C.R. Spencer

Radiotherapeutic Management of Cervical Lymph Node Metastases From an Unknown Primary Site

OBJECTIVE To determine whether ipsilateral radiotherapy affects overall survival, cause-specific survival, or local control in patients with a cancer from an unknown primary of the head and neck compared with comprehensive radiotherapy. DESIGN Retrospective medical record review. SETTING Academic tertiary care hospital. PATIENTS The study population comprised 46 patients with cervical metastases from an unknown primary cancer treated with radiotherapy from 1989 through 2008. Median follow-up was 4.6 years. INTERVENTIONS All patients were treated with radiation therapy. Radiotherapy target volumes were categorized as either ipsilateral neck only (IPSI) or comprehensive (COMP), including both the potential mucosal surfaces and ipsilateral or bilateral neck. Human papillomavirus (HPV) status, as determined by p16 immunohistochemical analysis, was evaluated for 36 patients (74%). MAIN OUTCOME MEASURES Overall survival, cause-specific survival, locoregional control, and rate of distant metastases were analyzed. RESULTS Overall survival at 2 years and 5 years was 87% and 77%, respectively. Cause-specific survival at 2 years and 5 years was 89% and 81%, respectively. There were no ipsilateral neck failures. There was no difference in overall survival between patients treated with IPSI or COMP radiation therapy. The contralateral neck was controlled in all patients receiving bilateral neck irradiation and in 95% receiving ipsilateral neck irradiation. Of the 34 patients evaluated with p16 immunohistochemical analysis, results for 16 (47%) were positive. There was a nonsignificant trend toward improved overall survival in p16-positive patients (P = .06). CONCLUSION IPSI radiation therapy demonstrated excellent locoregional control with no adverse effect on disease-free survival or overall survival.

Cervical cancer histology and tumor differentiation affect 18F‐fluorodeoxyglucose uptake

This study aimed to evaluate the variation in cervical cancer glucose metabolism for different tumor histologies and levels of differentiation, as measured by the uptake of 18F‐fluorodeoxyglucose (FDG) by positron emission tomography (PET).

Comparison of onboard low-field magnetic resonance imaging versus onboard computed tomography for anatomy visualization in radiotherapy.

ABSTRACT Background. Onboard magnetic resonance imaging (OB-MRI) for daily localization and adaptive radiotherapy has been under development by several groups. However, no clinical studies have evaluated whether OB-MRI improves visualization of the target and organs at risk (OARs) compared to standard onboard computed tomography (OB-CT). This study compared visualization of patient anatomy on images acquired on the MRI-60Co ViewRay system to those acquired with OB-CT. Material and methods. Fourteen patients enrolled on a protocol approved by the Institutional Review Board (IRB) and undergoing image-guided radiotherapy for cancer in the thorax (n = 2), pelvis (n = 6), abdomen (n = 3) or head and neck (n = 3) were imaged with OB-MRI and OB-CT. For each of the 14 patients, the OB-MRI and OB-CT datasets were displayed side-by-side and independently reviewed by three radiation oncologists. Each physician was asked to evaluate which dataset offered better visualization of the target and OARs. A quantitative contouring study was performed on two abdominal patients to assess if OB-MRI could offer improved inter-observer segmentation agreement for adaptive planning. Results. In total 221 OARs and 10 targets were compared for visualization on OB-MRI and OB-CT by each of the three physicians. The majority of physicians (two or more) evaluated visualization on MRI as better for 71% of structures, worse for 10% of structures, and equivalent for 14% of structures. 5% of structures were not visible on either. Physicians agreed unanimously for 74% and in majority for > 99% of structures. Targets were better visualized on MRI in 4/10 cases, and never on OB-CT. Conclusion. Low-field MR provides better anatomic visualization of many radiotherapy targets and most OARs as compared to OB-CT. Further studies with OB-MRI should be pursued.

Eliminating radiotherapy to the contralateral retropharyngeal and high level II lymph nodes in head and neck squamous cell carcinoma is safe and improves quality of life

Radiation treatment volumes in head and neck squamous cell carcinoma (HNSCC) are controversial. The authors report the outcomes, patterns of failure, and quality of life (QOL) of patients who received treatment for HNSCC using intensity‐modulated radiation therapy (IMRT) that eliminated the treatment of contralateral retropharyngeal lymph nodes (RPLNs) in the clinically uninvolved neck.

Reevaluation of postoperative radiation dose in the management of human papillomavirus-positive oropharyngeal cancer.

The purpose of this study was to compare outcomes of patients with p16‐positive oropharyngeal squamous cell carcinoma (SCC) treated with postoperative intensity‐modulated radiotherapy (IMRT) before and after an institutional dose reduction policy effective on February 2009.

Pre-radiotherapy feeding tube identifies a poor prognostic subset of postoperative p16 positive oropharyngeal carcinoma patients

BackgroundThis study explores variables associated with poor prognosis in postoperative p16 positive oropharyngeal squamous cell carcinoma (OPSCC) patients undergoing adjuvant radiotherapy or chemoradiotherapy. Specifically, analysis was done related to timing of feeding tube insertion relative to radiotherapy.MethodsFrom 1997–2009, of 376 consecutive patients with OPSCC, 220 received adjuvant IMRT, and 97 were p16 positive and eligible. Of these, 23 had feeding tube placement before IMRT (B-FT), 32 during/after IMRT (DA-FT), and 42 had no feeding tube (NO-FT). Feeding tubes were not placed prophylactically. These three groups were analyzed for differential tumor, patient, treatment, and feeding tube characteristics, as well as differences in overall survival (OS), disease free survival (DFS), and distant metastasis free survival (DMFS).ResultsPre-RT FT insertion was associated with higher tumor size and depth, T (but not N) and overall stage, comorbidities, presence of chemotherapy, and less use of transoral laser microsurgery/transoral bovie. Additionally, time from surgery to IMRT completion was also statistically longer in the B-FT group. The feeding tube was permanent in 52% of patients in the B-FT group versus 16% in the DA-FT group (p = 0.0075). The 5-year OS for the NO-FT, DA-FT, and B-FT groups was 90%, 86%, and 50%, respectively. The 5-year DFS for the NO-FT, DA-FT, and B-FT groups was 87.6%, 83.6%, and 42.7%, respectively. Multivariate analysis showed that for OS and DFS, feeding tube placement timing and smoking history were statistically significant.ConclusionDue to the poor prognosis of early FT insertion, the presence of FTs at time of radiotherapy consultation can be used as an alternate marker to identify a subset of p16 positive OPSCC patients that have a poor prognosis.

Comparison of unilateral versus bilateral intensity‐modulated radiotherapy for surgically treated squamous cell carcinoma of the palatine tonsil

The authors hypothesized that unilateral intensity‐modulated radiotherapy (IMRT) would decrease toxicity compared with bilateral IMRT for patients with lateralized palatine tonsillar cancer and a neck classification of N0 to N2b, with similar oncological outcomes.

Quantitative FDG-PET/CT predicts local recurrence and survival for squamous cell carcinoma of the anus

Purpose 18F-fluorodeoxyglucose (FDG) positron emission tomography–(PET)/computed tomography (CT) imaging is used for staging and treatment planning of patients with anal cancer. Quantitative pre- and posttreatment metrics that are predictive of recurrence are unknown. We evaluated the association between pre- and posttreatment FDG-PET/CT parameters and outcomes for patients with squamous cell carcinoma of the anus (SCCA). Methods and materials The records of 110 patients treated between 2003 and 2013 with definitive radiation therapy for SCCA were reviewed under an institutional review board–approved protocol. The median radiation therapy dose was 50.4 Gy (range, 35-60 Gy). Concurrent chemotherapy was administered for 109 of 110 patients and generally consisted of 5-fluorouracil and mitomycin C (n = 94). All patients underwent pretreatment FDG-PET/CT and 101 of 110 underwent posttreatment FDG-PET/CT 3 months after completion of radiation therapy. The maximum standard uptake value (SUVmax) was analyzed, in addition to multiple patient and treatment factors, by univariate and multivariate Cox regression for correlation with local recurrence (LR) and overall survival (OS). Results The median follow-up was 28.6 months. LR occurred in 1 of 15 (6.7%), 5 of 47 (10.6%), and 6 of 48 (12.5%) patients with stage I, II, and III disease, respectively. On univariate analysis, a significant association was observed between reduced LR and posttreatment SUVmax <6.1 (P = .0095) and between increased OS and posttreatment SUVmax <6.1 (P = .0086). On multivariate analysis, a significant association was observed between reduced LR and posttreatment SUVmax <6.1 (P = .0013) and the use of intensity modulated radiation therapy (P < .001). A significant multivariate association was observed between increased OS and posttreatment SUVmax <6.1 (P = .0373) and the use of 5-fluorouracil/mitomycin C chemotherapy (P = .001). Conclusion Posttreatment SUVmax <6.1 is associated with reduced LR and increased OS after chemoradiation therapy for SCCA independent of T and N stage on multivariate analysis. Greater follow-up is required to confirm this association with late patterns of failure.