Development of a Classification Tree to Predict Implant-Based Reconstruction Failure with or without Postmastectomy Radiation Therapy for Breast Cancer.

PURPOSE: The aim of this study was to determine the complications, incidence, and predictors of implant-based reconstruction failure (RF) among patients treated with mastectomy for breast cancer. METHODS: We retrospectively reviewed 108 patients who underwent mastectomy, tissue expander, and implant-based breast reconstruction with or without radiation therapy (RT) at our institution (2000-2014). Descriptive statistics determined complication incidences, with major complications defined as any complications requiring surgical intervention or inpatient management. Chi square and Fisher's exact tests determined differences in RF incidences, defined as implant loss. Logistic regression analyses identified predictors of RF. RESULTS: Median follow-up was 42.5 months. Sixty patients (55.6%) experienced major complications. Overall, 27 patients (25%) experienced RF. Incidences of RF were significantly increased in patients who had any major complication (43.3% vs. 2.1%; p < 0.0001), especially infection (61.3% vs. 10.4%; p < 0.0001), delayed wound healing (83.3% vs. 21.7%; p = 0.004), and implant exposure (80.0% vs. 19.4%; p = 0.0002). Receiving RT, but not timing of RT, significantly predicted RF [odds ratio (OR) 4.00, 95% confidence interval (CI) 1.11-14.47; p = 0.03]. On multivariable analysis, infection (OR 7.69, 95% CI 2.12-27.89; p = 0.002) and delayed wound healing (OR 17.86, 95% CI 1.59-200.48; p = 0.02) independently predicted for RF. Our newly developed classification tree, which includes stepwise assessment of major infection, delayed wound healing, implant exposure, age ≥ 50 years, and total number of lymph nodes removed ≥ 10, accurately predicted 74% of RF events and 75% of non-RF events. CONCLUSIONS: Infection or delayed wound healing requiring surgical intervention or hospitalization and receipt of RT, but not radiation timing, were significant predictors of RF. Our classification tree demonstrated > 70% accuracy for stepwise prediction of RF.

Delays in Care Associated With Non-English-Speaking Patients With Breast Cancer.

BACKGROUND: Breast cancer care requires coordination between multiple diagnostic and treatment modalities. Disparities such as age, race/ethnicity, and socioeconomic status are associated with delays in care. This study investigates whether primary language is associated with delays in breast cancer diagnosis and treatment before and through radiotherapy (RT). PATIENTS AND METHODS: This study was an institutional retrospective matched-cohort analysis of women treated with breast RT over 2 years. A total of 65 non-English-speaking (NES) patients were matched with 195 English-speaking (ES) patients according to stage, age, and chemotherapy delivery. Key time intervals along the breast cancer care path from initial findings through RT were recorded. Data were analyzed in a mixed model with matching as the random effect. The impact of race and insurance status was analyzed in addition to language. RESULTS: Significant delays were found for NES patients, which varied by race. NES Latina patients experienced the longest delay, with a mean total care-path time of 13.53 months (from initial findings to end of RT) versus 8.18 months for all ES patients (P<.0001). Specifically, their mean total care-path time was 5.97 months longer than that of ES Latina patients (P=.001) and 5.80 months longer than that of ES White patients (P<.0001). In addition, NES Latina patients had a significantly longer total care-path time than NES patients of other races/ethnicities (P=.001). Delays were specifically seen between initial clinical or radiographic findings and diagnostic mammogram (P=.001) and between biopsy and resection (P=.044). Beyond language, race/ethnicity was itself associated with delays between resection and start of RT (P=.032) and between start and end of RT (P=.022). CONCLUSIONS: Language is associated with pre-RT delays in breast cancer care, especially for NES Latina patients. Delays are most pronounced before diagnostic mammograms, but they also exist before resection and RT. Future work should target NES patients to assist their progress along the care path.

Lymphopenia and clinical outcomes in patients with residual nodal disease after neoadjuvant chemotherapy for breast cancer.

BACKGROUND: Patients with residual nodal disease after neoadjuvant chemotherapy for breast cancer have a poor prognosis. We wanted to evaluate whether lymphopenia after treatment for breast cancer impacted clinical outcomes. MATERIALS AND METHODS: We assessed 99 patients with node-positive disease after neoadjuvant chemotherapy. Absolute lymphocyte count was recorded 1 year after radiation. Dates of local, regional, and distant failure were recorded. Time to event outcomes were evaluated using Kaplan-Meier analysis. Multivariable analysis determined factors predictive for overall survival. RESULTS: Median follow-up was 44 months (range 3-150). Median age was 48 years (range 23-79). Twenty-six patients (26%) had lymphopenia 1 year after RT. Patients with lymphopenia had a greater incidence of regional (p = 0.03) and distant failure (p = 0.009) compared to those with normal lymphocyte counts and had a 6.05 greater risk of death (p = 0.0002). CONCLUSIONS: In patients with residual nodal disease after neoadjuvant chemotherapy, lymphopenia after breast cancer treatment was associated with overall survival. The relationship between lymphopenia and breast cancer outcomes warrants further investigation.

Impact of mastectomy for breast cancer on spinal curvature: Considerations when treating patients with scoliosis.

OBJECTIVE: Mastectomy has been shown to influence body posture in women; however, there are limited data outlining changes in spine curvature after mastectomy in patients with scoliosis. We sought to quantify changes in spine curvature after mastectomy for breast cancer. METHODS: We conducted a retrospective review of 62 patients with scoliosis who underwent mastectomy for breast cancer at a single institution between 1995 and 2018. Preoperative and postoperative radiographs were used to measure Cobb angles to assess lateral spinal curvature. Changes in Cobb angle were compared using paired two-tailed t-tests. The relationship between mass of breast removed and changes in Cobb angle was modeled using a linear regression. RESULTS: The median follow-up after mastectomy was 7.9 years (range 0.9-21.5). Median age was 62 years (range 30-85). Of 62 patients, 10 (16%) expressed that their back pain became worse after mastectomy. Nineteen patients had evaluable radiographs before and after mastectomy. In these patients, the average change in Cobb angle was 4.7° (range -0.2-12.2). Cobb angle significantly increased after mastectomy (P < .0001). Although not statistically significant, average Cobb angle was greater for patients who underwent unilateral compared to bilateral mastectomy (P = .09). Mass of breast removed significantly correlated with the difference in Cobb angle for patients who underwent unilateral mastectomy (P = .0006), but not for bilateral mastectomy (P = .55). CONCLUSIONS: In this understudied patient population, mastectomy significantly increased the change in spine curvature. Further care should be taken to assess patient-reported pain and quality of life in patients with spine morbidity who undergo mastectomy for breast cancer.

Erythema of the skin after breast radiotherapy: It is not always recurrence.

Recurrence of breast cancer is a predominant fear for patients who were treated for breast cancer. Acute and late dermatologic effects of radiotherapy are not uncommon and could have similar characteristics to breast cancer recurrence. Thus, it is important to highlight key differences between the clinical and histologic presentations of radiation effects and recurrence. Herein, we present two patients who presented with late dermatologic effects of radiotherapy months to years after treatment, neither of whom had workup consistent with cancer recurrence. We provide clinical and microscopic descriptions of each case and provide a review to differentiate various dermatologic conditions. This report aims to outline potential late dermatologic effects of radiation treatment and emphasise that changes in the breast do not always signal breast cancer recurrence.

Association between primary language, a lack of mammographic screening, and later stage breast cancer presentation.

BACKGROUND: Health determinants are known to influence the stage of breast cancer presentation, but it is unclear to what extent language affects stage. This study investigates whether non-English-speaking (NES) patients present at a later stage than their English-speaking (ES) counterparts and whether language is associated with mammographic screening. METHODS: This study was a retrospective, single-institution cohort analysis of women undergoing breast radiotherapy from 2012 to 2017 (n = 1057). Patients were categorized as ES (n = 904) or NES (n = 153). Ordinal logistic regression analysis identified variables associated with later stage presentation, including language, race/ethnicity, and age. A subcohort analysis investigated the influence of mammographic screening on stage for NES patients. RESULTS: NES patients had greater odds of later stage disease than ES patients (odds ratio, 1.47; 95% confidence, 1.001-2.150). This association persisted across all races/ethnicities. An additional analysis examined age categories associated with mammographic screening. For women eligible for screening (ie, those 40-50 years old or older than 50 years), there was a significant association between language and stage. NES patients older than 50 years were twice as likely to present at an advanced stage in comparison with ES patients (16.19% vs 8.11%; P = .0082). An additional subset analysis accounted for mammograms. NES patients who did not undergo screening had a higher probability of stage III disease (40.3% of NES patients vs 12.7% of ES patients). There was no difference in stage between NES and ES patients who did undergo screening. CONCLUSIONS: Language is independently associated with later stage breast cancer for NES patients, regardless of race/ethnicity. NES patients may have difficulty in accessing the health care system. Future interventions should seek to reduce language barriers for mammographic screening and diagnosis.

Adjuvant treatment and survival in older women with triple negative breast cancer: A Surveillance, Epidemiology, and End Results analysis.

Patients with triple negative breast cancer were identified using the Surveillance, Epidemiology, and End Results database. Competing risks analysis was used to assess the cumulative incidence of breast cancer-specific mortality (BCSM). Multivariable Fine-Gray regression was used to identify predictors of BCSM. Women age 70+ (n = 4221) were less likely to receive chemotherapy and radiation treatment (P < 0.0001) and had higher BCSM compared to younger women (P < 0.0001). There were no differences in BCSM in patients who received adjuvant treatment (P = 0.10). Stage II patients derived the greatest relative and absolute benefit from adjuvant treatment. Age was not a significant predictor of BCSM.

Rising rates of bilateral mastectomy with reconstruction following neoadjuvant chemotherapy.

Neoadjuvant chemotherapy (NAC) is used to allow more limited breast surgery without compromising local control. We sought to evaluate nationwide surgical trends in patients with operable breast cancer treated with NAC and factors associated with surgical type. We used the National Cancer Database to identify 235,339 women with unilateral T1-3 N0-3 M0 breast cancer diagnosed between 2010 and 2014 and treated with surgery and chemotherapy. Of these, 59,568 patients (25.3%) were treated with NAC. Rates of pathological complete response (pCR) to NAC increased from 33.3% at the start of the study period in 2010 to 46.3% at the end of the period in 2014 (p = 0.02). Rates of breast-conserving surgery (BSC) changed little, from 37.0 to 40.8% (p = 0.22). Although rates of unilateral mastectomy decreased from 43.3 to 34.7% (p = 0.02) and rates of bilateral mastectomy without immediate reconstruction remained similar (11.7-11.5%; p = 0.82), rates of bilateral mastectomy with immediate reconstruction rose from 8.0 to 13.1% (p = 0.02). Patients who were younger, with private/managed care insurance, and diagnosed in more recent years were more likely to achieve pCR; however, these same characteristics were associated with receipt of bilateral mastectomy (vs. BCS). In addition, non-Hispanic white ethnic and higher area education attainment were both associated with bilateral mastectomy. These findings did not differ by age or molecular subtype. Further study of nonclinical factors that influence selection of more extensive surgery despite excellent response to NAC is warranted.

Outcomes Following Neoadjuvant Chemotherapy for Breast Cancer in Women Aged 40 Years and Younger: Impact of Pathologic Nodal Response.

Purpose: We sought to evaluate whether pathologic nodal response was predictive of outcomes in women aged ≤40 years with breast cancer treated with neoadjuvant chemotherapy (NAC). Methods: A total of 220 patients treated with NAC between 1991 and 2015 were retrospectively reviewed. Pathologic complete response (pCR) was defined as no evidence of residual invasive tumor in the breast and lymph nodes (LNs) (ypT0/Tis ypN0); partial response if there was no tumor in the LNs but residual tumor in the breast (ypT+ ypN0) or residual tumor in the LNs (ypT0/Tis ypN+); and limited response if there was residual tumor in both the breast and the LNs (ypT+ ypN+). Kaplan-Meier and Cox proportional hazards analyses were performed to identify factors predictive for overall survival (OS). Results: A total of 155 patients were included. Following NAC, 39 patients (25.2%) achieved pCR, 57 (36.8%) achieved a partial response (either ypT+ ypN0 or ypT0/Tis ypN+), and 59 (38.1%) had a limited response. A total of 22 patients (14.2%) experienced local failure, 20 (12.9%) experienced regional failure, and 59 (38.1%) experienced distant failure. Median OS for patients who achieved pCR was not reached, and was significantly worse for patients who had residual disease in the breast and/or LNs (P<.001). No difference in OS was seen among patients who had residual disease in the breast alone versus those who remained LN-positive (97 vs 83 months, respectively; P=.25). Subset analysis did not reveal differences in OS based on year of treatment or cN1 disease at the time of initial diagnosis. Conclusions: Women aged ≤40 years who achieved pCR had excellent outcomes; however, those who achieved a pathologic response in the LNs but had residual disease in the breast continued to have outcomes similar to those who remained LN-positive.

Characteristics and clinical outcomes of pleomorphic lobular carcinoma in situ of the breast.

Pleomorphic lobular carcinoma in situ (PLCIS) of the breast is a rare variant of lobular carcinoma in situ (LCIS). We reviewed 78 cases of PLCIS diagnosed at our institution from 1998 to 2012. Among all cases, 47 (60%) were associated with invasive carcinoma and/or ductal carcinoma in situ (DCIS) after final surgical excision. Of the 20 cases with PLCIS alone on core needle biopsy (CNB), 6 (30%) were upgraded to invasive carcinoma or DCIS after final surgical excision. Our findings support a recommendation for complete surgical excision of PLCIS when diagnosed on CNB.

Clinical Utility of the 12-Gene DCIS Score Assay: Impact on Radiotherapy Recommendations for Patients with Ductal Carcinoma In Situ.

OBJECTIVE: The aim of this study was to determine the impact of the results of the 12-gene DCIS Score assay on (i) radiotherapy recommendations for patients with pure ductal carcinoma in situ (DCIS) following breast-conserving surgery (BCS), and (ii) patient decisional conflict and state anxiety. METHODS: Thirteen sites across the US enrolled patients (March 2014-August 2015) with pure DCIS undergoing BCS. Prospectively collected data included clinicopathologic factors, physician estimates of local recurrence risk, DCIS Score results, and pre-/post-assay radiotherapy recommendations for each patient made by a surgeon and a radiation oncologist. Patients completed pre-/post-assay decisional conflict scale and state-trait anxiety inventory instruments. RESULTS: The analysis cohort included 127 patients: median age 60 years, 80 % postmenopausal, median size 8 mm (39 % ≤5 mm), 70 % grade 1/2, 88 % estrogen receptor-positive, 75 % progesterone receptor-positive, 54 % with comedo necrosis, and 18 % multifocal. Sixty-six percent of patients had low DCIS Score results, 20 % had intermediate DCIS Score results, and 14 % had high DCIS Score results; the median result was 21 (range 0-84). Pre-assay, surgeons and radiation oncologists recommended radiotherapy for 70.9 and 72.4 % of patients, respectively. Post-assay, 26.4 % of overall recommendations changed, including 30.7 and 22.0 % of recommendations by surgeons and radiation oncologists, respectively. Among patients with confirmed completed questionnaires (n = 32), decision conflict (p = 0.004) and state anxiety (p = 0.042) decreased significantly from pre- to post-assay. CONCLUSIONS: Individualized risk estimates from the DCIS Score assay provide valuable information to physicians and patients. Post-assay, in response to DCIS Score results, surgeons changed treatment recommendations more often than radiation oncologists. Further investigation is needed to better understand how such treatment changes may affect clinical outcomes.

CT-Guided Wire Localization for Involved Axillary Lymph Nodes After Neo-adjuvant Chemotherapy in Patients With Initially Node-Positive Breast Cancer.

Resection of biopsy-proven involved axillary lymph nodes (iALNs) is important to reduce the false-negative rates of sentinel lymph node (SLN) biopsy after neo-adjuvant chemotherapy (NAC) in patients with initially node-positive breast cancer. Preoperative wire localization for iALNs marked with clips placed during biopsy is a technique that may help the removal of iALNs after NAC. However, ultrasound (US)-guided localization is often difficult because the clips cannot always be reliably visible on US. Computed tomography (CT)-guided wire localization can be used; however, to date there have been no reports on CT-guided wire localization for iALNs. The aim of this study was to describe a series of patients who received CT-guided wire localization for iALN removal after NAC and to evaluate the feasibility of this technique. We retrospectively analyzed five women with initially node-positive breast cancer (age, 41-52 years) who were scheduled for SLN biopsy after NAC and received preoperative CT-guided wire localization for iALNs. CT visualized all the clips that were not identified on post-NAC US. The wire tip was deployed beyond or at the target, with the shortest distance between the wire and the index clip ranging from 0 to 2.5 mm. The total procedure time was 21-38 minutes with good patient tolerance and no complications. In four of five cases, CT wire localization aided in identification and resection of iALNs that were not identified with lymphatic mapping. Residual nodal disease was confirmed in two cases: both had residual disease in wire-localized lymph nodes in addition to SLNs. Although further studies with more cases are required, our results suggest that CT-guided wire localization for iALNs is a feasible technique that facilitates identification and removal of the iALNs as part of SLN biopsy after NAC in situations where US localization is unsuccessful.

ACR Appropriateness Criteria® Ductal Carcinoma in Situ.

Ductal carcinoma in situ (DCIS) is a breast neoplasm with potential for progression to invasive cancer. Management commonly involves excision, radiotherapy, and hormonal therapy. Surgical assessment of regional lymph nodes is rarely indicated except in cases of microinvasion or mastectomy. Radiotherapy is employed for local control in breast conservation, although it may be omitted for select low-risk situations. Several radiotherapy techniques exist beyond standard whole-breast irradiation (ie, partial-breast irradiation [PBI], hypofractionated whole-breast radiation); evidence for these is evolving. We present an update of the American College of Radiology (ACR) Appropriateness Criteria® for the management of DCIS. The ACR Appropriateness Criteria® are evidence-based guidelines for specific clinical conditions, which are reviewed every 3 years by a multidisciplinary expert panel. The guideline development and review includes an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi technique) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Solid malignancies in individuals with Down syndrome: a case presentation and literature review.

Individuals with Down syndrome (DS) are at elevated risk for acute leukemia, whereas solid tumors are uncommon, and most types, including breast cancers, have significantly lower-than-expected age-adjusted incidence rates. This article reports on a man with DS and breast cancer, thought to be the first in the literature, and presents the management of his cancer. The literature on malignancies in patients with DS is reviewed and the major epidemiologic studies that have examined the spectrum of cancer risk in individuals with DS are summarized. Potential environmental and genetic determinants of cancer risk are discussed, and the potential role of chromosomal mosaicism in cancer risk among patients with DS is explored. Trisomy of chromosome 21, which causes DS, provides an extra copy of genes with tumor suppressor or repressor functions. Recent studies have leveraged mouse and human genetics to uncover specific candidate genes on chromosome 21 that mediate these effects. In addition, global perturbations in gene expression programs have been observed, with potential effects on proliferation and self-renewal.

ACR Appropriateness Criteria local-regional recurrence (LRR) and salvage surgery-breast cancer.

Although both breast-conserving surgery and mastectomy generally provide excellent local-regional control of breast cancer, local-regional recurrence (LRR) does occur. Predictors for LRR include patient, tumor, and treatment-related factors. Salvage after LRR includes coordination of available modalities, including surgery, radiation, chemotherapy, and hormonal therapy, depending on the clinical scenario. Management recommendations for breast cancer LRR, including patient scenarios, are reviewed, and represent evidence-based data and expert opinion of the American College of Radiology Appropriateness Criteria Expert Panel on LRR.The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel.The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Individualized Stereotactic Ablative Radiotherapy for Lung Tumors: The iSABR Phase 2 Nonrandomized Controlled Trial.

Importance: Stereotactic ablative radiotherapy (SABR) is used for treating lung tumors but can cause toxic effects, including life-threatening damage to central structures. Retrospective data suggested that small tumors up to 10 cm3 in volume can be well controlled with a biologically effective dose less than 100 Gy. Objective: To assess whether individualizing lung SABR dose and fractionation by tumor size, location, and histological characteristics may be associated with local tumor control. Design, Setting, and Participants: This nonrandomized controlled trial (the iSABR trial, so named for individualized SABR) was a phase 2 multicenter trial enrolling participants from November 15, 2011, to December 5, 2018, at academic medical centers in the US and Japan. Data were analyzed from December 9, 2020, to May 10, 2023. Patients were enrolled in 3 groups according to cancer type: initial diagnosis of non-small cell lung cancer (NSCLC) with an American Joint Committee on Cancer 7th edition T1-3N0M0 tumor (group 1), a T1-3N0M0 new primary NSCLC with a history of prior NSCLC or multiple NSCLCs (group 2), or lung metastases from NSCLC or another solid tumor (group 3). Intervention: Up to 4 tumors were treated with once-daily SABR. The dose ranged from 25 Gy in 1 fraction for peripheral tumors with a volume of 0 to 10 cm3 to 60 Gy in 8 fractions for central tumors with a volume greater than 30 cm3. Main outcome: Per-group freedom from local recurrence (same-lobe recurrence) at 1 year, with censoring at time of distant recurrence, death, or loss to follow-up. Results: In total, 217 unique patients (median [IQR] age, 72 [64-80] years; 129 [59%] male; 150 [69%] current or former smokers) were enrolled (some multiple times). There were 240 treatment courses: 79 in group 1, 82 in group 2, and 79 in group 3. A total of 285 tumors (211 [74%] peripheral and 74 [26%] central) were treated. The most common dose was 25 Gy in 1 fraction (158 tumors). The median (range) follow-up period was 33 (2-109) months, and the median overall survival was 59 (95% CI, 49-82) months. Freedom from local recurrence at 1 year was 97% (90% CI, 91%-99%) for group 1, 94% (90% CI, 87%-97%) for group 2, and 96% (90% CI, 89%-98%) for group 3. Freedom from local recurrence at 5 years ranged from 83% to 93% in the 3 groups. The proportion of patients with grade 3 to 5 toxic effects was low, at 5% (including a single patient [1%] with grade 5 toxic effects). Conclusions and Relevance: The results of this nonrandomized controlled trial suggest that individualized SABR (iSABR) used to treat lung tumors may allow minimization of treatment dose and is associated with excellent local control. Individualized dosing should be considered for use in future trials. Trial Registration: ClinicalTrials.gov Identifier: NCT01463423.

ACR appropriateness criteria(®) ductal carcinoma in situ.

Ductal carcinoma in situ (DCIS) describes a wide spectrum of non-invasive tumors which carry a significant risk of invasive relapse, thus prevention of local recurrence is vital. For appropriate patients with limited disease, management with breast conserving surgery (BCS) followed by whole-breast radiation (RT) is supported by multiple Phase III studies, but mastectomy may be appropriate in selected patients. Omission of RT may also be reasonable in some patients, though which criteria are to be utilized remain unclear, and the existing data are contradictory with limited follow-up. Various RT techniques such as boost to the tumor bed, partial breast radiation or hypofractionated, whole-breast RT are increasingly utilized but the data to support their use specifically in DCIS is limited. Tamoxifen also increases local control for ER + DCIS, adding to the complexity of the local treatment management. This article reviews the existing scientific evidence, the controversies surrounding local management, and clinical guidelines for DCIS based on the group consensus by the ACR Breast Expert Panel. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

ACR appropriateness criteria® locally advanced breast cancer.

Locally advanced breast cancer (LABC) is a disease that is heterogeneous in its presentation, potentially curable, and generally necessitating multidisciplinary management. Radiation therapy (RT) plays an important role in the management of LABC. The integration of radiation with surgery, chemotherapy, and sometimes breast reconstruction can be complex. The American College of Radiology Appropriateness Criteria Breast Committee aims to provide guidance for the management of a variety of LABC cases. The American College of Radiology Appropriateness Criteria is evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is either lacking or not definitive, expert opinion may be used to recommend imaging or treatment.