Can Cyberknife SBRT Be An Alternative to Brachytherapy for Cervical Cancer Treatment?
T Podder1*, D Fried1, B Holland1, J Rosenman2, T Biswas1, (1) East Carolina University, Greenville, NC, (2) Univ North Carolina, Chapel Hill, NCSU-E-T-412 Sunday 3:00:00 PM - 6:00:00 PM Room: Exhibit Hall
To investigate the effectiveness of stereotactic body radiation therapy (SBRT) with Cyberknife for treatment of squamous cell carcinoma (SCCa) of cervix that are commonly treated with brachytherapy.
SCCa of cervix is routinely treated with external beam radiation therapy (EBRT) followed by brachytherapy. Common practice is to use high-dose-rate (HDR) brachytherapy, mainly with Ir-192; however, low-dose-rate (LDR) brachytherapy with Cs-137 is also used. Three of our patients with cervical SCCa who were chosen to have LDR brachytherapy (Cs-137 with tandem and ovoids) could not tolerate the prolonged treatment or applicator placement. All these patients previously received 45Gy (1.8Gy/fratction) from EBRT and well tolerated. Planned LDR treatment dose and time were for patient-1: 42.63Gy in 73.5hr, patient-2: 42.34Gy in 73hr, patient-3: 41.76Gy in 72hr. Delivered LDR dose and time were: 3.75Gy in 6.5hr, 0Gy in 0hr, and 17.3Gy in 19.8hr, for patient-1, -2 and -3, respectively. Two of the three patients tolerated LDR treatment partially; the second patient could not tolerate the applicator, which required immediate removal after placement. Treatments were completed with Cyberknife SBRT (CK-SBRT) doses of 25Gy, 15Gy and 25Gy for patient-1, -2 and -3, respectively; all had 5Gy/fraction and 3fractions/week. Prescriptions were at 80% isododelines; CTV coverages were 96.6%, 99.9% and 100% for patient-1, -2 and -3, respectively.
Till their last follow-up in February 2012, all three patients were doing fine clinically without any evidence of disease; none of these patients had any complications that could be related to CK-SBRT.
Appears that CK-SBRT can be a viable treatment alternative to brachytherapy. CK-SBRT may also be more appealing to patients and physicians for a variety of reasons such as out-patient procedure, shorter treatment time, no need for operating room, and no need for applicator insertion and tolerance. However, extensive clinical study is warranted in this regard.