph nodes from these patients were re-evaluated by intensified pathologic methods (serial sectioning with H&E levels plus IHC). Occult metastases were categorized by detection method and size. The clinical significance of the occult metastases was determined. RESULTS: Thirty-nine patients (15%) who had lymph node-negative results on routine evaluation of their ALND specimens had occult metastases identified. Eight of these patients (20%) had macrometastases >2.0 mm, 15 (40%) had micrometastases (range, >0.2 mm to ≤2 mm), and 16 (40%) had isolated tumor cells (≤0.2 mm). The presence of occult metastases and the size of metastases did not affect recurrence-free or overall survival. CONCLUSIONS: The presence of occult metastasis did not have clinical significance in this cohort of patients with early stage breast cancer.

Evaluation of the MD Anderson Prognostic Index for local-regional recurrence after breast conserving therapy in patients receiving neoadjuvant chemotherapy.

BACKGROUND: We previously developed a prognostic index for assessing local-regional recurrence (LRR) risk in patients undergoing breast conservation therapy (BCT) after neoadjuvant chemotherapy. The prognostic index assigns a point for each of the following variables: clinical N2/N3 disease, lymphovascular invasion, residual pathologic tumor size >2 cm, and multifocal residual disease on pathology. The current study was undertaken to evaluate this prognostic index in an independent cohort. METHODS: We identified 551 patients treated from 2001 to 2005 with neoadjuvant chemotherapy, mastectomy or BCT, and radiation. These patients were not used in the original development of the prognostic index. Outcomes were stratified by prognostic index. The 5-year LRR-free survival was calculated using the Kaplan-Meier method, and differences were compared using the log-rank test. RESULTS: For patients undergoing BCT, the 5-year LRR-free survival rates were 92, 92, 84, and 69% when the prognostic index was 0 (n = 91), 1 (n = 82), 2 (n = 38), or 3-4 (n = 13) (P = 0.01). The 5-year LRR-free survival rates were similar between patients undergoing mastectomy or BCT when the prognostic index score was 0, 1, or 2. When the prognostic index score was 3-4, the 5-year LRR-free survival was significantly lower for patients treated with BCT compared with mastectomy (69 vs. 93%, P = 0.007). CONCLUSION: The previously developed prognostic index was successful in stratifying patients with respect to LRR in an independent cohort undergoing BCT after neoadjuvant chemotherapy. The prognostic index can be used to identify patients at high risk for LRR who may be considered for more extensive surgery or enrollment into clinical trials evaluating novel strategies for local-regional control.

American College of Surgeons Oncology Group (ACOSOG) Z0011: impact on surgeon practice patterns.

INTRODUCTION: The ACOSOG Z0011 trial has been described as practice-changing. The goal of this study was to determine the impact of the trial on surgeon practice patterns at our institution. METHODS: This is a review of practice patterns comparing the year before release of Z0011 to the year after an institutional multidisciplinary meeting discussing the results. Patients meeting Z0011 inclusion criteria were identified. Clinicopathologic data were compared between the cohorts. RESULTS: There were 658 patients with clinical T1-2 tumors planned for breast conservation: 335 in the pre-Z0011 cohort and 323 post-Z0011. Sixty-two (19 %) patients were sentinel lymph node (SLN) positive in the pre-Z0011 group versus 42 (13 %) post-Z0011 (p = 0.06). Before Z0011, 85 % (53/62) of SLN-positive patients underwent axillary node dissection (ALND) versus 24 % (10/42) after Z0011 (p < 0.001). After Z0011, surgeons were more likely to perform ALND on patients with larger tumors (2.2 vs. 1.5 cm, p = 0.09), lobular histology (p = 0.01), fewer SLNs (1 vs. 3, p = 0.09), larger SLN metastasis size (4 vs. 2.5 mm, p = 0.19), extranodal extension present (20 vs. 6 %, p = 0.16), or a higher probability of positive non-SLNs (p = 0.03). Surgeons were less likely to perform intraoperative nodal assessment post-Z0011 (26 vs. 69 %, p < 0.001) resulting in decreased median operative times for SLN-negative patients (79 vs. 92 min, p < 0.001). CONCLUSIONS: Surgeons at our institution have implemented Z0011 results for the majority of patients; however, clinicopathologic factors still impact the decision to perform ALND. Z0011 results have significantly impacted practice by decreasing rates of ALND, use of intraoperative nodal evaluation, and operative times.

Coexpression of alpha6beta4 integrin and guanine nucleotide exchange factor Net1 identifies node-positive breast cancer patients at high risk for distant metastasis.

Preclinical data indicate that alpha6beta4 integrin signaling through Ras homolog gene family, member A, plays an important role in tumor cell motility. The objective of this study was to determine whether the combined expression of alpha6beta4 integrin and neuroepithelioma transforming gene 1 (Net1), a guanine nucleotide exchange factor specific for Ras homolog gene family member A, is associated with adverse clinical outcome in breast cancer patients. Immunohistochemical expression of each protein was evaluated in a tumor tissue microarray prepared from the primary tumors of 94 node-positive patients with invasive breast carcinoma treated with total mastectomy and doxorubicin-based chemotherapy without radiation with a median follow-up of 12.5 years. Associations between staining results and multiple clinicopathologic variables were investigated. Although there was no significant association between alpha6beta4 integrin or Net1 expression and clinical outcome when each marker was considered individually, coexpression of alpha6beta4 and Net1 was associated with decreased distant metastasis-free survival (P = 0.030). In the subset of patients with hormone receptor-positive tumors, coexpression of alpha6beta4 and Net1 was associated with a decrease in distant metastasis-free and overall survival (P < 0.001 and P = 0.006, respectively). Although an association between human epidermal growth factor receptor 2 expression and coexpression of alpha6beta4 and Net1 (P = 0.008) was observed, coexpression of alpha6beta4 and Net1 (hazard ratio, 1.63; P = 0.02) and lymphovascular invasion (hazard ratio, 2.35; P = 0.02) were the only factors independently associated with the development of distant metastasis in multivariate analysis. These findings suggest that coexpression of alpha6beta4 integrin and Net1 could be a useful biomarker for aggressive disease in node-positive breast cancer patients.

Validation of Effective Dose as a Better Predictor of Radiation Pneumonitis Risk Than Mean Lung Dose: Secondary Analysis of a Randomized Trial.

PURPOSE: To confirm the superiority of effective dose (Deff) over mean lung dose (MLD) for predicting risk of radiation pneumonitis (RP), using data from patients on a randomized trial of intensity modulated radiation therapy (IMRT) versus passively scattered proton therapy (PSPT). METHODS AND MATERIALS: The prescribed target dose for the 203 evaluated patients was 66 to 74 Gy (relative biological effectiveness) in 33 to 37 fractions with concurrent carboplatin/paclitaxel. Time to grade ≥2 RP was computed from the start of radiation therapy, with disease recurrence or death considered censoring events. Generalized Lyman models of censored time to RP were constructed with MLD or Deff as the dosimetric parameter. Smoking status (current, former, never) was also analyzed. RESULTS: Of the 203 patients, 46 experienced grade ≥2 RP (crude incidence 23%) at a median 3.7 months (range, 0.6-12.6 months). The volume parameter estimated for the Deff model was n = 0.5, confirming estimates from earlier studies. Compared with MLD (in which n = 1), the dosimetric parameter Deff, computed using n = 0.5, resulted in a better fit of the Lyman model to the clinical data (P = .010). Using Deff, the model describes RP risk for IMRT and PSPT data combined because no further improvement was found from separate fits (P = .558). Based on Deff, predicted RP risk per patient ranged from 24 percentage points lower to 19 percentage points higher than predictions based on MLD. For patients with similar MLD, Deff predicted higher risk, on average, for PSPT over IMRT. Current smokers had a lower risk of RP compared with former smokers and nonsmokers (P = .021). CONCLUSIONS: We used data from a randomized trial to validate our previous finding that Deff with n = 0.5 (corresponding to root mean squared dose) is a better predictor of RP than is MLD. Differences between Deff and MLD indicate that delivering higher doses to smaller lung volumes (vs lower doses to larger volumes) increases RP risk. We further corroborated that current smoking is associated with decreased RP risk.

Risk factors for pericardial effusion in inoperable esophageal cancer patients treated with definitive chemoradiation therapy.

PURPOSE: To identify clinical and dosimetric factors influencing the risk of pericardial effusion (PCE) in patients with inoperable esophageal cancer treated with definitive concurrent chemotherapy and radiation therapy (RT). METHODS AND MATERIALS: Data for 101 patients with inoperable esophageal cancer treated with concurrent chemotherapy and RT from 2000 to 2003 at our institution were analyzed. The PCE was confirmed from follow-up chest computed tomography scans and radiologic reports, with freedom from PCE computed from the end of RT. Log-rank tests were used to identify clinical and dosimetric factors influencing freedom from PCE. Dosimetric factors were calculated from the dose-volume histogram for the whole heart and pericardium. RESULTS: The crude rate of PCE was 27.7% (28 of 101). Median time to onset of PCE was 5.3 months (range, 1.0-16.7 months) after RT. None of the clinical factors investigated was found to significantly influence the risk of PCE. In univariate analysis, a wide range of dose-volume histogram parameters of the pericardium and heart were associated with risk of PCE, including mean dose to the pericardium, volume of pericardium receiving a dose greater than 3 Gy (V3) to greater than 50 Gy (V50), and heart volume treated to greater than 32-38 Gy. Multivariate analysis selected V30 as the only parameter significantly associated with risk of PCE. CONCLUSIONS: High-dose radiation to the pericardium may strongly increase the risk of PCE. Such a risk may be reduced by minimizing the dose-volume of the irradiated pericardium and heart.

Quantification of prostate and seminal vesicle interfraction variation during IMRT.

PURPOSE: To quantify the interfraction variability in prostate and seminal vesicle (SV) positions during a course of intensity-modulated radiotherapy (IMRT) using an integrated computed tomography (CT)-linear accelerator system and to assess the impact of rectal and bladder volume changes. METHODS AND MATERIALS: We studied 15 patients who had undergone IMRT for prostate carcinoma. Patients had one pretreatment planning CT scan followed by three in-room CT scans per week using a CT-on-rails system. The prostate, bladder, rectum, and pelvic bony anatomy were contoured in 369 CT scans. Using the planning CT scan as a reference, the volumetric and positional changes were analyzed in the subsequent CT scans. RESULTS: For all 15 patients, the mean systematic internal prostate and SV variation was 0.1 +/- 4.1 mm and 1.2 +/- 7.3 mm in the anteroposterior axis, -0.5 +/- 2.9 mm and -0.7 +/- 4.5 mm in the superoinferior axis, and 0.2 +/- 0.9 mm and -0.9 +/- 1.9 mm in the lateral axis, respectively. The mean magnitude of the three-dimensional displacement vector was 4.6 +/- 3.5 mm for the prostate and 7.6 +/- 4.7 mm for the SVs. The rectal and bladder volume changes during treatment correlated with the anterior and superior displacement of the prostate and SVs. CONCLUSION: The dominant prostate and SV variations occurred in the anteroposterior and superoinferior directions. The systematic prostate and SV variation between the treatment planning CT and daily therapy as a result of the rectal and bladder volume changes emphasizes the need for daily directed target localization and/or immobilization techniques.

Analysis of radiation pneumonitis risk using a generalized Lyman model.

PURPOSE: To introduce a version of the Lyman normal-tissue complication probability (NTCP) model adapted to incorporate censored time-to-toxicity data and clinical risk factors and to apply the generalized model to analysis of radiation pneumonitis (RP) risk. METHODS AND MATERIALS: Medical records and radiation treatment plans were reviewed retrospectively for 576 patients with non-small cell lung cancer treated with radiotherapy. The time to severe (Grade >/=3) RP was computed, with event times censored at last follow-up for patients not experiencing this endpoint. The censored time-to-toxicity data were analyzed using the standard and generalized Lyman models with patient smoking status taken into account. RESULTS: The generalized Lyman model with patient smoking status taken into account produced NTCP estimates up to 27 percentage points different from the model based on dose-volume factors alone. The generalized model also predicted that 8% of the expected cases of severe RP were unobserved because of censoring. The estimated volume parameter for lung was not significantly different from n = 1, corresponding to mean lung dose. CONCLUSIONS: NTCP models historically have been based solely on dose-volume effects and binary (yes/no) toxicity data. Our results demonstrate that inclusion of nondosimetric risk factors and censored time-to-event data can markedly affect outcome predictions made using NTCP models.

Daily bone alignment with limited repeat CT correction rivals daily ultrasound alignment for prostate radiotherapy.

PURPOSE: To compare the effectiveness of daily ultrasound (US)- and computed tomography (CT)-guided alignments with an off-line correction protocol using daily bone alignment plus a correction factor for systematic internal prostate displacement (CF(ID)). METHODS AND MATERIALS: Ten prostate cancer patients underwent CT scans three times weekly using an integrated CT-linear accelerator system, followed by alignment using US for daily radiotherapy. Intensity-modulated radiotherapy plans were designed with our current clinical margins. The treatment plan was copied onto the repeat CT images and aligned using several methods: (1) bone alignment plus CF(ID) after three off-line CT scans (bone+3CT), (2) bone alignment plus CF(ID) after six off-line CT scans (bone+6CT), (3) US alignment, and (4) CT alignment. The accuracy of the repeated US and CT measurements to determine the CF(ID) was compared. The target dosimetric effect was quantified. RESULTS: The CF(ID) for internal systematic prostate displacements was more accurately measured with limited repeat CT scans than with US (residual error, 0.0 +/- 0.7 mm vs. 2.0 +/- 3.2 mm). Bone+3CT, bone+6CT, and US provided equivalent prostate and seminal vesicle dose coverage, but bone+3CT and bone+6CT produced more precise daily alignments. Daily CT alignment provided the greatest target dose coverage. CONCLUSION: Daily bone alignment plus CF(ID) for internal systematic prostate displacement provided better daily alignment precision and equivalent dose coverage compared with daily US alignment. The CF(ID) should be based on at least three repeat CT scans, which could be collected before the start of treatment or during the first 3 treatment days. Daily bone alignment plus CF(ID) provides another option for accurate prostate cancer patient positioning.

Long-term results of the M. D. Anderson randomized dose-escalation trial for prostate cancer.

PURPOSE: To report the long-term results of a randomized radiotherapy dose escalation trial for prostate cancer. METHODS AND MATERIALS: From 1993 to 1998, a total of 301 patients with stage T1b to T3 prostate cancer were accrued to a randomized external beam dose escalation trial using 70 Gy versus 78 Gy. The median follow-up is now 8.7 years. Kaplan-Meier analysis was used to compute rates of prostate-specific antigen (PSA) failure (nadir + 2), clinical failure, distant metastasis, disease-specific, and overall survival as well as complication rates at 8 years post-treatment. RESULTS: For all patients, freedom from biochemical or clinical failure (FFF) was superior for the 78-Gy arm, 78%, as compared with 59% for the 70-Gy arm (p = 0.004, and an even greater benefit was seen in patients with initial PSA >10 ng/ml (78% vs. 39%, p = 0.001). The clinical failure rate was significantly reduced in the 78-Gy arm as well (7% vs. 15%, p = 0.014). Twice as many patients either died of prostate cancer or are currently alive with cancer in the 70-Gy arm. Gastrointestinal toxicity of grade 2 or greater occurred twice as often in the high dose patients (26% vs. 13%), although genitourinary toxicity of grade 2 or greater was less (13% vs. 8%) and not statistically significantly different. Dose-volume histogram analysis showed that the complication rate could be significantly decreased by reducing the amount of treated rectum. CONCLUSIONS: Modest escalation in radiotherapy dose improved freedom from biochemical and clinical progression with the largest benefit in prostate cancer patients with PSA >10 ng/ml.

Lymphovascular invasion and lobular histology are associated with increased incidence of isolated tumor cells in sentinel lymph nodes from early-stage breast cancer patients.

BACKGROUND: Isolated tumor cells (ITC) are more likely to be identified when serial sectioning and immunohistochemical staining are used to evaluate sentinel lymph nodes (SLN). Our goal was to identify clinicopathologic features associated with ITC in patients undergoing sentinel lymph node dissection (SLND). METHODS: We reviewed clinicopathologic data for 3557 patients with no clinical evidence of lymph node metastases undergoing SLND between November 1993 and March 2007. Patients were staged according to the 6th edition of the American Joint Committee on Cancer staging system, with metastasis

Cyclin E-associated kinase activity predicts response to platinum-based chemotherapy.

PURPOSE: The role of cyclin E as a predictive marker of response to chemotherapy remains unknown. We have previously shown that deregulation of cyclin E in an ovarian tumor cell line model enhances cyclin E-associated kinase activity and sensitizes tumor cells to cisplatinum. We hypothesized that cyclin E deregulation would predict for responsiveness to platinum-based regimens in ovarian cancer patients. EXPERIMENTAL DESIGN: Patients who met the following criteria were retrospectively identified from the institutional tumor bank records: (a) high-grade ovarian epithelial malignancy, (b) stage III/stage IV disease, (c) optimally debulked, (d) completed platinum-based therapy. Tumor samples were analyzed for cyclin E, p21, and p27 by Western blot analysis and assessed for cyclin E-associated kinase activity. RESULTS: Seventy-five patients, who met the study criteria, were identified. Cyclin E protein levels did not correlate with cyclin E-cdk2 kinase activity (Spearman's rho, 0.07; P = 0.58). Cyclin E-associated kinase activity was the only significant predictive marker for response to platinum-based therapy, with higher response rates seen in patients with higher levels of activity (P = 0.045). Cyclin E protein levels did not predict for platinum sensitivity (P = 0.20). In contrast, cyclin E protein levels, but not cyclin E-associated kinase activity, was a significant predictor for freedom from recurrence (P = 0.01 and P = 0.25, respectively). CONCLUSIONS: Cyclin E overexpression and cyclin E-associated kinase activity have distinct roles in predicting for response to chemotherapy and outcome in ovarian cancer patients. These results suggest a compartmentalization of cyclin E functions in the oncogenic process.