Digestive System

Disease site

Presentation

Recommended treatment

Pancreas

Resectable

Surgery +/− adjuvant chemoradiotherapy or chemotherapy

Borderline resectable (adequate KPS)

Neoadjuvant chemoradiation followed by restaging and resection if feasible

Borderline resectable (poor KPS) unresectable

Definitive chemoradiation, conventionally fractionated radiation alone, chemotherapy alone, or SBRT

Metastatic

Palliation with stents, surgical bypass, chemotherapy, RT, and supportive care as indicated; SBRT not indicated except for expedient palliation

Liver

Resectable HCC or oligometastatic disease with controlled primary

Partial hepatectomy

Unresectable/medically inoperable HCC or oligometastatic disease with controlled primary

Upfront Liver transplant

Restaging and resection if feasible following transarterial chemoembolization, radiofrequency ablation, cryotherapy, alcohol, SBRT, or sorafenib

Abdominal, retroperitoneal, and pelvic lymph nodes

Metastatic disease

Systemic therapy preferred, although surgery and SBRT should be discussed in oligometastatic settings or for palliation of pain

Adrenal glands

Metastatic disease

Systemic therapy preferred, although surgery and SBRT should be discussed in oligometastatic settings or for palliation of pain

Radiosurgical Technique

Simulation and Field Design

Gold seed marker (GSM) placement by EUS (pancreas) or CT-guidance (liver ) 1+ week prior to simulation to allow inflammation to subside.
Oral contrast 30–60 min prior to simulation , unless MRI used for planning.
Supine with arms above head and wingboard or alpha cradle to stabilize torso. Consider abdominal compression depending on image guidance modality.
Pancreas lies at L1-L2, celiac axis at T12, and SMA at L1.
Treatment planning:
- Contrast-enhanced CT and/or MRI useful for delineating pancreatic tumor volume; triphasic CT and/or MRI for hepatic malignancies.
Image guidance:
- Preferred: 4D-CT to define ITV with daily on-board imaging for set-up and tracking.
- Acceptable: Active breathing control (ABC ), orthogonal MV imaging and kV fluoroscopy .
Field Design: ITV based on 4D-CT plus 3–5 mm margin.
- Optimal: ITV based on 4D-CT plus 3–5 mm margin for PTV .
- Other tracking/immobilization strategies typically require 5–7 mm radial and 1–1.5 cm craniocaudal expansions on GTV for adequate coverage.
- Caution regarding inclusion of edema surrounding pancreatic tumor s due to excessively large field size.
- Consider reducing PTV to allow for 2 mm margin to critical structures , especially in patients with poor performance status who are unlikely to tolerate exploratory laparotomy for bleeding , perforation, etc.
- Avoid or minimize elective nodal stations in SBRT field due to toxicity.

Dose Prescription

Pancreas : 33 Gy in 5 fractions.
Liver: Based on location and underlying liver function .
- Peripheral: 23–30 Gy in 1 fraction, 27.5–60 Gy in 3–6 fractions.
- Central: 40 Gy in 5 fractions.
Abdominal lymph node s based on retrospective case series: 45–60 Gy in 3–6 fractions.
Adrenal metastases based on retrospective case series: 23 Gy in 1 fraction, 36 Gy in 3–5 fractions (Figs. 8.1 and 8.2).

Fig. 8.1.
Pancreatic SBRT . 88-year-old male with locally advanced, unresectable pancreatic adenocarcinoma . A 4D CTV with an ITV expansion was used for treatment planning, which was carried out via robotic radiosurgery to a total dose of 3000 cGy in 5 fractions with 6 MV photons prescribed to the 73 % isodose line . Proceeding clockwise from the top left, beam angles, and axial, coronal, and sagittal CT images with isodose lines and the PTV in red color wash are shown

Fig. 8.2.
Liver SBRT . 61-year-old male with a history of hepatitis C and recurrent hepatocellular carcinoma of the porta hepatis status post transcatheter arterial chemoembolization on four occasions, and alcohol injection twice. A single intra-lesional fiducial marker was used for tracking during robotic radiosurgery . The tumor was treated to a total dose of 4000 cGy in 5 fractions with 6 MV photons prescribed to the 82 % isodose line . Proceeding clockwise from the top left, beam angles, and axial, coronal, and sagittal CT images with isodose lines and the PTV in red color wash are shown

Dose Limitations

Structure	Fractions	Constraints	Dose limiting toxicity	Study
Stomach	1	V_{22.5 Gy} < 4 % Distal lumen wall free from 50 % isodose line	Ulceration, fistula	Chang et al. Cancer 2009
	3	D_max < 30 Gy		Kavanagh et al. IJROBP 2010
	6	D_max < 32 Gy D_{3 cc} < 36 Gy		Bujold et al. JCO 2013, Tozzi et al. Rad Onc 2013
Small bowel	1	V_{12.5 Gy} < 30 cc	Ulceration, fistula	Kavanagh et al. IJROBP 2010
	3	D_max < 30 Gy		Bujold et al. JCO 2013
	6	D_max < 36 Gy		Kavanagh et al. IJROBP 2010
Duodenum	1	V_22.5% < 5 % V_{12.5 Gy} < 50 % Distal lumen wall free from 50 % isodose line	Ulceration, fistula	Chang et al. Cancer 2009
Duodenum	6	D_max < 33 Gy D_{1 cc} < 36 Gy	Ulceration, fistula	Bujold et al. JCO 2013, Tozzi et al. Rad Onc 2013
Large bowel	6	D_max < 36 Gy	Colitis, fistula	Bujold et al. JCO 2013
Liver	1	V_{5 Gy} < 50 % V_{2.5 Gy} < 70 %	Liver function, cirrhosis/hepatitis, biliary stricture, radiation-induced liver disease (RILD)	Chang et al. Cancer 2009
	1, 3-5	700 cc < 15 Gy		Rusthoven et al. JCO 2009, Pan et al. IJROBP 2010, Goodman et al. IJROBP 2010
	3-6	HCC: MNLD < 13 Gy (3 fx), <18 Gy (6 fx) Metastases: MNLD < 15 Gy (3 fx), < 20 Gy (6 fx)		Pan et al. IJROBP 2010
	5	V_{30 Gy} < 60 % V_{27 Gy} < 70 % for cirrhosis/hepatitis		Katz et al. IJROBP 2007
	6	V_tot–V_{21 Gy} > 700 cc		Tozzi et al. Rad Onc 2013
Kidney	1	V_{5 Gy} < 75 %	Kidney function, malignant hypertension	Goodman et al. IJROBP 2010
Kidney	6	V_{15 Gy} < 35 % Mean dose < 12 Gy	Kidney function, malignant hypertension	Rusthoven et al. JCO 2009, Tozzi et al. Rad Onc 2013, Bujold et al. JCO 2013
Spinal cord	1	D_max < 12 Gy	Myelitis	Goodman et al. IJROBP 2010
Spinal cord	6	D_max < 18 Gy	Myelitis	Rusthoven et al. JCO 2009, Tozzi et al. Rad Onc 2013
Chest wall	3	V_{30 Gy} < 10 mL	Pain or fracture	Rusthoven et al. JCO 2009 Only gold members can continue reading. Log In or Register to continue Share this: Click to share on Twitter (Opens in new window) Click to share on Facebook (Opens in new window) Related posts: Introduction to Stereotactic Radiosurgery and Stereotactic Body Radiotherapy Physics of Stereotactic Radiosurgery and Stereotactic Body Radiotherapy Gynecologic Sites Lung Head and Neck Soft Tissue Sarcoma Stay updated, free articles. Join our Telegram channel Tags: Handbook of Evidence-Based Stereotactic Radiosurgery and Stereotactic Body Radiotherapy Sep 16, 2016 \| Posted by admin in GENERAL RADIOLOGY \| Comments Off on Digestive System Full access? Get Clinical Tree Get Clinical Tree app for offline access Get Clinical Tree app for offline access