Ezekiel.egan: Created page with "Intraoperative radiotherapy (IORT) is designed to provide a large radiation dose to a target tissue while sparing normal tissues. The therapeutic advantage is derived by delivering low-energy photons or electrons to a tumor bed with a gross total or near gross total resection, thereby allowing a steep dose fall off, which will spare normal tissues. IORT is often combined with external-beam radiation therapy (EBRT) to provide the best combination of local and locoregional..."

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Created page with "Intraoperative radiotherapy (IORT) is designed to provide a large radiation dose to a target tissue while sparing normal tissues. The therapeutic advantage is derived by delivering low-energy photons or electrons to a tumor bed with a gross total or near gross total resection, thereby allowing a steep dose fall off, which will spare normal tissues. IORT is often combined with external-beam radiation therapy (EBRT) to provide the best combination of local and locoregional..."

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Intraoperative radiotherapy (IORT) is designed to provide a large radiation dose to a target tissue while sparing normal tissues. The therapeutic advantage is derived by delivering low-energy photons or electrons to a tumor bed with a gross total or near gross total resection, thereby allowing a steep dose fall off, which will spare normal tissues. IORT is often combined with external-beam radiation therapy (EBRT) to provide the best combination of local and locoregional treatment<ref name=":0">Debenham, B. J., Hu, K. S., & Harrison, L. B. (2013). Present status and future directions of intraoperative radiotherapy. ''Lancet Oncology, 14''(11), e457-64. doi:<nowiki>https://doi.org/10.1016/S1470-2045(13)70270-5</nowiki></ref><ref>Christopher G. Willett et al. Intraoperative Radiation Therapy. ''J Clin Oncol'' 25, 971-977(2007).DOI:10.1200/JCO.2006.10.0255</ref>. It does, however, require an invasive surgical procedure to locally treat the tumor. It can be used to treat breast, head & neck, pelvic<ref>Roth TM, Secord AA, Havrilesky LJ, et al. High dose rate intraoperative radiotherapy for recurrent cervical cancer and nodal disease. Gynecol Oncol. 2003;91:258–260. doi: 10.1016/s0090-8258(03)00443-8.</ref>, and gastrointestinal<ref>Alfieri S, Morganti AG, Di Giorgio A, et al. Improved Survival and Local Control After Intraoperative Radiation Therapy and Postoperative Radiotherapy: A Multivariate Analysis of 46 Patients Undergoing Surgery for Pancreatic Head Cancer. Arch Surg. 2001;136(3):343–347. doi:10.1001/archsurg.136.3.343</ref> malignancies. IORT can be delivered by using Linac-based electron beam radiation therapy (IOERT), low-energy photons, or by high-dose-rate brachytherapy catheters (HDR-IORT). All of these techniques deliver high doses of radiation to the target site while protecting normal surrounding structures through retraction or shielding using lead sheets<ref>Moningi S, Armour EP, Terezakis SA, Efron JE, Gearhart SL, Bivalacqua TJ, Kumar R, Le Y, Kien Ng S, Wolfgang CL, Zellars RC, Ellsworth SG, Ahuja N, Herman JM. High-dose-rate intraoperative radiation therapy: the nuts and bolts of starting a program. J Contemp Brachytherapy. 2014 Mar;6(1):99-105. doi: 10.5114/jcb.2014.42027. Epub 2014 Apr 3. PMID: 24790628; PMCID: PMC4003434.</ref>.

These procedures are resource intensive and require complex patient selection and logistical planning. An IORT program requires the combined planning and efforts of surgical and/or medical oncology, radiation oncology, OR staff, and anesthesiology.{{Infobox surgical procedure
| anesthesia_type =General
| airway =ETT
| lines_access =PIV x2
+/- Arterial line
+/- Central line
| monitors =Standard
BIS
+/- ABP
+/- CVP
| considerations_preoperative =Frailty, chemotherapy sequelae (pancytopenia), tumor size and location, "full stomach"
| considerations_intraoperative =Access, resuscitation, equipment contingencies
| considerations_postoperative =Potential ICU transport, ongoing resuscitation
}}

==Overview==
===Indications===

* Subtotal resection of malignancy
* Recurrent malignancy for which external beam radiation is deemed unsafe

===Surgical procedure===
The basic principles are well described by Debenham et al<ref name=":0" />

=== Resection ===
The first step is total or sub-total resection of tumor

* Whether the tumor is large or small, the IORT equipment usually requires a large laparotomy
* Each tumor is different and will carry distinct risks in terms of bleeding potential, compression of vital structures, invasion of large vessels

=== Intraoperative Radiation ===
The next step is positioning the radiation equipment

* The radiation oncology team decides on technique, dose, and equipment
* Some equipment require special lead shielded rooms or other radiation barriers, while others are self shielding
* Generally once the equipment is positioned correctly, everyone must leave the room during treatment so as not to be exposed to radiation. Treatment times vary, but are usually 5-10 minutes. Confirm with the surgeon and radiation oncologist how long they plan on treating
** Every institution approaches monitoring during this time differently, some use cameras, some place monitors at windows, some have shielded subrooms in the OR
** Whatever approach is used, the goal is to have the patient in a steady, stable state at the time of treatment. If you are not in a stable state, inform the surgical team that you need to stabilize the patient prior to proceeding with treatment
** Discuss with the surgeon, radiation oncologist, and physicists what the protocol is for ending treatment and re-entering the room in case of emergency. Generally, the radiation equipment can be turned off quickly and once turned off it is safe to enter the room

=== Closure ===
The final step is finalizing any remaining surgical procedures and closure

==Preoperative management==
===Patient evaluation===
{| class="wikitable"
|+
!System
!Considerations
|-
|Airway
|Large abdominal tumors or patients with ascites may require RSI
|-
|Neurologic
|Neoadjuvent chemotherapy or radiation can cause neuropathy
|-
|Cardiovascular
|Standard evaluation
|-
|Pulmonary
|Standard evaluation
|-
|Gastrointestinal
|Tumor size, location, possible compression or invasion of other structures
|-
|Hematologic
|Pancytopenia in setting of chemotherapy
|-
|Renal
|Standard evaluation
|-
|Endocrine
|Standard evaluation
|}
===Labs and studies===

* Type and screen - cross units depending on patient and procedure
* CBC
* +/- EKG, TTE, stress test
* Otherwise indicated by history and presentation

===Operating room setup===

* Arterial catheter and transducer
* Fluid warmer
* Infusion pumps
* Vasopressor infusions available
* Push dose pressors
* +/- blood tubing

===Patient preparation and premedication===

* Standard

===Regional and neuraxial techniques===

* Useful for multimodal pain control
* Epidurals are frequently used for intraoperative autonomic control and postoperative pain control for abdominal or thoracic tumors
** If epidural contraindicated, regional blocks can be used for postoperative pain control

==Intraoperative management==
===Monitoring and access===

* PIV x2
* Standard monitors
* Frequently radial arterial line
* Central line as indicated by tumor and patient

===Induction and airway management===

* Standard
** For abdominal tumors cosider RSI

===Positioning===

* Standard, depends on tumor location and planned procedure

===Maintenance and surgical considerations===

* Standard maintenance, patient is chemically paralyzed to assist with adequate surgical exposure and ensure immobility during radiation treatment
* IORT procedures are highly variable in terms of tumor size, position, vascularity, etc. and, therefore, need to be approached on a case by case basis in terms of planning induction, intubation, access, and blood product preparation
* Review imaging and discuss with surgeons their expectation for the extent of resection and possible difficulties to help guide your decisions about access and preparation
* Stay in communication with the surgery team about timing of the radiation treatment as well as the expected length of treatment
* The goal is to reach a steady state as they are arming and positioning the radiation equipment so that the patient can be left alone for 5-10 minutes
* As an extra precaution, you can connect a few extension tubings and thread that line into the shielded area in order to administer medication if needed
* Position the monitors so that they can be seen from the shielded area, consider being able to see two monitors in case one fails

===Emergence===

* Standard

==Postoperative management==
===Disposition===

* Depends on patient and surgical factors, but usually stepdown, occasionally ICU or floor

===Pain management===

* Depends on tumor location and size
* For abdominal tumors, usually large incision, painful procedure
* Neuraxial or regional pain control always, unless contraindicated
* Multimodal pharmacologic pain control

===Potential complications===

* IORT itself carries very low intraoperative and immediately postoperative complications
* Most complications are related to the tumor resection itself
* For large or vascular abdominal tumors concerns include:
** Aspiration
** IVC compression
** Hemorrhage due to bleeding of tumor or damage to surrounding vessels during resection
** Standard general anesthetic and operative complications

==References==

[[Category:Surgical procedures]]

Intraoperative radiation therapy (IORT) - Revision history