Retroperitoneal sarcoma

Question 1

What is the treatment for low grade tumors?

Answer 1

Surgery alone

Question 2

What is the treatment for intermediate/high grade tumors?

Answer 2

Preoperative RT + surgery

Question 3

What imaging is needed?

Answer 3

CT scan of the abdomen/pelvis with IV and PO contrast

MRI of abdomen

Question 4

What tissue biopsy is needed?

Answer 4

Core needle biopsy but biopsy in a site that can be excised

It may not be needed for low grade appearing tumors

Question 5

What is involved with surgery?

Answer 5

En bloc resection of tumor and involve organs with resection of positive nodes

Surgical clips at the periphery of the surgical field and any gross disease left

Question 6

When should RT be delivered? What dose?

Answer 6

Preop

50.4 Gy

Question 7

RT volumes?

Answer 7

GTV
CTV = GTV + 2 cm
PTV= CTV + 0.5

• consider adding more margin superiorly and inferiorly for liposarcoma

Question 8

Bowel bowel constraint?

Answer 8

V45 < 150 cc

V15 < 120 cc

Question 9

What is the local control with RT+ surgery?

Answer 9

Overall 50%

+ margin: 39%
- Margin: 67%

Question 10

What dose is used post-operatively?

Answer 10

CTV inital: 50.4 Gy at 1.8 Gy/fx

CTV boost: 60-66 Gy depending the precense of gross disease

Question 11

Kidney constraint?

Answer 11

Mean bilateral kidney dose < 18

If one kidney is left or if one kidney is overdose, contralateral kidney V6<30