[ROQs] Constraints Flashcards by Muneeb Khan

What is the usual CW constraint for peripheral lung SBRT lesions?

For 3 fx lung SBRT
- V30 < 30 cc

Caveats:
- May not always be possible for peripheral lesions
- Do not compromise target coverage
- ASTRO guidelines explicitly forbid from trimming PTV to meet this CW constraint
- CW tox (pain, etc) is usually amenable to conservative management

How well did you know this?

Not at all

Perfectly

What is the threshold for CW dose before Gr ≥ 2 CW tox is observed in lung SBRT pts>

V30 Gy > 70 cc
– V30Gy < 70 cc may be a more practical constraint for peripheral lung SBRT pts

How well did you know this?

Not at all

Perfectly

What are the usual OAR constraints for lung SBRT?

How well did you know this?

Not at all

Perfectly

What are the SRS D_max constraints for the Optic nerve (ON)?

SRS constraints for ON:
- D_max < 8 Gy
– Rare (~0%) risk of optic neuropathy
- D_max < 12 Gy
– <10% risk of optic neuropathy

How well did you know this?

Not at all

Perfectly

What are the NCCN dose constraints for the lungs for pts receiving CFRT for esophageal or gastric cancers?

Lung constraints for esophageal cancer CFRT?
- V40Gy ≤ 10%
- V30Gy ≤ 15%
- V20Gy ≤ 20%
- V10Gy ≤ 40%
- V5Gy ≤ 50%
- D_mean < 20 Gy

How well did you know this?

Not at all

Perfectly

What are acceptable lung constraints for centrally located lesions undergoing 5 fx SBRT?

V20Gy < 10% (minor deviation < 15%)
D1500cc max 12.5 Gy
D1000cc max 13.5 Gy

How well did you know this?

Not at all

Perfectly

What are the NCCN dose constraints for the spine for pts receiving CFRT for esophageal or gastric cancers?

Spine constraints for esophageal cancer CFRT:
- D_max ≤ 45 Gy

How well did you know this?

Not at all

Perfectly

What are the NCCN dose constraints for the bowel for pts receiving CFRT for esophageal or gastric cancers?

Bowel constraints for esophageal cancer CFRT:
- Dmax < 54 Gy
- V 45Gy < 195 cc

How well did you know this?

Not at all

Perfectly

What are the NCCN heart dose constraints for pts receiving CFRT for esophageal or gastric cancers?

Heart constraints for esophageal cancer CFRT:
- V30Gy ≤ 30 % (20% preferred)
- D_mean < 30 Gy (26 Gy preferred)

How well did you know this?

Not at all

Perfectly

What are the NCCN stomach dose constraints for pts receiving CFRT for esophageal or gastric cancers?

Stomach constraints for esophageal cancer CFRT:
- D_mean < 45 Gy
- D_max < 54 Gy

How well did you know this?

Not at all

Perfectly

What are the NCCN liver dose constraints for pts receiving CFRT for esophageal or gastric cancers?

Liver constraints for esophageal cancer CFRT:
- V30Gy ≤ 33%
- D_mean < 25 Gy

How well did you know this?

Not at all

Perfectly

What are the NCCN kidney dose constraints for pts receiving CFRT for esophageal or gastric cancers?

Kidney constraints for esophageal cancer CFRT:
- V20Gy ≤ 33%
- D_mean <18 Gy
– Corresponds to a <5% risk of relevant kidney dysfunction

How well did you know this?

Not at all

Perfectly

For liver SBRT, what are the allowed D_mean for the liver?

Liver constraints for Lung SBRT:
- 50 Gy in 5 fx:
– D_mean < 13 Gy
- 27.5 Gy in 5 fx:
– D_mean < 17 Gy

How well did you know this?

Not at all

Perfectly

What is the % risk of developing symptomatic pneumonitis when using the lung dose constraint (V20Gy < 30%)?

< 20%

How well did you know this?

Not at all

Perfectly

What are the dose constraints for the cochlea for CFRT?

D_mean ≤ 45 Gy (≤ 35, preferred)
– < 30% risk of sensory-neural hearing loss
D_mean < 32 Gy
– < 20% risk of grade 2+ tinnitus

How well did you know this?

Not at all

Perfectly

What are the dose constraints for the cochlea for SRS?

D_max < 9 Gy
D_mean < 3 Gy

How well did you know this?

Not at all

Perfectly

What are the QUANTAC rectal dose constraints to keep grade ≥2 late rectal toxicity < 15% and grade ≥3 late rectal toxicity < 10%?

Rectal Dose Constraints:
- V50Gy < 50%
- V60Gy < 35%
- V65Gy < 25% (65+25=90)
- V70Gy < 20% (70+20=90)
- V75Gy < 15% (75+15=90)

Rule of 90s for the three highest constraints!
Also, related to bladder constraints:
- V75 < 25%; Subtract 10% for rectum (V75 < 15%)
- V70 < 35%; Subtract 15% for rectum (V70 < 20%)
- V65 < 50%; Subtract 25% for rectum (V65 < 25%)

How well did you know this?

Not at all

Perfectly

What are the QUANTAC bladder dose constraints for CFRT?

Bladder Dose Constraints:
- V65Gy < 50%
- V70Gy < 35%
- V75Gy < 25%
- V85Gy < 15%

Memory Hook:
- Bladder:
– V75 < 25%; Subtract 10% for rectum (V75 < 15%)
– V70 < 35%; Subtract 15% for rectum (V70 < 20%)
– V65 < 50%; Subtract 25% for rectum (V65 < 25%)

How well did you know this?

Not at all

Perfectly

What is the SRS brainstem constraint to keep the risk of necrosis or cranial neuropathy < 5%?

SRS Brainstem constraint
- D_max < 12.5 Gy

How well did you know this?

Not at all

Perfectly

What are the QUANTAC pharyngeal constrictor dose constraint to keep the risk of dysphagia or symptomatic aspiration < 20%?

D_mean < 50 Gy

How well did you know this?

Not at all

Perfectly

What is the QUANTAC penile bulb dose constraint to keep the risk of ED < 35%?

D_mean to 95% < 50 Gy
D90 < 50 Gy
D70 < 70 Gy

How well did you know this?

Not at all

Perfectly

Which sites in an adult human body harbor bone marrow and in what proportions?

How well did you know this?

Not at all

Perfectly

What were the trachea/bronchus constraints on the RTOG 0813 dose-escalation trial for centrally located NSCLC?

V18 Gy < 4 cc
D_max < 105% of Rx
decreases the risk of stenosis and fistula formation

How well did you know this?

Not at all

Perfectly

What duodenal, stomach, small blowel constraints can be used for pancreas SBRT?

Study These Flashcards

V15 < 9cc
V20 < 3cc
V33 < 1 cc
Dmax < 23 Gy

What is the dose constraint for the brachial plexus for a 5 fx SBRT/SABR?

D3cc < 6 Gy per fx (30 Gy total)

What are the usual esophageal constraints for pts undergoing CRT for NSCLC?

- V60 < 17% -- > 60 Gy has been reliably linked to esophagitis - Mean esophageal dose < 34 Gy (17 x 2)

What is the constraint for the contralateral lung for pts w/ malignant pleural mesothelioma s/p extrapleural pneumonectomy f/b CHT undergoing RT?

Contralateral - D_mean < 15 Gy - D20 < 7%

For pts undergoing def CRT for lung cancer, what is the contralateral lung constraint?

- Lung V20 < 30% -- Yields a <20% risk of sx pneumonitis

What are the NCCN heart constraints for CFRT for lung cancer?

- Heart: -- D_mean < 20% -- V50 < 25%

What are the spinal cord, lung, and heart constraints for 45 Gy in 30 fx BID tx for SCLC?

- Spinal cord D_max < 42 Gy - (Lungs - PTV) V20 < 35% - Heart -- D100% < 30% -- D50% < 50%

What are the spinal cord, lung, and heart constraints for 66 Gy in 33 fx BID tx for SCLC?

- Spinal cord D_max < 48 Gy - (Lungs - PTV) V20 < 35% - Heart -- D100% < 30% -- D50% < 50%

What are common lung dose constraints for def CRT for esophageal cancers?

- Lung -- V40Gy ≤ 10% -- V30Gy ≤ 15% -- V20Gy ≤20% -- V10Gy ≤40% -- V05Gy ≤50% -- Mean < 20 Gy

What are common heart dose constraints for def CRT for esophageal cancers?

- V30Gy ≤30% (closer to 20% preferred) - Mean < 30 Gy (closer to 26 Gy preferred =)

What are common kidney dose constraints for def CRT for esophageal cancers?

- V20Gy ≤33% - Mean < 18 Gy

What are the common liver constraints for the def CRT for esophageal cancers?

- V30Gy ≤33% - Mean < 25 Gy

What are the dose constraints per the NRG GI006 trial for gastric cancer?

- PTV V100% (50.4Gy) ≥ 95% - Heart V40 < 50% - V20 Gy of each kidney < 30% - Liver V30Gy < 30%

What bowel constraint should be used for post-op cervical cancer cases?

V40 < 30%

What are the normal tissue constraints per RTOG 0724 for post-op cervix?

- Kidney: 2/3 of each kidney < 18 Gy - Spinal cord: 0.03 cc should receive > 45 Gy - Bowel ("bowel space" includes small bowel, colon, and sigmoid out to the edge of the peritoneum) -- V40 Gy < 30% - Rectum: V45 Gy < 60% * Bladder: V45 Gy < 35%

What are the recommended normal tissue dose constraints for OARs for brachytherapy?

- ICRU bladder point, ICRU rectal point: ≤ 3.7 Gy x 5 fractions - D2cc bladder: ≤ 90 Gy EQD2 (80 preferred) - D2cc rectum: ≤ 75 Gy EQD2 - D2cc sigmoid: ≤ 75 Gy EQD2

Why is the duodenum especially vulnerable to RT compared to other parts of the small and large bowels?

- Duodenum is relatively immobile, leading to consistent exposure to RT doses - Most of the duodenum is retroperitoneal, lying in close proximity to the PA nodes

Per QUANTEC, what is the risk of optic neuropathy (ON) w/ D_max < 55, 55-60, and > 60 Gy?

- Risk of ON: -- < 55 Gy → < 3% -- 55-60 Gy → 3-7% -- > 60 Gy → 7-20%

Per QUANTEC, what is the risk of gastric ulceration with D100 < 45 Gy?

< 7%

Per QUANTEC, what is the risk of radiation myelitis (RM) w/ spinal cord D_max 50 Gy?

- Dose and risk of RM -- D_max 50 Gy → 0.2% -- D_max 60 Gy → 6% -- D_max 69 Gy → 50%.

Per QUANTEC, what are the dose constraints and the corresponding risk of pneumonitis for lungs using CFRT

- Lung Constraints for CFRT -- V20Gy to ≤ 30-35% -- D_mean ≤ 20-23 Gy - Corresponds to a risk of symptomatic pneumonitis to ≤ 20%

What are the bowel constraints for CFRT and moderately hypofractionated RT for prostate cancer?

- CFRT: -- D_max <52Gy -- V50Gy< 10%. - 28 fx regimen -- D_max <52Gy -- V46.5Gy<2cc. - 20fx regimen -- D_max < 40Gy -- V37Gy < 90cc -- V33Gy < 130cc

What are the cochlea constraints and the corresponding risk of serviceable hearing loss for SRS and CFRT for acoustic neuroma?

- SRS: D_max ≤ 14 Gy -- Risk of serviceable hearing loss ≤ 25% - DFRT: D_mean ≤ 45 -- Risk of serviceable hearing loss ≤ 30%

What are the constraints for the liver and the corresponding risk of radiation-induced liver disease (RILD) when treating intrahepatic cholangiocarcinoma?

- D_mean 30-32 Gy → < 5% RILD (excludes cirrhosis) - D_mean 28 Gy → < 5% RILD in Child-Pugh A / HCC per QUANTEC - D_mean 42 Gy → ~50% risk of RILD

What are the usual dose constraints for cardiac implantable devices (CIED)?

D_max < 2-5 Gy

What are the dose constraints for the b/l hippocampis when tx w/ HA-WBRT?

- HA-WBRT constraints for the hippocampus -- D100% ≤ 9 Gy -- D_max ≤ 16 Gy

Per QUANTEC, what are the D_max constraints and the corresponding risk of radionecrosis (RN)?

- D_max ≤ 60 Gy → <3% risk of RN - D_max ≤ 72 Gy → 5% risk of RN - D_max ≤ 90 Gy → 10% risk of RN

What are the spinal cord constraints for single, three, and five fx SRS/SRT?

- 1 fx: D_max ≤ 14 Gy - 3 fx: D_max ≤ 20 Gy - 5 fx: D_max ≤ 30 Gy

For CFRT, what are the dose constraints for spinal cord, optic chiasm, optic nerves, and brainstem?

- Optic Chiasm and Nerves -- Desired D0.03cc ≤ 54Gy (acceptable ≤ 60 Gy) - Brainstem -- Desired D0.03cc ≤ 54Gy (acceptable ≤ 60 Gy) - Spinal Cord -- Desired DO.03cc ≤ 45Gy (acceptable ≤ 50 Gy)

For CFRT, what are the dose constraints for the brainstem?

- D_max ≤ 54 Gy - D1-10cc ≤ 59 Gy - corresponds to <5% 5 risk of neuropathy

What are the optic pathway constraints for a single fx SRS?

- D_max < 10 Gy -- Risk of ON < 5%

Per QUANTEC, what are the usual dose constraints for the parotid gland and the corresponding risk of gland dysfunction?

- b/l parotid D_mean < 25 Gy - < 20% risk of long-term parotid gland function reduced to 25% of the pre-RT level - b/l parotid D_mean < 39 Gy - < 20% risk of long-term parotid gland function reduced to 50% of the pre-RT level - Single parotid D_mean < 20 Gy

For CFRT, what is the usual dose constraint for the esophagus and the associated risk of ≥ Gr 3 esophagitis?

- D_mean < 24 Gy -- risk of ≥ gr 3 esophagitis 5-20%

After biochemical failure, how long does it take for bone metastases to develop and the pt to die?

- time to distant mets: ~ 5 yrs - time to PCSM: ~ 10 yr

What are the SRS constraints for the cauda equina?

- D0.03cc < 16 Gy - D5cc < 14

[ROQs] Constraints Flashcards

(58 cards)