Dr. Frankel is the Medical Director of the Tower Imaging Women's Center in Beverly Hills, CA. Dr. Brenner is the Medical Director of the Eisenberg­Keefer Breast Cancer Center (Tower Imaging) at the John Wayne Cancer Institute, Santa Monica, CA.

The leading cause of lawsuits against physicians is the delay in diagnosis of breast cancer. In these types of actions, the most frequently named defendant is the radiologist. ¹ It has been reported that approximately 10% of lawsuits against radiologists are related to image-guided procedures. ² Additionally, a review of jury verdicts suggests that about one-third of lawsuits against radiologists are related to interventional procedures. ³ Because of the high legal exposure of radiologists who interpret breast imaging studies and the concurrent exposure of those who perform image-guided interventional procedures, it is imperative that the interventional breast radiologist understand the relevant legal issues.

These types of lawsuits may occur so frequently partially due to public expectation of early detection and cure, perhaps amplified by clinical studies reporting decreased mortality with regular mammography screening. ⁴ A common misperception may relate to the presumed (inflated) accuracy of interpretation of breast imaging (specifically mammographic) studies. As is well known to those interpreting breast imaging studies, there is considerable overlap in the appearance of benign and malignant processes by mammography. ⁵ Additionally, there is both interobserver and intraobserver variability in visual perceptions, in diagnostic criteria, and in biopsy rates. Due to the increased frequency of women undergoing mammographic examinations, legal exposure of the radiologist is potentially increased. ⁶

At least for the short term, image-guided breast interventions are likely to continue to increase. Given the relatively high cost of surgical excision for nonspecific breast lesions, image-directed tissue sampling (by stereotactic methods and ultrasound guidance) has gained favor with patients, payers, and many clinicians, though some resistance is still present within the surgical community.

Medical-legal exposure

Most medical malpractice cases are resolved as issues of civil law, specifically tort law. Tort law arises when there is a presumed departure from a reasonable standard of care perpetrated by one party upon another. Civil law derives from statutory law and common law, with most lawsuits for medical malpractice covered by common law. Common law is based upon decisions of appellate courts. These decisions can establish legal precedent to be used as guidance in future lawsuits. Statutes are laws passed by legislative bodies and are less relevant in cases of medical malpractice. One exception, which is very relevant for breast imaging, is the Mammography Quality Standards Act (MQSA) passed by Congress in 1992. ⁷

Negligence

The law of negligence covers most medical malpractice cases. Negligence is concerned with a physician's conduct rather than with the actual outcome related to that conduct. However, it is generally an adverse outcome that prompts a lawsuit to be brought and to come to the court's attention. In law, medical negligence is based upon a departure from an acceptable standard of care of a reasonable and prudent physician. ⁸ The standard of care to which radiologists, and physicians in general, are held is one of reasonable care, not optimal care. Proof of negligence often requires the testimony of experts to establish the standard of care.

Intentional torts

Intentional torts may be defined as prohibited acts that one person intends to commit upon another and that actually occur. Battery is the unlawful, nonconsensual touching of another person and, as such, is an intentional tort. If there is the possibility of adding another interventional component or step to an intended and consented procedure, this contingency must be discussed first, during the initial consent process, or a new consent must be obtained. For example, battery may be found for performing a core biopsy if a fine-needle aspiration biopsy (FNAB) was the only procedure discussed during the informed consent process. This situation exemplifies the notion that exceeding consent may constitute battery. Because any invasive procedure is legal battery, it is recommended that consent be obtained for all breast interventional procedures. Properly obtained consent is a defense for, and will defeat, the charge of battery.

Informed consent

Most medical malpractice lawsuits that involve informed consent are pursued under the law of negligence. Certain questions must be asked of the physician. Has the physician obtained the consent in a manner in which a reasonable physician would have obtained consent under similar circumstances? Has a substantial injury occurred? Have the physician's actions breached the duty to obtain consent and been the cause of the injury? Alternatively, some states use the "reasonable patient" standard in which a "reasonable patient"may be thought of as an average "typical" person. In this situation, proper consent is complied with if relevant information is disclosed in such a way that it is deemed what a reasonable patient would expect to know.

Classic federal appellate courts define "informed consent" as "disclosure of risks, complications, and alternatives to the procedure." ⁹ The physician's discussion with the patient of risks, complications, and alternatives should include mention of the possibility of the following: the physician's inability to make the diagnosis in a finite number of cases, nondiagnostic yield, findings of atypical ductal hyperplasia (ADH), and disconcordant results as related to the preprocedural images, ^10,11 which may prompt additional surgery. Patients should be informed that post-procedural imaging/pathology correlation is necessary to assure concordance; if the results are discordant, appropriate further management steps are necessary. ¹² Additionally, possible serious complications and milder ones that occur with a relatively high frequency should be discussed.

The physician who will perform the procedure is responsible for the patient being informed of the risks, possible complications, and alternatives to the procedure. The discussion itself--not the signed consent form that is obtained prior to the procedure--is the critical aspect of the informed consent process. The patient's signature on a consent form is only evidence that such a discussion took place.

Performance of the procedure

All images obtained that lead up to a recommendation for tissue diagnosis or other intervention should be analyzed. Performance of any breast interventional procedure should be predicated on determining that an imaged abnormality has been evaluated appropriately by the interventionalist. It is the duty of the mammographer to detect and analyze possible abnormalities and then determine the best approach to attempt to diagnose the abnormality. This requires knowledge and experience in diagnostic breast imaging. The mammographer has the duty to recommend appropriate action based upon his or her interpretation of the findings. ¹³

The interventionalist must corroborate that the lesion truly exists, and if so, must validate its location. Following these determinations, the final question is to determine whether it lends itself to either needle biopsy (including which type) or preoperative localization. Under most circumstances, it is necessary to define a mammographic abnormality in two orthogonal projections prior to performing a needle localization procedure or stereotactic procedure. This is especially important when initially deciding if a lesion is real or is representative of superimposition artifact. Abnormalities demonstrated in only one projection require further diagnostic work-up before evaluation is considered to be complete. Assuring that a lesion is real and that it has been found in two orthogonal planes is also needed prior to performing a diagnostic sonographic evaluation of a mammographic finding. Once tissue diagnosis has been recommended, the appropriate interventional procedure must be chosen.

Reasonable performance of any procedure requires educational training and experience. Continuing Medical Education (CME) courses may be advisable prior to actually performing any of these procedures on patients. Alternatively, watching and working with an experienced colleague prior to performing any procedure may be enough, and there should be sufficient documentation of gained experience. An important component of risk management is establishing competency when a new procedure is introduced to the practice, especially if a patient challenges this skill, which may occur after a (perceived) complication occurs.

Stereotactic and ultrasound-guided breast biopsies

A key question is actually a somewhat technical one: whether or not the lesion is accessible. On most commercially available stereotactic equipment, very deep lesions or those in the axillary tail may be inaccessible because the mammographic abnormality cannot be placed within the field of view of the equipment. With some digital equipment in which resolution capabilities are limited, certain lesions may be difficult to identify confidently ¹⁴ due to diminished contrast resolution compared with mammographic film. The stereotactic digital devices have a relatively small field of view, and the entire breast cannot be visualized; therefore, determining the correct target can be difficult. If the lesion cannot be recognized with sufficient confidence by the interventionalist performing the stereotactic biopsy, there may arise a duty to not perform the biopsy and to instead refer the patient for a more appropriate procedure (e.g., needle localization for excision).

Another key aspect to performance of any procedure is familiarity with the equipment. For stereotactic procedures, two of the most important pieces of equipment are the guidance unit and needle being used to obtain the tissue samples. The stereotactic unit operates on the principle of triangulation with the position of the lesion localized in the horizontal (x) and the vertical (y) axes; the depth (z axis) is calculated from the surface of the breast using two angled (15š along the x axis) images. ¹⁵ Prone units or attachable upright units are available. A variety of needle designs are available to perform large core procedures, including vacuum-assisted devices using an 11-gauge needle.

Ultrasound-guided procedures (fine-needle aspiration biopsy or large-core biopsy) are also effective methods of obtaining a cytologic or histologic diagnosis. Sonography is also useful for cyst aspirations and preoperative needle/wire placement for excisional biopsy. Most devices used for sonographically guided breast-core biopsy are spring-loaded with 14-gauge needles (16- and 18-gauge needles are less commonly used); however, 11-gauge vacuum-assisted devices specifically designed for ultrasound are now on the market. The ability to introduce a metallic clip during an ultrasound procedure is now possible. A linear array transducer is also the preferred sonographic device for breast interventional procedures given the relative ease in verifying needle location. Use of other transducers requires similar ability to document needle tip location.

Other issues

Because the interventionalist is the main participant in the actual procedure, it is important that he or she obtain results for all image-directed biopsies. The breast interventionalist should discuss the results and management strategies with the referring (ordering) clinician in cases in which additional procedures or treatment is indicated (i.e., cases that are discordant or show atypia, as well as positive cases diagnosing breast cancer). This type of action and involvement by the breast interventionalist is that of reasonable management .

Another important issue to keep in mind is the self-referred patient--the woman who requests a mammogram herself but is not under the care of a primary care clinician. In such situations, the radiologist places himself or herself in the role of the primary care provider with respect to breast health care. ^16,17 If the final recommendation is to obtain tissue diagnosis, the radiologist becomes responsible for informing the patient, discussing the different procedure options, and ensuring that the obtaining of a tissue diagnosis (eventually) occurs. This more active primary care role by the radiologist requires a mechanism to help verify that the patient has complied with the radiologist's recommendations or that there are documented efforts to achieve compliance.

Other torts or civil actions of which the interventionalist should be aware are the torts of abandonment and negligent referral. ¹⁸ Abandonment may arise if a patient suffers a complication of a procedure requiring further care or if the results of a procedure necessitate additional care (such as surgery or other treatment options for positive cases), and these issues have not been resolved by the primary physician, who may possibly be the radiologist (in self-referred cases, for example).

Negligent referral occurs if complication occurs related to the patient's care or treatment after the patient is referred by the interventionalist to another physician or facility for additional care, follow-up, or treatment when that interventionalist knows or has reason to believe that the physician or facility may not be competent to manage the patient's medical situation. AR