Gynecological Cancer

PV QA 4 - Poster Viewing Q&A 4

TU_14_3459 - Intensity Modulated Radiation Therapy Utilizing Dose-Escalated Simultaneous Integrated Boost (IMRT-SIB) to PET-Avid Gross Nodal Disease in Gynecologic Malignancies

Tuesday, October 23
2:45 PM - 4:15 PM
Location: Innovation Hub, Exhibit Hall 3

Intensity Modulated Radiation Therapy Utilizing Dose-Escalated Simultaneous Integrated Boost (IMRT-SIB) to PET-Avid Gross Nodal Disease in Gynecologic Malignancies
S. Hasan1, M. A. Mezera2, L. Sager1, G. Axelrud1, and M. N. El-Ghamry1; 1Baylor Scott & White Health, Temple, TX, 2University of Louisville, Louisville, KY

Purpose/Objective(s): Regional nodal irradiation improves survival and reduces development of metastases in locally advanced gynecologic cancers. However, typical doses of 45-50 Gy have been shown to be inadequate to control gross nodal disease. Sequential boost may have low effect due to accelerated repopulation. At our institutions, we utilize a regimen of IMRT to 45-50.4 Gy at 1.8 Gy/fraction to elective nodal volumes (e.g. pelvic and para-aortic nodes) with SIB up to 56.25-63 Gy at 2.25 Gy/fraction to PET avid gross nodal disease. The purpose of this study is to evaluate toxicity and tumor control using this dose-escalated regimen.

Materials/Methods: Patients with gynecologic cancers presenting with PET avid para-aortic, pelvic, and/or inguinal lymph nodes were treated with IMRT-SIB between 2009 and 2017. Toxicity was evaluated throughout treatment and at routine follow up visits. Disease recurrence and response was identified by imaging and/or biopsy.

Results: A total of 52 patients were evaluated. The mean age was 54.2 years (± 11.7). Median follow up from completion of treatment was 11.2 months (0.9-90.4). The primary site of disease consisted of the cervix (50%), uterine (32.7%), and vulva (7.7%). Concurrent chemotherapy was given to 61.5% of patients. Brachytherapy was given to 82.7% of patients. The median SIB volume was 74.24 cc (range 6.75-858.42). Local control within the high dose integrated boost region was 97%. Radiologic complete and partial response was 65% and 21% respectively. A majority of the recurrences (63.6%) were distant with only 13.6% of patients having a recurrence in the elective dose field and 31.8% of patients having both a low dose and out of field recurrences. Median time to recurrence was 3.7 months (0-56.6). ≥Grade 3 acute toxicities were observed in 6% of patients. Late recto-vaginal fistula was observed in 13.5%, and was related to brachytherapy.

Conclusion: Dose escalated SIB results in excellent local control with acceptable toxicity. Almost all patients achieved radiographic partial or complete response with exceptionally low rate of recurrence within the dose-escalated boost volume.

Author Disclosure: S. Hasan: None. M.A. Mezera: None. G. Axelrud: None. M.N. El-Ghamry: None.

Send Email for Salman Hasan


Assets

TU_14_3459 - Intensity Modulated Radiation Therapy Utilizing Dose-Escalated Simultaneous Integrated Boost (IMRT-SIB) to PET-Avid Gross Nodal Disease in Gynecologic Malignancies



Attendees who have favorited this

Please enter your access key

The asset you are trying to access is locked. Please enter your access key to unlock.

Send Email for Intensity Modulated Radiation Therapy Utilizing Dose-Escalated Simultaneous Integrated Boost (IMRT-SIB) to PET-Avid Gross Nodal Disease in Gynecologic Malignancies