Cavity Margins Research Articles

A comparative study between crack analysis and a mechanical test for assessing the polymerization stress of restorative composites

ObjectivesTo verify the hypothesis that crack analysis and a mechanical test would rank a series of composites in a similar order with respect to polymerization stress. Also, both tests would show similar relationships between stress and composite elastic modulus and/or shrinkage. MethodsSoda-lime glass discs (2-mm thick) with a central perforation (3.5-mm diameter) received four Vickers indentations 500μm from the cavity margin. The indent cracks were measured (500×) prior and 10min after the cavity was restored with one of six materials (Kalore/KL, Gradia/GR, Ice/IC, Wave/WV, Majesty Flow/MF, and Majesty Posterior/MP). Stresses at the indent site were calculated based on glass fracture toughness and increase in crack length. Stress at the bonded interface was calculated using the equation for an internally pressurized cylinder. The mechanical test used a universal testing machine and glass rods (5-mm diameter) as substrate. An extensometer monitored specimen height (2mm). Nominal stress was calculated dividing the maximum shrinkage force by the specimen cross-sectional area. Composite elastic modulus was determined by nanoindentation and post-gel shrinkage was measured using strain gages. Data were subjected to one-way ANOVA/Tukey or Kruskal–Wallis/Mann–Whitney tests (alpha: 5%). ResultsBoth tests grouped the composites in three statistical subsets, with small differences in overlapping between the intermediate subset (MF, WV) and the highest (MP, IC) or the lowest stress materials (KL, GR). Higher stresses were developed by composites with high modulus and/or high shrinkage. SignificanceCrack analysis demonstrated to be as effective as the mechanical test to rank composites regarding polymerization stress.

Bonding effectiveness of a new ‘multi-mode’ adhesive to enamel and dentine

ObjectivesSelf-etch adhesives are well adopted in general practice, obviously primarily thanks to their ease of use and fast application time. Nevertheless, phosphoric acid is still often recommended to beforehand etch enamel following a so-called ‘selective’ enamel-etch technique, this in particular when most cavity margins end in enamel. The purpose of this study was to test if a new one-step adhesive can be applied in a multi-mode manner, this following different, either ‘full’ or ‘selective’, self-etch and etch-and-rinse approaches. Specific research hypotheses tested were that prior phosphoric-acid etching did not affect the bonding effectiveness of the one-step adhesive to enamel and dentine, and that the bonding effectiveness to dentine was also not affected when the adhesive was applied either following a ‘dry-bonding’ or ‘wet-bonding’ etch-and-rinse technique. MethodsThe micro-tensile bond strength (μTBS) of the one-step self-etch adhesive G-Bond Plus (GC, Tokyo, Japan; 1-SEA) was measured when it was bonded to bur-cut enamel following either a ‘self-etch’ or an ‘etch-and-rinse’ adhesive protocol, and to bur-cut dentine when applied following either a ‘self-etch’, a ‘dry-bonding’ or a ‘wet-bonding’ etch-and-rinse adhesive protocol. Bond-strength testing was corroborated by ultra-structural analysis of the interfacial interaction at enamel and dentine using transmission electron microscopy (TEM). ResultsPrior phosphoric-acid etching significantly increased the bonding effectiveness of the 1-SEA to enamel. A clearly enhanced micro-retentive surface was revealed by TEM. To dentine, no statistically significant difference in bonding effectiveness was recorded when the 1-SEA was either applied following a self-etch or both etch-and-rinse approaches. The ‘dry-bonding’ etch-and-rinse protocol was significantly more effective than its ‘wet-bonding’ version. TEM however revealed indications of low-quality hybridisation following both etch-and-rinse approaches, in particular in the form of a porous and poorly resin-infiltrated collagen mesh. ConclusionsWhile phosphoric-acid etching definitely improved bonding of the one-step self-etch adhesive to enamel, one should be more careful with additional phosphoric-acid etching of dentine. Although the bond strength was not reduced, the resultant adhesive interface appeared ultra-structurally more vulnerable to biodegradation.

Effect of different adhesive systems on microleakage in class II composite resin restorations

The success of a restoration depends on the interaction between the adhesive system and the dental substrate. The aim of this study was to evaluate the occurrence of microleakage in class II resin restorations using different adhesive systems light cured in enamel and dentin: conventional and self-etching acrylic. For that purpose 40 human molars were sectioned in buccal–lingual direction, making up 80 samples (40 mesial and 40 distal halves). Each sample had cavities class II prepared and the occlusal margins were kept in enamel while the cervical margins were kept in dentin. The specimens were divided into four groups (n=20) according to the adhesive system used. After restorative and thermocycling procedures the degree of dye leakage was qualified using a stereomicroscopic loupe (45X). Data were analyzed by ANOVA and Kruskal–Wallis tests (α=0.05). Results obtained for occlusal (enamel) and cervical (dentin) margins (μm) were, respectively: GI-11.45, 20.7; GII-15.4, 19.4; GIII-23.3, 24.05; GIV-31.85, 17.85. In enamel, the self-etching adhesive systems presented the less control of marginal leakage in the occlusal and cervical margins. Although for the dentin there was no difference among the adhesive systems used. It was concluded that no adhesive system hermetically sealed the restorations with cavity margins in enamel or dentin and self-etching adhesives did not improve microleakage controlling when compared to conventional systems.

Evaluation of Microleakage in Class V Composite Restoration using Different Techniques of Polymerization

ABSTRACT Aims The purpose of this study was to evaluate the effect of light intensity and curing cycle of quartz tungsten halogen (QTH) and plasma arc curing (PAC) lights on the microleakage of class V composite restorations. Materials and methods A total of 60 freshly extracted human maxillary premolars were used for this study. Standardized class V cavities were prepared and restored with microhybrid resin composite. According to the curing protocol, the teeth were then divided into three groups (n = 20): QTH curing (standard and soft start mode) and PAC high intensity irradiation. The microleakage was evaluated by immersion of the samples in 50% silver nitrate solution. The samples were then sectioned, evaluated under a stereomicroscope and scored for microleakage. Statistical analysis used Dye leakage scores were obtained, and analysis was done using Student's t-test. Results Light curing with QTH light in the soft start mode, showed the least leakage in the composite restoration, which was highly significant when compared with the other groups (p < 0.01). Light curing with QTH light in the standard mode, showed moderate microleakage, which was statistically significant (p < 0.05), when compared with the PAC high intensity curing. Curing with PAC light in high intensity mode resulted in severe microleakage along the cavity margins. Conclusion Within the limitations of the study, it may be concluded that: 1. The high intensity PAC light resulted in maximum leakage, when compared to the other groups in the study. 2. The soft start polymerization mode offers a distinctive advantage over the standard curing protocol, in terms of microleakage, for the QTH curing lights. Clinical significance In the clinical scenario, soft start curing regimen offers a distinctive advantage over the conventional mode of the QTH curing and the high intensity rapid curing offered by the PAC light. How to cite this article Chandurkar AM, Metgud SS, Yakub SS, Kalburge VJ. Evaluation of Microleakage in Class V Composite Restoration using Different Techniques of Polymerization. Int J Prosthodont Restor Dent 2012;2(1): 10-15.

Optimizing Surgical Margins in Breast Conservation

Adequate surgical margins in breast-conserving surgery for breast cancer have traditionally been viewed as a predictor of local recurrence rates. There is still no consensus on what constitutes an adequate surgical margin, however it is clear that there is a trade-off between widely clear margins and acceptable cosmesis. Preoperative approaches to plan extent of resection with appropriate margins (in the setting of surgery first as well as after neoadjuvant chemotherapy,) include mammography, US, and MRI. Improvements have been made in preoperative lesion localization strategies for surgery, as well as intraoperative specimen assessment, in order to ensure complete removal of imaging findings and facilitate margin clearance. Intraoperative strategies to accurately assess tumor and cavity margins include cavity shave techniques, as well as novel technologies for margin probes. Ablative techniques, including radiofrequency ablation as well as intraoperative radiation, may be used to extend tumor-free margins without resecting additional tissue. Oncoplastic techniques allow for wider resections while maintaining cosmesis and have acceptable local recurrence rates, however often involve surgery on the contralateral breast. As systemic therapy for breast cancer continues to improve, it is unclear what the importance of surgical margins on local control rates will be in the future.

Effect of Three Different Mouthrinses on Microleakage of Composite Resin Restorations with Two Adhesive Systems after Bleaching with 10% Carbamide Peroxide

The aim was to evaluate the effects of Oral-B (OB), Listerine (LN) and Rembrandt Plus (RM) mouthrinses on microleakage of composite resin restorations bonded with two adhesive systems after bleaching with 10% carbamide peroxide. A total of 60 Cl V cavities were prepared on human premolars. The occlusal and gingival margins were placed 1 mm occlusal to and apical to CEJ respectively. The teeth were randomly divided into two groups based on the adhesive system used: Excite (EX) and Clearfil SE Bond (CSE) groups. After composite resin restoration of cavities, thermocycling and bleaching with 10% carbamide peroxide for 2 hours daily for 14 days, the teeth in each adhesive group were further subdivided into three subgroups and were immersed for 12 hours in the three OB, RM and LN mouthrinses. The teeth were then placed in 2% basic fuschin for 24 hours. After dissecting the teeth, microleakage was evaluated under a stereomicroscope at 16×. Data was analyzed with multifactor ANOVA and Bonferroni test at p < 0.05. Microleakage with EX was significantly higher than that with CSE (p = 0.009). Microleakage at gingival margins was significantly higher than that at occlusal margins (p = 0.15). Microleakage with OB was higher than that with LN (p = 0.02). However, there were no significant differences in microleakage between LN and RM (p = 1) and between RM and OB (p = 0.15). In addition, with the EX adhesive system, microleakage with OB was higher than that with LN and RM (p = 0.02). In the present study, microleakage of composite resin restorations was influenced by the type of the adhesive system, mouthrinse type and the location of the cavity margin. Use of some mouthrinses, such as OB after bleaching can increase postrestoration microleakage of resin composite restorations bonded with etch-and-rinse adhesive systems.

Seven-year clinical performance of CEREC-2 all-ceramic CAD/CAM restorations placed within deeply destroyed teeth

Adhesively luted all-ceramic restorations represent a promising way to preserve and stabilize weakened tooth substance, but little information is published about the clinical performance of extensive all-ceramic restorations. A total of 78 large CEREC 2™ single-tooth all-ceramic restorations had been placed in 35 patients. After 7years, 59 teeth in 25 patients were reevaluated according to USPHS or modified USPHS criteria regarding aesthetic properties, e.g., "anatomic form," "color match," and "marginal discoloration"; functional properties, e.g., "marginal integrity," wear expressed by the criteria "proximal contact" and "static/dynamic occlusal relationship"; and biological properties, e.g., "tooth vitality" and "secondary caries". Additionally, the "proportion of margin below/above cemento-enamel junction" was included. Two restorations had failed prior to the 7-year recall, one due to a bulk fracture of the restoration and one due to poor marginal integrity (rated "Charlie") after 4years. Other six restorations were rated as failure at the 7-year evaluation (three restorations revealed secondary caries, one was bulk fracture of the Cerec 2 restoration, and two failures were related to endodontic problems resulting in extraction or amputation of one root, respectively), resulting in a failure rate of 13.1% after 7years. A total of 96.4% of the restorations revealed sufficient ratings for esthetic properties "anatomic form," "color match," "marginal discoloration," and "marginal integrity". The survival rate of 86.9% at the 7-year recall demonstrates that adhesively luted all-ceramic CAD/CAM-generated restorations are suitable for restoration of extended coronal defects. CAD/CAM-generated all-ceramic restorations facilitate the reconstruction of deeply destroyed teeth irrespectively of the location of the cavity margins.

Cavity Margin Status Is an Independent Risk Factor for Local-Regional Recurrence in Breast Cancer Patients Treated with Neoadjuvant Chemotherapy Before Breast-Conserving Surgery

The objection of this study is to investigate whether the cavity margin (CM) status has different predictive efficacy for local-regional recurrence (LRR) in patients who have received or have not received neoadjuvant chemotherapy (NAC) before breast-conserving surgery. We identified 61 patients who received NAC before breast-conserving surgery. A nonrandomized unmatched cohort of 295 patients without history of receiving NAC were also included in this study. Clinicopathological features and follow-up data were abstracted and analyzed. Patients in the NAC-treated group had more advanced diseases when compared with patients in the nonNAC-treated group. With a median follow-up of 42 months, the LRR-free survival rate of patients with positive CMs was significantly lower than that of patients with negative CMs in the NAC-treated group. This distinction was not observed in the nonNAC-treated group. Univariate and multivariate analysis revealed that positive CM was the only independent predictive factor for LRR in the NAC-treated group but not in nonNAC-treated patients. CM status had different predictive efficacy for LRR in different settings. Association between CM status and LRR was observed in NAC-treated patients rather than nonNAC-treated patients. More extensive surgical treatment might be needed in NAC-treated patients when their CMs are positive.

In vitro evaluation of marginal and internal adaptation after occlusal stressing of indirect class II composite restorations with different resinous bases and interface treatments. “Post-fatigue adaptation of indirect composite restorations”

The present study evaluated the influence of different composite bases and surface treatments on marginal and internal adaptation of class II indirect composite restorations, after simulated occlusal loading. Thirty-two class II inlay cavities were prepared on human third molars, with margins located in cementum. A 1-mm composite base extending up to the cervical margins was applied on all dentin surfaces in the experimental groups; impressions were made and composite inlays fabricated. The following experimental conditions were tested: no liner (control group), flowable composite treated with soft air abrasion (experiment 1), flowable composite sandblasted (experiment 2) and restorative composite sandblasted (experiment 3). All specimens were submitted to 1,000,000 cycles with a 100-N eccentric load. Tooth-restoration margins were analysed semi-quantitatively by scanning electron microscopy before and after loading; internal adaptation was also evaluated after test completion. The percentage of perfect adaptation in enamel was 79.5% to 92.7% before loading and 73.3% to 81.9% after loading. Perfect adaptation to dentin was reduced before loading (54.8% to 77.6%) and after loading (41.9% to 63%), but no difference was found among groups for pre- and post-loading conditions. No debonding occurred between the base and composite luting. A significant, negative influence of cyclic loading was observed. The results of the present study support the use of flowable or restorative composites as base/liner underneath large class II restorations. Soft air abrasion represents a potential alternative to airborne particle abrasion for treating cavities before cementation. The application of a composite base underneath indirect composite restorations represents a feasible non-invasive alternative to surgical crown lengthening to relocate cavity margins from an intra-crevicular to supra-gingival position.

Lumpectomy Cavity Shaved Margins Do Not Impact Re-excision Rates in Breast Cancer Patients

The benefits of taking shaved cavity margins (SCM) at the time of lumpectomy are unclear. We sought to determine if taking SCM decreases re-excision rates by increasing the total breast tissue volume excised. We undertook a retrospective review of breast cancer patients who underwent lumpectomy from 2004 to 2006. Patients were divided into three groups. Group 1 had lumpectomy alone, group 2 had lumpectomy plus select (1-3) SCM, and group 3 had lumpectomy plus complete (≥4) SCM. Pathologic findings and surgical outcomes were compared between groups. 773 cancers treated by lumpectomy were included in this study; 197 were in group 1, 130 were in group 2, and 446 were in group 3. The mean total volume of breast tissue excised in group 1 (106.6 cm(3)) was significantly larger than the volume excised in groups 2 (79.3 cm(3)) and 3 (76.3 cm(3)). Rates of re-excision and successful breast-conservation therapy (BCT) were not significantly different between groups. Despite a lower total volume of breast tissue excised in groups 2 and 3, there was no significant increase in locoregional recurrence rates (LRR) at median follow-up of 54 months. Taking additional SCM during lumpectomy resulted in a significantly lower overall volume of breast tissue excised, with no increase in LRR. Contrary to prior studies, we found that SCM did not decrease re-excision rates or impact the success of BCT. Therefore, the main advantage of taking SCM appears to be that less breast tissue is excised, which could potentially improve cosmetic outcomes.

Cavity margins examination in breast-conserving therapy

There is a good consensus that the pathologic lumpectomy margin status is the most important factor to determine the risk of local recurrence of carcinoma after breast-conserving therapy. However, there is no consensus regarding the definition of a complete excision or an adequate margin and the reported rates of repeat surgery for positive margins range from 10 to 57%. Therefore, an alternative technique of margin evaluation, called cavity shaving or cavity margin shaving has been proposed and applied by some surgical teams in order to reduce the need for re-excisions and to detect multifocality. We aim to describe in this review how to handle, analyse and report breast lumpectomy specimens with associated cavity margins and to discuss the potential advantages and drawbacks of this method.

Can evaluation of a dental procedure at the outset of learning predict later performance at the preclinical level? A pilot study

The purpose of this study was to examine the effectiveness of conventional pre-clinical training in dentistry and to determine if evaluation of a dental procedure at the beginning of dental training can be a predictor for future performance. A group of second year dental students with no previous experience in operative dentistry were asked to prepare a conventional class I cavity on a lower first molar typodont. Their first preparation was carried out after an introductory lecture and a demonstration and their second at the end of conventional training. The prepared typodonts were coded and blindly scored for the traditional assessment criteria of outline form, retention form, smoothness, cavity depth and cavity margin angulation. Once the codes were broken, a paired t-test was used to compare the difference between the means of before and after scores (P<0.0001) and a Pearson's linear correlation to test the association (r=0.4). From the results of this study, we could conclude that conventional preclinical training results in a significant improvement in the manual skills of the dental students and that the dental procedure used had only a limited predictive value for later performance at the preclinical level.

Absence of carious lesions at margins of glass-ionomer cement and amalgam restorations: An update of systematic review evidence

BackgroundThis article aims to update the existing systematic review evidence elicited by Mickenautsch et al. up to 18 January 2008 (published in the European Journal of Paediatric Dentistry in 2009) and addressing the review question of whether, in the same dentition and same cavity class, glass-ionomer cement (GIC) restored cavities show less recurrent carious lesions on cavity margins than cavities restored with amalgam.MethodsThe systematic literature search was extended beyond the original search date and a further hand-search and reference check was done. The quality of accepted trials was assessed, using updated quality criteria, and the risk of bias was investigated in more depth than previously reported. In addition, the focus of quantitative synthesis was shifted to single datasets extracted from the accepted trials.ResultsThe database search (up to 10 August 2010) identified 1 new trial, in addition to the 9 included in the original systematic review, and 11 further trials were included after a hand-search and reference check. Of these 21 trials, 11 were excluded and 10 were accepted for data extraction and quality assessment. Thirteen dichotomous datasets of primary outcomes and 4 datasets with secondary outcomes were extracted. Meta-analysis and cumulative meta-analysis were used in combining clinically homogenous datasets. The overall results of the computed datasets suggest that GIC has a higher caries-preventive effect than amalgam for restorations in permanent teeth. No difference was found for restorations in the primary dentition.ConclusionThis outcome is in agreement with the conclusions of the original systematic review. Although the findings of the trials identified in this update may be considered to be less affected by attrition- and publication bias, their risk of selection- and detection/performance bias is high. Thus, verification of the currently available results requires further high-quality randomised control trials.

Interest in cavity shaving in breast conservative treatment does not depend on lumpectomy technique

In breast conserving surgery (BCS), the usefulness to perform systematic cavity shaving is actively debated. Some investigators argued that systematic cavity shaving could avoid surgical re-excision and make diagnosis of unexpected multifocality. Others argued that usefulness of cavity shaving depends on volumes of resection. In this study one hundred patients undergoing BCS with systematic cavity shaving were included. Margins less than 3 mm were considered to be insufficient. We tested clinico-pathological characteristics in order to identify predictive model of cavity margin shaving utility and we sought to determine if cavity margin shaving usefulness depends on volumes of resection. We showed that cavity shaving avoids the need for re-excision in 24% of cases as well as diagnosis of multifocality in 6% of cases. However, the clinical usefulness of cavity shaving was not related to the volumes of resection.

Current concepts and techniques for caries excavation and adhesion to residual dentin.

The advent of "Adhesive Dentistry" has simplified the guidelines for cavity preparation enormously. The design and extent of the current preparations are basically defined by the extent and shape of the caries lesion, potentially slightly extended by bevelling the cavity margins in order to meet the modern concept of minimally invasive dentistry. New caries excavation techniques have been introduced, such as the use of plastic and ceramic burs, improved caries-disclosing dyes, enzymatic caries-dissolving agents, caries-selective sono/air abrasion and laser ablation. They all aim to remove or help remove caries-infected tissue as selectively as possible, while being minimally invasive through maximum preservation of caries-affected tissue. Each technique entails a specific caries-removal endpoint and produces residual dentin substrates of different natures and thus different receptiveness for adhesive procedures. This paper reviews the newest developments in caries excavation techniques and their effect on the remaining dentin tissue with regard to its bonding receptiveness.

SEM evaluation of the effect of fiber placement or flowable resin lining on microleakage in Class II adhesive restorations: An in vitro study

Aims : To evaluate the effect of two fibers (polyethylene or glass) and a flowable resin liner on microleakage in Class II adhesive restorations. Materials and Methods : Class II cavities were prepared on mesial and distal surfaces of 40 extracted sound human molars. The cavity margins were below the CEJ on one side and above the CEJ on the other. The teeth were randomly divided into four groups according to the restoration technique: group 1: restored with a resin composite in bulk after SE Bond application; group 2: flowable resin liner was used before composite restoration; group 3: polyethylene fibre and in group 4: glass fiber was placed into the bed of flowable resin before composite restoration. Samples were finished, stored in distilled water and then thermocycled. Apices were sealed and tooth surfaces were coated with nail polish within 1 mm of the margins and placed in basic fuschin dye for 24 h at 37oC. Teeth were rinsed and sectioned longitudinally through the restorations. Microleakage was evaluated and scored. Statistical Analysis Used : Kruskal-Wallis, Mann-Whitney U -test. Results : Flowable resin, everStick NET, and Ribbond THM used in combination with flowable resin significantly reduced leakage at occlusal enamel margins ( P Conclusions : Use of flowable composite alone or in combination with polyethylene or glass fibers reduces occlusal leakage in Class II adhesive cavities with enamel margins.

Endodontic surgery failure: SEM analysis of root-end filling

This study investigated the quality of root-end filling in cases of periapical lesions persisting after endodontic surgery. Ten patients requiring extraction of an endodontically treated tooth were included. The root-ends of extracted teeth were examined by scanning electron microscopy. Defects at the interface between the root-end filling and cavity margin were classified as ideal, imperfect (some marginal disruption) or inadequate (continuous marginal disruption involving >30% of the interface). Four cases were scored as imperfect, and six were scored as inadequate. A defective apical seal could favour continuous leakage of surviving bacteria and their by-products from the infected root canal system to periapical tissues, thereby sustaining inflammation.

Abstract P5-14-03: The Impact of Routine Cavity Margins on Reducing the Need for Re-Excision in Women Undergoing Breast-Conserving Surgery for Invasive or Non-Invasive Breast Cancer

Abstract Background: The goal of breast conserving surgery (BCS) in women with invasive breast cancer (IBC) or ductal carcinoma in situ (DCIS) is to remove all malignant cells from the breast or to reduce the residual tumor burden to a level that is likely to be eradicated by adjuvant radiation therapy and/or systemic therapy. Theoretical concerns exist that radiography of lumpectomy specimens and subsequent pathologic processing may lead to artifactually positive lumpectomy margins (LM), and the need for subsequent re-excision. To improve the chances of obtaining negative final margins (FM) (generally defined as 2 mm or greater), a number of surgeons in the US and abroad have adopted a technique in which 4-6 additional margins surrounding the main lumpectomy specimen, so-called “cavity margins” (CM), are routinely obtained. The purpose of this study was to assess the clinical utility of the routine use of CM in reducing the need for re-excision. Methods: The surgical pathology records at our institution were searched for all cases of BCS with additional complete routine CM sampling performed by a single surgeon between May 2008 and April 2010. Patients in whom additional CM were obtained based on intraoperative findings of grossly close margins were excluded from the analysis. The demographic characteristics of the patients and the histological features of the tumor were recorded. We then tabulated the number of patients who had positive LM, CM, and FM, defined as either DCIS or invasive carcinoma at or less than 2 mm from inked specimen margin. The number needed to treat (NNT) to prevent one re-excision was calculated. Results: We identified 97 women (74 with IBC and 33 with DCIS-only) who had undergone BCS with routine CM sampling during the study period. Mean patient age was 62. Median specimen volume was 178 cc3. 90% of the IBCs were ductal subtype. Mean IBC size was 1.5 cm. 63% of tumors were ER+, 58% PR+, and 7% HER2+. Of the 97 patients in this study, 64 had +LM and 33 had -LM. Of the 64 with +LM, 38 did not have tumor in the CM and 26 had tumor in the CM. Of these 26, 18 had +FM (re-excision needed) and 8 had -FM (no re-excision needed). The proportion of patients with actual tumor at ink (not just close margins) in the lumpectomy specimen was significantly higher among the group with tumor present in the CM than it was in the group with no tumor present in the CM (14/26 versus 7/38, p = 0.006). The NNT with routine CM compared with standard BCS to prevent one re-excision was 2.0 (95% CI, 1.5 — 2.1). Discussion: In this study the routine use of CM reduced the need for reexcision in women undergoing BCS for IBC or DCIS; one re-excision was avoided for every two patients treated with this surgical approach. The absence of tumor in the CM in the majority of patients with positive LM suggests that specimen radiography and/or pathologic processing techniques may result in artifactually positive LM. Our results indicate that improved specimen imaging and pathological processing techniques are needed to increase the fidelity of margin assessment. In the meantime, the routine use of cavity margins may reduce the need for re-excision in women undergoing BCS. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-14-03.

Gamma Knife surgery combined with resection for treatment of a single brain metastasis: preliminary results

Resection and whole-brain radiation therapy (WBRT) have classically been the standard treatment for a single metastasis to the brain. The objective of this study was to evaluate the use of Gamma Knife surgery (GKS) as an alternative to WBRT in patients who had undergone resection and to evaluate patient survival and local tumor control. The authors retrospectively reviewed the charts of 150 patients treated with a combination of stereotactic radiosurgery and resection of a cranial metastasis at their institution between April 1997 and September 2009. Patients who had multiple lesions or underwent both WBRT and GKS were excluded, as were patients for whom survival data beyond the initial treatment were not available. Clinical and imaging follow-up was assessed using notes from clinic visits and MR imaging studies when available. Follow-up data beyond the initial treatment and survival data were available for 68 patients. The study included 37 women (54.4%) and 31 men (45.6%) (mean age 60 years, range 28-89 years). In 45 patients (66.2%) there was systemic control of the primary tumor when the cranial metastasis was identified. The median duration between resection and radiosurgery was 15.5 days. The median volume of the treated cavity was 10.35 cm(3) (range 0.9-45.4 cm(3)), and the median dose to the cavity margin was 15 Gy (range 14-30 Gy), delivered to the 50% isodose line (range 50%-76% isodose line). The patients' median preradiosurgery Karnofsky Performance Scale (KPS) score was 90 (range 40-100). During the follow-up period we identified 27 patients (39.7%) with recurrent tumor located either local or distant to the site of treatment. The median time from primary treatment of metastasis to recurrence was 10.6 months. The patients' median length of survival (interval between first treatment of cerebral metastasis and last follow-up) was 13.2 months. For the patient who died during follow-up, the median time from diagnosis of cerebral metastasis to death was 11.5 months. The median duration of survival from diagnosis of the primary cancer to last follow-up was 30.2 months. Patients with a pretreatment KPS score ≥ 90 had a median survival time of 23.2 months, and patients with a pretreatment KPS score < 90 had a median survival time of 10 months (p < 0.008). Systemic control of disease at the time of metastasis was not predictive of increased survival duration, although it did tend to improve survival. Although the debate about the ideal form of radiation treatment after resection continues, these findings indicate that GKS combined with surgery offers comparable survival duration and local tumor control to WBRT for patients with a diagnosis of a single metastasis.

Metastasis Infiltration: An Investigation of the Postoperative Brain–Tumor Interface

This study aims to evaluate brain infiltration of metastatic tumor cells past the main tumor resection margin to assess the biological basis for the use of stereotactic radiosurgery treatment of the tumor resection cavity and visualized resection edge or clinical target volume. Resection margin tissue was obtained after gross total resection of a small group of metastatic lesions from a variety of primary sources. The tissue at the border of the tumor and brain tissue was carefully oriented and processed to evaluate the presence of tumor cells within brain tissue and their distance from the resection margin. Microscopic assessment of the radially oriented tissue samples showed no tumor cells infiltrating the surrounding brain tissue. Among the positive findings were reactive astrocytosis observed on the brain tissue immediately adjacent to the tumor resection bed margin. The lack of evidence of metastatic tumor cell infiltration into surrounding brain suggests the need to target only a narrow depth of the resection cavity margin to minimize normal tissue injury and prevent treatment size-dependent stereotactic radiosurgery complications.