Multi-Institutional Phase II Trial Using Dose Escalated Five Fraction Stereotactic Partial Breast Irradiation (S-PBI) with GammaPodTM for Early-Stage Breast Cancer

PURPOSE/OBJECTIVE(S)

We report on our early experience of a multi-institutional phase II study of dose escalated five fraction stereotactic partial breast irradiation (S-PBI) for early-stage breast cancer after partial mastectomy using the GammaPodTM stereotactic radiation system.

MATERIALS/METHODS

Patient eligibility included DCIS or invasive epithelial histologies, AJCC clinical stage 0, I, or II with tumor size < 3 cm, and negative margins. Prior safety of Phase I dose escalation has been reported. Dose was 40 Gy delivered in 5 fractions to the CTV, and minimum dose 30 Gy in 5 fractions to the PTV. CTV margin was 1 cm and PTV margin 3 mm. For PTV cavities larger than 100cc, dose was reduced to 35Gy in 5 fractions to the CTV and 30 Gy in 5 fractions to the PTV. Primary endpoint of the study is to determine the 3-year patient global cosmesis score (4-point scale excellent, good, fair, or poor) and adverse cosmesis using a dose escalated approach with smaller PTV margins than conventional methods. Both patients and physicians completed baseline and subsequent cosmesis outcome questionnaires. Treatment related toxicity was graded using the NCI version 4.0 and RTOG/EORTC late radiation scale.

RESULTS

From 3/2019-10/2021, 74 patients were treated respectively. Of these, 38 were treated to 40Gy and 36 were treated to 35 Gy. Median follow up (f/u) was 24 months (mo), range (r) 3-39mo. Median age was 63 years (r 43-77). Histology included 28 DCIS, and 46 invasive carcinomas. 45/46 invasive tumors were ER+. 60/74 (81%) patients received endocrine therapy, and 7/74 patient received chemotherapy. There were 221 acute grade 1 toxicities, and 28 Grade 2 toxicities. No grade 3 or higher acute toxicities were reported (< 90 days). The most common Grade 2 toxicities were radiation dermatitis (10), breast pain (8), blister (4), skin infection (2), nipple discharge (2), and fatigue (2). In the late period, there were 54 Grade 1 late toxicities, 4 Grade 2 late toxicities, and no Grade 3 or higher late toxicities. Grade 2 toxicities included fibrosis (2), and pain (2). Two patients developed grade 1 asymptomatic nonpalpable fat necrosis both diagnosed at 12 months after radiation treatments. The most common grade 1 late toxicities were breast pain (14), hyperpigmentation (8), fibrosis (10), and fatigue (5). Physicians scored cosmesis excellent or good 70/73 (95.8%), 58/60 (96.7%), 36/36 (100%),17/17(100%) respectively at baseline, 12 months, 24 months, and 36months post SBRT, while patients scored the same periods 62/71 (83.7%), 53/59 (89.8%), 33/36 (91.6%), 17/18 (94.4%). There have been no reports of disease recurrences.

CONCLUSION

Results at 24-month median follow-up, of our dose escalated stereotactic partial breast 5 fraction regimen, has low acute and late toxicity, while maintaining high proportion of excellent/good cosmetic outcomes. Continued analysis of all cohorts is in progress.

CLINICAL TRIALS

gov identifier is NCT03581136.

The effect of missing data and imputation on the detection of bias in cognitive testing using differential item functioning methods

Background

Item response theory (IRT) methods for addressing differential item functioning (DIF) can detect group differences in responses to individual items (e.g., bias). IRT and DIF-detection methods have been used increasingly often to identify bias in cognitive test performance by characteristics (DIF grouping variables) such as hearing impairment, race, and educational attainment. Previous analyses have not considered the effect of missing data on inferences, although levels of missing cognitive data can be substantial in epidemiologic studies.

Methods

We used data from Visit 6 (2016–2017) of the Atherosclerosis Risk in Communities Neurocognitive Study (N = 3,580) to explicate the effect of artificially imposed missing data patterns and imputation on DIF detection.

Results

When missing data was imposed among individuals in a specific DIF group but was unrelated to cognitive test performance, there was no systematic error. However, when missing data was related to cognitive test performance and DIF group membership, there was systematic error in DIF detection. Given this missing data pattern, the median DIF detection error associated with 10%, 30%, and 50% missingness was -0.03, -0.08, and -0.14 standard deviation (SD) units without imputation, but this decreased to -0.02, -0.04, and -0.08 SD units with multiple imputation.

Conclusions

Incorrect inferences in DIF testing have downstream consequences for the use of cognitive tests in research. It is therefore crucial to consider the effect and reasons behind missing data when evaluating bias in cognitive testing.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-022-01572-2.

Assessing Bias in Cognitive Testing for Older Adults with Sensory Impairment: An Analysis of Differential Item Functioning in the Baltimore Longitudinal Study on Aging (BLSA) and the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS)

OBJECTIVES

Vision and hearing impairments affect 55% of people aged 60+ years and are associated with lower cognitive test performance; however, tests rely on vision, hearing, or both. We hypothesized that scores on tests that depend on vision or hearing are different among those with vision or hearing impairments, respectively, controlling for underlying cognition.

METHODS

Leveraging cross-sectional data from the Baltimore Longitudinal Study of Aging (BLSA) and the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS), we used item response theory to test for differential item functioning (DIF) by vision impairment (better eye presenting visual acuity worse than 20/40) and hearing impairment (better ear .5-4 kHz pure-tone average > 25 decibels).

RESULTS

We identified DIF by vision impairment for tests whose administrations do not rely on vision [e.g., Delayed Word Recall both in ARIC-NCS: .50 logit difference between impaired and unimpaired (p = .04) and in BLSA: .62 logits (p = .02)] and DIF by hearing impairment for tests whose administrations do not rely on hearing [Digit Symbol Substitution test in BLSA: 1.25 logits (p = .001) and Incidental Learning test in ARIC-NCS: .35 logits (p = .001)]. However, no individuals had differences between unadjusted and DIF-adjusted measures of greater than the standard error of measurement.

CONCLUSIONS

DIF by sensory impairment in cognitive tests was independent of administration characteristics, which could indicate that elevated cognitive load among persons with sensory impairment plays a larger role in test performance than previously acknowledged. While these results were unexpected, neither of these samples are nationally representative and each has unique selection factors; thus, replication is critical.

Abstract P4-10-18: Patterns of failure in a predominately black, inner city cohort of triple negative breast cancer patients at a single institution

Introduction: Triple negative breast cancer (TNBC) accounts for 12-17% of breast cancer (BC) in the US, but behaves much more aggressively. It occurs more commonly in younger, black women and death within two years of diagnosis is more common in this subset of BC compared to hormone receptor positive BC. At the University of Maryland Greenebaum Comprehensive Cancer Center, we see a higher proportion of TNBC and present our comprehensive evaluation of the patterns of failure in women with TNBC treated at our urban breast center.

Materials/Methods: A retrospective review of TNBC patients treated from 2005-2017 identified 198 patients with Stage I (33%), Stage II (47%), Stage III (16%) and Stage IV (4%) TNBC. The patients were all female, median age of 54 years (range 22-86 years), 64% black, 40% married, 7% BRCA mutated, and 3% HIV positive. Tumor characteristics revealed 93% infiltrating ductal carcinoma, 68% grade 3, and 18% with lymphovascular space invasion. Self-palpation of the lesion occurred in 76% of women, and the lesion was in the upper outer quadrant 62% of the time. Thirty percent of pts had neoadjuvant and 67% adjuvant chemotherapy. Ninety-eight percent of pts underwent surgical resection, 55% had lumpectomy and 61% sentinel lymph node biopsy. Adjuvant radiation was given in 56% of patients with a median dose of 60 Gy (range 16-70 Gy). Chi-square testing was used to compare variables, while logistic regression with Kaplan-Meier estimate was used to calculate overall survival (OS) and freedom from recurrence (FFR).

Results: With a median follow up of 45 months, 33 (17%) documented failures occurred. At time of first documented failure, 30% were local (L), 6% regional (R), 22% distant (D), 6% combination of L/R, 12% combination of L/R/D, 9% L/D, and 15% R/D, with a total combined failure pattern in 42% of pts. There was no significant difference in failure patterns between white and black pts (p=0.50, Table 1). The 2 and 5 year OS was 88% and 80%, respectively. Median survival was not reached in our cohort. The 2 and 5-year FFR was 90% and 84%, respectively with a median time to any failure of 16 months after initiation of therapy and median OS of 29 months for these pts.

Conclusion: Our work shows that with modern BC therapies treatment outcomes for pts with TNBC are improved and 84% are free of disease at 5 yrs after the initial diagnosis. The patterns of failure in TNBC are complex, did not vary by race, and showed the largest proportion of our pts (58%) failing in distant and locoregional sites simultaneously, while an additional 30% of pts fail locally only. These failure patterns did not differ significantly based on race. Future efforts will identify pts most at risk for treatment failure for consideration of treatment intensification, as salvage options are limited when treatment failure occurs.

Comparison of Failure Patterns Between White and Black PatientsFailure PatternWhite (n,%)Black (n,%)p-valueLocal only2 (22.5)8 (33) Regional only1 (11)1 (4) Distant only2 (22.5)5 (21)p=0.496Local and Regional0 (0)2 (8) Local and Distant0 (0)3 (13) Regional and Distant3 (33)2 (8) Local, Regional and Distant1 (11)3 (13) 

Citation Format: Rice SR, Cherng H-R, Hamza M, Murali S, Rosenblatt P, Bellavance E, Cheston S, Amin N, Nichols EM. Patterns of failure in a predominately black, inner city cohort of triple negative breast cancer patients at a single institution [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-10-18.

Abstract OT2-03-03: Delivery of a single fraction lumpectomy cavity boost using a novel immobilization device and treatment delivery system

Background: The lumpectomy cavity (LPC) boost has been shown in 2 randomized studies to improve local control in breast cancer. Hypofraction is now being used for delivery of the LPC boost in some early-stage patients. This trial delivers the LPC boost in a single fraction using a novel breast immobilization device/treatment delivery system.

Trial design: Patients are enrolled in this trial after standard resection with lumpectomy/sentinel lymph node biopsy (as appropriate) and chemotherapy (as indicated per standard of care). At the time of CT simulation for whole-breast radiation therapy (RT), the radiation oncologist evaluates breast size and LPC position. If consented for treatment, the patient receives a single fraction “boost” treatment of 8 Gy in 1 fraction followed by standard whole-breast RT to start within 7 days of completion of the boost. Whole-breast radiation is delivered in the supine or prone position with the following fractionation schemes: 4005 cGy in 15 fractions or 5000 cGy in 25 fractions.

On the day of the boost treatment, the patient is fitted with the breast immobilization device, with a plastic inner cup that is fitted so that the breast fills all or most of the cup. A rigid outer cup with a built-in stereotactic fiducial system is attached. Moderate negative pressure is applied to immobilize the breast within the cup system. Patients then undergo CT simulation in the prone position. Clip placement and LPC cavity location must meet eligibility criteria before proceeding with treatment planning and delivery.

Eligibility criteria:

Eligibility criteria: age &gt;60 yo; female only; dx of invasive ductal or lobular carcinoma or ductal carcinoma in situ; estrogen receptor positive; successful completion of lumpectomy ± sentinel lymph node biopsy with negative margins for invasive or noninvasive cancer; greatest tumor dimension &lt;4 cm before surgery; weight &lt;330 lb; height &lt;76 inches; nonlactating and nonpregnant. Various additional dosimetric factors must be met prior to treatment. If these are unable to be met, the patient will become ineligible for treatment.

Specific aims: The aim of this study is to demonstrate the feasibility and safety of delivering the LPC boost RT using a single fraction with a novel immobilization device/treatment delivery system while ensuring coverage of the target volume with appropriate dose homogeneity and conformity. Secondary aims are evaluation of patient comfort, acute toxicity (1 month), and late toxicity (1 year).

Statistical methods: A Simon 2-stage design is utilized for this trial. After evaluating the device and treatment on 8 patients in the first stage, the trial was designed to be terminated and device rejected if the dose distribution was acceptable for ≤5 patients. The first stage was completed in spring 2017 and progressed to the second stage, designed to include a total of 17 patients.

Accrual and target accrual: Target accrual for this study is 14 patients successfully treated while meeting all protocol constraints. As of 6/2017, 16 patients have been enrolled, of whom 13 have been successfully treated while meeting all protocol constraints.

Citation Format: Nichols EM, Becker S, Hong J, Cohen RJ, Mishra MV, Citron W, Cheston SB, Niu Y, Mutaf Y, Yu CX, Feigenberg SJ. Delivery of a single fraction lumpectomy cavity boost using a novel immobilization device and treatment delivery system [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr OT2-03-03.

Abstract OT3-03-03: A prospective study of glycoprotein 88 (GP-88) blood test in healthy women undergoing screening for breast cancer (BC) with mammography (MM)

Background: Population based BC screening with XRAY mammography (MM) has been widely accepted as standard of care for women aged 40+ with average risk of developing BC. Sensitivity and specificity of MM is dependent on breast tissue density and up to ∼20% of BC are undetected by MM. The development of a dependable, low cost blood-based BC screening test to increase the sensitivity and specificity of currently existing BC screening methods is needed.

Rationale: GP88 is expressed & secreted by BC cells & is not expressed by normal mammary epithelial cells, 2 retrospective randomized multi-site trials (a training study & a validation study of 300 cases each) demonstrated that elevated GP88 expression in estrogen positive (ER+) invasive BC was statistically correlated with a 4-fold increase in the risk of 5-yr BC recurrence. GP88 was an independent predictor of BC recurrence in multivariate analysis of other factors such as PR expression, tumor size, grade, lymph node status & stage. The quantitative GP88 EIA was developed to determine the amount of GP88 in biological fluids. The blood based EIA assay is highly specific for GP88 & both sensitive & linear over a wide dynamic range, i.e. detection of GP88 concentrations from 0.1 to 20ng/ml. A baseline GP-88 level of28.4 ± 5 ng/ml was established by us for healthy volunteers (HV). In BC pts a statistically significant increase of serum GP88 was observed in early stage pts (40.7 ± 16 ng/ml; p=0.007). Stratification of BC pts according to their clinical outcomes shows that pts having no evidence of disease (NED) have serum GP88 levels within the range of HV. These data suggest that pts with breast tumors express & secrete high levels of GP88.

Objectives: 1. To determine prospectively GP-88 blood levels in HV at average risk of developing BC screened by MM & in women with recently biopsy-confirmed BC. 2. To establish the statistical distribution of GP88 serum levels in subjects by baseline BIRAD classification (1-6). 3. To determine if the initial GP88 level is predictive of change in BIRADS classification from baseline to 12-mos follow-up. 4. To determine if baseline GP88 level is predictive of the appearance of BC at 12 mos follow-up in HV who were cancer-free at study entry.

Inclusion Criteria: Female, aged &gt;=40 yrs old, presenting for screening or diagnostic MM or diagnostic workup and/or biopsy due to abnormal MM &lt;= to 12 wks before study entry.

Study procedures: Serum levels of GP88 in subjects with average BC risk factors will be measured prospectively at baseline; 3-6 mos & 6-12 mos & correlated with BIRADS reading of the screening MM, BIRADS 1-6; GP88 serum level will be correlated with pathologic results of breast biopsies performed on subjects with suspicious BIRADS (4 & 5) MM & final pathologically confirmed diagnosis of breast cancer as BIRADS 6.

Study Progress: The study is ongoing; currently we have 308 subjects enrolled, the total number of subjects will be up to 725 & screened up to 1400. Study is UM IRB approved & is conducted at the University od Maryland Medical Center (UMMC) and UM Baltimore Washington Medical Center (BWMC). Funding is provided by Maryland Industry Partnership Grant (MIPS)& Avon Grant No. 02-2013-018.

Citation Format: Tkaczuk KHR, Campassi C, Kesmodel S, Bellavance E, Rosenblatt P, Nichols E, Feigenberg SJ, Coughlin P, Drogula C, Urban B, Galandak J, Dromi S, Kuo L, Yue B, Hicks D, Serrero G. A prospective study of glycoprotein 88 (GP-88) blood test in healthy women undergoing screening for breast cancer (BC) with mammography (MM). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT3-03-03.

Abstract OT3-01-07: Phase II study of trastuzumab and pertuzumab alone and in combination with hormonal therapy or chemotherapy with eribulin in women aged ≥60 with HER2/neu overexpressed locally advanced and/or metastatic breast cancer

Her2 overexpression is both a predictive and prognostic marker with tumors overexpressing Her2 having an aggressive natural history, but also responding to targeted therapy. The standard of care for Her2 positive metastatic cancer is docetaxel paired with combined antibody therapy of pertuzumab (P) and trastuzumab (T). Older patients are known to have more difficulty tolerating traditional cytotoxic chemotherapy. Neoadjuvant studies have shown a proportion of patients have pathologic complete responses (pCR) with dual Her2 targeted therapy without chemotherapy. The NEOSPHERE trial demonstrated at 17% pCR after 3 cycles of T+P. The Translational Breast Cancer Research Consortium has shown 12-28% pCR with the combination of estrogen deprivation, trastuzumab, and lapatinib (TBCRC 006 and 023). We have designed a phase II study of T+P alone and then in combination with hormonal or chemotherapy after progression in women age ≥ 60 with Her2 overexpressed locally advanced or metastatic breast cancer (BC). As a primary endpoint, this study seeks to evaluate the overall response rate (ORR) of dual Her2 targeted therapy with T+P without chemotherapy in older patients with locally advanced or metastatic Her2 positive BC (cohort 1). At progression,depending on tumor characteristics and disease status, chemotherapy with eribulin or hormone therapy with anastrozole plus fulvestrant will be added (cohort 2 – A and B). ORR for cohorts 1, 2A and 2B will be determined. Secondary end points will evaluate clinical benefit, progression free survival, overall survival, tolerability, safety, and quality of life. Translational studies involving circulating tumor cells identified through OncoCEE – Biocept system and glycoprotein 88 expression will be performed. Eligibility includes patients' age ≥60 with locally advanced or metastatic Her2 positive BC treated with 0-3 lines of chemotherapy. Patients must have an ejection fraction &gt;50% and meet set hematologic and metabolic lab criteria. Her2 status is per ASCO/ACP guidelines. Excluded patients include patients with active brain metastasis, second malignancies, anticancer treatment &lt;3 weeks prior to the start of therapy. Patients must have not received pertuzumab, eribulin, anastrozole, or fulvestrant in the metastatic setting. A true ORR of 40% will be considered active. The study was designed assuming 25% of patients initially respond to T+P and 75% progress to cohort 2. With a type I error rate of 0.05 and power of 0.90, 40 patients will need to enroll in order to have 30 patients in cohort 2 (15 per arm). Data will be analyzed after eight patients are enrolled. If there are no responders in cohort 1 and 2, the accrual will be stopped and declared inefficient. After 15 patients are enrolled, if no more than 3 of the 15 respond, the therapy will be considered not promising and halted. Currently there are two patients enrolled at the University of Maryland. We are in negotiations to expand to additional sites. Questions can be directed to prosenblatt@umm.edu.

Citation Format: Rosenblatt PY, Kesmodel SD, Bellavance E, Nichols EM, Feigenberg SJ, Tait N, Lewis J, Sivisailam SS, Couzi R, Goloubeva O, Tkaczuk KHR. Phase II study of trastuzumab and pertuzumab alone and in combination with hormonal therapy or chemotherapy with eribulin in women aged ≥60 with HER2/neu overexpressed locally advanced and/or metastatic breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT3-01-07.

Risk of breast fibrosis following irradiation using a breast-specific SBRT system compared with conventional APBI

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Background: To determine the dosimetric characteristics and risk of breast fibrosis using a normal tissue complication probability (NTCP) model in conjunction with a novel preoperative stereotactic radiotherapy system called the GammaPod. Results are compared with linac based post-lumpectomy APBI plans for the same cohort.

Methods: The GammaPod breast SBRT system consists of a Co-60 irradiation unit in combination with an immobilization device with embedded fiducials. Eight patients were enrolled in an IRB-approved protocol and underwent CT scans in the prone position with breast immobilization. A preoperative target (GTV) was synthesized to match the tumor location and volume reported in imaging studies obtained prior to surgery (0.3-2.4 cc). The GTV was expanded by 1.5 cm to create a CTV, and a PTV was created using an additional 0.3 cm margin. The PTV was prescribed 25.5 Gy in 3 fx, which is radiobiologically equivalent to conventional APBI doses of 38.5 Gy in 10 fx. Following the radioablative experience in NSCLC, we also planned to deliver 60.0 Gy to the GTV+0.3 cm as a simultaneous boost in conjunction with the 25.5 Gy PTV prescription dose. For comparison, linac-based treatment plans were created for the same cohort following NSABP B-39 guidelines. Whole breast dosimetry was analyzed in terms of biologically equivalent dose (BED) and Lyman NTCP analysis was performed.

Results: The volume of ipsilateral breast receiving 10, 20, 50, and 100% of the prescribed dose was substantially smaller in GammaPod vs. APBI plans, with cohort averages of 19.3, 13.0, 7.1 and 4.0% vs. 75.8, 67.3, 48.1 and 27.6% respectively (p<0.001). Even though the PTV equivalent uniform BED (EUD) was substantially higher in GammaPod plans (87.9 Gy vs. 57.3 Gy), the ipsilateral breast EUD was still smaller in these plans, 18.9 ± 5.0 Gy vs. 47.2 ± 3.2 Gy (p<0.001). Corresponding NTCP predictions for breast fibrosis rates following GammaPod and APBI treatments were 0.2 ± 0.1% vs. 2.8 ± 0.8% (p<0.001), respectively.

Conclusions: The GammaPod system improves upon traditional post-lumpectomy linac-based APBI by decreasing dose to the ipsilateral breast as well as the predicted rates of breast fibrosis.

The Rookwood Driving Battery: Normative older adult performance

OBJECTIVES

The current study aimed to obtain older adult normative data on a neuropsychological battery in relation to functions underlying driving ability. The effect of age on performance on the battery was previously unknown; normative data revision was necessary to enable more appropriate use of the battery with older clients.

DESIGN

Cross-sectional cohort study.

METHODS

Volunteers were sought from healthy older people living independently in the community to complete the Rookwood Driving Battery. A group of 202 volunteers above the age of 70 were recruited from local social groups to complete the battery. Of these, 184 completed a screening test of cognitive integrity (Mini Mental State Examination, MMSE). The age ranged from 70 to 96 (mean age=81 years, SD=5.438). In the total sample, 155 (77%) were females.

RESULTS

Results of the MMSE indicated that 161 (87.5%) of the group fell above a cut-off (25/30) typically used in epidemiological studies to identify age-related cognitive decline. Of these cognitively intact volunteers, performance was marked by higher battery error scores (mean=5.12, SD=3.75) than those observed in an earlier normative study using younger volunteers below 70 years of age (mean=1.41, SD=1.87). The two age groups differed significantly on all 10 battery subtests; in all cases the level of significance was .002 or less; for nine subtests, significance fell below .001. In the 'intact' older group, battery performance was observed to be closely related to score on the MMSE, a test of general cognitive integrity (r=.558, p=.01).

CONCLUSIONS

Performance on the Rookwood Battery differs for the over 70s and under 70s. The authors suggest essential modifications in its use with older people.

Abstract P4-11-11: Preoperative Radiotherapy Increases Eligibility for Partial Breast Irradiation by Significantly Reducing Normal Tissue Exposure

Introduction: External-beam accelerated partial breast irradiation (EB-APBI) is the most common technique used on NSABP B-39 primarily due to the non-invasive nature of the treatment. Many patients thought to be eligible for EB-APBI become ineligible at the time of planning due to inability to meet dose-volumetric constraints. EB-APBI in the preoperative setting will reduce the volume of normal tissue treated potentially increasing the number of patients eligible for APBI. This study tested the hypothesis that pre-operative EB-APBI will not only decrease target volumes but will decrease normal tissue exposure significantly increasing eligibility for APBI.

Materials and Methods: Forty patients with 41 previously treated early stage breast cancers (tumors ≥4 cm) were retrospectively analyzed from a prospective cohort. Imaging studies (MRI, US and mammogram) were utilized to create a spherical pre-op tumor volume using the largest reported dimension centered within the previously contoured lumpectomy cavity (LPC). Plans were created and optimized for each patient using the pre-operative tumor volume (pre-op) and LPC (post-op) using NSABP B-39 guidelines. Dose-volumetric constraints were analyzed between the cohorts using a t-test analysis. The primary end-point was to evaluate for differences in patient eligibility and normal tissue exposure.

Results: The median tumor volume was 93 cc (range 24-570 cc) and 250 cc (range 46-879 cc) in the pre-and post-operative setting respectively. This reduction in tumor volume translated into an increase in patient eligibility for EB-APBI with 35/41 (85%) cases being eligible for EB-APBI in the preop setting versus 18/41 (44%) cases in the post-op setting (p=0.0002). In the pre-op setting 6 cases were ineligible due to violation of one constraint by 5% and no case violated multiple constraints. In the post-op setting, 12 cases had 1 and 11 cases multiple reasons for ineligibility due to exceeding dose constraints by 5%. The most common reason for ineligibility in both groups was &gt; 60% of the ipsilateral breast volume receiving 50% of the dose. The mean volume of ipsilateral breast receiving 50% of the dose was 42% and 63% in the pre-and post-op groups respectively. The mean contralateral breast dose and ipsilateral lung V20 in the pre-and post-op groups were 1 versus 4% and 3 versus 9%. All DVH criteria were statistically significantly improved in the pre-op setting including heart V5 and V40, ipsilateral breast V5, V20, V50 and V80, contralateral breast dose, chest wall V5, V10 and V20; ipsilateral lung V5, V10, V20 and volume of skin receiving 50% of the dose. Contralateral lung dose and thyroid max dose were not significantly different between plans.

Conclusions: Administration of EB-APBI in the pre-op setting decreases the size of the target volume which significantly increases the utility of APBI nearly doubling the eligibility for APBI in this cohort. The largest benefit is seen by reducing the volume of breast receiving 50% of the dose. This decreased dose to normal tissues will potentially result in decreased morbidity and improved cosmesis.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-11-11.

Comparative analysis of the post-lumpectomy target volume versus the use of pre-lumpectomy tumor volume for early stage breast cancer: implications for the future

Abstract #5134

Purpose: Accelerated partial breast irradiation (APBI) is increasingly being utilized for the treatment of early stage breast cancer. Planning target volume (PTV) generation with this approach is based on the post-lumpectomy cavity volume (post-LPC) and is often associated with treatment of large amounts of normal breast tissue which can result in patient ineligibility for external beam APBI (EB-APBI). In malignancies such as soft tissue sarcomas, neoadjuvant radiation therapy (RT) has been shown to be associated with smaller volumes of tissue irradiated compared to adjuvant RT. However, neoadjuvant RT has not been attempted in the setting of APBI. We hypothesized that a PTV generation based on an expansion of the pre-lumpectomy (pre-LP) intact tumor volume would result in a significant reduction in the volume of irradiated normal breast tissue compared to the current approach of using the post-LPC. We further hypothesize that the use of EB-APBI utilizing the pre-LP tumor will result in greater patient eligibility for APBI.&#x2028; Materials and Methods: 40 patients with 41 early stage breast cancers previously treated with breast conserving lumpectomy and RT were analyzed. Pre-operative imaging and pathology reports were used to determine a pre-LP tumor volume. A sphere, the diameter of which was the largest determined radiographic dimension, representing the pre-LP tumor volume was placed in the center of the previously contoured and treated lumpectomy cavity. PTVs were developed for the pre-LP tumor volume and the post-LPC volume as per the NSABP-B39 protocol guidelines. The pre-LP and post-LPC PTV volumes were compared. Suitability for APBI was analyzed using criteria set forth by NSABP-B39 guidelines.&#x2028; Results: For all patients, the pre-LP PTV was smaller than the post-LPC PTV. The median volume for the pre and post-LPC PTVs were 93 cc (range 24 – 570 cc) and 250 cc (range 45 – 879 cc), respectively. Paired t-test analysis demonstrated the pre-LP PTV to be significantly smaller than the post-LPC PTV, p &lt; 0.001. The average difference between pre-LP and post-LPC PTVs represented 173 cc (range 21 – 482 cc) or 18% (range 3 - 42%) of the whole breast volume. Based on our analysis, only 3 of 41 cases were ineligible for EB-APBI when using the pre-LP tumor volume, (2 based on pathologic criteria and 1 based on dose/volume constraints) while 13 of 41 cases were ineligible when using the post-LPC PTV (2 based on pathologic criteria and 11 based on dose/volume constraints).&#x2028; Conclusion: PTVs based on the pre-LP tumor expansion are likely to be associated with a significantly reduced amount of normal breast tissue irradiated compared to post-LPC PTVs potentially leading to improved breast cosmesis, decreased dose to critical structures and decreased toxicities. Additionally, eligibility for EB-APBI would potentially increase if administered in the pre-lumpectomy setting. The findings from this study support future investigation as to the implications and feasibility of neoadjuvant APBI.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5134.

Patient education in thyrotoxicosis

The aim of the study was to assess the need for a thyrotoxicosis patient education programme and to evaluate a group education session. Patients with thyrotoxicosis were sent questionnaires on knowledge, satisfaction and mood. Patients showed limited knowledge about thyrotoxicosis. Newly diagnosed patients did not differ significantly from those who had been diagnosed more than a year previously. There was no significant relation between knowledge and other measures, but satisfaction was significantly correlated with mood. A further 82 patients were recruited to evaluate a group education session. Patients were randomly allocated either to receive a leaflet about thyrotoxicosis or to attend a group education session in addition to a leaflet. Comparison of the two groups showed a significant difference in anxiety (p = 0.02) but no significant difference in knowledge. Only 9 of 31 patients attended the group education session, and no significant differences were found between those who did and did not attend. Patients in the trial who all received leaflets, were more knowledgeable (p = 0.05) and more satisfied (p < 0.05), than those in the initial survey. Patients with thyrotoxicosis have limited knowledge about their condition. The offer of a group education programme had little effect on that knowledge but was associated with a reduction in anxiety. The provision of leaflets alone seemed to improve knowledge and satisfaction compared with no leaflets, but as this was not a randomised comparison, further evaluation is needed.

Release of luteinizing hormone-releasing hormone from enzymatically dispersed rat hypothalamic explants is pulsatile

This study was conducted to investigate 1) the utility of a cell perifusion system to examine questions dealing with the regulation of pulsatile LHRH release and 2) the necessity of cell-cell connections for communication between LHRH neurons and for coordination of LHRH release. To this end, cell perifusion of both hemihypothalamic tissue and enzymatically dispersed hypothalamic tissue isolated from adult male rats was performed. Periodic perfusate samples were collected and assayed to measure LHRH release. LHRH release from both hemihypothalami and dispersed hypothalamic tissue was clearly pulsatile, with comparable pulse frequencies and amplitudes. These results were interpreted to support the hypothesis that coordination of pulsatile LHRH release can be maintained in the absence of most cell-cell connections. This suggests a paracrine rather than a neural mechanism for the coordination of LHRH secretory events leading to the distinct signals we observe as pulses of LHRH in situ.

The effect of turning and backrub on mixed venous oxygen saturation in critically ill patients

OBJECTIVE: To examine the effect of a change in body position (right or left lateral) and timing of backrub (immediate or delayed) on mixed venous oxygen saturation in surgical ICU patients. METHODS: A repeated-measures design was used to study 57 critically ill men. Mixed venous oxygen saturation was recorded at 1-minute intervals for 5 minutes in each of three periods: baseline, after turning, and after backrub. Subjects were randomly assigned to body position and timing of backrub. Subjects in the immediate-backrub group were turned and given a 1-minute backrub. Mixed venous oxygen saturation was measured at 1-minute intervals for 5 minutes at two points: after the backrub and then with the patient lying on his side. For subjects in the delayed-backrub group, saturation was measured at 1-minute intervals for 5 minutes at two different points: after the subject was turned to his side and after the backrub. RESULTS: Both position and timing of backrub had significant effects on mixed venous oxygen saturation across conditions over time. Subjects positioned on their left side had a significantly greater decrease in saturation when the backrub was started. At the end of the backrub, saturation was significantly lower in subjects lying on their left side than in subjects lying on their right side. The pattern of change differed according to the timing of the backrub, and return to baseline levels of saturation after intervention differed according to body position. CONCLUSIONS: Two consecutive interventions (change in body position and backrub) cause a greater decrease in mixed venous oxygen saturation than the two interventions separated by a 5-minute equilibration period. Turning to the left side decreases oxygen saturation more than turning to the ride side does. Oxygen saturation returns to clinically acceptable ranges within 5 minutes of an intervention. In patients with stable hemodynamic conditions, the standard practice of turning the patient and immediately giving a backrub is recommended. However, it is prudent to closely monitor individual patterns of mixed venous oxygen saturation, particularly in patients with unstable hemodynamic conditions.

The effect of turning and backrub on mixed venous oxygen saturation in critically ill patients

OBJECTIVE

To examine the effect of a change in body position (right or left lateral) and timing of backrub (immediate or delayed) on mixed venous oxygen saturation in surgical ICU patients.

METHODS

A repeated-measures design was used to study 57 critically ill men. Mixed venous oxygen saturation was recorded at 1-minute intervals for 5 minutes in each of three periods: baseline, after turning, and after backrub. Subjects were randomly assigned to body position and timing of backrub. Subjects in the immediate-backrub group were turned and given a 1-minute backrub. Mixed venous oxygen saturation was measured at 1-minute intervals for 5 minutes at two points: after the backrub and then with the patient lying on his side. For subjects in the delayed-backrub group, saturation was measured at 1-minute intervals for 5 minutes at two different points: after the subject was turned to his side and after the backrub.

RESULTS

Both position and timing of backrub had significant effects on mixed venous oxygen saturation across conditions over time. Subjects positioned on their left side had a significantly greater decrease in saturation when the backrub was started. At the end of the backrub, saturation was significantly lower in subjects lying on their left side than in subjects lying on their right side. The pattern of change differed according to the timing of the backrub, and return to baseline levels of saturation after intervention differed according to body position.

CONCLUSIONS

Two consecutive interventions (change in body position and backrub) cause a greater decrease in mixed venous oxygen saturation than the two interventions separated by a 5-minute equilibration period. Turning to the left side decreases oxygen saturation more than turning to the ride side does. Oxygen saturation returns to clinically acceptable ranges within 5 minutes of an intervention. In patients with stable hemodynamic conditions, the standard practice of turning the patient and immediately giving a backrub is recommended. However, it is prudent to closely monitor individual patterns of mixed venous oxygen saturation, particularly in patients with unstable hemodynamic conditions.

Topically applied recombinant tissue plasminogen activator for the treatment of venous ulcers. Preliminary report

BACKGROUND

Increasing evidence suggests that fibrin deposition is an important pathogenic component of venous ulceration and that fibrin removal could accelerate ulcer healing.

OBJECTIVE

We sought to determine whether topical application of recombinant tissue plasminogen activator (tPA) compounded in 1% hyaluronate acid (HA) can be used safely in venous ulcers and whether it can accelerate healing.

METHODS

Twelve patients were randomized in a double-blind fashion in three sequential groups of four subjects each, so as to receive daily topical application of either placebo (HA alone, one patient) or tPA/HA (three patients) at escalating doses of 0.25, 0.5, and 1.0 mg/ml of tPA for 4 weeks.

RESULTS

No safety problems occurred, and we found a close direct correlation between mean ulcer reepithelialization, fibrin removal, and the dose of topically applied tPA (r = 0.991).

CONCLUSION

In this first study to examine its usefulness, topically applied tPA appears to be a safe and promising agent for treating venous ulcers.

Tumor cell retention of antibody Fab fragments is enhanced by an attached HIV TAT protein-derived peptide

Two peptide analogs of the 37-62 sequence region of the HIV TAT protein bind tightly to the surface of A431 breast carcinoma cells. After conjugation to either of two poorly internalized anti-tumor antibody Fab fragments, the analogs enhanced the in vitro cell surface retention and internalization of the Fab fragments to the level of the whole antibodies. This was at the expense of some binding specificity in the case of 1.6 peptides/NRLU-10 Fab, but not in the case of 1.1 peptides/Fab. Enhanced retention may occur by enhanced bivalent binding of the Fab fragments. The internalized fraction of free peptide, but not of the Fab conjugates, is enhanced by chloroquine. The conjugates which were less specific for tumor cell binding may be useful for enhanced retention/internalization of specifically acting agents, for use at specific sites of injection, or against pre-separated target cell populations, while the more specific conjugate may be of interest for further development.

Nephrology nursing care plan and patient education plan for the patient receiving Epogen

This article presents a nursing care plan and patient education plan for patients receiving recombinant human erythropoietin in the form of Epogen (Epoetin alfa). Eight nursing diagnoses and a standard and outcomes for patient education are included.

Control of methicillin-resistant Staphylococcus aureus in a burn unit: role of nurse staffing

We investigated retrospectively the spread of methicillin-resistant Staphylococcus aureus (MRS) in a burn unit. During 8 months, 34% of the patients acquired MRS, and transmission continued despite barrier isolation precautions and treatment of colonized personnel with topical intranasal antibiotics. Several findings suggested MRS was spread primarily by contact transmission involving personnel: case-control comparison showed burn size to be the major host risk factor for colonization; correlation analysis of environmental factors revealed a significant (p = 0.001) association of new cases with increased patient load and with staffing by overtime or temporary nurses; and environmental sampling yielded few colonies of MRS. The outbreak halted following implementation of control measures, among which assignment of separate nurses to colonized patients appeared to be essential. The association of different nurse staffing variables with persistence then eradication of MRS suggests nurse staffing may have been an important factor in staphylococcal transmission.

Comparative study involving bitoric effect of hard resin lenses mounted in optyl frames, zylonite frames, and metal frames

It has been noted clinically that hard resin lenses mounted in rimmed frames exhibited bitoricity. The manufacturers of optyl plastic frames claim that the molecular structure of optyl eliminates the bitoric effect. This study involves "clocking" hard resin lenses mounted in frames fashioned of optyl, zylonite plastic, and metal mountings to test this hypothesis. The results are important because of the increasing use of optical CR 39 plastic in the fabrication of eyewear.

Identification of a mouse gene required for binding of Rauscher MuLV envelope gp70

Mouse chromosome segregating somatic cell hybrids were established between a mouse thymic leukemai cell line (GRSL) and Chinese hamster E36 cells. The GRSL cells specifically bound purified Rauscher leukemia virus gp70 while the E36 cells exhibited no binding. The hybrids selectively bound Ruascher gp70 depending on the presence of a mouse cellular gene for the ecotropic murine luekemia gp70 receptor. A syntenic relationship was observed between the DIP-3 chromosome marker (on chromosome 5) and the gp70 receptor in primary clones and subclones of these hybrids; this was confirmed by chromosome analysis. The involvement of H-2 in the binding of Rauscher MuLV gp70 could be ruled out, because discordancies of the receptor presence and H-2 absence as well as of the receptor absence and H-2 presence type could be observed. Our results indicate that the Rec-1 (replication ecotropic MuLV) gene of Gazdar et al. (4) may well be the receptor gene for the ecotropic murine leukemia virus.

Assignment of the gene for glyoxylase I to mouse chromosome 17 by somatic cell genetics

Evidence is presented for the assignment of the gene for glyoxylase I to mouse chromosome 17 using mouse X Chinese hamster somatic cell hybrids. GLO I was not expressed concordantly with any known marker enzymes which represented 11 linkage groups. The presence of chromosome 17 and expression of GLO I were concordant in 31/31 clones. GLO I is thus linked to the H-2 histocompatibility locus in the mouse.

Gene linkage analysis in the mouse by somatic cell hybridization: assignment of adenine phosphoribosyltransferase to chromosome 8 and alpha-galactosidase to the X chromosome

Somatic cell hybridization techniques were applied to gene linkage analysis in the laboratory mouse. Cells of an established line of Chinese hamster lung fibroblasts were fused with mouse embryo fibroblasts and with mouse peritoneal macrophages obtained from different inbred strains. From 3 hybridization experiments, 123 primary and secondary clones were isolated in HAT selective medium and 24 were back-selected in 8-azaguanine. Hybrid clones were characterized for the expression of 16 murine isozymes by starch, acrylamide, and Cellogel electrophoresis, and on the basis of segregation data, 3 syntenic associations could be made. Malate oxidoreductase decarboxylating (MOD) and mannose phosphate isomerase (MPI) segregated concordantly, confirming an established linkage relationship; adenine phosphoribosyltransferase (APRT) segregated concordantly with glutathione reductase (GR) which is known to be on chromosome 8; alpha-galactosidase was observed to be syntenic with hypoxanthine phosphoribosyltransferase (HPRT), and X-linked enzyme. All other isozymes examined segregated independently of one another.