Pathology/Radiation Flashcards
Discuss Silva Pattern
Stratify endocervical adenocarcinoma to correlate with LN mets - based off 352 cases
pattern A (21%): well-demarcated glands frequently forming clusters or groups with relative lobular architecture and lacking destructive stromal invasion or lymphovascular invasion (LVI) - all were stage I and no N mets or recurrence
pattern B (26%) : localized destructive invasion (small clusters or individual tumor cells within desmoplastic stroma often arising from pattern A glands)
- All stage I
- 4% nodal mets and these had LVSI
pattern C (54%): diffusely infiltrative glands and associated desmoplastic response
- 17% stg II or greater
- 62% LVSI
- 23.8% nodal mets
- 21.7% recurrence
What is a CPS score
Tumor cells, lymphocytes, macrophages / viable tumor cells x 100
Discuss LDR vs HDR brachytherapy
The International Commission on Radiation Units (ICRU) defines LDR brachytherapy as 0.4 to 2 Gy per hour, whereas HDR brachytherapy is delivered at >12 Gy per hour.
How does radiation dose change with distance?
radiation inverse square law specifies that: the intensity of the radiation goes down by the square of the distance from the source.
For instance if you move twice as far from the source the intensity of the radiation will decrease by a factor of 4.
What is the max radiation dose in pregnancy
5Gy
What is PET resolution
7-10mm
When should you do a post RT response PET CT
3 months - post therapy changes can persist for months
Herrera Frontiers Oncology 2013
Discuss GOG 165 and GOG 120
120 Mandated
165 Imaging improved omiting surgical staging - did not mandate surgical staging
Discuss GOG 233 and ACRIN 6671
PET Detection of Nodes
Preop PET CT -> surgical staging
97% specific
NPV 93%
PET CT modestly better than CT
Discuss MRI
95% accuracy over 10mm for nor
PET CT more accurate for nodal mets >10mm
Errors in clinical staging vs MRI
- MRI»_space;> Clinical exam to exclude parametrium (poored meta-analysis)
Stage I-II 25% error rate
40% for advanced stage
80% accurate to assess tumor response
Discuss MRI and PET compared to clinical exam
Local staging changes 27% of the time comparing MRI and clinical exam
IB1-IIA2 changed to IIB (parametrial) in 31%
50% have positive nodes
Sedlis
> 1/3 invasion of cervix and anything else gets treatment
GOG 109
Clinical stgage 1A2, IB, IIA Had positive nodes parametrium or margins
CRT improved from 70% to 80%
Armstrong 2006
risk of LN involvement by stage
Multiply stage by 15
Landoni 1997
edian dose to point A a liuttle older
Ldr
64% surgery arm received adjuvant RT
