WBRT dose/#, setup
I would offer palliative WBRT 20gy/5#/1week 30gy/10#/2weeks. I would treat with 6MV photons, lateral POP, prescribed to the mid-plane.
Immobilised supine with a head shell.
Volume is 2 cm below Reid’s baseline from ext Auditory meatus to sup orbital ridge.
Suuportive meds: Dex 8mg BD with PPI cover, gradually reducing to the minimum effective dose.
Supportive meds = same for SVCO.
EQD2 for 8Gy/1# and 20Gy/5# and 30Gy/10#
Also 10Gy/1#
20Gy
30Gy (also for 10Gy/1#)
38Gy
RT spiel for pall lung RT
- I will treat this to a dose of 17Gy/2#/a week apart or 36Gy/12# over 2 ½ weeks (or 10Gy/1# if poor PS) using an anterior-posterior parallel prescribing to mid plane dose using an energy of 6MV. A wedge with the thick end superior, may be required depending on the contour of the chest.
*I will treat this patient with palliative intent (category 3) - I will treat the patient supine with a neck rest and their arms
supported above their head.
QART Lung - External immobilisation will be provided by a wingboard (arms up), or thermoplastic shell (arms down). - I will perform a planning CT scan
- I will outline the GTV and expand this by 2 cm to the field edge (OR 1cm to my PTV with a further 0.5cm margin to my field edge). I will cover the contralateral mediastinum ensureing I cover the contralateral edge of the vertebral body.
- I will apply MLCs and ensure the area of my field does not exceed 200cm2.
- I will consent the patient for fatigue, skin soreness, oesophagitis and mild cough/breathlessness.
RT endometrial spiel for palliative gynae
*I will treat this patient with palliative intent
*I will treat this to a dose over 20Gy/5# over 5 days using an anterior-posterior parallel opposed pair prescribing to mid plane dose using an energy of 6-10MV.
* I will treat the patient supine with a headrest, knee support, ankle stocks and a comfortably full bladder
* I will perform a planning CT scan
* I will outline the GTV and expand this by 2cm to my PTV with a further 0.5cm margin to my field edge.
* I will put my superior borders at L5/S1, inferior to obturator foramen and laterally to 1.5-2cm from the pelvic brim.
* I will consent the patient for tiredness, skin soreness, temporary worsening of pain and mild bladder and bowel symptoms.
Describe pelvic field for cervix
Sup L4/L5
Inf 3cm below disease
Lat 1.5-2cm from pelvic brim
Describe pelvic field for endometrium
superior L5/S1,
inferior to obturator foramen
laterally to 1.5-2cm from the pelvic brim
Describe pelvic field for bladder
Dose/#
superior mid SI joint
inferior to obturator foramen
laterally to 1.5-2cm from the pelvic brim
If poor PS or co-morbidity can give high dose palliative 36Gy/6#/6weeks (RCR and QART).
21Gy/3#/alternate days in 1 week.
Usuals: 20/5, 8/1.
Describe pelvic field for rectum
superior L5/S1,
Inf 3cm below disease
laterally to 1.5-2cm from the pelvic brim
8Gy/1#
30Gy/10, 20Gy/5#
Describe pelvic field for vulva
sup: top of acetabulum
Inf - 2cm below marker
Lat = 2/3 of femoral head (nearly including whole acetabulum on image)
Describe pelvic field for prostate
Dose/#
20Gy/5#
10 x 10cm field cantered on the pubic symphisis
POP prescribed to mid-plane
Beam set up for spine?
single posterior field if C7 or lower, sometimes ANT-POST POP for lumbar,
Cervical spine can treat as lateral POP.
Depth >6cm, consider POP.
At what depth should you add an opposing field?
> 6cm
At what separation should you switch to 10X?
If separation at mid-plane is >24
How to treat base of skull mets?
I would offer palliative RT 20Gy/5#.
I would treat using 6MV photons, using a lateral parallel opposes pair.
Starting at Reid’s baseline (?? tip of C1) (ext auditory meatus to sup orbital ridge), I would extend 3cm sup and inf and approx 12cm ant/post to create a field of approx 6 x 12cm.
Patient would be immobilised supine with a head shell.
Post OP RT to path#/post prophylactic surgery.
Pre-op:
Assess risk of fracture with mirel’s score (site (upper/lower limb, peritrochanteric), pain (functional = 3), size of lesion (cortex involvement <1/3, 2/3 = 3), type (lytic = 3).
I would offer post-op radiotherapy 8Gy/1#.
The patient would be immobilised (supine with a knee support and ankle stocks).
I would use 6MV photons, ant-post parallel opposed pair prescribed to the mid-plane.
I would include the whole bone involved (or prosthesis with a margin). For femur, this would usually need an extended FSD (max field size on linac is 40cm (39.9).
Aim: local control of cancer and pain.
Consent: Usuals + lymphoedema.
DMax for MV
bolus for skin involvement?
Energy/4
6MV DMax = 1.5cm
1cm bolus 6MV achieves approx 90-100% skin dose (wouldn’t choose 10MV if need to irradiate skin due to skin sparing).
Rib pall RT
Tangiental pair 6MV photons
Alternative 220kv photons - treats approx 2cm depth
Electrons if surface is flat
Treatment of choroidal metastases?
Setup: supine with neck straight and eyes looking at a fixed point straight ahead. A thermoplastic shell may be required for multi-fraction treatments.
CT planned. Single lateral beam. Typical field size is 4cm x 4cm field, centred on reid’s baseline, with half beam block to avoid divergence through the contra-lateral lens.
Consider bilateral treatment if clinically indicated.
Dose Prescription
Use 6MV photons to deliver a dose of 20Gy/5# (or 30Gy in 9-10#) prescribed to a depth of 2.5cm.
The organs at risk are the lens of the ipsilateral eye and also the lens of the contralateral eye.
MSCC dose/#?
Presc point?
8Gy/1# or 20Gy/5#. Prescribed to the anterior spinal canal.
Choice depends on: patient’s ambulatory status, performance status, primary site and prognosis.
Treatment using higher doses (30 Gy in 10#) may be occasionally considered, such as in lymphoma/solitary plasmacytoma/myeloma patients, higher doses should be considered due to better prognosis
In patients with established paraplegia for more than 24 hours, or an expected prognosis of <6 months, a single dose of 8Gy is acceptable for pain control.
