WHY brachytherapy as WELL as external pelvic radiation?

Dear All,

Diagnosed with stage IB uterine cancer six months ago, I was originally told I'd need "sandwich treatment:

three rounds of carbo/taxol;
25 sessions of IMRT pelvic radiation sessions;
three brachytherapy treatments
three final rounds of carbo/taxol.

Three weeks through the pelvic radiation (with no adverse reactions so far), my radiological oncologist said last week, "I'm not sure you'll really need brachytherapy; there was no cervical involvement ..."

WHAT?

Why would thre be a sudden change of mind about my prescribed course of treatment?

Although it was stage IB, with 18 clear pelvic lymph node samplings, my tumor is rare and agressive (carcinosarcoma, formerly known as MMMT) and although it didn't reach my cervix, it was large (6.0 centimeters) and low in the uterus, with sixty percent myometrial invasion.

Three second opinions all agreed on the chemo regimen.

But they disagreed on the radiation protocols. One questioned why IMRT pelvic radiation when my lymph nodes were clear.

Most agreed that I needed at least brachytherapy since vaginal vault recurrence is such a threat.

Yet now my onc tells me that external pelvic radiation is nearly as effective as brachytherapy in preventing vaginal vault recurrence and MORE effective at preventing pelvic recurrence..

I do NOT look forward to brachyterhapy and the need to use a dilator every night for the rest of my life (which I'll have to as I am single again and have been celibate for a few years.)

But saving my life is more important--so I need to know whether all of you who had brachytherapy had tumors that extended beyond your uterus to invade your cervix.

Any advice would be appreciated because I now have a new decision to make within two weeks

Gratefully,
Rosey R