J.M. Melotek

Response-Adapted Volume De-escalation (RAVD) in Locally Advanced Head and Neck Cancer

BACKGROUND Efforts to reduce the late toxicity associated with chemoradiation (CRT) for locally advanced head and neck squamous cell cancer (LA-HNSCC) have focused on radiotherapy (RT) dose de-escalation. In this phase I/II protocol investigating the addition of everolimus to induction chemotherapy (IC), we incorporated a novel response-adapted volume de-escalation (RAVD) approach using IC response to guide the extent of RT volume reduction. PATIENTS AND METHODS Patients with measurable LA-HNSCC received two cycles of IC (cisplatin, paclitaxel, cetuximab ± everolimus). Patients with ≥50% reduction in the sum of tumor diameters [good response (GR)] received TFHX (paclitaxel, fluorouracil, hydroxyurea, and 1.5 Gy twice daily RT every other week) to a dose of 75 Gy with the single planning target volume (PTV1) encompassing exclusively gross disease. Patients with <50% response [non-response (NR)] were treated with TFHX encompassing PTV1 and the next nodal station at risk (PTV2) to a dose of 45 Gy followed by a sequential boost to PTV1 to a dose of 75 Gy. RESULTS Ninety-four patients were enrolled. Randomization to everolimus was discontinued on interim analysis after 50 patients due to futility. IC response was evaluable in 89 patients. Thirty-seven patients (41.6%) had GR and 52 (58.4%) had NR. There was a trend for improved progression-free (P = 0.086) but not overall survival (P = 0.94) for GR versus NR. The 2-year PFS and OS were 86.0% and 83.5% for GR and 68.7% and 85.4% for NR, respectively. NR were significantly more likely to undergo G-tube placement during treatment (50.0% GR versus 73.5% NR, P = 0.040) and be G-tube dependent at 6-month follow-up (5.7% GR versus 32.6% NR, P = 0.005). CONCLUSIONS The addition of everolimus to IC was not beneficial. The elimination of elective nodal coverage in patients with GR to IC did not appear to compromise outcomes and resulted in significantly decreased late toxicity. Further investigation of RAVD is warranted. CLINICALTRIALSGOV NCT01133678.

Safety and Clinical Activity of Pembrolizumab and Multisite Stereotactic Body Radiotherapy in Patients With Advanced Solid Tumors

Purpose Stereotactic body radiotherapy (SBRT) may stimulate innate and adaptive immunity to augment immunotherapy response. Multisite SBRT is an emerging paradigm for treating metastatic disease. Anti-PD-1-treatment outcomes may be improved with lower disease burden. In this context, we conducted a phase I study to evaluate the safety of pembrolizumab with multisite SBRT in patients with metastatic solid tumors. Patients and Methods Patients progressing on standard treatment received SBRT to two to four metastases. Not all metastases were targeted, and metastases > 65 mL were partially irradiated. SBRT dosing varied by site and ranged from 30 to 50 Gy in three to five fractions with predefined dose de-escalation if excess dose-limiting toxicities were observed. Pembrolizumab was initiated within 7 days after completion of SBRT. Pre- and post-SBRT biopsy specimens were analyzed in a subset of patients to quantify interferon-γ-induced gene expression. Results A total of 79 patients were enrolled; three patients did not receive any treatment and three patients only received SBRT. Patients included in the analysis were treated with SBRT and at least one cycle of pembrolizumab. Most (94.5%) of patients received SBRT to two metastases. Median follow-up for toxicity was 5.5 months (interquartile range, 3.3 to 8.1 months). Six patients experienced dose-limiting toxicities with no radiation dose reductions. In the 68 patients with imaging follow-up, the overall objective response rate was 13.2%. Median overall survival was 9.6 months (95% CI, 6.5 months to undetermined) and median progression-free survival was 3.1 months (95% CI, 2.9 to 3.4 months). Expression of interferon-γ-associated genes from post-SBRT tumor biopsy specimens significantly correlated with nonirradiated tumor response. Conclusion Multisite SBRT followed by pembrolizumab was well tolerated with acceptable toxicity. Additional studies exploring the clinical benefit and predictive biomarkers of combined multisite SBRT and PD-1-directed immunotherapy are warranted.

Quality of Life after Post-Prostatectomy Intensity Modulated Radiation Therapy: Pelvic Nodal Irradiation Is Not Associated with Worse Bladder, Bowel, or Sexual Outcomes

Background Limited data exist regarding toxicity and quality of life (QOL) after post-prostatectomy intensity modulated radiation therapy (IMRT) and whether pelvic nodal RT influences these outcomes. Methods 118 men were treated with curative-intent RT after radical prostatectomy. 69 men (58%) received pelvic nodal RT. QOL data and physician-assigned toxicity were prospectively collected. Changes in QOL from baseline were assessed with Wilcoxon signed-rank tests and risk factors associated with each domain were identified with generalized estimating equation (GEE) models. Late freedom from (FF) toxicity was estimated by the Kaplan-Meier method and comparisons were tested using the log-rank test. Results Urinary irritation/obstruction, bowel, and sexual domain scores declined at 2 months (all P ≤ 0.01) but were no different than baseline at subsequent visits through 4 years of follow-up. At 4 years, FF grade 2+ GI toxicity was 90% and FF grade 2+ GU toxicity was 89%. On GEE analysis, pelvic nodal RT was associated with decreased bowel function (P = 0.09) and sexual function (P = 0.01). On multivariate analysis, however, there was no significant association with either decreased bowel (P = 0.31) or sexual (P = 0.84) function. There was also no association with either FF grade 2+ GI toxicity (P = 0.24) or grade 2+ GU toxicity (P = 0.51). Conclusions Receipt of pelvic nodal RT was not associated with inferior QOL or toxicity compared to prostate bed alone RT. For the entire cohort, RT was associated with only temporary declines in patient-reported urinary, bowel, or sexual QOL.

Weekly versus every-three-weeks platinum-based chemoradiation regimens for head and neck cancer.

BackgroundThe majority of chemoradiation (CRT) trials for locally advanced head and neck squamous cell carcinoma (HNSCC) have relied on platinum-based chemotherapy regimens administered every-3-weeks. However, given the increased utilization of weekly platinum regimens, it remains unclear how different chemotherapy schedules compare regarding efficacy and toxicity.MethodsWe retrospectively identified 212 patients with HNSCC who were treated at a single academic medical center with concurrent platinum-based CRT given weekly (N = 68) or every-three-weeks (N = 144). JMP version 10 (SAS Institute) was used for statistical analysis. Discrete variables were compared with the chi-square test and differences in the medians were assessed using the Wilcoxon test. Survival curves were constructed using the Kaplan-Meier method and significance was assessed using the log rank test. For univariate analysis and multivariate analysis, we used Cox proportional hazard or logistic regression models to compare differences in survival or differences in categorical variables, respectively.ResultsPatients receiving weekly platinum regimens were more likely to be older (median age 61.4 vs. 55.5 y; P < .001), have high or very high Charlson comorbidity index (45.6% vs. 27.8%; P = .01), and receive carboplatin-based chemotherapy (6.3% vs. 76.5%; P < .001). Weekly and every-3-week platinum regimens had similar locoregional control (HR 1.10; 95% CI 0.63–1.88; P = .72), progression-free survival (HR 1.13; 95% CI 0.75–1.69; P = .55), and overall survival (HR 1.11; 95% CI 0.64–1.86; P = .71). Every-3-weeks platinum regimens were associated with increased days of hospitalization (median: 3 days vs. 0 days; P = .03) and acute kidney injury (AKI) during radiotherapy (50.0% vs. 22.1%; P < .001). On multivariate analysis, AKI was significantly associated with every-3-weeks regimens (OR: 24.38; 95% CI 3.00–198.03; P = .003) and high comorbidity scores (OR: 2.74; 95% CI 2.15–5.99; P = .01).ConclusionsOur results suggest that every-3-weeks and weekly platinum-containing CRT regimens have similar disease control but weekly platinum regimens are associated with less acute toxicity.

Definitive chemoradiation for locally-advanced oral cavity cancer: A 20-year experience

OBJECTIVES Definitive chemoradiation (CRT) for oral cavity squamous cell carcinoma (OC-SCC) is often criticized for poor efficacy or toxicity. We describe a favorable 20-year experience of primary CRT for locally-advanced OC-SCC. MATERIALS AND METHODS Patients with locally-advanced, stage III/IV OC-SCC receiving primary concomitant CRT on protocols from 1994 to 2014 were analyzed. Chemotherapy included fluorouracil and hydroxyurea with other third agents. Radiotherapy (RT) was delivered once or twice daily to a maximum dose of 70-75 Gy. Intensity-modulated RT (IMRT) was exclusively used after 2004. Progression-free survival (PFS), overall survival (OS), locoregional control (LRC), and distant control (DC) were calculated by the Kaplan-Meier method and compared across treatment decades using the log-rank test. Rates of osteoradionecrosis (ORN) requiring surgery were compared across treatment decades using the Chi-square test. RESULTS 140 patients with locally-advanced OC-SCC were treated with definitive CRT. Of these, 75.7% had T3/T4 disease, 68.6% had ≥N2 nodal disease, and 91.4% had stage IV disease. Most common primary sites were oral tongue (47.9%) and floor of mouth (24.3%). Median follow-up was 5.7 years. Five-year OS, PFS, LRC, and DC were 63.2%, 58.7%, 78.6%, and 87.2%, respectively. Rates of ORN and long-term feeding tube dependence were 20.7% and 10.0%, respectively. Differences in LRC (P = 0.90), DC (P = 0.24), PFS (P = 0.38), OS (P = 0.10), or ORN (P = 0.38) were not significant across treatment decades. CONCLUSION Definitive CRT is a viable and feasible strategy for organ preservation for patients with locally-advanced OC-SCC.

Bladder dose-volume parameters are associated with urinary incontinence after postoperative intensity modulated radiation therapy for prostate cancer

PURPOSE Urinary incontinence is a potential side effect of prostatectomy and intensity modulated radiation therapy (IMRT) for prostate cancer. There are limited data on dosimetric parameters that may predict for poor continence recovery in men who receive postoperative IMRT. METHODS AND MATERIALS Eighty-seven men with nonmetastatic prostate cancer who underwent prostatectomy followed by adjuvant (13%) or salvage (87%) IMRT were identified. The Expanded Prostate Cancer Index composite questionnaire was prospectively collected at baseline, 6 weeks, and 6, 12, 18, 24, 36, and 48 months post-IMRT. Relevant critical structures were contoured and dose-volume metrics collected. The primary endpoint was urinary continence global score. Longitudinal analysis using a generalized estimating equation model was performed. RESULTS There was no statistically significant change in Expanded Prostate Cancer Index composite urinary continence global scores over time as compared with baseline (all P > .05). In univariate analysis, bladder volume receiving 70 Gy (V70 Gy) and penile bulb V70 Gy were associated with urinary continence (odds ratio, 0.82; P < .05). In a multivariable model that included body mass index, distance between vesicourethral junction and genitourinary diaphragm, time from surgery, use of antihypertensive medications, age, diabetes, and bladder V70 Gy, only bladder V70 Gy (odds ratio, 0.82; P = .03) was associated with outcome. After 2 years, there was a significant difference in global score for those with V70 Gy < 42.27 versus ≥42.27 mL (all P < .05 at 2 and 3 years post-IMRT). CONCLUSION There was no significant change in patient-reported urinary continence scores after postprostatectomy IMRT. Bladder V70 Gy was independently associated with a decrease in urinary continence scores. Further evaluation is necessary to optimize quality of life in these men.

Salivary Gland Tumors

Salivary gland malignancies are uncommon, representing 1–6% of head and neck malignancies and 0.3% of all cancers (55% occur in parotid gland, 30% in submandibular gland, 10–15% in the sublingual and minor salivary glands). The majority of salivary gland tumors are primarily managed surgically followed by radiation ± chemotherapy. Indications for postoperative radiation include intermediate-/high-grade tumor, close/positive margins, lymph node metastases, and lymphovascular invasion as well as T3/T4 tumors or recurrent disease in some circumstances. The role of postoperative chemoradiation for high-risk salivary tumors is currently the subject of the ongoing RTOG 10-08 trial (NCT01220583). Unresectable cases are often managed with radiation therapy, preferably with concurrent systemic therapy.