Rectal cancer : brachytherapy... and RT side effects

Question 1

HDR Brachy:
-uses
-Benefits
-dose

Answer 1

-Boost with Chemo/EBRT
◦ HDR only for small localised tumours

-High dose with rapid fall-off
-6Gy-36Gy

Question 2

Intraoperative RT (IORT)
-benefits
-dose

Answer 2

• High dose with rapid fall-off
  -10-20Gy

Question 3

why MRI Guided RT

Answer 3

-Dose escalation with very high doses= ↑ chance to achieve a complete response

-Rectal primaries are poorly visualized on CBCT.
inter- fractional motion, margins > 10 mm to ensure adequate tumour coverage

Question 4

Benefits of MRI Guided RT

Answer 4

• allows daily adaptation of the treatment plan to the current anatomy and therefore has the potential to reduce dose to OAR
• tumours mid rectum, who are candidates for sphincter sparing surgery, benefit most from such daily online MR guided adaptive workflow via lower doses to the anal sphinter

Question 5

Acute Toxicity for each Multimodality treatment
-Chemo
-Surgery

Answer 5

-Significant GI toxicity
-Anastomosis

Question 6

Acute Toxicity:GI

Answer 6

◦ Diarrhoea
◦ Increased bowel frequency
◦ Proctitis
◦ PR bleeding
◦ Rectal discomfort

Question 7

Acute Toxicity:GU

Answer 7

◦ Cystitis
◦ Increased urinary frequency
◦ Urgency
◦ Dysuria
◦ Nocturia

Question 8

Acute Toxicity: Skin

Answer 8

◦ Hair loss
◦ Erythema – moist desquamation in the perineum region

Question 9

Management

Answer 9

MDT approach
Nutritional support
Medication
◦ Antidiarrhoeals
◦ Analgesia
◦ Antiemetics

Question 10

Late Effects

Answer 10

ØFaecal incontinence
ØFemoral head fracture
ØUrinary incontinence
ØSmall bowel obstructions