Dose escalation in advanced floor of the mouth cancer: a pilot study using a combination of IMRT and stereotactic boost

Abstract

Purpose We evaluated the efficiency and toxicity of stereotactic hypofractionated boost in combination with conventionally fractionated radiotherapy in the treatment of advanced floor of the mouth cancer. Methods Thirty-seven patients with advanced stage of the floor of the mouth cancer, histologically confirmed squamous cell carcinoma (p16 negative) ineligible for surgical treatment, were indicated for radiochemotherapy or hyperfractionated accelerated radiotherapy (HART). The radiotherapy protocol combined external beam radiotherapy (EBRT) and a stereotactic hypofractionated boost to the primary tumor. The dose delivered from EBRT was 70–72.5 Gy in 35/50 fractions. The hypofractionated boost followed with 10 Gy in two fractions. For the variables—tumor volume, stage and grade a multivariate analysis was performed to find the relationship between overall survival, local progression and metastasis. Toxicity was evaluated according to CTCAE scale version 4. Results After a median follow-up of 16 months, 23 patients (62%) achieved complete remission. The median time to local progression and metastasis was 7 months. Local control (LC) at 2 and 5-years was 70% and 62%, respectively. Progression-free survival (PFS) and overall survival (OS) were 57% and 49% at 2 years and 41% and 27% at 5 years, respectively. Statistical analysis revealed that larger tumors had worse overall survival and a greater chance of metastasis. Log-Rank GTV > 44 ccm (HR = 1.96; [95% CI (0.87; 4.38)]; p = 0.11). No boost-related severe acute toxicity was observed. Late osteonecrosis was observed in 3 patients (8%). Conclusion The combination of EBRT and stereotactic hypofractionated boost is safe and seems to be an effective option for dose escalation in patients with advanced floor of the mouth tumors who are ineligible for surgical treatment and require a non-invasive approach.

HPV and RAD51 as Prognostic Factors for Survival in Inoperable Oral and Oropharyngeal Cancer in Patients Unfit for Chemotherapy Treated with Hyperfractionated Radiotherapy

“…Accelerated hyperfractionated radiotherapy was previously shown to be a more effective treatment option for head and neck cancer than normofractionated radiotherapy. In the case of radioresistance, dose escalation led to overcoming this problem [ 23 ].…”

High-dose stereotactic radiotherapy boost in the treatment of squamous cell carcinoma of the head and neck region

“…Due to the patient’s declining systemic therapy during radiotherapy, the stereotactic single fraction boost may have contributed to compensating for the lack of chemotherapy by stimulating the immune system. Curious results were obtained from a Czech study involving patients ineligible for surgical treatment with advanced-stage floor of the mouth cancer [ 14 ]. After radical radiotherapy to a total dose of 70–72.5 Gy in 35/50 fractions, a 10 Gy boost in two fractions was applied.…”

High PD-L1 expression on immune cells along with increased density of tumor-infiltrating lymphocytes predicts a favorable survival outcome for patients with loco-regionally advanced head and neck cancer: early results from a prospective study

“…Patients deemed unsuitable for chemoradiation were directed towards either hyperfractionated RT or accelerated RT ( 29 , 30 ). Within a subgroup of patients with advanced oral cavity tumors, a dose escalation regimen employing CyberKnife stereotactic radiotherapy (SRT) was implemented ( 31 ).…”