Michelle Echevarria, MD from Moffitt Cancer Center discusses an ASCO 2020 Phase I dose escalation of stereotactic body radiation therapy and concurrent cisplatin for re-irradiation of unresectable, recurrent head and neck squamous cell carcinoma
Bottom line:
A stereotactic body radiation therapy (SBRT) has become an appealing choice for patients with unresectable, previously radiated, locoregionally recurrent head and neck cancer. The intrinsic radiation tolerance of these recurrent cancers can be overcome by the use of high regular doses of radiotherapy. The addition of chemotherapy to radiotherapy is usually prescribed as a radiosensitizer, considering the resistant and advanced nature of many of these cancers. Therefore, in order to assess the optimal tolerated dose of SBRT with concurrent chemotherapy for locoregional recurrent head and neck cancer, we conducted a phase I clinical trial.
Approaches:
The key conditions for inclusion were the recurrence of previous head and neck squamous cell carcinoma in patients who had previously received radiotherapy at doses of ⇠45 Gy in the area of recurrence, ⇠6 months prior to admission, and who were medically unfit for surgery, found unresectable, or denied surgery. Patients received radiation therapy every other day at three dose ranges for five fractions; 30 Gy, 35 Gy and 40 Gy. Cisplatin was administered with a dose of 15 mg / m2 prior to each SBRT fraction. Patients were monitored for protection and tolerability for any toxicity of grade 4 or greater (per CTCAE v4.0) occurring within 3 months of SBRT onset. The maximum tolerated dose (MTD) was the primary endpoint.
Reviews:
Twenty patients were registered, and the primary outcome was assessable for those 17 patients. There were nine patients with a primary tumor in the oropharynx, four in the oral cavity, three in the ear, one in the larynx, and one in the larynx and the ear at the same time. Of the three patients who could not be tested, two withheld their consent and one at a dosage level of 30 Gy died from unexplained causes two weeks after completion of treatment. Due to safety issues, an additional three patients were extended to the 30 Gy dose range, and no additional dose limiting toxicity (DLT) was observed. There were no recorded grade 4 or 5 adverse effects (per CTCAE v4.0) at the 35 Gy and 40 Gy dose levels. Grade 3 toxicities were registered in 5 (27 percent) and Grade 2 toxicities in 12 (66 percent).
Findings:
This Phase I study demonstrates that 40 Gy SBRT is feasible, healthy, and well tolerated with concurrent cisplatin at a dose of 15mg / m2. Patients continue to be tracked for secondary local control and general survival outcomes. Details about clinical trials: NCT02158234.