What Do We Really Know About Intraoperative Radiotherapy? Mylin A. - - PDF document

7/28/2014 1 Winship Cancer Institute of Emory University

What Do We Really Know About Intraoperative Radiotherapy?

Mylin A. Torres, M.D. Assistant Professor Department of Radiation Oncology Winship Cancer Institute Emory University

Disclosures

• Nothing relevant to report

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Background

• 80-90% of patients with IBTR recur at

same site or directly adjacent to the lumpectomy cavity

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Inclusion/Exclusion Criteria

• 45 years or older
• Invasive ductal carcinoma

– Lobular carcinoma excluded

• Unifocal disease confirmed by imaging

– MRI not required

• Training required for center to enroll pts
• Each center allowed to stipulate further exclusion criteria and

pathologic criteria that would require supplemental EBRT in TARGIT pts – All pts with invasive lobular, + margins or EIC received supplemental EBRT

• Also a “post-path” enrollment group
• Clear margins

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Stratification Variables

• Treatment Center

– Each site had the option to restrict inclusion criteria beyond the core protocol – Each site determined EBRT fractionation and dose (40-56 Gy with a 10-16 Gy boost) whether it was given as a supplement to TARGIT or in the EBRT alone arm

• Timing of delivery of TARGIT (at the time
• f lumpectomy vs. post-lumpectomy)
• Previous contralateral breast cancer

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Endpoints

• Primary endpoint – biopsy confirmed local

recurrence within ipsilateral breast

• Secondary endpoint: toxicity

– Assessed frequency/grade of hematoma, seroma, skin breakdown, delayed wound healing, pain in RT field, telangectasia/dermatitis within RT field

Initial Publication

• No difference in ipsilateral breast tumor

recurrence or significant side effects

Lancet 2010

Vaidya et al. Lancet 2014

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Initial Publication

• No difference in ipsilateral breast tumor

recurrence or significant side effects

– >80% had Grade I or II tumors – >80% had < 2.0cm tumors – >80% were > 55 years old – >80% were node negative – >80% without angiolymphatic invasion – >80% ER+

Lancet 2010

Initial Publication

• No difference in ipsilateral breast tumor

recurrence or significant side effects

– >80% had Grade I or II tumors – >80% had < 2.0cm tumors – >80% were > 55 years old – >80% were node negative – >80% without angiolymphatic invasion – >80% ER+

• Outcomes reported at 4 years with only 1/3 of

patients having reached a median follow-up

• f 4 years and <20% of subjects with longer

follow-up

Lancet 2010

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Study Aim

• To report updated local recurrence and

survival data from the TARGIT-A Trial with longer follow-up and a larger cohort of patients

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Follow-up

• n=1222 patients with median f/u of 5 years
• n=2020 patients with median f/u of 4 years
• n=3451 patients with median f/u of 2 years

5 months

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Take Home

• With limited follow-up, TARGIT has a

statistically higher rate of local recurrence than traditional external beam radiation in select, low risk patients with <2.0cm, low/intermediate grade tumors that are node negative. However, the absolute difference is only 2%.

Unanswered Questions

• Are the TARGIT results durable?

– Only 1/3 of patients had >5 years of f/u

• How much of an effect did the

supplemental EBRT have on results?

• Is the supplemental EBRT necessary

following TARGIT?

• Can TARGIT be applied to higher risk

patients?

• Do the included patients need XRT at all?

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ELIOT Trial

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Ipsilateral Breast Recurrence

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Overall Survival Side Effects

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