1. INTERPRETATION OF hCG LEVELS?

2.

Glycoprotein withandchains

subunit is specific to hCG

Secreted by trophoblastic tissue, some amount by fetal tissues, adult ant pituitary

Many isoforms of hCG with variable crossreactivity between various assays

More than 100 commercial assays

Sandwich type immunoassay: Sens - 1mIU/ml

Immuno radiometric assays: more Sensitive

3.

Pregnancy

Gestational trophoblastic neoplasia

Non gestational

Trophpoblastic neoplasia

Mixed germ cell tumors

4.

Always rule out pregnancy whenever hCG is positive.

It does not localize the pregnancy

USG to lacalise the pregnancy

Significantly higher levels

Multiple pregnancy

Erythroblastosis fetalis

Downs syndrome

Low levels : ectopic pregnancy, abortions

5.

+ve 7-9 days after the midcycle surge that precedes ovulation.(time of blastocyst implantation)

Blood levels rise rapidly, double every 1.4 - 2 days, max value at 8-10 wks.

Peak values: 60-80 days of LMP(1 lac mIU/ml)

10-20 wks POG: begin to fall, nadir levels by 20 wks & maintained at lower levelsthru out pregnancy

6. Return of hCGNVD3 wks Abortions 6 wks Molar pregnancy 8-9 wks 7.

Discriminatorylevel

• Lower limit above which one can reliably visualise

• pregnancy

• 1500 mIU/ml for TVS

Doubling time

• IUP : serum hCG levels 66% every 48 hrs

• Inappropirately rising serum hCG-> dying pregnacy & not its location

8. Positive urinary hCG TVS Pregnancy of Unknown location Serial serum hCG and progesterone Initial progesterone 66% rise IUP TVS Failing pregnancy D&C 12.

Medical treatment

• Pre T/t level:5000 mIU/ml 92% success

• Follow up: D 1 -- baseline

D 4 -- level >D 1

D 7 -- 15% fall from D 4

Every week till 15 IU/L

• 20% will have decline of hCG < 15% :second dose of Methotrexate

• Average duration for hCG levelto reach normal-36 days

Longestduration- 109 days

Expectant treatment

< 1000 mIU/ml

< 200 IU/L-----spontaneous resolution in 88-96 %

13.

High risk molar: > one lac mIU/ml

Follow up :within 48 hrs of evacuation

every wk till hCG is normalx 3wks

every month x 6 months

FIGO criteria for chemo

Plateauing ( +10% value ,4 values over 3 wks)

Rising hCG(increase of > 10% of 3 values recorde over a 2 week duration)

Persistent hCG after 6 months of evacuation

14. FIGO score 0 1 2 4 Age (years) 39 Antecedent pregnancy Hydatidiform mole Abortion Term pregnancy Interval from index pregnancy (months) 12 Pretreatment hCG (mIU/mL) 100,000 Largest tumor size including uterus (cm) 3-4 5 Site of metastases Spleen Kidney Gastrointestinal Brain lever Number of metastases identified 0 1-4 4-8 >8 Previous failed chemotherapy Single drug >2 drugs 15. Category Criteria Non-metastatic GTN No evidence of metastases; not assigned to prognostic categoryMetastatic GTN Any extrauterine metastases Good prognosis metastatic GTN No risk factors: Short duration ( 40,000 mIU/ mL Brain or liver metastases Antecedent term pregnancy Prior chemotherapy 16. Surveillance During And After Therapy of GTN

Monitor serum quantitative hCG levels every week during chemotherapy:

Response:> 10% decline in hCG during one cycle

Plateau:+10% change in hCG during one cycle

Resistance:>10% rise in hCG during one cycle or plateau for two Remission: 3 consecutive normal weekly hCG values

Surveillance of remission:

hCG values every 2 weeks X 3 months

hCG valuesevery month to complete one year of follow-up

hCG values every 6-12 months indefinitely; at least 3-5 years

17.

75 -110 mIU/L ( max reported 300 mIU/L)

After chemo/ surgery of GTN

No clinical/radiological evidence of trophoblastic tissue

phantom hCGQuiscent GTN

(false +ve)(real +ve)

(Benign or inactive)

18.

Phantom hCG

Heterophilic abs

React with animal Ag in immuno sandwich assay

Confirm by

• Urine hCG ve

• different assays

• no change in dilutions

• other techniques to srip/ block/ inactivate abs

Quiscent GTN

Most often after molar, GTN, pregnancy

Do not respond to chemo

Diagnosis

• Hyperglycosylated hCG < 6%

• (hCG H)

• Serial hCG titres: plateau5,10,20,22,8,25,24

• Withhold chemo

Premalignant (1-11%)

Monthly FU, glycosylated hCG,

Slow growing syncytiotrophoblast

19. 20.