Surgical Clip Placement Research Articles

Endoscopic Endonasal Transplanum Approach to the Paraclinoid Internal Carotid Artery

Objective To investigate the relevance of an endoscopic transnasal approach to the surgical treatment of paraophthalmic aneurysms. Setting Binasal endoscopic transplanum surgery was performed. Participants Seven cadaver heads were studied. Main Outcome Measures (1) Dimensions of the endonasal corridor, including the operative field depth, lateral limits, and the transplanum craniotomy. (2) The degree of vascular exposure. (3) Surgical maneuverability and access for clip placements. Results The mean operative depth was 90 ± 4 mm. The lateral corridors were limited proximally by the alar rim openings (29 ± 4 mm) and distally by the distance between the opticocarotid recesses (19 ± 2 mm). The mean posteroanterior distance and width of the transplanum craniotomy were 19 ± 2 mm and 17 ± 3 mm, respectively. Vascular exposure was achieved in 100% of cases for the clinoidal internal carotid artery (ICA), ophthalmic artery, superior hypophyseal artery, and the proximal ophthalmic ICA. Surgical access and clip placement was achieved in 97.6% of cases for vessels located anterior to the pituitary stalk (odds ratio [OR] 73.8; 95% confidence interval [CI] 7.66 to 710.8; p = 0.00). Conclusion The endoscopic transnasal approach provides excellent visualization of the paraclinoid region vasculature and offers potential surgical alternative for paraclinoid aneurysms.

Clipless Versus Conventional Laparoscopic Cholecystectomy

Abstract Laparoscopic cholecystectomy has been the gold standard technique for cholecystectomy and has proven more effective than the conventional open technique. The laparoscopic technique utilizes surgical clips for cystic duct occlusion, which come with their own set of complications. With the advent of new vessel and duct sealing technology, alternative energy instruments have been explored for the occlusion of the cystic duct without the use of clips. The Harmonic(®) scalpel (Ethicon Endo-Surgery, Cincinnati, OH) has become one of the more widely used instruments. In this retrospective study, 208 patients received surgical clip placement or the Harmonic scalpel was used for cystic duct occlusion. The postoperative complications were documented, and rates were calculated for outpatient follow-up, for re-admission, and specifically for the complications of a bile leak. When adjusted for the cause of bile leak (cystic duct versus common bile duct versus accessory duct), the use of the Harmonic scalpel versus clip placement had comparable rates of bile leak at 1.75% and 0.66%, respectively. The use of the Harmonic scalpel is deemed safe and comparable to clip placement at the discretion of the surgeon for cystic duct ligation. Further research with larger homogeneous studies and assessments of cost-effectiveness would further enhance the increasing use of the Harmonic scalpel in laparoscopic cholecystectomy.

Factors and Outcomes Associated With Early and Delayed Aneurysm Treatment in Subarachnoid Hemorrhage Patients in the United States

Recent studies from selected centers have shown that early surgical treatment of aneurysms in subarachnoid hemorrhage (SAH) patients can improve outcomes. These results have not been validated in clinical practice at large. To identify factors and outcomes associated with timing of ruptured intracranial aneurysm obliteration treatment in patients with SAH after hospitalization in the United States. We analyzed the data from the Nationwide Inpatient Sample (2005-2008) for all patients presenting with primary diagnosis of SAH, receiving aneurysm treatment (endovascular coil embolization or surgical clip placement). Early treatment was defined as aneurysm treatment performed within 48 hours and delayed treatment if treatment was performed after 48 hours of admission. Of 32 048 patients with SAH who underwent aneurysm treatment, 24 085 (75.2%) underwent early treatment and 7963 (24.8%) underwent delayed treatment. Female sex (P = .002), endovascular embolization (P < .001), and weekday admission (P < .001) were independent predictors of early treatment. In the early treatment group, patients were more likely discharged with none to minimal disability (odds ratio [OR] 1.30, 95% confidence interval [CI] 1.14-1.47) and less likely to be discharged with moderate to severe disability (OR 0.77, 95%CI 0.67-0.87) compared with those in the delayed treatment group. The in-hospital mortality was higher in the early treatment group compared with the delayed treatment group (OR 1.36 95%CI 1.12-1.66). Patients with SAH who undergo aneurysm treatment within 48 hours of hospital admission are more likely to be discharged with none to minimal disability. Early treatment is more likely to occur in those undergoing endovascular treatment and in patients admitted on weekdays.

Abstract 45: A Comparison of Outcomes with Early and Delayed Aneurysm Treatment in Subarachnoid Hemorrhage Patients in United States

Objective: To identify factors and outcomes associated with timing of ruptured cerebral aneurysm obliteration treatment in patients with subarachnoid hemorrhage (SAH) after hospitalization in United States. Background: Recent studies have shown that early surgical treatment of aneurysm in SAH patients can improve outcomes. These results have not been validated in actual clinical practice to date. Material and Methods: We analyzed the data from Nationwide Inpatient Sample (NIS 2005-2009) for all patients presenting with primary diagnosis of SAH, receiving aneurysm treatment (endovascular coil embolization or surgical clip placement). Early treatment was defined as aneurysm treatment performed within 48 hours of the hemorrhage and delayed treatment was performed after 48 hours. Clinical outcome was defined as minimal or no disability (self-care), moderate to severe disability (extended care facility) based on discharge disposition; and in-hospital death. Multivariate logistic regression analysis was used to identify the predictors of delayed treatment. Results: Out of the 32,048 patients with SAH who underwent aneurysm treatment, 24,085 (75.2%) underwent early treatment and7,963 (24.8%) underwent delayed treatment. Female gender (p=0.0018), teaching hospital status (p=0.103), endovascular embolization (p&lt;0.0001) and weekday admission (p&lt;0.0001) were independent predictors of early treatment. The mean hospital stay was 17.3 days in early treatment group and 19.7 days in late treatment group (p&lt;0.001). In the early treatment group, patients were more likely to discharge with minimal disability (51.1% vs. 47.1% p=0.004, adjusted OR 1.15, 95% CI 1.03-1.29) and less likely to be discharged with moderate to severe disability (34.4% vs. 41.8% p&lt;0.0001, adjusted OR 0.7, 95% CI 0.67-0.86) as compared with those in the delayed treatment group. The in-hospital mortality was higher in the early treatment group compared with delayed treatment (14% vs. 11%, p=0.001, adjusted OR 1.4 95% CI 1.12-1.67). Conclusion: Patients with SAH who undergo aneurysm treatment within 48 hours of hospital admission are more likely to be discharged with minimal disability. Early treatment is more likely to occur in teaching hospitals, those undergoing endovascular treatment, and in patients admitted on weekdays.

Has Placement of Surgical Clips in the Lumpectomy Bed Fallen Out of Favor?

Surgical clips were originally developed in the early 1900s, and initially utilized for hemostasis in intracranial operations. Since then, the clinical applications of surgical clips have broadened to include procedures across all surgical disciplines. In oncologic procedures, surgeons may place clips in the cavity of a tumor bed for a myriad of reasons, with the most common being to control hemostasis; other uses include placement to mark extent of dissection, denote anatomic location during a future operation or for accuracy of postoperative imaging. Another value of surgical clips is technical efficiency, which may allow for decreased operative time. In reality, appreciation for surgical clip application extends beyond the surgical theater. Just as surgeons rely on percutaneously placed clips to target a nonpalpable lesion for wire localization, radiation oncologists rely on clips in the tumor bed to accurately delineate the surgical cavity, as postoperative changes on computed tomography (CT) scans may be difficult to visualize. Typically, surgical clips are made of titanium or steel, both of which are radio opaque and can be visualized on plain film or CT scans. In early-stage breast cancer, clips placed in the surgical bed at time of definitive surgical resection have traditionally been used by radiation oncologists to direct the boost treatment after whole-breast irradiation. More recently, however, with the advent of accelerated partial-breast irradiation (APBI) using external-beam radiation therapy, detection and delineation of the surgical cavity are of even greater importance, given the large radiotherapy fraction doses delivered over a short period of time. Accurate delineation of lumpectomy cavity target volumes by relying on seroma formation or location of lumpectomy incision has been shown to be largely inaccurate. The seroma is a postoperative serous fluid accumulation and is sometimes used to estimate the lumpectomy cavity borders when no metallic marker is present. Seroma formation after lumpectomy, however, is variable, making it difficult to assess the true cavity borders accurately. The lumpectomy incision scar has also been used in an effort to define lumpectomy borders, but accuracy in this technique has also been unsuccessful. In a small, prospective series by Krawczyk and colleagues, measurement from lumpectomy scar to breast tissue border was found to be an inadequate prediction tool for radiation planning. In fact, relying on the lumpectomy scar may result in a significant risk of underdosing of the lumpectomy cavity. From a radiation oncologist perspective, it may be best for clips to be placed along all margins of a cavity to improve targeted radiation therapy. In fact, published data from our group suggest that directed placement of fiducial markers on the walls of the surgical cavity allowed for improved interphysician accuracy in delineation of the lumpectomy cavity. However, in many centers, including ours, surgical clip placement is left to surgeon discretion. To our knowledge, no standard recommendation for clip placement exists, and patterns of variation have prompted discussion amongst radiation oncologist and breast surgical oncologist at our institution. Multiple studies over the past 10–20 years have evaluated the clinical importance of surgical clip placement in radiotherapy planning. In 2008, Coles et al. performed an audit of titanium clip placement utilized in the Society of Surgical Oncology 2011

Has Placement of Surgical Clips in the Lumpectomy Bed Fallen Out of Favor?

Surgical clips were originally developed in the early 1900s, and initially utilized for hemostasis in intracranial operations. Since then, the clinical applications of surgical clips have broadened to include procedures across all surgical disciplines. In oncologic procedures, surgeons may place clips in the cavity of a tumor bed for a myriad of reasons, with the most common being to control hemostasis; other uses include placement to mark extent of dissection, denote anatomic location during a future operation or for accuracy of postoperative imaging. Another value of surgical clips is technical efficiency, which may allow for decreased operative time. In reality, appreciation for surgical clip application extends beyond the surgical theater. Just as surgeons rely on percutaneously placed clips to target a nonpalpable lesion for wire localization, radiation oncologists rely on clips in the tumor bed to accurately delineate the surgical cavity, as postoperative changes on computed tomography (CT) scans may be difficult to visualize. Typically, surgical clips are made of titanium or steel, both of which are radio opaque and can be visualized on plain film or CT scans. In early-stage breast cancer, clips placed in the surgical bed at time of definitive surgical resection have traditionally been used by radiation oncologists to direct the boost treatment after whole-breast irradiation. More recently, however, with the advent of accelerated partial-breast irradiation (APBI) using external-beam radiation therapy, detection and delineation of the surgical cavity are of even greater importance, given the large radiotherapy fraction doses delivered over a short period of time. Accurate delineation of lumpectomy cavity target volumes by relying on seroma formation or location of lumpectomy incision has been shown to be largely inaccurate. The seroma is a postoperative serous fluid accumulation and is sometimes used to estimate the lumpectomy cavity borders when no metallic marker is present. Seroma formation after lumpectomy, however, is variable, making it difficult to assess the true cavity borders accurately. The lumpectomy incision scar has also been used in an effort to define lumpectomy borders, but accuracy in this technique has also been unsuccessful. In a small, prospective series by Krawczyk and colleagues, measurement from lumpectomy scar to breast tissue border was found to be an inadequate prediction tool for radiation planning. In fact, relying on the lumpectomy scar may result in a significant risk of underdosing of the lumpectomy cavity. From a radiation oncologist perspective, it may be best for clips to be placed along all margins of a cavity to improve targeted radiation therapy. In fact, published data from our group suggest that directed placement of fiducial markers on the walls of the surgical cavity allowed for improved interphysician accuracy in delineation of the lumpectomy cavity. However, in many centers, including ours, surgical clip placement is left to surgeon discretion. To our knowledge, no standard recommendation for clip placement exists, and patterns of variation have prompted discussion amongst radiation oncologist and breast surgical oncologist at our institution. Multiple studies over the past 10–20 years have evaluated the clinical importance of surgical clip placement in radiotherapy planning. In 2008, Coles et al. performed an audit of titanium clip placement utilized in the Society of Surgical Oncology 2011

Transoral Robotic Surgery (TORS) for Parapharyngeal and Retromolar Trigone Tumors

 Robotic console time for the first resection was 40 minutes and 54 minutes for the second TORS. The traditional approaches to the parapharyngeal space allow for a maximum of two-handed surgery within the narrow operative field. TORS affords an approach in which the retraction/dissection carried out by the patient side assistant translates into four-handed surgery. Although the majority of dissection in the parapharyngeal space is carried out bluntly, the patient side assistant provides the exposure and tension required for precise electrocautery. Additionally the magnified view also allows for placement of surgical clips for hemostasis.

Placement and Visualization of Surgical Clips in the Lumpectomy Cavity of Patients with Stage 0, I, and II Breast Cancer Treated with Breast Conserving Surgery and Radiation Therapy (BCS+RT)

Placement and Visualization of Surgical Clips in the Lumpectomy Cavity of Patients with Stage 0, I, and II Breast Cancer Treated with Breast Conserving Surgery and Radiation Therapy (BCS+RT)

Traitement conservateur du cancer du sein : optimisation du repérage du lit tumoral

Purpose The main objective was to assess contributions and limits of surgical clips combined with computed tomography to define the tumor bed after conservative treatment of breast cancer. This retrospective observational study enrolled 16 patients treated by lumpectomy with surgical clips placed in the tumor bed. Patients and methods We assessed the difficulties in localizing the tumour bed based on collected data (i.e. clinical description, mammography, ultrasound examination, surgical procedure and pathology data). The clip's number and localization, and the volumes of the boost were also analyzed. Results There was no preoperative occurrence of localization in 57 % of cases for palpable tumours, and in 13 % of cases where the lesion was subclinical. The collected data did not allow establishing a precise localization. The mean number of surgical clips per patient was 4 (range 1–9), and the delineation of the target volumes by radiation oncologists was not standardized. Oncoplastic techniques may produce difficulties in the localization of tumour bed. Conclusion The placement of surgical clips by the surgeon is helpful, primarily when oncoplastic techniques are used. In many situations, these clips may cause problems of interpretation. In order to optimize the delineation of the boost, we propose a multidisciplinary approach and methodology to be used at the Henri Becquerel Cancer Centre.

3D-conformal accelerated partial breast irradiation treatment planning: the value of surgical clips in the delineation of the lumpectomy cavity.

BackgroundAccurate localisation of the lumpectomy cavity (LC) volume is one of the most critical points in 3D-conformal Partial breast irradiation (3D-APBI) treatment planning because the irradiated volume is restricted to a small breast volume. Here, we studied the role of the placement of surgical clips at the 4 cardinal points of the lumpectomy cavity in target delineation.MethodsForty CT-based 3D-APBI plans were retrieved on which a total of 4 radiation oncologists, two trainee and two experienced physicians, outlined the lumpectomy cavity. The inter-observer variability of LC contouring was assessed when the CTV was defined as the delineation that encompassed both surgical clips and remodelled breast tissue.ResultsThe conformity index of tumour bed delineation was significantly improved by the placement of surgical clips within the LC (median at 0.65). Furthermore, a better conformity index of LC was observed according to the experience of the physicians (median CI = 0.55 for trainee physicians vs 0.65 for experienced physicians).ConclusionsThe placement of surgical clips improved the accuracy of lumpectomy cavity delineation in 3D-APBI. However, a learning curve is needed to improve the conformity index of the lumpectomy cavity.

Surgical Clips Assist in the Visualization of the Lumpectomy Cavity in Three-Dimensional Conformal Accelerated Partial-Breast Irradiation

To determine to what extent the placement of surgical clips helps delineate the cavity in three-dimensional conformal accelerated partial-breast irradiation. Planning CT images of 100 lumpectomy cavities were reviewed in a cohort of 100 consecutive patients. The cavities were determined and categorized by two radiation oncologists according to cavity visualization score criteria and the breast density score. The two physicians first attempted to delineate the lumpectomy cavity without clips and then with clips. In the case of high-density mammary tissue, the breast remodeling done during surgery does not enable the lumpectomy cavity to be sufficiently visualized. The use of surgical clips significantly improved the ability to visualize the lumpectomy cavity, with a 69% rate of concordance between physicians regardless of the breast tissue density. The placement of surgical clips at lumpectomy enables visualization of the lumpectomy cavity and allows upgrading of the cavity visualization score on CT scans obtained for accelerated partial-breast irradiation treatment planning.

Recent trends in the treatment of cerebral aneurysms: analysis of a nationwide inpatient database

The most appropriate treatment for cerebral aneurysms, both ruptured and unruptured, is currently under debate, and updated guidelines have yet to be defined. The authors attempted to identify trends in therapy for cerebral aneurysms in the US as well as outcomes. The authors retrospectively reviewed data from the Nationwide Inpatient Sample hospital discharge database (Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality) for the period 1993-2003. Multiple variables were categorized and subjected to statistical analysis for International Classification of Diseases, 9th Revision, Clinical Modification codes related to subarachnoid hemorrhage (SAH), unruptured aneurysm, and clipping and endovascular treatment of cerebral aneurysm. During the study period, the numbers of discharges remained stable for SAH but doubled for unruptured aneurysms. Concomitantly, the number of aneurysms treated with clip placement remained stable, and the number treated by means of endovascular procedures doubled. By the study's end, the mortality rates had decreased 20% for SAH and 50% for unruptured aneurysms. Increasing age was associated with increased mortality rates, mean length of hospital stay (LOS), and mean charges (p < 0.01). Endovascular treatment was used more often in older patients (p < 0.01). Teaching status and larger hospital size were associated with higher charges and longer hospital stays (although the association was not statistically significant) and with better outcomes (p < 0.05) and lower mortality rates (p < 0.05), especially in patients who underwent aneurysm clipping (p < 0.01). Endovascular treatment was associated with significantly higher mortality rates in small hospitals (p < 0.001) and steadily increasing morbidity rates (45%). Morbidity rates, mean LOS, and mean charges were higher for aneurysm clipping (p < 0.01). From 1993 to 2003, endovascular techniques for aneurysm occlusion have been increasingly used, while the use of surgical clipping procedures has remained stable. Toward the end of the study period, better overall outcomes were observed in the treatment of cerebral aneurysms, both ruptured and unruptured. Large academic centers were associated with better results, particularly for surgical clip placement.

How to Boost the Breast Tumor Bed? A Multidisciplinary Approach in Eight Steps

To describe a new procedure for breast radiotherapy that will improve tumor bed localization and radiotherapy treatment using a multidisciplinary approach. This pilot study was conducted by departments of radiation oncology, surgery, and radiology. A new procedure has been implemented, summarized as eight steps: from pre-surgery contrast CT to surgery, tumor bed planning target volume (PTV) determination, and finally breast and tumor bed irradiation. Twenty patients presenting with T1N0M0 tumors were enrolled in the study. All patients underwent lumpectomy with the placement of surgical clips in the tumor bed region. During surgery, 1 to 5 clips were placed in the lumpectomy cavity before the plastic procedure. All patients underwent pre- and postoperative CT scans in the treatment position. The two sets of images were registered with a match-point registration. All volumes were contoured and the results evaluated. The PTV included the clips region, the gross tumor volume, and the surgical scar, with an overall margin of 5-10 mm in all directions, corresponding to localization and setup uncertainties. For each patient the boost PTV was discussed and compared with our standard forward-planned PTV. We demonstrate the feasibility of a tumor bed localization and treatment procedure that seems adaptable to routine practice. Our study shows the advantages of a multidisciplinary approach for tumor bed localization and treatment. The use of more than 1 clip associated with pre- to postoperative CT image registration allows better definition of the PTV boost volume.

Surgical treatment of blood blister–like aneurysms of the supraclinoid internal carotid artery with extracranial–intracranial bypass and trapping

Blood blister-like aneurysms (BBAs) arise from the supraclinoid internal carotid artery (ICA) at non-branching sites. These aneurysms are challenging to treat primarily with either surgical clip placement or endovascular therapy. The authors describe a series of 4 patients who presented with high-grade subarachnoid hemorrhage (SAH) due to a BBA, which was treated with an extracranial-intracranial (EC-IC) bypass followed by trapping of the aneurysm. Four patients presented with SAH due to a BBA of the ICA. Three of these patients were treated with an endovascular procedure; following the vasospasm period, definitive treatment with EC-IC bypass followed by trapping of the aneurysmal parent vessel was performed. Two of the patients who were treated endovascularly suffered rebleeding prior to bypass and trapping. Three of the 4 patients had a good outcome (modified Rankin Scale Score 1 or 2), and 1 patient who suffered 2 episodes of rebleeding died. Treatment of BBAs of the ICA remains difficult, particularly in the setting of high-grade SAH. Patients with this challenging condition often require multiple procedures and have a high incidence of rebleeding. Definitive treatment of these aneurysms consists of EC-IC bypass and surgical or endovascular trapping.

Loss of visual evoked potential following temporary occlusion of the superior hypophyseal artery during aneurysm clip placement surgery

✓The authors report a case in which a 62-year-old woman with a history of subarachnoid hemorrhage due to a ruptured aneurysm was found to have a de novo paraclinoid aneurysm in the right internal carotid artery during a routine medical examination. Surgical clip placement was performed via a contralateral pterional approach under visual evoked potential (VEP) monitoring. The superior hypophyseal artery (SHA) was found to originate from the aneurysm body. The artery was temporarily occluded prior to application of the clip to the aneurysm neck. The VEP signal was lost 3 minutes after the SHA was occluded, and the potentials gradually recovered 10 minutes after the artery was released. The disappearance of VEP signal was reproducible with SHA occlusion. The clip was applied to the aneurysm body to preserve the origin of the SHA. The patient did not have any deterioration of vision after surgery. Intraoperative VEP monitoring can be used to help determine whether the SHA can be sacrificed safely.

Loss of visual evoked potential following temporary occlusion of the superior hypophyseal artery during aneurysm clip placement surgery

The authors report a case in which a 62-year-old woman with a history of subarachnoid hemorrhage due to a ruptured aneurysm was found to have a de novo paraclinoid aneurysm in the right internal carotid artery during a routine medical examination. Surgical clip placement was performed via a contralateral pterional approach under visual evoked potential (VEP) monitoring. The superior hypophyseal artery (SHA) was found to originate from the aneurysm body. The artery was temporarily occluded prior to application of the clip to the aneurysm neck. The VEP signal was lost 3 minutes after the SHA was occluded, and the potentials gradually recovered 10 minutes after the artery was released. The disappearance of VEP signal was reproducible with SHA occlusion. The clip was applied to the aneurysm body to preserve the origin of the SHA. The patient did not have any deterioration of vision after surgery. Intraoperative VEP monitoring can be used to help determine whether the SHA can be sacrificed safely.

A Computed Tomography-based Protocol vs Conventional Clinical Mark-up for Breast Electron Boost

Aims Computed tomography planning of whole breast radiotherapy (WBRT) improves breast coverage and reduces the normal tissue dose. Computed tomography planning may increase tumour bed boost treatment accuracy. The aims of this investigation were (1) to compare the breast boost volume treated with clinical mark-up with the volume delineated with computed tomography planning and (2) to study tumour bed volume changes between the initial planning computed tomography scan and a second computed tomography scan at the time of breast boost mark-up. Materials and methods Women receiving adjuvant WBRT and an electron boost after breast-conserving surgery were eligible. As per standard practice, WBRT was computed tomography planned while the boost electron portal was clinically defined. Electron field borders were then traced with wire and a second computed tomography scan was carried out in the boost treatment position. Post-surgical radiological abnormalities were contoured to create a tumour bed clinical target volume (CTV) on both scans (CTV1 and CTV2). A 1 cm margin to CTV2 defined the planning target volume (PTV). The proportions of the CTV2 and PTV receiving 90% (V90) and 80% (V80) of the dose were calculated. Changes in volume between CTV1 and CTV2 were analysed. Results Data from 47 eligible patients were analysed. The mean V90 for the PTV was 61%. Lower electron energy ( P < 0.001) and small field sizes ( P = 0.004) were associated with a low V90. The mean CTV decreased by 4.3 cm 3 ( P = 0.014) and was smaller in those with a long surgery to computed tomography interval ( P = 0.008). On average, the 90% isodose covered 61 cm 3 of normal tissue. Conclusions Conventional clinical breast boost planning is inaccurate. Electron boost computed tomography planning together with appropriate surgical clip placement and the use of mammograms and pathological information should provide optimal coverage of the tumour site. The boost could usually be planned from the initial computed tomography scan.

Contribution of endovascular therapy to the management of poor-grade aneurysmal subarachnoid hemorrhage: clinical and angiographic outcomes

Treatment of patients presenting with poor-grade (Hunt and Hess Grade IV or V) subarachnoid hemorrhage (SAH) is controversial. Endovascular coil embolization has been considered a valuable therapeutic alternative to surgical clip placement for this kind of patient. The aim of the present study was to evaluate immediate and long-term angiographic and clinical outcomes in patients with poor-grade SAH treated by endovascular embolization. One hundred eleven patients with Hunt and Hess Grade IV or V SAH were treated with endovascular embolization at the University of California at Los Angeles Medical Center between October 1990 and December 2004. Eighty patients harbored Grade IV hemorrhages and 31 patients had Grade V ones. Immediate and long-term anatomical and clinical outcomes were evaluated in all patients. Long-term clinical outcome assessments were based on follow-up data obtained over an average of 32 months posttherapy. Technical complications occurred in 15 patients (13.5%). Immediate complete aneurysm occlusion was observed in 51.4% of aneurysms. Angiographic, long-term follow-up review revealed aneurysm recanalization in 16.2% of cases. Thirty-nine patients (35.1%) demonstrated a favorable long-term clinical outcome. The overall mortality rate in this patient series was 32.4%. The mortality rate associated with vasospasm was significantly higher in patients with Grade IV SAHs than in those with Grade V hemorrhages. The results of this study demonstrate a valuable contribution of endovascular therapy of ruptured intracranial aneurysms in patients with Hunt and Hess Grade IV or V SAH. This technique was successful in decreasing repeated aneurysm rupture and in enabling aggressive medical management during the acute phase of SAH. This is particularly important in patients with Grade IV SAH because of their potential for obtaining higher physical and functional recoveries.

1091 PUBLICATION Combined modality for treatment of buccal cancer

Computed tomography planning of whole breast radiotherapy (WBRT) improves breast coverage and reduces the normal tissue dose. Computed tomography planning may increase tumour bed boost treatment accuracy. The aims of this investigation were (1) to compare the breast boost volume treated with clinical mark-up with the volume delineated with computed tomography planning and (2) to study tumour bed volume changes between the initial planning computed tomography scan and a second computed tomography scan at the time of breast boost mark-up.Women receiving adjuvant WBRT and an electron boost after breast-conserving surgery were eligible. As per standard practice, WBRT was computed tomography planned while the boost electron portal was clinically defined. Electron field borders were then traced with wire and a second computed tomography scan was carried out in the boost treatment position. Post-surgical radiological abnormalities were contoured to create a tumour bed clinical target volume (CTV) on both scans (CTV1 and CTV2). A 1 cm margin to CTV2 defined the planning target volume (PTV). The proportions of the CTV2 and PTV receiving 90% (V90) and 80% (V80) of the dose were calculated. Changes in volume between CTV1 and CTV2 were analysed.Data from 47 eligible patients were analysed. The mean V90 for the PTV was 61%. Lower electron energy (P < 0.001) and small field sizes (P = 0.004) were associated with a low V90. The mean CTV decreased by 4.3 cm3 (P = 0.014) and was smaller in those with a long surgery to computed tomography interval (P = 0.008). On average, the 90% isodose covered 61 cm3 of normal tissue.Conventional clinical breast boost planning is inaccurate. Electron boost computed tomography planning together with appropriate surgical clip placement and the use of mammograms and pathological information should provide optimal coverage of the tumour site. The boost could usually be planned from the initial computed tomography scan.

Image Guidance in External Beam Accelerated Partial Breast Irradiation: Comparison of Surrogates for the Lumpectomy Cavity

Purpose/Objective: Image guidance for external beam accelerated partial breast irradiation depends upon precise localization of the lumpectomy cavity during the abbreviated course of treatment. This study evaluates breast surface matching as a localization technique and compares it to localization using surgical clips. Materials/Methods: Twenty-seven breast cancer patients with surgical clip placement in the lumpectomy bed and ≥ 2 CT scans (mean time between scans: 27 days) had CT registration performed: 1) with respect to bony anatomy, 2) to the center of mass of the surgical clips (translation only, relative to the bony registration), 3) to obtain the best average breast surface match. The center of mass (COM) of the lumpectomy cavity in both the initial and second CT scans was defined for each registration for each patient. For each registration, the distance between the COMs in the two scans (ΔCOMBone, ΔCOMClips, ΔCOMSurface) was determined. A smaller ΔCOM was taken to reflect better localization. Correlation coefficients were calculated for ΔCOM vs. several variables including breast volume, cavity volume, change in cavity volume, and cavity location. Results: The mean value of ΔCOMBone was 7±2mm. This was taken as a reference, unlocalized value that considers 1) shift of the whole breast relative to bony anatomy as well as 2) local changes to the cavity itself. Consistent with 1), ΔCOMBone was found to be relatively greater for large breasted patients and/or patients with cavities situated far from the chest wall. Relative to bony registration, clip registration provided better localization (ΔCOMClips < ΔCOMBone) in 25 of 27 cases. Breast surface registration resulted in improved cavity localization (ΔCOMSurface < ΔCOMBone) in 19 of 27 cases. The mean improvement (ΔCOMBone − ΔCOMClips or Surface) was 4±3mm for clip registration and 4±4mm for surface registration. In the more unusual cases of worse localization (ΔCOMClips or Surface > ΔCOMBone), the average increase in ΔCOM was 2±1mm and 2±2mm, respectively. The reliability of surface registration (i.e. confidence that localization will improve) tended to increase with patient breast volume. This is consistent with the notion that, in larger breasted patients, the contribution of whole breast shift vs. local cavity shift might be expected to be relatively greater. When directly comparing clip vs. surface registration (ΔCOMClips vs. ΔCOMSurface), the relative superior-inferior position of the lumpectomy cavity was found to be significant. Clip registration consistently outperformed surface registration (ΔCOMSurface − ΔCOMClips = 2.5±1.2mm) when the lumpectomy cavity was located superior to the breast COM. Surface registration slightly outperformed clip registration (ΔCOMClips − ΔCOMSurface = 0.7±0.5 mm) for cavities located > 4 cm inferior to the breast COM. Conclusions: The use of either the breast surface or surgical clips as surrogate for the lumpectomy cavity results in similarly improved localization for most patients compared to bony registration. However, clip registration is more broadly applicable to all patients, whereas surface registration has most relevance for patients in whom whole breast shift relative to bony anatomy might be expected to dominate cavity position (i.e., large breasted patients).