Unilateral neck treatment with either surgery and/or radiotherapy for squamous cell carcinoma for the tonsil.

INTRODUCTION: Strategies for treatment of tonsil carcinoma are under active investigation. Limiting surgical and radiation treatment volumes to the primary tumor and ipsilateral neck in appropriately selected patients is one such approach. Here, we present our institutional experience with treatment through ipsilateral surgical or radiotherapeutic neck management. METHODS: We retrospectively reviewed our institutional database of patients with tonsil carcinoma treated from 2012 to 2020. Patients were included for analysis if they received definitive radiation therapy (RT), definitive surgery (S), or surgery with post-operative radiation therapy (S-PORT) and whose treatment volumes were limited to the primary tumor and involved/elective ipsilateral neck. Patients who received radiation and/or surgery to the contralateral neck (including those with bilateral nodal involvement), as well as patients with metastatic disease, were excluded. Clinical factors including T- and N-stage (AJCC 7th edition), and HPV status (by p16 and/or HPV DNA PCR) were recorded, as were pathologic factors (when applicable) including margin status, extracapsular extension (ECE), lymphovascular invasion (LVSI), and perineural invasion (PNI). Overall survival (OS), progression free survival (PFS), and locoregional control (LRC) at 2 years were estimated using the Kaplan-Meier method. RESULTS: In total, 71 patients were treated with unilateral neck approaches: S (n=49), RT (n=10), and S+PORT (n=12). Among these patients, 32, 36, and 3 had T1, T2, and T3 disease, respectively. N-stage was N0, N1, N2a, N2b, and N3 in 22, 20, 5, 23, and 1 patient(s), respectively. Concurrent chemotherapy was administered in 12 patients. From those with recorded risk factors, 86% were HPV-positive, 20% had LVSI, 7% had PNI, 13% had ECE, and 5% had positive margins. From a median follow-up of 27 months, local, regional, and distant failures occurred in 5, 6, and 5 patients, respectively. No contralateral neck failures were recorded. At 2 years, OS, PFS, and LRC were 92% (95% CI 85-99%), 85% (95% CI 75-95%), and 88% (95% CI 80-98%), respectively. CONCLUSIONS: In patients with early T-stage tonsil carcinoma, treatment of the primary tumor and ipsilateral neck is associated with acceptable OS, PFS, and LRC. In this population, the risk of contralateral neck failure is likely very low regardless of primary treatment modality. Additional prospective studies are needed to determine the impact of limiting treatment extent to the unilateral neck.

Survival and Swallowing Function after Primary Radiotherapy versus Transoral Robotic Surgery for Human Papillomavirus-Associated Oropharyngeal Squamous Cell Carcinoma.

INTRODUCTION: The aim of this study was to investigate the impact of primary transoral robotic surgery (TORS) versus radiotherapy (RT) on progression-free survival (PFS), overall survival (OS), and 1-year swallowing function for patients with early-stage HPV-associated oropharyngeal squamous cell carcinoma (OPSCC). METHODS: Patients with stage I-II (AJCC 8th Ed.) HPV-associated OPSCC treated with TORS followed by risk-adapted adjuvant therapy or (chemo)radiotherapy between 2014 and 2019 were identified. PFS, OS, and swallowing outcomes including gastrostomy tube (GT) use/dependence, and Functional Oral Intake Scale (FOIS) change over 1 year were compared. RESULTS: One hundred sixty-seven patients were analyzed: 116 treated with TORS with or without adjuvant RT and 51 treated with RT (50 chemoRT). The RT group had more advanced tumor/nodal stage, higher comorbidity, and higher rates of concurrent chemotherapy. There were no differences in 3-year PFS (88% TORS vs. 75% RT) or OS (90% vs. 81%) between groups, which persisted after adjusting for stage, age, and comorbidity. GT use/dependence rates were higher in the RT group. Mean (SD) FOIS scores in the TORS group were 6.9 (0.4) at baseline and 6.4 (1.0) at 1 year, compared with 6.7 (0.6) and 5.6 (1.7) for the RT group. Only clinical nodal stage was found to be significantly associated with FOIS change from baseline to 1 year. CONCLUSION: There were no differences in PFS or OS between patients treated with primary TORS or RT for early-stage HPV-associated OPSCC. Clinical N2 status is associated with FOIS change at 1 year and may be the major factor affecting long-term swallowing function, irrespective of primary treatment modality.

Intensity-modulated radiotherapy with planned Gamma Knife radiosurgery boost for head and neck cancer with extensive disease in proximity to critical structures.

BACKGROUND: To describe intensity-modulated radiotherapy (IMRT) with Gamma Knife Radiosurgery (GKRS) boost for locally advanced head and neck cancer (HNC) with disease near dose-limiting structures. METHODS: Patients with HNC treated with IMRT/GKRS as part of a combined modality approach between 2011 and 2021 were reviewed. Local control, overall survival and disease-specific survival were estimated using the Kaplan Meier method. RESULTS: Twenty patients were included. Nineteen patients had T3-4 tumors. Median follow-up was 26.3 months. GKRS site control was 95%. Two patients progressed at the treated primary site, one patient failed at the edge of the GKRS treatment volume, with no perineural or intracranial failure. 2-year OS was 94.7% (95% CI: 85.2%-100%). Concurrent chemotherapy was given in nine patients (45%). One patient (5%) received induction/concurrent chemotherapy. Brain radionecrosis occurred in three patients, one of which was biopsy-proven. CONCLUSIONS: IMRT plus GKRS boost results in excellent disease control near critical structures with minimal toxicity.

Timing of radiotherapy and chemotherapy start for patients treated with definitive concurrent chemoradiation for head and neck cancer.

BACKGROUND: The ideal timing for the initiation of chemotherapy and radiation therapy (RT) in the use of definitive chemoradiation (CRT) for patients with head and neck cancer is not well established. We sought to evaluate the impact of the timing of initiating these two modalities on clinical outcomes. MATERIALS AND METHODS: Patients with squamous cell carcinoma of the head and neck who were treated using definitive chemoradiation from 2012 to 2018 were identified. Patients undergoing re-irradiation, post-op CRT, had recurrent or second primaries, or ECOG 3-4 were excluded. Outcomes including locoregional control (LRC), distant control (DC), progression-free survival (PFS), and overall survival (OS) were estimated and compared between subgroups of the cohort based on the timing in which chemotherapy or RT were initiated: chemotherapy first, same day start, within 24 h, or start on Monday/Tuesday/Wednesday. RESULTS: A total of 131 patients were included for analysis consisting of oropharynx (64%), larynx (22.9%), nasopharynx (6.9%), hypopharynx (3.1%), oral cavity (1.5%), and unknown primary (1.5%). Chemotherapy was administered as bolus cisplatin every 3 weeks in 40% of patients and weekly cisplatin in 60% with a median cumulative dose of 240 mg/m2. In the multivariable analysis (MVA), starting chemotherapy before RT was associated with improved LRC (HR 0.33, 95% CI: 0.11-0.99). Three-year LRC for patients starting chemotherapy first was 90.9% compared to 78.2% in those starting RT first. In the MVA, cisplatin regimen and cumulative cisplatin dose were associated with improved OS, while no factors were significantly associated with DC or PFS. CONCLUSION: Starting chemotherapy prior to radiation therapy improves LRC, but did not impact DC, PFS, or OS. Clinical outcomes were not different when stratifying by the other differences in the timing of initiating chemotherapy or RT.

Chemoradiotherapy with high-dose cisplatin compared with weekly cisplatin for locally advanced head and neck squamous cell carcinoma.

INTRODUCTION: Concurrent chemoradiotherapy (CRT) using high-dose cisplatin (HDC) is standard for patients with locally advanced head and neck squamous cell carcinoma (HNSCC); weekly cisplatin (WC) is an alternative. We aim to compare retrospectively the survival and disease control outcomes between these regimens in our institutional experience. METHODS: Patients with stage III-IV HNSCC treated with definitive or postoperative CRT between 2012 and 2018 were identified. Patients were stratified by intent-to-treat CRT. Overall survival (OS) and disease-free survival (DFS) were generated and multivariable Cox models were performed. RESULTS: 193 patients were treated with concurrent HDC (n = 69), WC at 40 mg/m2 (WC40, n = 88) or WC at <40 mg/m2 (WC<40, n = 36). Treatment intent was definitive in 74% and adjuvant in 26%. Baseline differences included age, performance status and HPV status. Cumulative cisplatin dose ≥200 mg/m2 was achieved in 89% (HDC), 86% (WC40) and 25% (WC<40, P < 0.0001). For HDC, WC40 and WC<40, 2-year OS rates were 87%, 77%, 60% and 2-year DFS rates were 75%, 68% and 52%, respectively. Multivariable analysis revealed gender, performance status, primary site, T/N stage and chemotherapy as predictive of OS. Primary site, T/N stage and chemotherapy regimen were associated with DFS. Compared with HDC, no differences in locoregional control (LRC) or distant metastasis were observed between groups. CONCLUSION: Concurrent HDC is associated with increased total cisplatin intensity, OS and DFS compared with weekly cisplatin regimens. LRC was not associated with chemotherapy regimen. HDC remains the standard of care; WC40 is a reasonable alternative that does not appear to sacrifice LRC.

Perineural Invasion As the Sole Pathologic Risk Factor After Surgical Resection for Head and Neck Squamous Cell Carcinoma.

Introduction Postoperative radiotherapy (PORT) is routinely recommended for patients with head and neck squamous cell carcinoma (HNSCC) based on pathologic risk factors (pRFs) such as perineural invasion (PNI). Patients with PNI as the sole pRF after resection of HNSCC are uncommon and their prognosis is less clear. The aim of this study is to assess the role of PNI as a sole risk factor in patients with otherwise pathologically low-risk HNSCC. Methods Patients with HNSCC of the oral cavity, pharynx, or larynx treated with primary surgical resection from 2013 to 2018 were identified from an institutional cancer registry. Those with pRFs (pathologic T3-4 disease, lymphovascular space invasion [LVSI], multiple positive lymph nodes, close [within 2 mm] or positive margins, extranodal extension [ENE], or recurrent disease) were excluded, yielding an otherwise pathologically low-risk cohort with or without incidental, pathologic PNI. Locoregional control (LRC), overall survival (OS) and disease-specific survival (DSS) were estimated and compared between PNI groups and by adjuvant therapy. Results A total of 1,058 patients were identified as having undergone surgical resection. Exclusion of patients with other pRFs, those with unknown PNI, and oral cavity patients with depth of invasion > 10 mm yielded a study cohort of 85 patients. Eight patients (10% of study group, <1% of all patients) had PNI as the sole pRF, none of which had clinical signs or symptoms of perineural tumor spread. The remaining 77 were negative for PNI and thus pathologically low risk. Patients with PNI were more likely to have oral cavity cancer, to be younger, and to have received PORT than those without PNI; no patient received concurrent chemotherapy. At a median follow-up of 46.4 months, two- and five-year LRC rates were 81.4% and 78.5%, respectively. No differences were noted between PNI-positive and PNI-negative groups (p=0.73) or PORT v. no-PORT groups (p=0.39). While the utility of PORT is not possible to assess given limited sample size, four patients with PNI who did not receive PORT did not experience locoregional failure. Seventeen patients overall experienced locoregional failure and 14 were ultimately salvaged. Five-year OS and DSS were 77.4% and 90.8%, respectively. Conclusion Patients with pathologically low-risk HNSCC after surgical resection experience high rates of LRC. In this large institutional cohort, PNI as the sole pRF was exceedingly rare, and the benefit of adjuvant therapies is difficult to assess. Within this limitation, PORT remains the standard of care for patients with PNI to reduce the risk of locoregional failure. Further collaborative studies are required to adequately assess the prognostic impact of PNI alone in resected HNSCC.

Comparing Outcomes for Patients with Human Papillomavirus (HPV) Type 16 versus Other High-Risk HPV Types in Oropharyngeal Squamous Cell Carcinoma.

Human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC) is related to improved treatment outcomes. What remains unclear is whether all HPV DNA genotypes carry similar prognostic relevance. We aimed to evaluate disease control and survival outcomes by HPV DNA genotype. Patients with primary OPSCC without distant metastases treated with curative intent were retrospectively identified from an IRB-approved institutional database. Patients that underwent HPV DNA polymerase chain reaction (PCR) testing with available genotype were included and dichotomized by the presence of HPV type 16 (HPV-16) or other high-risk HPV genotype (HPV-non16). Overall survival (OS), disease-free survival (DFS), locoregional control (LRC) and distant control (DC) were determined using the Kaplan-Meier method and compared using the log-rank test. In our cohort of 193 patients treated from 2012 to 2018 with HPV DNA PCR, 10% were detected as HPV-non16 high-risk types. Patients with HPV-16 were significantly younger than those with HPV-non16, but no other baseline factors were associated with HPV-non16. With a median follow-up of 42.9 months, there were no significant differences in outcomes between the HPV-16 and HPV-non16 groups for 3-year OS (87.7% v. 73.6%), DFS (82.9% v. 68.7%), LRC (92.8% v. 88.5%) or DC (91% v. 89.2%). There is no statistically significant difference in outcomes between OPSCC with HPV-16 and HPV-non16 high-risk genotypes in our cohort, though trends of overall worse survival and disease-free survival in HPV-non 16 OPSCC were seen. Further studies with larger cohorts of patients with HPV-non 16-associated OPSCC are required to make definitive conclusions regarding the prognostic and clinical significance of HPV type.

Human papillomavirus-associated squamous cell carcinoma of the larynx or hypopharynx: Clinical outcomes and implications for laryngeal preservation.

OBJECTIVES: Human papillomavirus (HPV) can be detected in approximately 25% of squamous cell carcinomas (SCC) of the larynx and hypopharynx. Though HPV is associated with improved survival and disease control in patients with oropharyngeal SCC, the role of HPV as a marker of favorable treatment outcomes in laryngeal and hypopharyngeal cancer is unclear. MATERIALS AND METHODS: Patients treated for laryngeal or hypopharyngeal SCC were reviewed. HPV status detected by p16 and/or HPV DNA PCR were abstracted from the medical record. A subset of samples (stage III-IV treated with primary radiotherapy) was retrospectively tested for p16 and HPV DNA. Overall survival (OS), disease-free survival (DFS), and locoregional control (LRC) were determined and compared between HPV-positive (p16+, PCR+ or both) and HPV-negative (p16- or PCR-) patients. RESULTS: In total, 279 patients were identified, 94 of which were tested for HPV. Eighty-two (87%) were negative and 12 (13%) were positive for HPV. At 3 years, there were no significant differences in OS (72% v. 83%), DFS (60% v. 71%) and LRC (80% v. 89%). Performance status, smoking history and stage predicted for OS, while performance status and stage predicted for DFS. Analysis of patients treated with primary radiotherapy revealed non-significantly higher rates of laryngeal preservation at 3 years (75% v. 100%). CONCLUSION: HPV was detected in 13% of tested laryngeal/hypopharyngeal cancers. HPV does not appear to significantly impact survival or disease control in patients with SCC of the larynx or hypopharynx. Non-significant improvements in laryngeal preservation were observed in HPV-positive patients.

Omitting Elective Irradiation of the Contralateral Retropharyngeal Nodes in Oropharyngeal Squamous Cell Carcinoma Treated with Intensity-modulated Radiotherapy.

INTRODUCTION: The use of intensity-modulated radiation therapy (IMRT) in head and neck cancers has allowed for selective sparing of low-risk or uninvolved lymph nodes. In oropharyngeal cancers, the benefits and risks of omitting contralateral retropharyngeal lymph nodes (RPLN) remain uncertain. This study examines the outcomes of elective coverage of contralateral RPLN in oropharyngeal cancer treated with definitive IMRT. METHODS: We analyzed 54 patients with newly diagnosed unilateral tonsil or base of tongue squamous cell carcinoma with at most unilateral neck involvement (cN0-N2b) and no RPLN involvement. These patients had no prior head and neck irradiation and were treated with definitive radiotherapy or chemoradiotherapy between 2012 and 2017. Cumulative incidences of local/regional/distant failure were estimated using competing risks methodology, and overall survival (OS) was estimated using the Kaplan-Meier method. RESULTS: All patients received elective nodal coverage to the ipsilateral RPLN, and 38 (62%) patients did not receive elective treatment of the contralateral RPLN. There were no significant differences in baseline characteristics. There were no contralateral RPLN failures observed. When comparing patients who received contralateral RP treatment with those who did not, there were no significant differences in two-year local failure (23% vs. 9%, p = 0.09), regional failure (18% vs. 4%, p = 0.12), or distant failure (15% vs. 9%, p = 0.62). Two-year OS was 89%. Mean parotid dose was not significantly lower after sparing vs. treating the contralateral RPLN (median 25.6 vs. 32.7 Gy, p = 0.15). CONCLUSIONS: The omission of contralateral RPLN irradiation in tonsil or tongue base carcinomas with unilateral neck involvement is safe without compromising disease control.

Effect of ArginMax on sexual functioning and quality of life among female cancer survivors: results of the WFU CCOP Research Base Protocol 97106.

BACKGROUND: Problems with sexual functioning are common following therapy for breast and gynecologic cancers, although there are few effective treatments. OBJECTIVE: To assess the impact of ArginMax, a nutritional supplement comprised of extracts of L-arginine, ginseng, gingko, and damiana, as well as multivitamins and minerals, on sexual functioning and quality of life in female cancer survivors. METHODS: This was a 12-week, randomized, placebo-controlled trial of eligible patients who were 6 months or more from active treatment and reporting problems with sexual interest, satisfaction, and functioning after therapy. The participants took 3 capsules of Arginmax or placebo twice daily. Outcome measures were the Female Sexual Function Inventory (FSFI) and the Functional Assessment of Cancer Therapy - General (FACT-G). Assessments were done at baseline, 4, 8, and 12 weeks. RESULTS: 186 patients with a median age of 50 years were accrued between May 10, 2007 and March 24, 2010. 76% of the patients were non-Hispanic white. Most had breast or a gynecologic cancer (78% and 12%, respectively). At 12 weeks, there were no differences between the ArginMax group (n = 96) and placebo (n = 92) group in sexual desire, arousal, lubrication, orgasm,satisfaction or pain. However, FACT-G total scores were significantly better for participants who took ArginMax compared with those who took placebo (least squares [LS] means, 87.5 vs 82.9, respectively; P = .009). The Fact-G subscales that were most affected were Physical (25.37 vs. 23.51, P = .001) and Functional Well-Being (22.46 vs. 20.72, P = .007). Toxicities were similar for both groups. LIMITATIONS: Study results are limited by a lack of data on the participants' psychological and physical symptoms and sexual partner variables. CONCLUSIONS: ArginMax had no significant impact on sexual functioning, but patient quality of life was significantly better at 12 weeks in participants who received ArginMax.

The KRAS-variant and miRNA expression in RTOG endometrial cancer clinical trials 9708 and 9905.

OBJECTIVE: To explore the association of a functional germline variant in the 3'-UTR of KRAS with endometrial cancer risk, as well as the association of microRNA (miRNA) signatures and the KRAS-variant with clinical characteristics and survival outcomes in two prospective RTOG endometrial cancer trials. METHODS/MATERIALS: The association of the KRAS-variant with endometrial cancer risk was evaluated by case-control analysis of 467 women with type 1 or 2 endometrial cancer and 582 age-matched controls. miRNA and DNA were isolated for expression profiling and genotyping from tumor specimens of 46 women with type 1 endometrial cancer enrolled in RTOG trials 9708 and 9905. miRNA expression levels and KRAS-variant genotype were correlated with patient and tumor characteristics, and survival outcomes were evaluated by variant allele type. RESULTS: The KRAS-variant was not significantly associated with overall endometrial cancer risk (14% controls and 17% type 1 cancers), although was enriched in type 2 endometrial cancers (24%, p = 0.2). In the combined analysis of RTOG 9708/9905, miRNA expression differed by age, presence of lymphovascular invasion and KRAS-variant status. Overall survival rates at 3 years for patients with the variant and wild-type alleles were 100% and 77% (HR 0.3, p = 0.24), respectively, favoring the variant. CONCLUSIONS: The KRAS-variant may be a genetic marker of risk for type 2 endometrial cancers. In addition, tumor miRNA expression appears to be associated with patient age, lymphovascular invasion and the KRAS-variant, supporting the hypothesis that altered tumor biology can be measured by miRNA expression, and that the KRAS-variant likely impacts endometrial tumor biology.

Alternative dose for choroidal melanoma treated with an iodine-125 radioactive plaque: a single-institution retrospective study.

PURPOSE: The Collaborative Ocular Melanoma Study (COMS) established iodine-125 plaque brachytherapy as an accepted standard treatment for medium-size choroidal melanoma. In the COMS, the prescription dose was 85 Gy. This is a retrospective review of our outcomes in patients treated with lower doses than those used in the COMS. METHODS AND MATERIALS: From 1990 to 2004, 62 patients were treated with iodine-125 plaque brachytherapy for choroidal melanoma. COMS eye plaques were used with dose prescribed to the apex of the tumor. The median and average dose rates at the tumor apex were 63.5 cGy/h and 62.7 cGy/h, respectively. The median and average total doses were 63.0 Gy and 62.5 Gy (range, 56-69 Gy), respectively. The median and mean durations of implant were 100.0 hours and 101.1 hours (range, 71-165 hours). RESULTS: Median follow-up time was 58.2 months. The 5-year outcomes including overall survival, disease-free survival, cause-specific survival, local failure, secondary enucleation rate, and visual acuity (VA) <20/200 were estimated using the Kaplan-Meier method. Overall, there were 7 local failures, 4 distant failures, and 10 secondary enucleations (6 due to local failure and 4 due to treatment complications). Univariate analysis was performed to identify significant prognostic factors associated with disease-free survival (baseline VA in tumor eye, tumor shape), cause-specific survival (diabetic retinopathy), local failure (none found), secondary enucleation rate (diabetic retinopathy, basal tumor dimension) and VA <20/200 (diabetic retinopathy, tumor shape, age, retinal detachment, treatment depth, and history of vision-limiting condition). CONCLUSIONS: Our survival and local control outcomes are comparable to those of the COMS. However, VA at 5 years seems to be better. Lower doses of radiation could potentially lead to better visual outcomes.

Swallowing dysfunction is a common sequelae after chemoradiation for oropharynx carcinoma.

INTRODUCTION: A retrospective review of all patients with advanced oropharynx cancer from a single institution was performed. METHODS: Sixty-seven patients with stage III/IV oropharynx cancer were treated with definitive radiotherapy with or without concurrent chemotherapy from 1990 to 2004. Follow-up ranged from 6 to 91 months with a median of 32 months. RESULTS: Patients treated with concurrent chemotherapy had a statistically significant benefit for control above the clavicles, primary control, disease-free survival, and overall survival but no difference in distant control at 3 years. Cox proportional regression model demonstrated the use of concurrent chemotherapy to be the only independent variable that reached significance for control above the clavicles, primary control, and overall survival. Complete dysphagia for solids and/or gastrostomy tube dependence was observed in more patients who were treated with chemoradiation than those treated with radiation alone; 18% and 0%, respectively (P = 0.04). CONCLUSIONS: Concurrent chemotherapy decreases the recurrence at the primary site and above the clavicles. The most notable difference in sequelae between the 2 groups was the increase in swallowing dysfunction with concurrent chemotherapy.

Radiographic complete response on post treatment CT imaging eliminates the need for adjuvant neck dissection after treatment for node positive head and neck cancer.

OBJECTIVE: The primary purpose of this study was to correlate radiographic response in the neck to clinical outcomes for patients with node positive head and neck cancer. METHODS: One hundred three patients with stage III/IV node positive cancer were treated with definitive radiotherapy or chemoradiation at a single institution from 1990 to 2004. Follow-up ranged from 8 months to 144 months with a median of 42 months. Posttreatment CT scans were called complete radiographic response (rCR) or partial radiographic response. RESULTS: Actuarial 36 month rates of survival, control above the clavicles, and nodal control were 66%, 74%, and 90%, respectively. Patients, who had rCR on posttreatment CT scan, who had a neck dissection had a nodal control rate of 94% compared with those without neck dissection of 97%. Patients with partial radiographic response who were treated with neck dissection had a nodal control rate of 94% compared with those without neck dissection of 73%. CONCLUSIONS: Based on this data, there was no suggestion that neck dissection improved outcome for patients with rCR on posttreatment imaging 4 to 6 weeks after radiation.

Can post-RT neck dissection be omitted for patients with head-and-neck cancer who have a negative PET scan after definitive radiation therapy?

PURPOSE: A prospective, single institution study was conducted to evaluate the role of positron emission tomography with fluoro-deoxyglucose (FDG) before and after definitive radiation therapy for patients with head-and-neck cancer. Correlation with CT or MRI imaging and pathologic findings at the time of planned neck dissection was made. METHODS AND MATERIALS: Twelve patients with AJCC Stages III-IV cancer of the head and neck received CT or MRI and PET imaging before treatment with definitive radiation therapy. One month after completion of treatment, repeat CT or MRI and PET imaging was obtained. All images were reviewed independently by radiologists who were blind to the results of the other modality. Patients then underwent planned neck dissection. Pathologic correlation with posttreatment scans allowed calculation of the sensitivity, specificity, negative predictive value, and the positive predictive value for both CT/MRI and PET. RESULTS: Comparison of CT/MRI to PET obtained before definitive RT revealed both primary tumor and nodal disease were detected by both modalities in all cases where primary tumor was known. After RT, comparison of CT/MRI imaging to findings of neck dissection revealed a sensitivity of 90%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 50%. Comparison of PET imaging with pathologic findings demonstrated sensitivity of 45%, specificity of 100%, positive predictive value of 100%, and a negative predictive value of 14%. CONCLUSIONS: In this small series of patients, the presence of a positive PET 1 month after RT accurately indicated the presence of residual disease in all cases; however, a negative PET indicated absence of disease in only 14%. Further investigation is warranted before FDG-PET should be used to determine whether post-RT neck dissection should be omitted.