Kitt Shaffer

Analysis of prostate and seminal vesicle motion: Implications for treatment planning

PURPOSE To quantify prostate and seminal vesicle positional changes (target motion) between treatment planning and delivery, and to identify the factors contributing to target motion. METHODS AND MATERIALS Thirty patients with adenocarcinoma of the prostate were prospectively evaluated by analyzing two sequential planning computerized tomography (CT) scans (S1, obtained prior to treatment, and S2, obtained during the fourth week of treatment) for each patient. All anatomical volumes of interest (soft tissue and bony) were reconstructed from transverse CT images and projected onto anterior and lateral beams-eye view projections. Positional changes between S1 and S2 were eliminated by applying a rigid body translation and rotation. Target motion was then measured by recording the positional change between S1 and S2 at the edges (right, left, superior, inferior). Potential correlation of target motion with bladder volume, rectal volume, and rectal diameter changes were evaluated by linear regression analysis. RESULTS Neither the prostate nor seminal vesicles remained fixed with respect to bony anatomy between S1 and S2. The distribution of positional changes were generally small (< 0.5 cm), but maximum displacements of 1.5-2.2 cm did occur, particularly in the lateral view. In this study, bladder volume changes between the scans were small and did not correlate with target motion (P = 0.67). Both rectal volume and rectal diameter changes correlated with target motion for both the prostate (p = 0.004 and 0.005, respectively) and seminal vesicles (p < 0.001 and < 0.001, respectively). However, neither the initial rectal volume nor the initial rectal diameter could be used to predict subsequent target motion when evaluated either singly or as part of a multiple regression model. CONCLUSIONS Target motion occurs during the course of treatment planning and delivery and should be considered when designing conformal radiation fields. Although the target position at the time of planning CT may differ substantially from the mean treatment position, target motion cannot be predicted by evaluating simply measured parameters from a single scan, or double scan sequence.

Large-cell and immunoblastic lymphoma of the mediastinum: prognostic features and treatment outcome in 57 patients.

PURPOSE A retrospective study was performed to define clinical characteristics and therapeutic outcome for patients with large-cell and immunoblastic lymphoma of the mediastinum. PATIENTS AND METHODS Fifty-seven patients who presented with primary, mediastinal large-cell and immunoblastic lymphoma were retrospectively studied to determine initial sites of disease, radiologic characteristics, treatment, outcome, and factors that have prognostic significance for progression-free and overall survival. RESULTS Fifty-six of the 57 patients had disease that was confined to sites above the diaphragm. Bulky disease and extensive intrathoracic infiltration were common in these patients. All patients were treated with intensive chemotherapy regimens, and 44% of patients received chest irradiation. The overall 5-year survival by Kaplan-Meier estimation was 50% with a freedom-from-relapse rate of 45%. Predictors of disease relapse after chemotherapy included the presence of a pleural effusion (P = .015), a number of involved extranodal sites (P < .01), and a lactic dehydrogenase (LDH) ratio > 3.0 (LDH value/upper limit of assay; P = .04) as well as an incomplete treatment response as evidenced by residual mass on chest radiograph (P = .02) or persistent gallium 67 avidity (P = .01) after chemotherapy. Predictors of decreased survival included the presence of pleural effusion (P = .001), the number of involved extranodal sites (P = .022), and a positive posttreatment 67Ga scan (P = .027). CONCLUSION Patients with primary mediastinal large-cell and immunoblastic lymphoma have an approximate 50% chance of surviving disease-free after initial therapy. The presence of pleural effusion at presentation was associated with an extremely poor outcome. Bulk disease per se was a negative predictive factor only in patients without pleural effusions when compared with patients who did not have bulk disease. In addition, all patients with involvement of two or more extranodal sites relapsed when treated with standard chemotherapy.

Breast Cancer Screening in Women Previously Treated for Hodgkin’s Disease: A Prospective Cohort Study

PURPOSE Young women who are exposed to chest irradiation for Hodgkins disease (HD) are at increased risk of breast cancer; this study investigated patient awareness of breast cancer risk and patient screening behavior and assessed the utility of mammographic screening in HD survivors. PATIENTS AND METHODS This is a prospective cohort study of 90 female long-term survivors of HD who had been treated > or = 8 years previously with mantle irradiation (current age, 24 to 51 years). Participants completed surveys of their perceptions of breast cancer risk and screening behaviors and received written recommendations for breast examinations and mammography. Annual follow-up was conducted through medical records, telephone, and/or mailed questionnaires. RESULTS At baseline, women were often unaware of their increased risk of breast cancer; 40% (35 of 87) reported themselves to be at equal or lower risk than women of the same age. Only 47% (41 of 87) reported having had a mammogram in the previous 24 months. Women who had received information from an oncologist were more likely to assess correctly their risk than women who received information from other sources (P <.001). Ten women developed 12 breast cancers (ductal carcinoma-in-situ [n = 2], invasive ductal carcinoma [n = 10]) during the study; two were diagnosed at study entry, and 10 during follow-up (median, 3.1 years). All cancers were evident on mammogram, and eight of 10 invasive cancers were node negative. CONCLUSION Practitioners who care for women after HD therapy need to educate patients regarding their risks and begin early screening. Screening by mammography can detect small, node-negative breast cancers in these patients.

Choosing a specialty in medicine: Female medical students and radiology

OBJECTIVE The purpose of this study was to determine whether there are identifiable factors that dissuade female medical students from entering the field of radiology. MATERIALS AND METHODS An anonymous survey was completed by medical students at the end of their third- or fourth-year radiology clinical clerkships at five institutions. In addition to demographic data and residency choice, respondents ranked 10 factors in order of importance to their choice of career. For respondents who did not consider radiology a possible career, a second set of eight factors was ranked for importance in dissuading them. RESULTS Two hundred eighty-eight respondents completed the survey, 152 (53%) men and 136 (47%) women. Both men and women reported direct patient contact and intellectual stimulation as the most important factors in deciding on a specialty. For those who chose radiology, intellectual stimulation and use of emerging technology were significantly (p < 0.05) more important than other factors. The factor that most strongly (96%) dissuaded men and women from a career in radiology was lack of direct patient contact. There was no significant difference between men and women in ranking factors that dissuaded them from applying to radiology residencies; however, nearly one third of the female respondents cited competitiveness of the residency process as important. CONCLUSION Patient contact remains an important factor for medical students choosing a career. To attract high-caliber students, medical schools should expose students to areas of radiology involving patient interaction. Academically qualified women should be identified early during their careers and encouraged to apply for radiology residencies.

Profile of medical student teaching in radiology: Teaching methods, staff participation, and rewards

RATIONALE AND OBJECTIVES The purpose of this study was to collect demographic information about radiology departments and rewards for teaching activities, as well as the impact of new digital imaging methods on teaching. MATERIALS AND METHODS Two surveys were conducted of directors of medical school clerkships in radiology. The initial survey focused on numbers of staff and students, courses taught, and perception of rewards for teaching. The follow-up survey more specifically addressed teaching methods. RESULTS Sixty-nine (50%) of the initial surveys sent to 139 departments and 46 (39% of a total of 119) of the follow-up surveys were returned. Clerkship directors spent an average of 9 hours per week teaching and performing administrative tasks, with most given no additional time off. Eighty-four percent of departments provide either no or insignificant rewards for teaching. Many departments have integrated the use of computers in teaching, and most have computers that students use during the radiology course. At the same time, digital imaging and picture archiving and communication systems (PACS) are used, or will be used within 1 year, in most departments. CONCLUSION Clerkship directors receive little compensation in terms of time and rewards for medical student teaching. Teaching methods are evolving in response to the increasing use of computers, digital imaging, and PACS for at least part of the workload in most radiology departments.

Dynamic Infrared Imaging of Newly Diagnosed Malignant Lymphoma Compared with Gallium-67 and Fluorine-18 Fluorodeoxyglucose (FDG) Positron Emission Tomography

Staging and therapy monitoring of malignant lymphomas relies heavily on imaging using arbitrary size criteria from computed tomography (CT) and sometimes non-specific radionuclide studies to assess the activity of the disease. Treatment decisions are based on early assessment of the response to therapy and the residual volume of the disease. Our initial experience is reported using a new noninvasive, inexpensive, and reproducible passive imaging modality, Dynamic Infrared Imaging (DIRI), which may add a new dimension to functional imaging. This system relies on its ability to filter the raw infrared signal using biological oscillatory behavior. It detects and analyzes minute oscillations of temperature and heat distribution in tumors.

Incorporating Electronic Media into Medical Student Education: A Survey of AMSER Members on Computer and Web Use in Radiology Courses

RATIONALE AND OBJECTIVES The purpose of this study was to define the current use of information technology in radiology tutorials for medical students. MATERIALS AND METHODS The authors conducted a Web-based survey of directors of medical school courses in radiology. The survey dealt with the details of the courses and the use of computers and the Web during the courses. RESULTS There were 48 responses. Most radiology courses were elective (73%) and were offered monthly. Most institutions (79%) had picture archiving and communication systems (PACS) available or were completely filmless. The teaching case presentations, however, often included film images displayed on a view box or by an overhead projector. Computers dedicated to student use were uncommon (28%). The Web was used infrequently as a teaching resource, and a Web site was not available in most courses. Computer technical support was variable and usually provided by the course director. Course directors at institutions with PACS were more likely to use digital technology for case presentations and more likely to use the Web for teaching purposes. CONCLUSION Despite the widespread use of digital technology and PACS in the field of radiology, digital technology is underused in radiology courses. However, departments with PACS tend to use digital technology more frequently in education than do departments without PACS.

Primary mediastinal leiorayoma

An elderly woman was seen with a left mediastinal mass in the region of the aortic arch on chest roentgenography. Further imaging with computed tomography, angiography, and magnetic resonance demonstrated a highly vascular neoplasm adjacent to the aortic arch. Pathological analysis of the resected specimen showed a leiomyoma. A brief review of the 10 previous reported cases of primary mediastinal leiomyoma is provided.

Imaging features of nonmyxomatous primary neoplasms of the heart and pericardium

We present the imaging findings in 13 patients with nonmyxomatous primary neoplasms of the heart and pericardium. Ten patients had abnormal chest films. While echocardiography was useful for determining origin of the tumor, CT (computed tomography) and MRI (magnetic resonance imaging) were better at delineating extent of disease. The radiographic appearance of these rare neoplasms of the heart and pericardium is varied. Cross-sectional imaging plays a crucial role in the surgical planning and management of these patients.

Clinical competence assessment in radiology: introduction of an objective structured clinical examination in the medical school curriculum.

RATIONALE AND OBJECTIVES Traditional oral and written examinations can be limited in predicting future clinical performance. Therefore Objective Structured Clinical Examinations (OSCEs) have been introduced in other specialties. The authors assessed their value in radiology. MATERIALS AND METHODS The study includes 122 Harvard medical students who undertook 1-month compulsory clerkships at one of three hospitals (A, B, or C) in their 3rd and 4th year and a compulsory OSCE in their 4th year. The OSCE was constructed from five cases. Each had eight or nine standardized questions designed to test, within a set time, the perception of essential findings, their interpretation, and clinical judgment (maximum possible score, 100). Clerkship grades were high honors (score of 3), honors (score of 2), satisfactory (score of 1), and fail (score of 0). Predictors of OSCE scores-clerkship grade and affiliated hospital-were modeled as linear functions. Time elapsed between clerkship and OSCE was modeled as a nonlinear function. RESULTS Although there was a positive relation between clerkship grade and OSCE grade, it accounted for an increase of only 5.7% in OSCE score per clerkship grade and did not predict performance of individual students. Students who trained in hospital B showed significantly higher OSCE grades. OSCE scores were highest when the examination was taken 8 months after the clerkship. CONCLUSION The OSCE may be useful to uncover deficits in individuals and groups beyond the ones detected with traditional clerkship evaluations and provide guidance for remediation. The improved performance after additional clinical exposure suggests that the OSCE may be well suited to test the integration of radiologic and clinical knowledge.