Emerging applications of stereotactic radiotherapy in head and neck cancer

A national cancer database analysis on stereotactic body radiation therapy of head and neck cancers

BACKGROUND

To evaluate demographic, clinicopathological, treatment factors including biological effective radiation dose (BED) that influence overall survival in head and neck cancer (HNC) patients treated with stereotactic body radiation therapy (SBRT).

METHODS

Between 2004 and 2015, 591 SBRT-treated HNC patients were identified from the National Cancer Data Base. A BED using an alpha/beta ratio of 10 (BED₁₀), was used to compare dose fractionation of different SBRT regimens. Overall survival was estimated using the Kaplan Meier method, and log-rank tests were used to determine statistical significance. Cox regression modeling was used to compute crude and adjusted hazard ratios (HR) with 95% confidence intervals (CI).

RESULTS

Median follow-up was 11.9 (interquartile range, 5.5 to 26.7) months. The 5-year overall survival rate was 15.5%. On multivariate analysis, older age, Charlson-Deyo comorbidity score ≥ 1, history of cancer, tumor, nodal and metastatic stage, and receiving treatment at academic/research program were associated with poor survival. Compared to SBRT alone, superior survival was observed with SBRT with chemotherapy, surgery with SBRT, but not surgery with SBRT and chemotherapy. Improved survival was observed with aa BED₁₀ of ≥59.5 Gy (adjusted HR 0.57, 95% CI 0.46-0.70, P < 0.0001).

CONCLUSIONS

Factors affecting associated with worse survival in HNC patients treated with SBRT included older age, patient comorbidities, advanced tumor stage, cancer history, and lower biological effective SBRT dose.

LEVEL OF EVIDENCE

2b (individual cohort study).

Oral complications of cancer and cancer therapy: from cancer treatment to survivorship

Answer questions and earn CME/CNE Oral complications resulting from cancer and cancer therapies cause acute and late toxicities that may be underreported, underrecognized, and undertreated. Recent advances in cancer treatment have led to changes in the incidence, nature, and severity of oral complications. As the number of survivors increases, it is becoming increasingly recognized that the aggressive management of oral toxicities is needed to ensure optimal long-term oral health and general well-being. Advances in care have had an impact on previously recognized oral complications and are leading to newly recognized adverse effects. Here, the authors briefly review advances in cancer therapy, including recent advances in surgery, oral care, radiation therapy, hematopoietic cell transplantation, and medical oncology; describe how these advances affect oral health; and discuss the frequent and/or severe oral health complications associated with cancer and cancer treatment and their effect upon long-term health. Although some of the acute oral toxicities of cancer therapies may be reduced, they remain essentially unavoidable. The significant impact of long-term complications requires increased awareness and recognition to promote prevention and appropriate intervention. It is therefore important for the primary oncologist to be aware of these complications so that appropriate measures can be implemented in a timely manner. Prevention and management is best provided via multidisciplinary health care teams, which must be integrated and communicate effectively in order to provide the best patient care in a coordinated manner at the appropriate time.

Prospective evaluation of patient-reported quality-of-life outcomes following SBRT ± cetuximab for locally-recurrent, previously-irradiated head and neck cancer

PURPOSE

Stereotactic body radiotherapy (SBRT) has emerged as a promising salvage strategy for unresectable, previously-irradiated recurrent squamous cell carcinomas of the head and neck (rSCCHN). Here-in, we report the first prospective evaluation of patient-reported quality-of-life (PR-QoL) following re-irradiation with SBRT±cetuximab for rSCCHN.

MATERIALS AND METHODS

From November 2004 to May 2011, 150 patients with unresectable, rSCCHN in a previously-irradiated field receiving >40 Gy were treated with SBRT to 40-50 Gy in 5 fractions ± concurrent cetuximab. PR-QoL was prospectively acquired using the University of Washington Quality-of-Life Revised (UW-QoL-R).

RESULTS

Overall PR-QoL, health-related PR-QoL, and select domains commonly affected by re-irradiation progressively increase following an initial 1-month decline with statistically significant improvements noted in swallowing (p=0.025), speech (p=0.017), saliva (p=0.041), activity (p=0.032) and recreation (p=0.039).

CONCLUSIONS

Especially for patients surviving >1-year, improved tumor control associated with SBRT re-irradiation may ameliorate decreased PR-QoL resulting from rSCCHN. These improvements in PR-QoL transcend all measured domains in a validated PR-QoL assessment tool independent of age, use of cetuximab, tumor volume, and interval since prior irradiation.

Clinical outcomes of single or oligo-fractionated stereotactic radiotherapy for head and neck tumors using micromultileaf collimator-based dynamic conformal arcs

PURPOSE

To assess the clinical outcomes of single or oligo-fractionated stereotactic radiotherapy (SRT) using dynamic conformal arcs (DCA) for head and neck tumors (HNTs).

METHODS

Thirty-four consecutive patients with 35 lesions treated between 2005 and 2009 were retrospectively evaluated, of whom 85.7 % had recurrent or metastatic disease, and 45.7 and 34.3 % had previous radiotherapy and surgery, respectively. The median SRT dose was 22.3 Gy (11.2-32.8) in 2-4 fractions with a median interval of 7 days and 10.4 Gy (9.2-12.4) in one fraction. SRT was combined with upfront conventionally fractionated RT in 48.6 % of patients.

RESULTS

The median follow-up periods were 18.4 months (2-84.1) for the entire cohort and 49.6 months for the survivors. The 1- and 2-year local control (LC) rates were 84.3 and 70.5 %, with the 1- and 2-year overall survival (OS) rates of 78.6 and 51.6 %. LC was significantly better for tumor volumes <25.6 cm(3) (p = 0.001). OS was significantly longer in patients without any disease outside the SRT site (p < 0.001), whereas LC after the SRT did not affect the OS. Late adverse events occurred in 9 patients, including cranial nerve (CN) injury (grade 3/4) in 2, brain radionecrosis in 5 (grade 1), and fatal bleeding in 2 patients harboring uncontrolled lesions abutting the carotid artery.

CONCLUSIONS

DCA-based SRT can confer relatively long-term LC with acceptable toxicity in selected patients with HNTs. The patients with CN involvement or tumor volume ≥25.6 cm(3) were deemed unsuitable for this treatment regimen.

The use of RapidArc volumetric-modulated arc therapy to deliver stereotactic radiosurgery and stereotactic body radiotherapy to intracranial and extracranial targets

Twenty-three targets in 16 patients treated with stereotactic radiosurgery (SRS) or stereotactic body radiotherapy (SBRT) were analyzed in terms of dosimetric homogeneity, target conformity, organ-at-risk (OAR) sparing, monitor unit (MU) usage, and beam-on time per fraction using RapidArc volumetric-modulated arc therapy (VMAT) vs. multifield sliding-window intensity-modulated radiation therapy (IMRT). Patients underwent computed tomography simulation with site-specific immobilization. Magnetic resonance imaging fusion and optical tracking were incorporated as clinically indicated. Treatment planning was performed using Eclipse v8.6 to generate sliding-window IMRT and 1-arc and 2-arc RapidArc plans. Dosimetric parameters used for target analysis were RTOG conformity index (CI(RTOG)), homogeneity index (HI(RTOG)), inverse Paddick Conformity Index (PCI), D(mean) and D5-D95. OAR sparing was analyzed in terms of D(max) and D(mean). Treatment delivery was evaluated based on measured beam-on times delivered on a Varian Trilogy linear accelerator and recorded MU values. Dosimetric conformity, homogeneity, and OAR sparing were comparable between IMRT, 1-arc RapidArc and 2-arc RapidArc plans. Mean beam-on times ± SD for IMRT and 1-arc and 2-arc treatments were 10.5 ± 7.3, 2.6 ± 1.6, and 3.0 ± 1.1 minutes, respectively. Mean MUs were 3041, 1774, and 1676 for IMRT, 1-, and 2-arc plans, respectively. Although dosimetric conformity, homogeneity, and OAR sparing were similar between these techniques, SRS and SBRT fractions treated with RapidArc were delivered with substantially less beam-on time and fewer MUs than IMRT. The rapid delivery of SRS and SBRT with RapidArc improved workflow on the linac with these otherwise time-consuming treatments and limited the potential for intrafraction organ and patient motion, which can cause significant dosimetric errors. These clinically important advantages make image-guided RapidArc useful in the delivery of SRS and SBRT to intracranial and extracranial targets.

Stereotactic body radiation therapy for locally recurrent, previously irradiated nonsquamous cell cancers of the head and neck

BACKGROUND

Stereotactic body radiotherapy (SBRT) has emerged as a promising salvage strategy for patients with recurrent, previously irradiated head and neck cancer; however, data are limited predominantly to squamous cell carcinomas. Herein, we report the efficacy of SBRT in recurrent, nonsquamous cell cancers of the head and neck (NSCHNs).

METHODS

In all, 34 patients with pathologically proven NSCHN were re-irradiated with SBRT to a median dose of 40 Gy in 5 fractions (interquartile range, 30-44 Gy). Toxicity and quality of life were followed prospectively.

RESULTS

Median follow-up was 10 months (absolute range, 0-55 months). The 6-month/1-year local control rate was 77/59%, with a 6-month/1-year overall survival of 76/59%. Local control was significantly improved for tumors <25 mL (p = .030). Acute/late grade 3 toxicity was 15/6%, with no grade 4-5 toxicity.

CONCLUSIONS

SBRT for previously irradiated, locally recurrent NSCHN provides promising local control, especially for tumors <25 mL, with minimal toxicity. The optimal dose for larger tumors remains to be defined.