Hernan I. Vargas

Focused microwave phased array thermotherapy for primary breast cancer

BackgroundA pilot safety study of focused microwave phased array thermotherapy in the treatment of primary breast carcinomas was conducted.MethodsTen patients with breast carcinomas beneath the skin surface that ranged in maximal clinical size from 1 to 8 cm (mean, 4.3 cm) were treated with the breast compressed in the prone position. We planned to deliver a tumor thermal dose equivalent to 60 minutes at 43°C. Breast imaging and pathology data were used to assess efficacy.ResultsFor the 10 patients, the mean tumor equivalent thermal dose was 51.7 minutes, the mean peak tumor temperature was 44.9°C, and the mean treatment time was 34.7 minutes. Ultrasound imaging demonstrated a significant reduction in tumor size (mean, 41%) 5 to 18 days after thermotherapy in 6 (60%) of 10 patients. A significant tumor response on the basis of reduction in tumor size or significant tumor cell kill occurred in 8 (80%) of 10 patients.ConclusionsWith sufficient skin cooling, delivery of focused microwave phased array thermotherapy is safe in treating breast carcinomas when used alone, and some potential efficacy was demonstrated at the tumor thermal doses administered. Increased tumor thermal dose efficacy studies in larger patient populations for improved breast conservation should be investigated.

Focused microwave phased array thermotherapy for ablation of early-stage breast cancer: results of thermal dose escalation

Background: Tumor ablation as a means of treating breast cancer is being investigated. Microwave energy is promising because it can preferentially heat high-water-content breast carcinomas, compared to adipose and glandular tissues.Methods: This is a prospective, multicenter, nonrandomized dose-escalation study of microwave treatment. Thermal dose was measured as (1) thermal equivalent minutes (cumulative equivalent minutes; CEM) of treatment relative to a temperature of 43°C and (2) peak tumor temperature. Microwaves were guided by an antenna-temperature sensor placed percutaneously into the tumor. Outcomes measured were pathologic response (tumor necrosis) side effects.Results: Twenty-five patients (mean age, 57 years) were enrolled. The mean tumor diameter was 1.8 cm. Tumoricidal temperatures (>43°C) were reached in 23 patients (92%). Tumor size was unchanged after thermotherapy (P = not significant). Pathologic necrosis was achieved in 17 (68%) patients. Complete necrosis of the invasive component was achieved in two patients. One hundred forty CEM is predictive of a 50% tumor response, and 210 CEM is predictive of a 100% tumor response (P = .003). Univariate linear regression predicts that peak tumor temperatures of 47.4°C and 49.7°C cause a 50% tumor response and a 100% tumor response, respectively.Conclusions: Thermotherapy causes tumor necrosis and can be performed safely with minimal morbidity. The degree of tumor necrosis is a function of the thermal dose. Future studies will evaluate the impact of high doses of thermotherapy on margin status and complete tumor ablation.

Nonoperative management of perforated appendicitis without periappendiceal mass

BACKGROUND Initial nonoperative treatment for patients with periappendiceal mass has been shown to be safe and effective. Our goal was to evaluate the safety and efficacy of initial nonoperative management for perforated appendicitis not accompanied by a palpable mass. METHODS The study population consisted of 77 patients with appendicitis treated initially nonoperatively between 1992 and 1998. All had localized abdominal tenderness and computed tomography findings of abscess or phlegmon. None had a palpable abdominal mass. Outcome parameters evaluated were rate of failure, complication, and recurrence. RESULTS There were 49 males and 28 females with a mean age of 35 years (range 16 to 75). Initial nonoperative management was successful in 95% of patients. Complications occurred in 12% of patients. Recurrent appendicitis developed in 6.5% of patients after an average follow-up of 30 weeks. CONCLUSIONS Perforated appendicitis patients with localized abdominal tenderness and abscess or phlegmon can safely and effectively be treated in an initial nonoperative fashion.

Breast Cancer in Limited-Resource Countries: Diagnosis and Pathology

Abstract:  In 2002 the Breast Health Global Initiative (BHGI) convened a panel of breast cancer experts and patient advocates to develop consensus recommendations for diagnosing breast cancer in countries with limited resources. The panel agreed on the need for a pathologic diagnosis, based on microscopic evaluation of tissue specimens, before initiating breast cancer treatment. The panel discussed options for pathologic diagnosis (fine‐needle aspiration biopsy, core needle biopsy, and surgical biopsy) and concluded that the choice among these methods should be based on available tools and expertise. Correlation of pathology, clinical, and imaging findings was emphasized. A 2005 BHGI panel reaffirmed these recommendations and additionally stratified diagnostic and pathology methods into four levels—basic, limited, enhanced, and maximal—from lowest to highest resources. The minimal requirements (basic level) include a history, clinical breast examination, tissue diagnosis, and medical record keeping. Fine‐needle aspiration biopsy was recognized as the least expensive reliable method of tissue sampling, and the need for comparing its clinical usefulness with that of core needle biopsy in the limited‐resource setting was emphasized. Increasing resources (limited level) may enable diagnostic breast imaging (ultrasound ± mammography), use of tests to evaluate for metastases, limited image‐guided sampling, and hormone receptor testing. With more resources (enhanced level), diagnostic mammography, bone scanning, and an onsite cytologist may be possible. Mass screening mammography is introduced at the maximal‐resource level. At all levels, increasing breast cancer awareness, diagnosing breast cancer at an early stage, training individuals to perform and interpret breast biopsies, and collecting statistics about breast cancer, resources, and competing priorities may improve breast cancer outcomes in countries with limited resources. Expertise in pathology was reaffirmed to be a key requirement for ensuring reliable diagnostic findings. Several approaches were again proposed for improving breast pathology, including training pathologists, establishing pathology services in centralized facilities, and organizing international pathology services.

Overview of breast health care guidelines for countries with limited resources.

Abstract: Among women around the globe, breast cancer is both the most common cancer and the leading cause of cancer‐related death. Women in economically disadvantaged countries have a lower incidence of breast cancer, but poorer survival rates for the disease relative to women in affluent countries. Evidence suggests that breast cancer mortality can be reduced if resources are applied to the problem in a systematic way. The purpose of the Global Summit Consensus Conference was to begin a process to develop guidelines for improving breast health care in countries with limited resources—those with either low‐ or medium‐level resources based on World Health Organization (WHO) criteria. Breast cancer experts and patient advocates representing 17 countries and 9 world regions participated in the conference. They reviewed the existing breast health guidelines, which generally assume unlimited resources. Individual panels then discussed and debated how limited resources can best be applied to improve three areas of breast health care—early detection, diagnosis, and treatment—and how to integrate these areas in building a breast health care program. The panelists unanimously agreed on the guiding principle that all women have the right to access to health care. They also agreed that collecting data on breast cancer is imperative for deciding how best to apply resources and for measuring progress. The panelists acknowledged the considerable challenges in implementing breast health care programs when resources are limited, as well as the need to build a program that is specific to each countrys unique situation. The panelists noted that the development of centralized, specialized cancer centers may be a cost‐effective way to deliver breast cancer care to some women when it is not possible to deliver such care to women nationwide. In countries with limited resources, at least half of the women have advanced or metastatic breast cancer at the time of diagnosis. Because advanced breast cancer has the poorest survival rate and is the most resource intensive to treat, measures to reduce the stage at diagnosis are likely to have the greatest overall benefit in terms of both survival and costs. Women should have access to diagnosis and treatment if efforts are undertaken to improve early detection of breast cancer. The panels’ findings outline specific steps for prioritizing the use of limited resources to decrease the impact of breast cancer around the globe. 

Initial nonoperative management for periappendiceal abscess.

PURPOSE: Our goal was to compare initial operative and nonoperative management for periappendiceal abscess complicating appendicitis. METHODS: This study is a retrospective review of 155 consecutive patients with appendicitis complicated by periappendiceal abscess treated between 1992 and 1998. Eighty-eight patients were treated initially nonoperatively, and 67 patients were treated operatively. All patients had localized abdominal tenderness and either computed tomography or intraoperative documentation of an abscess. RESULTS: Our patient population consisted of 107 males and 48 females, with an average age of 33 (range, 16–75) years. Age, gender, comorbidity, white blood cell count, temperature, and heart rate did not differ significantly between groups. For the initial nonoperative management group, the failure rate was 5.8 percent and the appendicitis recurrence rate was 8 percent after a mean follow-up of 36 weeks. The response to treatment of the initial nonoperative group and the initial operative group was compared by length of stay (9±5 daysvs. 9±3 days;P=not significant), days until white blood cell count normalized (3.8±4 daysvs. 3.1±3 days;P=not significant), days until temperature normalized (3.2±3 daysvs. 3.1±2 days;P=not significant), and days until a regular diet was tolerated (4.7±4 daysvs. 4.6±3 days;P=not significant). Complication rate was significantly lower in the nonoperative group (17vs. 36 percent;P=0.008). CONCLUSIONS: Initial nonoperative management of appendicitis complicated by periappendiceal abscess is safe and effective. Patients undergoing initial nonoperative management have a lower rate of complications, but they are at risk for recurrent appendicitis.

Evaluation of Three Scoring Systems Predicting Non Sentinel Node Metastasis in Breast Cancer Patients with a Positive Sentinel Node Biopsy

BackgroundCompletion axillary lymph node dissection (cALND), performed after a positive sentinel lymph node biopsy (SLNB) in breast cancer patients, often results in no additional positive nodes. Scoring systems have been published to aid in the prediction of nonsentinel node metastasis. Our purpose was to assess the validity of these scoring systems in our patient population.MethodsFor 39 consecutive patients who underwent cALND after a positive SLNB, scores were calculated using retrospective patient data for each of the three scoring systems used. Receiver operating characteristics (ROC) curves were drawn, and the areas under the curves were calculated to assess the discriminative power of each system. Univariate analysis was performed to assess the predictability of individual patient and tumor characteristics.ResultsNonsentinel nodes were positive in 23 (59%) patients. The areas under the ROC curves were 0.63, 0.70, and 0.68, respectively. The proportion of sentinel nodes that were positive and the total number of sentinel nodes retrieved were the only individual predictors of nonsentinel node metastasis.ConclusionsGiven the high incidence of retrieving no additional metastasis on cALND, individualized patient management according to risk is desirable. Scoring systems provide additional information regarding the likelihood of metastasis in nonsentinel nodes, but their predictability remains less than optimal. The use of scoring systems must be applied with caution until future studies provide a more accurate assessment of risk for patients with a positive SLNB.

Diagnosis of Breast Cancer in Countries with Limited Resources

Abstract: Accurate diagnosis is a necessary step in the management of breast cancer. In women with breast cancer, diagnosis can confirm the presence of the disease, reduce treatment delays, and clarify the predictive and prognostic features of the cancer, which help in planning treatment and counseling women. In women with benign breast conditions, accurate diagnosis avoids erroneous treatment for breast cancer, which can have devastating consequences for the woman and unnecessarily consumes resources. The panel distinguishes between a “clinical diagnosis” of breast cancer (one based on signs and symptoms and imaging findings) and a “pathologic diagnosis” of breast cancer (one based on microscopic examination of cellular or tissue samples). The panel agrees that all women should have a pathologic diagnosis of breast cancer before they are given definitive treatment for the disease, no matter how strongly their clinical findings suggest cancer. The tools for clinical diagnosis include history, clinical breast examination, ultrasound, and diagnostic mammography; these tools provide valuable information and play important supplemental roles in ascertaining the presence of breast cancer. Mammography and ultrasound also help determine the extent of disease within the breast, which is essential when breast‐conserving therapy can be offered to women. The tools for pathologic diagnosis include fine‐needle aspiration biopsy, core needle biopsy, and standard surgical biopsy. The panel noted that each of these tools has potential benefits and limitations in the limited‐resource setting, and concluded that the choice among them must be based on the available tools and expertise. The triple test—checking for correlation of pathology findings, imaging findings, and clinical findings—was identified as a critical practice in diagnosing breast cancer. Panelists uniformly agreed that mastectomy should not be used to diagnose breast cancer, noting that accurate diagnosis can be made by less invasive means. Expertise in pathology was identified as a key requirement for ensuring reliable diagnostic findings. Several approaches were proposed for improving breast pathology, including training pathologists, establishing pathology services in centralized facilities, and organizing international pathology services. 

Can perforated appendicitis be diagnosed preoperatively based on admission factors

The optimal initial treatment for selected patients with perforated appendicitis may be nonoperative. For this reason it is important to be able to diagnose perforated appendicitis preoperatively. The purpose of this study was to determine the accuracy of diagnosing perforated appendicitis using only admission factors. The study population was comprised of 366 adult patients who underwent appendectomy for presumed appendicitis during 1997. Admission factors associated with perforated appendicitis were determined using univariate and multivariate analyses. These variables were then used to formulate a rule for the diagnosis of perforated appendicitis. Sensitivity and specificity were calculated for this rule. The admission factors analyzed were sex, race, age, days of pain, temperature, heart rate, symptoms, physical examination findings, and laboratory findings. Multivariate regression analysis revealed days of pain, temperature, and localized tenderness outside the right lower quadrant to be significant (P <0.05). Using two or more days of pain, a temperature of >101° F (38.3° C), or localized tenderness outside the right lower quadrant as criteria to indicate perforation, we achieved a sensitivity of 86% and a specificity of 58% for distinguishing perforated from nonperforated appendicitis. We concluded that (1) perforated appendicitis cannot reliably be distinguished from nonperforated appendicitis based on admission factors, and (2) two or more days of pain, localized tenderness outside the right lower quadrant, and a temperature of ±101° F (38.3° C) define a group of patients with appendicitis who have a high incidence of perforation.

Balloon dissection facilitated laparoscopic extraperitoneal hernioplasty

BACKGROUND With the goals of minimizing perioperative morbidity and obtaining direct inguinal access without transgressing the peritoneal cavity, we developed a balloon dissection device to facilitate laparoscopic extraperitoneal hernioplasty. PATIENTS AND METHODS We have performed balloon facilitated dissection on 113 patients (105 males) on an outpatient basis. Some patients were repaired under regional anesthesia. A total of 150 hernias have been repaired: 72 indirect, 70 direct, 3 scrotal, 2 sliding, 2 spigelian, and 1 femoral. RESULTS Mean operating time was 60 minutes. All patients were ambulatory on discharge. Half reported minimal or no immediate postoperative pain. Over 80% had only minimal irritation or discomfort on the third postoperative day. Nearly 60% returned to work within 2 weeks. None required hospital readmission for an immediate complication of hernioplasty. With a mean follow-up of 6.3 months, only three recurrences are reported. Except for one persistent neuropathy which resolved after staple removal, there were no significant complications. CONCLUSIONS We conclude that balloon dissection facilitates laparoscopic extraperitoneal hernioplasty and obviates the need for general anesthesia. Our approach minimizes perioperative pain. It can be done on an outpatient basis and permits prompt return to full activity including physical work.