High-Dose-Rate Remote Afterloaders for Intraoperative Radiation Therapy

Gao, Song; Delclos, Marc E.; Tomas, Lyvia C.; Crane, Christopher H.; Beddar, Sam

doi:10.1016/j.aorn.2007.07.002

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Volume 86, Issue 5 , Pages 827-840, November 2007

High-Dose-Rate Remote Afterloaders for Intraoperative Radiation Therapy

Song Gao, PhD
- Song Gao, PhD, is a medical physicist in the Department of Radiation Physics at the University of Texas, MD Anderson Cancer Center, Houston. Dr Gao has no declared affiliation that could be perceived as a potential conflict of interest in publishing this article.
Marc E. Delclos, MD
- Marc E. Delclos, MD, is an associate professor in the Department of Radiation Oncology at the University of Texas, MD Anderson Cancer Center, Houston. Dr Delclos has no declared affiliation that could be perceived as a potential conflict of interest in publishing this article.
Lyvia C. Tomas, RN
- Lyvia C. Tomas, RN, is a perioperative nurse in the Department of Surgery at the University of Texas, MD Anderson Cancer Center, Houston. Ms Tomas has no declared affiliation that could be perceived as a potential conflict of interest in publishing this article.
Christopher H. Crane, MD
- Christopher H. Crane, MD, is an associate professor in the Department of Radiation Oncology at the University of Texas, MD Anderson Cancer Center, Houston. Dr Crane has no declared affiliation that could be perceived as a potential conflict of interest in publishing this article.
Sam Beddar, PhD
- Sam Beddar, PhD, is an associate professor in the Department of Radiation Physics at the University of Texas, MD Anderson Cancer Center, Houston. Dr Beddar has no declared affiliation that could be perceived as a potential conflict of interest in publishing this article.

Article Outline

ABSTRACT

INTRAOPERATIVE RADIATION THERAPY (IORT) is a treatment option that directly irradiates a surgically exposed tumor or tumor bed while preventing radiation exposure of normal tissues.

THIS ARTICLE DISCUSSES the high-dose-rate intraoperative radiation therapy (HDR-IORT) technique by reviewing the roles of IORT team members, discussing needed equipment and supplies, describing quality assurance processes, explaining the HDR-IORT treatment delivery procedure, and reviewing the post-treatment phase. AORN J 86 (November 2007) 827–836.

Intraoperative radiation therapy (IORT) is single-fraction, external beam radiation treatment or high-dose-rate (HDR) brachytherapy that is administered at the time of surgery. In IORT treatment, a large-fraction dose of radiation is focused on a surgically exposed tumor or tumor bed while the surrounding healthy organs and tissues are either shielded by lead shields or displaced from the radiation field by gauze packing or retractors. The primary advantage of IORT is its ability to deliver a higher radiation dose to a tumor or tumor bed while minimizing radiation exposure of normal tissues.

In general, IORT is effective for tumors that might not be resectable or for which resection might be difficult, thus leaving close or positive margins. Specifically, IORT has been used to treat advanced or recurrent colorectal, gynecologic, genitourinary, pancreatic, and gastrointestinal cancers as well as primary, locally advanced cancers that have a low likelihood of cure with surgery alone. Intraoperative radiation therapy also is used as primary treatment for

•soft tissue sarcomas,

•retroperitoneal sarcomas,

•cancers in pediatric patients,

•head and neck cancers, and

•breast cancer.

It also is used for palliative treatment of hepatic colorectal metastases and cancers that recur in lymph nodes.¹, ²

Intraoperative radiation therapy can be delivered in several different ways. One of the most commonly used treatment methods is intraoperative electron beam radiation therapy (IOERT), which uses accelerator-produced electron beams.³, ⁴, ⁵, ⁶ Another method is high-dose-rate intraoperative radiation therapy (HDR-IORT) in which radioactive sources are used.⁷, ⁸, ⁹, ¹⁰

A linear accelerator and shielded OR are needed for IOERT. For the HDR-IORT technique, the HDR afterloader unit is less expensive, but an existing shielded OR still is needed or the OR must be reconstructed with shields, which adds to costs.¹⁰, ¹¹

The overall concepts and treatment outcomes of IOERT and HDR-IORT are almost the same. A nonflexible, rigid cone applicator is used in the IOERT technique, however, so this technique is less feasible in sites containing narrow cavities such as

•the paranasal sinuses,

•sites deep in the inferior pelvis,

•subpubic locations,

•some lateral pelvic side walls,

•the anterior chest wall,

•the anterior abdominal walls, and

•the subdiaphragmatic area.⁵, ⁶, ¹²

Because HDR-IORT uses various sizes of flexible Harrison-Anderson-Mick (HAM) applicators, this treatment can be used for sites that are inaccessible with the IOERT technique.

Although the techniques in these two treatment methods are different, the methods are similar in that they supply high, effective radiation doses to the high-risk area while appropriate surgical procedures are used to protect adjacent sensitive structures. This article focuses specifically on HDR-IORT by reviewing the roles of IORT team members, discussing needed equipment and supplies, describing quality assurance processes, explaining the HDR-IORT treatment delivery procedure, and reviewing the post-treatment phase.

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Roles of IORT Team Members

This multidisciplinary approach to cancer treatment combines surgery and HDR-IORT; consequently, staff members from both the Surgery and Radiation Oncology Departments are involved. The team consists of the surgeon, radiation oncologist, medical physicist, anesthesia care providers, and perioperative nursing staff members. Close collaboration between these members is essential to successfully implement an HDR-IORT program. Each team member, therefore, should clearly understand his or her own responsibilities and should be knowledgeable about the other practitioners' roles.¹³

Surgeon

In addition to performing the conventional surgical procedure, the surgeon works closely with the radiation oncologist to determine the size of the tumor or tumor bed to be treated. The surgeon is responsible for the entire procedure.

Radiation oncologist

During preoperative consultation, the radiation oncologist evaluates the patient and, jointly with the surgeon, determines if the patient is an appropriate candidate for the IORT procedure. During surgery, the radiation oncologist is responsible for determining the size of the radiation area, the appropriate applicator size to use, and the prescription of radiation doses. After the radiation oncologist places the applicator into the patient's cavity or onto the tumor bed, he or she connects the transfer tubes to the HAM applicator.

Medical physicist

The responsibilities of the medical physicist include quality assurance (QA) of the HDR afterloader machine, the treatment planning system, and the remote monitoring system in the OR. The medical physicist generates the treatment plan, sets up the HDR afterloader machine for treatment, performs a radiation survey of the patient before and after treatment, delivers the radiation treatment, and documents the HDR-IORT procedure. The physicist also is responsible for ensuring that radiation emergency procedures are implemented if needed. The medical physicist visually inspect the equipment before initial use, and after completion of the surgical procedure, sends nondisposable supplies to the Central Processing Department.

Anesthesia care providers

The entire HDR-IORT procedure is administered to surgical patients under general anesthesia. The anesthesia care provider induces anesthesia and then is responsible for monitoring the patient closely from an adjacent room using video and treatment monitors.

Nursing staff members

The perioperative nursing staff members have responsibilities before, during, and after the HDR-IORT procedure.³, ⁵, ⁶ The circulating nurse and scrub person are responsible for obtaining the equipment and sterile supplies necessary for the opening procedure, HDR-IORT, and closing procedure. The circulating nurse is responsible for ensuring that the patient is safe while in the OR. He or she accomplishes this in a variety of ways, such as ensuring that surgical time outs and counts are performed, a thorough skin prep is performed, and aseptic technique is observed by all team members.

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HDR-IORT Equipment

High radiation activity Iridium-192 (¹⁹²Ir) is the primary source of radiation; therefore, a special shielded OR is needed. Another room adjacent to the shielded OR houses the HDR control console, treatment planning system, video monitors, and other pieces of required equipment and supplies. The control console operates the HDR remote afterloader that delivers the radioactive source to the applicators that will be in contact with the patient's body cavity.

HDR remote afterloader

A computer-controlled machine called a remote afterloader delivers the HDR treatments (Figure 1). The HDR remote afterloader contains a single source of ¹⁹²Ir with a half-life of 73.83 days, mean energy of 0.38 million electron volts (MeV), and half-value layer of 2.5-mm lead. The activity of the ¹⁹²Ir source is about 10 curies (Ci). Physically, the ¹⁹²Ir source is a small cylindrical wire approximately 4 mm long and 1 mm in diameter. The source is welded to the end of a flexible drive cable (ie, the source cable). The radioactive source is stored in a tungsten-shielded safe when the afterloader system is not in use, and this source is exchanged every three months because of the half-life of ¹⁹²Ir. A stepper motor drives the source cable toward the applicator or retracts it back into the safe. A separate cable with a dummy source (ie, a metal cylindrical wire) called the check cable is used to check the pathway of the source before actual delivery of the radiation source. It is driven by another stepper motor, and a solid cylindrical piece of metal, similar to the shape of the source, is welded to its distal end. Any improper connection between the HDR afterloader and the applicator can be detected when the dummy source is run through the check cable; errors should be corrected before delivery of the radioactive source.

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Figure 1.
A mobile high-dose-rate afterloader unit.

Ancillary equipment for treatment delivery

In addition to the HDR remote afterloader, the following supplies and equipment are required to successfully perform HDR-IORT: the HAM applicator, transfer tube, lead shields (Figure 2), and remote monitoring system.

•The HAM applicator with permanently embedded catheters and radiopaque markers is manufactured to be compatible with the HDR remote afterloader. This flexible applicator provides optimal area coverage for the HDR treatments. The HAM applicator consists of a flexible silicone rubber pad (ie, superflab) and an array of embedded catheters. The catheters are parallel to each other and spaced 10 mm apart, and the distance from each of the two outer catheters to the edge of the applicator is 5 mm. The width of the HAM applicator varies from 3 cm to 24 cm depending on the number of catheters (ie, three to 24). Standard HAM applicators are 0.8 cm thick and 22 cm long. The distance from the center of each catheter to the surface facing the tumor bed is 5 mm, and the label “Keep This Side Away From Tissue” on the applicator ensures that the proper surface is facing the tumor bed. The radiation oncologist and surgeon select the appropriate size of HAM applicator according to the size of the tumor bed. The HAM applicators are presterilized.

•Sterile transfer tubes connect to the catheter in the HAM applicator on one end and insert in the appropriate channel of the HDR afterloader on the other end. The oncologist and physicist visually inspect the transfer tube connection to ensure that smooth transportation of the radioactive source from the HDR afterloader into the HAM applicator is achieved.

•Sterile lead shields with different shapes, curvatures, and sizes are used to protect radiosensitive structures that cannot be displaced from the irradiation area with retractors and gauze packing.

•A remote monitoring system also is necessary. Three video cameras are installed in the OR to allow remote monitoring of the patient by the anesthesia care provider, surgeon, radiation oncologist, and circulating nurse for the entire treatment delivery period during which all personnel are required to leave the OR. The remote video system allows the surgical field and the irradiated area to be monitored by the surgeon and radiation oncologist. Remote clinical monitors allow the anesthesia care provider to closely observe the patient's vital signs, electrocardiogram, and arterial line. Any problems that could affect the patient's safety and treatment delivery can be observed, and the treatment can be interrupted immediately if necessary.

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Figure 2.
The transfer tube (center) is used to connect the Harrison-Anderson-Mick applicator (top center) to the high-dose-rate afterloader. Five lead shields of varying sizes (left) are used as needed to protect radiosensitive structures.

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Quality Assurance Before Treatment Delivery

Before the treatment is performed, the medical physicist ensures that the HDR afterloader and shielded storage container are brought to the shielded OR. In addition, the medical physicist must perform the appropriate QA checks on the HDR afterloading system, the treatment planning system, and the video monitoring system in the OR. The medical physicist may perform the QA procedures on the afternoon before or the morning of the surgery, depending on the time the surgical procedure is scheduled and the availability of the shielded OR. The QA checks include performing safety monitoring system verifications, radiation safety interlock system tests, and radioactive source verification.

First, to ensure an intact and properly working monitoring system, the medical physicist verifies the function of the in-room cameras, video monitors, and audio intercom. Next, he or she checks the radiation interlock system. Its components include the console interrupt, the emergency stop, and the doors interrupt. When performing these interrupt operations, it is important for the medical physicist to confirm that the radiation source is retracted into the HDR afterloader unit. He or she also tests the radiation monitor in the console area and the radiation lights above the doors. Lastly, the medical physicist checks the source position for two different positions (ie, 1,300 mm and 1,500 mm) and ensures that source position deviation is ± 1 mm.

The medical physicist also checks the treatment planning system, which is used to create the HDR-IORT plan. He or she checks the radioactive source and confirms that the source activity in the planning system correlates with the value on the decay table (ie, a list of the information of daily source activity after the initial calibration date) in the QA logbook. The physicist ensures that the system can load the plan from the library (ie, the electronic storage location of the treatment plan); transfer the plan to the treatment control console; and print out the plan. The medical physicist then checks the functionality of the portable Geiger-Müller survey meter, which identifies the presence of radiation.

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Preoperative Preparation

Before starting the surgical procedure, the circulating nurse and scrub person prepare the OR.¹³ This may include cleaning the OR according to facility policy and ensuring availability of necessary anesthesia and surgical equipment. In addition to checking the remote video monitoring system and surgical lights that are permanently installed in the shielded OR, the circulating nurse and scrub person ensure that the radiation treatment system (ie, the HDR afterloader unit, treatment console, planning system, transfer tubes, lead shields, HAM applicator) is ready in the OR or the adjacent room. The circulating nurse ensures that additional blood products are available because the treatment time for radiation delivery could take up to an hour. He or she also is responsible for helping to maintain a safe, comfortable environment for the patient and making sterile and nonsterile IORT supplies available and ready for use in the OR. The circulating nurse and scrub person obtain and open sterile supplies onto the sterile back table.

The circulating nurse conducts a complete assessment of the patient in the preoperative holding area and develops a personalized nursing care plan (Table 1). The circulating nurse then transports the patient to the OR and assists the patient onto the OR bed in the proper position for surgery and IORT treatment. The scrub person performs a surgical hand scrub and then gowns and gloves for the procedure and prepares the back table and instruments.

Table 1. Nursing Care Plan for Patients Undergoing Intraoperative Radiation Therapy

Diagnosis	Nursing interventions	Interim outcome criteria	Outcome statement
Risk for impaired skin integrity related to radiation exposure, immobilization, positioning, pressure, and shearing forces	•Assesses skin integrity, sensory impairments, and musculoskeletal status. •Assesses for preexisting conditions that may affect procedure-specific positioning. •Positions the patient according to correct anatomic principles. •Implements protective measures to prevent tissue injury caused by thermal, chemical, radiological, or mechanical sources. •Evaluates for signs and symptoms of skin and tissue injury.	The patient's skin remains intact throughout the perioperative period.	The patient demonstrates wound and tissue perfusion consistent with or improved from baseline levels established preoperatively.
Risk for acute or chronic pain related to tissue trauma secondary to intraoperative radiation or the surgical procedure	•Assesses patient's preoperative pain, previous experiences of pain, and cultural and value components related to pain and pain control. •Identifies accepted postoperative pain threshold and understanding of the pain management plan and pain management techniques. •Provides pain management instruction and pain scale to assess pain control and explains the need to report pain in a timely manner. •Implements pain management guidelines. •Evaluates patient's response to pain management interventions.	The patient reports pain and demonstrates adequate pain management throughout the perioperative period.	The patient's postoperative vital signs and other nonverbal symptoms remain stable, indicating adequate pain control.
Risk of anxiety related to knowledge deficit, stress of surgery, and altered physical status	•Assesses the patient's knowledge level, including expected outcomes and risk of radiation and surgical side effects. •Determines readiness to learn and identifies barriers to communication and psychosocial status on plan of care. •Provides instruction (ie, verbal, written) for surgical procedure. •Provides resources for psychological support (eg, social service contact, prostate cancer support group). •Evaluates patient's and family members' response to instructions.	The patient verbalizes decreased anxiety and an ability to cope, understanding of individualized procedure and the sequence of events, expected outcomes, and that questions have been answered.	The patient participates in decisions affecting the plan of care. The patient demonstrates knowledge of psychological responses to the procedure, possible side effects, and discharge care.
Risk of infection related to length and type of procedure and tissue manipulation during radiation therapy and surgery	•Assesses preoperatively for susceptibility to infection (eg, chronic diseases, weight, laboratory values, skin integrity). •Implements, monitors, and maintains aseptic technique. •Administers prescribed antibiotic therapy at appropriate times. •Helps minimize length of intraoperative phase by planning and anticipating care.	The patient's surgical wound remains free from signs of infection and the patient remains normothermic throughout the perioperative period.	The patient is free from signs and symptoms of infection.

The circulating nurse ensures that a surgical time out is performed by all members of the surgical team and assists the anesthesia care provider with induction of anesthesia. After performing the surgical count with the scrub person according to facility policy, the circulating nurse performs the surgical skin prep of the appropriate area using an antimicrobial prep solution.

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HDR Intraoperative Procedure

The surgeon surgically exposes the tumor and resects it as much as possible. The radiation oncologist and medical physicist are notified one hour before the actual HDR treatment. This early notification gives the physicist time to prepare the HDR treatment system. The radiation oncologist and surgeon jointly determine the volume of the tumor that has been removed and have pathological tests performed to determine margin status. When tumor resection is complete, the surgeon and radiation oncologist measure the size of the tumor bed and determine the radiation volume area according to the tumor bed and the pathological test results. If there are some normal structures located near the treatment field, the surgeon and scrub person will either displace these structures with a retractor or gauze packing or shield them with appropriate lead shields. The oncologist then determines the prescription of the radiation treatment. The prescription includes the number of catheters (ie, width); length of the applicator (ie, number of stopping positions); and dose (eg, 12.5 Gy at 1 cm away from the center of the source). The radiation oncologist then verbally communicates the desired prescription to the physicist who repeats the prescription aloud to avoid communication errors.

Treatment planning

According to the verbal prescription, the physicist chooses the appropriate HAM applicator template and creates a treatment plan using the brachytherapy treatment planning system with the appropriate plan template that matches the prescription. The planning process usually takes about 10 minutes. The treatment plan contains the total dose (ie, total treatment time); dose rate (ie, the dwell time in seconds) for all of the treatment points in the HAM applicator; and the dose distributions. The dose distributions are optimized by varying the dwell time of the sources; the distance between active dwell positions is 5 mm by default. After the plan is verified, the physicist transfers the plan from the treatment planning computer to the console control computer for actual treatment delivery.

Treatment plan verification

The physicist checks the plan before delivering the treatment by checking the

•patient's name and identification number;

•number of catheters and treatment area (eg, six catheters, 5.0 cm);

•source type (ie, ¹⁹²Ir-HDR);

•source position separation (ie, 5.0 mm);

•source calibration time and the apparent source activity, which should be consistent with the decay table on the QA logbook;

•outline of the catheter and indexer (ie, indicates the appropriate channel on the afterloader unit), which should agree with the prescription;

•total treatment time calculated by the planning computer, which should agree with the manual calculations performed by the medical physicist (ie, deviation should be within 2%); and

•the dose distribution.

The treatment plan should be verified and signed by the radiation oncologist.

Treatment delivery

The radiation oncologist places (ie, aligns) the sterilized HAM applicator on the tumor bed and attaches the sterilized transfer tubes to the catheters that are embedded in the superflab of the HAM applicator. If necessary, the surgeon uses sterilized lead shields or retractors to protect the normal tissues from irradiation. The physicist assists with connecting the transfer tubes to the appropriate channels of the HDR afterloader. For example, catheter #1 should connect to channel #1 of the HDR afterloader. Every transfer tube should connect between the HAM applicators and the HDR afterloader in its proper order and position to avoid unwanted vibration and motion during source transportation. Figure 3 shows the tube connection between the HDR afterloader and the HAM applicator.

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Figure 3.
The high-dose-rate (HDR) afterloader is connected to a Harrison-Anderson-Mick (HAM) applicator using transfer tubes (top). The transfer tubes are attached to a five-channel HDR unit, which provides 18 access channels (bottom left). The transfer tubes are connected to the HAM applicator catheters; in this case, a five-channel catheter HAM applicator is shown (bottom right).

The circulating nurse hands the sterile items to the scrub person and the scrub person assists the oncologist with the actual setup. When the setup procedures are complete, the physicist performs a test run with the check cable that goes through every catheter to ensure the connections are correct and that the source pathway is clear. The physicist then can deliver the radiation treatments. All personnel leave the OR, and the physicist surveys the patient using the Geiger-Müller survey meter to ensure that no radiation material is in the patient's body. The physicist uses the treatment console to control the HDR machine as it drives the ¹⁹²Ir source to the appropriate active position for a proper amount of dwell time given by the treatment plan. The physicist can advance or retract the source wire through individual channels, transfer tubes, and applicators by a remote computer-controlled drive mechanism consisting of stepper motors. The positioning accuracy of the source at the programmed dwell position is specified at ± 1 mm. The dose control precision is provided by 0.1-second dwell-time resolution. The total treatment time varies from 10 to 20 minutes depending on the treatment area and the source activity. Figure 4 shows examples of actual HDR treatments with and without lead shields.

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Figure 4.
Transfer tubes are attached to the Harrison-Anderson-Mick (HAM) applicator, inserted into the patient's surgical cavity, and then connected to the high-dose-rate unit (top). The HAM applicator is placed on the tumor bed before placement of a lead shield (bottom left). The HAM applicator is placed on the tumor bed with a lead shield to protect radio sensitive structures (bottom right).

During the treatment delivery process, all personnel remain scrubbed in in the event the patient needs immediate attention. The physicist focuses on the control console to ensure that the HDR afterloader is working properly. The anesthesia care provider observes the patient's anesthesia monitor, and the oncologist observes the patient via the video monitors.

Emergency procedures

Emergency procedures are posted at the console as required by state regulations. The physicist who operates the HDR afterloader is required to respond in case of failure. The HDR afterloader is designed in such a way that the radiation source will be retracted into the tungsten shield if any failure condition arises. If the system completely fails, for instance, if the source gets stuck in the applicator pathways or does not return to the safe as expected, the physicist uses a hand-controlled crank to manually withdraw the source in approximately five seconds.

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Post-Treatment Phase

When treatment is complete, the HDR machine automatically retracts the radiation source into the tungsten shield of the HDR afterloader. The physicist surveys the patient and the OR using the Geiger-Müller survey meter to ensure that no radiation material remains and that it is safe for all scrubbed personnel to reenter the OR. The scrub nurse changes his or her gown and gloves and helps the surgeon and radiation oncologist regown and reglove for completion of the surgical procedure. The circulating nurse and scrub person perform additional surgical counts, if required, according to facility policy.

The physicist, respecting the sterile field, assists the oncologist with removal of the applicator, transfer tubes, and lead shields from the treatment site and the HDR afterloader. The scrub person helps the surgeon remove the sterile instruments and gauze pads. The physicist prints out the treatment record, signs it, and ensures that the oncologist also signs the record. The physicist then turns off the treatment planning computer and treatment console computer, disconnects the HDR afterloader from the console, and moves the HDR remote afterloading system from the OR to the adjacent room. The physicist cleans the system with antiseptic solution and puts it in storage. The surgeon then completes the surgical procedure. The circulating nurse is responsible for completing the intraoperative nursing documentation.

After the surgical procedure is completed and the patient is transferred out of the OR, the OR assistants clean the OR with a disinfectant solution. The radiation-contaminated supplies, such as the HAM applicator, surgical clamping system, and lead shields, should be processed according to the facility's decontamination procedure. The OR assistants clean the coupling and tube ends and then sterilize them using an US Food and Drug Administration (FDA)-approved ethylene oxide sterilant or another approved sterilization method. Finally, the OR assistants double package the tubes in groups of three and label them as “HDR transfer tubes.” The OR assistants clean the lead shields with an approved disinfectant and inspect for and remove blood from all surfaces. The lead shields are sterilized using an FDA-approved ethylene oxide sterilant then double packaged separately, and labeled as “HDR lead shields.” Although HAM applicators can be cleaned and sterilized for reuse, some facilities prefer single-use HAM applicators to simplify the cleaning process.

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An Achievable Technique

After HDR-IORT was developed in the United States and Europe in the late 1980s and early 1990s, implementation strategies were identified to build a shielded OR in which the entire surgical procedure and radiation treatment could be performed. This design avoids transportation of patients from one place to another. A computer-controlled remote afterloader delivers the high-intensity radiation source into precise locations within the applicator and controls precisely how long the source remains at each location. The development of the flexible HAM applicator and the portable HDR remote afterloader makes the HDR-IORT treatment technique achievable for any medical center.

Intraoperative radiation therapy requires remarkable cooperation between surgeons, radiation oncologists, medical physicists, perioperative nursing personnel, anesthesia care providers, and hospital scheduling personnel in order to take advantage of this high quality cancer treatment modality. It is important that perioperative nurses and other nurses who provide care to these patients any time during their course of treatment understand the procedure so they can provide quality nursing care.

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Examination

High-Dose-Rate Remote Afterloaders for Intraoperative Radiation Therapy

Purpose/Goal

To educate perioperative nurses about high-dose-rate intraoperative radiation therapy (HDR-IORT).

Behavioral Objectives

After reading and studying the article on HDR-IORT, nurses will be able to

1.discuss IORT techniques,

2.describe the roles of the IORT team members,

3.identify equipment used for HDR-IORT,

4.explain emergency interrupt procedures,

5.discuss perioperative care of a patient undergoing HDR-IORT, and

6.explain the HDR-IORT procedure.

Questions

1.Intraoperative radiation therapy (IORT)

1.focuses a large-fraction dose of radiation on a tumor or tumor bed.

2.minimizes radiation exposure of normal tissues.

3.is used to treat cancers that have a low likelihood of cure with surgery alone.

4.can be delivered using accelerator-produced electron beams.

a.1 and 4

b.2 and 3

c.1, 3, and 4

d.1, 2, 3, and 4

2.Because HDR-IORT uses a flexible applicator, this technique can be used to treat sites such as those containing narrow cavities that are inaccessible using intraoperative electron beam radiation therapy (IOERT).

a.true

b.false

3.The medical physicist is responsible for

1.performing quality assurance (QA) procedures on the HDR afterloader machine.

2.generating the treatment plan.

3.setting up the HDR afterloader machine.

4.performing a radiation survey of the patient.

5.delivering the radiation treatment.

6.documenting the HDR-IORT procedure.

7.initiating radiation emergency procedures.

a.1, 3, and 5

b.2, 4, and 6

c.1, 2, 3, 5, and 7

d.1, 2, 3, 4, 5, 6, and 7

4.A flexible Harrison-Anderson-Mick (HAM) applicator

1.comes in a variety of widths depending on the number of catheters needed.

2.has a flexible silicone rubber pad.

3.has permanently embedded catheters and radiopaque markers.

4.is compatible with the HDR remote afterloader.

a.1 and 2

b.2 and 4

c.1, 2, and 4

d.1, 2, 3, and 4

5.The radiation safety interlock system consists of

1.a console interrupt.

2.an emergency stop.

3.a doors interrupt.

a.1

b.1 and 3

c.1, 2, and 3

6.Appropriate nursing diagnoses for a patient undergoing HDR-IORT include risks for

1.acute or chronic pain.

2.alteration in cardiac tissue perfusion.

3.anxiety.

4.impaired skin integrity.

5.infection.

a.2 and 3

b.1, 4, and 5

c.1, 3, 4, and 5

d.1, 2, 3, 4, and 5

7.The oncologist determines the prescription of the radiation treatment, which includes the

1.dose.

2.length of the applicator.

3.number of catheters.

4.number of treatment sessions.

a.1 and 3

b.2 and 4

c.1, 2, and 3

d.1, 2, 3, and 4

8.All OR personnel, including the anesthesia care provider and surgeon, leave the OR during the treatment.

a.true

b.false

9.Total radiation treatment time varies from _____________ minutes.

a.10 to 20

b.20 to 30

c.30 to 40

d.40 to 50

10.If the source gets stuck in the applicator pathways or does not return to the safe as expected, the

a.afterloader will automatically turn off.

b.source can be manually withdrawn with a crank in approximately five seconds.

c.console computer will adjust the total treatment time.

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Answer Sheet

High-Dose-Rate Remote Afterloaders for Intraoperative Radiation Therapy

Event #07053

Session #8465

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Learner Evaluation

High-Dose-Rate Remote Afterloaders for Intraoperative Radiation Therapy

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This evaluation is used to determine the extent to which this continuing education program met your learning needs. Rate these items on a scale of 1 to 5.

Purpose/Goal

To educate perioperative nurses about high-dose rate intraoperative radiation therapy (HDR-IORT).

Objectives

To what extent were the following objectives of this continuing education program achieved?

1.Discuss IORT techniques.

2.Describe the roles of the IORT team members.

3.Identify equipment used for HDR-IORT.

4.Explain emergency interrupt procedures.

5.Discuss perioperative care of a patient undergoing HDR-IORT.

6.Explain the HDR-IORT procedure.

Content

To what extent

7.did this article increase your knowledge of the subject matter?

8.was the content clear and organized?

9.did this article facilitate learning?

10.were your individual objectives met?

11.did the objectives relate to the overall purpose/goal?

Test Questions/Answers

To what extent

12.were they reflective of the content?

13.were they easy to understand?

14.did they address important points?

Learner Input

15.Will you be able to use the information from this article in your work setting?

a.yes

b.no

16.I learned of this article via

a.the Journal I receive as an AORN member.

b.a Journal I obtained elsewhere.

c.the AORN Journal web site.

17.What factor most affects whether you take an AORN Journal continuing education examination?

a.need for continuing education contact hours

b.price

c.subject matter relevant to current position

d.number of continuing education contact hours offered

What other topics would you like to see addressed in a future continuing education article? Would you be interested or do you know someone who would be interested in writing an article on this topic?

Topic(s): ______________________________________________________________________________________________________________________

Author names and addresses: ___________________________________________________________________________________________________

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Acknowledgement

The authors thank Aloma Smith, surgical technologist; Miguel A. Rodriquez-Bigas, MD, professor of surgical oncology, and John M. Skibber, MD, professor of surgical oncology; at the University of Texas, MD Anderson Cancer Center, Houston.

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References

Hu KS , Enker WE , Harrison LB . High-dose-rate intraoperative irradiation: current status and future directions . Semin Radiat Oncol . 2002;12(1):62–80

Willett CG , Czito BG , Tyler DS . Intraoperative radiation therapy . J Clin Oncology . 2007;25(8):971–977
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Nag S , Petty LR , Parrott S . Comprehensive surgical radiation oncology . AORN J . 1994;60(1):27–37

Gunderson LL , Willett CG , Harrison LB , Calvo FA . Intraoperative Irradiation: Techniques and Results . Totowa, NJ: Humana Press; 1999;
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Beddar AS , Kubu ML , Domanovic MA , Ellis RJ , Kinsella TJ , Sibata CH . A new approach to intraoperative radiation therapy . AORN J . 2001;74(4):500–505

Beddar AS , Domanovic MA , Kubu ML , Ellis RJ , Sibata CH , Kinsella TJ . Mobile linear accelerators for intraoperative radiation therapy . AORN J . 2001;74(5):700–705

Nag S , Orton C . Development of intraoperative high dose rate for treatment of resected tumor bed in anesthetized patients . Endocuriether/Hypertherm Oncol . 1993;9:187–193
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Harrison LB , Enker WE , Anderson LL . High-dose-rate intraoperative radiation therapy for colorectal cancer . Oncology (Williston Park) . 1995;9(7):679–683
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Harrison LB , Enker WE , Anderson LL . High-dose-rate intraoperative radiation therapy for colorectal cancer . Oncology (Williston Park) . 1995;9(8):737–741
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Nag S , Martinez-Monge R , Gupta N . Intraoperative radiation therapy using electron-beam and high-dose-rate brachytherapy . Cancer J . 1997;10(2):94–101
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Calvo FA , Meirino RM , Gunderson LL , Willett CG . Intraoperative radiation therapy . In: Perez CA , Halperin EC , Brady LW , et al. editor. Principles and Practice of Radiation Oncology . 4th ed.. Philadelphia, PA: Lippincott Williams & Wilkins; 2004;
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Beddar AS , Biggs PJ , Chang S , et al. Intraoperative radiation therapy using mobile electron linear accelerators: report of AAPM Radiation Therapy Committee Task Group no. 72 . Med Phys . 2006;33(5):1476–1489

Palta JR , Biggs PJ , Hazle DJ , et al. Intraoperative electron beam radiation therapy, technique, dosimetry, and dose specification, report of Task Group 48 of the radiation therapy committee, American Association of Physicists in Medicine . Int J Radiat Oncol Biol Phys . 1995;33(3):725–746

indicates that continuing education contact hours are available for this activity. Earn the contact hours by reading this article and taking the examination on pages 837–838 and then completing the answer sheet and learner evaluation on pages 839–840.The behavioral objectives and examination for this program were prepared by Rebecca Holm, RN, MSN, CNOR, clinical editor, with consultation from Susan Bakewell, RN, MS, BC, director, Center for Perioperative Education.This program meets criteria for CNOR and CRNFA recertification, as well as other continuing education requirements.AORN is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's Commission on Accreditation.AORN is provider-approved by the California Board of Registered Nursing, Provider Number CEP 13019. Check with your state board of nursing for acceptance of this activity for relicensure.