Is planned neck dissection necessary for head and neck cancer after intensity-modulated radiotherapy?

Advances and residual knowledge gaps in the neck management of head and neck squamous cell carcinoma patients with advanced nodal disease undergoing definitive (chemo)radiotherapy for their primary

PURPOSE

Substantial changes have been made in the neck management of patients with head and neck squamous cell carcinomas (HNSCC) in the past century. These have been fostered by changes in cancer epidemiology and technological progress in imaging, surgery, or radiotherapy, as well as disruptive concepts in oncology. We aimed to review changes in nodal management, with a focus on HNSCC patients with nodal involvement (cN+) undergoing (chemo)radiotherapy.

METHODS

A narrative review was conducted to review current advances and address knowledge gaps in the multidisciplinary management of the cN+ neck in the context of (chemo)radiotherapy.

RESULTS

Metastatic neck nodes are associated with poorer prognosis and poorer response to radiotherapy, and have therefore been systematically treated by surgery. Radical neck dissection (ND) has gradually evolved toward more personalized and less morbid approaches, i.e., from functional to selective ND. Omission of ND has been made feasible by use of positron-emission tomography/computed tomography to monitor the radiation response in cN+ patients. Human papillomavirus-driven oropharyngeal cancers and their cystic nodes have shown dramatically better prognosis than tobacco-related cancers, justifying a specific prognostic classification (AJCC) creation. Finally, considering the role of lymph nodes in anti-tumor immunity, de-escalation of ND and prophylactic nodal irradiation in combination are intense areas of investigation. However, the management of bulky cN3 disease remains an issue, as aggressive multidisciplinary strategies or innovative combined treatments have not yet significantly improved their prognosis.

CONCLUSION

Personalized neck management is an increasingly important aspect of the overall therapeutic strategies in cN+ HNSCC.

Five-year outcomes of an oropharynx-directed treatment approach for unknown primary of the head and neck

PURPOSE

Squamous cell carcinoma of unknown primary (SCCHNUP) is commonly treated with comprehensive radiation to the laryngopharynx and bilateral necks. In 1998, we established a departmental policy to treat SCCHNUP with radiation directed to the oropharynx and bilateral neck.

METHODS

From 1998-2011, 60 patients were treated - N1: 18%, N2: 75% and N3: 7%. 82% underwent neck dissection. 55% received IMRT and 62% underwent concurrent chemoradiotherapy.

RESULTS

At median follow-up of 54months, 5 patients failed regionally and 4 emerged with a primary (tongue base, hypopharynx and thoracic esophagus). Five-year rates of regional control, primary emergence, distant metastasis, disease-free survival and overall survival were 90%, 10%, 20%, 72% and 79%, respectively. The 5year rate of primary emergence in a non-oropharynx site was 3%.

CONCLUSION

This is the first demonstration that an oropharynx-directed approach yields low rates of primary emergence in SCCHNUP with excellent oncologic outcomes.

Radiation treatment of head and neck cancer

Radiation therapy plays a central and continuously evolving role in the treatment of head and neck cancer. In this review, some basic principles of radiation oncology are explained and common clinical scenarios are addressed in which radiation therapy forms part of the treatment course, with a focus on issues most pertinent to the interaction of radiation oncology with surgical treatment. These issues include refinement of the indications guiding the choice of adjuvant radiation therapy or chemoradiotherapy, sequencing and timing of therapies before or after definitive surgical management, and scientific and technical advances with the potential to reduce radiation-related toxicity.

The role of neck dissection in squamous cell carcinoma of the head and neck

ORIGINAL STATEMENT

Lymph node metastases in the neck are a major prognostic factor in patients with head and neck squamous cell carcinoma (HNSCC). Assessment and treatment of lymph nodes in the neck are of utmost importance. Inappropriate management of lymph node metastases can result in regional failure. Radical neck dissection has been and is still considered the "gold standard" for the surgical management of lymph node metastases of HNSCC. However, the philosophy of treatment of the neck has evolved during the last decades. Surgeons progressively realized that extensive neck dissections were associated with a higher morbidity but not always with a better oncologic outcome than more limited procedures. Today, a comprehensive therapeutic approach of the neck is multidisciplinary, taking into account the patient's quality of life without jeopardizing cure and survival. A better understanding of the patterns of lymph node metastasis promoted the use of selective neck dissection in selected patients. Sentinel lymph node biopsy is a reliable diagnostic procedure for staging the neck in node-negative early oral cavity squamous cell carcinoma. With increasing use of chemoradiation in locally advanced HNSCC, paradigms are evolving. Currently, there are strong arguments supporting the position that neck dissection is no longer justified in patients without clinically residual disease in the neck.

Change of maximum standardized uptake value slope in dynamic triphasic [18F]-fluorodeoxyglucose positron emission tomography/computed tomography distinguishes malignancy from postradiation inflammation in head-and-neck squamous cell carcinoma: a prospective trial

PURPOSE

To evaluate dynamic [(18)F]-fluorodeoxyglucose (FDG) uptake methodology as a post-radiation therapy (RT) response assessment tool, potentially enabling accurate tumor and therapy-related inflammation differentiation, improving the posttherapy value of FDG-positron emission tomography/computed tomography (FDG-PET/CT).

METHODS AND MATERIALS

We prospectively enrolled head-and-neck squamous cell carcinoma patients who completed RT, with scheduled 3-month post-RT FDG-PET/CT. Patients underwent our standard whole-body PET/CT scan at 90 minutes, with the addition of head-and-neck PET/CT scans at 60 and 120 minutes. Maximum standardized uptake values (SUV(max)) of regions of interest were measured at 60, 90, and 120 minutes. The SUV(max) slope between 60 and 120 minutes and change of SUV(max) slope before and after 90 minutes were calculated. Data were analyzed by primary site and nodal site disease status using the Cox regression model and Wilcoxon rank sum test. Outcomes were based on pathologic and clinical follow-up.

RESULTS

A total of 84 patients were enrolled, with 79 primary and 43 nodal evaluable sites. Twenty-eight sites were interpreted as positive or equivocal (18 primary, 8 nodal, 2 distant) on 3-month 90-minute FDG-PET/CT. Median follow-up was 13.3 months. All measured SUV endpoints predicted recurrence. Change of SUV(max) slope after 90 minutes more accurately identified nonrecurrence in positive or equivocal sites than our current standard of SUV(max) ≥2.5 (P=.02).

CONCLUSIONS

The positive predictive value of post-RT FDG-PET/CT may significantly improve using novel second derivative analysis of dynamic triphasic FDG-PET/CT SUV(max) slope, accurately distinguishing tumor from inflammation on positive and equivocal scans.

The role of neck dissection after radical chemoradiation for locally advanced head and neck cancer: should we move back?

Until a few decades ago neck dissection (ND) was the standard surgical approach for node-positive tumours. Nowadays patients with locally advanced head and neck cancer can be treated with definitive chemoradiation (CRT), which includes the treatment of the neck; however, results on residual viable tumour after conservative treatment are heterogeneous and depend on initial node stage and primary treatment. Many authors accept adjuvant surgery in patients with N2-3 disease. Regardless of the results of upfront CRT, even if there is no evidence of lymph node metastases, when the risk for persistent positive neck nodes exceeds 15-20%, elective ND might be indicated. However, despite the diffusion of innovative technologies and therapies, there are controversies about both response evaluation and surgical management of initially involved neck nodes after definitive CRT and organ preservation treatment. In this paper we will analyse state of art of neck evaluation after CRT and discuss the role of ND.

Opportunities and challenges facing biomarker development for personalized head and neck cancer treatment

Head and neck oncologists have traditionally relied on clinical tumor features and patient characteristics to guide care of individual patients. As surgical, radiotherapeutic, and systemic treatments have evolved to become more anatomically precise and mechanistically specific, the opportunity for improved cure and functional patient recovery has never been more promising for this historically debilitating cancer. However, personalized treatment must be accompanied by sophisticated patient selection to triage the application of advanced therapies toward ideal patient candidates. In this monograph, we review current progress, investigative themes, and key challenges facing head and neck cancer biomarker development intended to make personalized head and neck cancer treatment a clinical reality.

Treatment outcome in the residually positive neck after definitive chemotherapy and irradiation

OBJECTIVE

Determine prevalence of viable malignancy in patients undergoing neck dissection (ND) for residual neck disease following concomitant chemotherapy and irradiation (chemo/xrt) for upper aerodigestive squamous carcinoma. To determine survival in groups with a neck complete response to those who had residual disease requiring neck dissection.

STUDY DESIGN

Retrospective chart review.

METHODS

Retrospective chart review of 230 patients who underwent definitive chemo/xrt for primary squamous cell carcinoma cancer (SCCa) of the head and neck from 2005 to 2009 in one institution.

RESULTS

Thirty-nine (17%) patients underwent ND for residual neck mass within 4 months posttreatment. Forty-nine percent (19/39) were pathologically positive for malignancy and 51% (20/39) were negative. The probability of a +ND based on original N-stage was not statistically significant (P = .368). Primary site did not yield significant probability of having +ND, except in the oral cavity (P = .02). Patients had similar overall 5-year survival, among those with a delayed complete response in the neck (66%), ND for residual disease (71%), or those with initial complete response (71%). Lower initial N-stage demonstrated improved survival in all outcome groups. Tonsil SCCa patients who underwent ND had improved survival compared to those with delayed complete response (87.5 vs. 75.8%), both of which had increased survival compared to initial complete responders (65%).

CONCLUSIONS

This study supports the use of ND in the postchemo/xrt positive neck regardless of primary site or initial N-stage. ND in this setting conveys survival equal to patients with complete response in the neck after chemo/xrt. These survivorship implications of postchemo/xrt neck dissection extend to all sites, including tonsils.

Selective neck dissection in the management of the neck after (chemo)radiotherapy for advanced head and neck cancer. Proposal for a classification update

For patients with advanced regional disease, neck dissection following (chemo)radiotherapy remains controversial. Selective neck dissection (SND) was reported as suitable after chemoradiation in patients with advanced regional disease. Reduced morbidity represents the major advantage of SND. In a situation in which there is a major fibrosis around the previously invaded nodes, resection of 1 or more nonlymphatic structures may be required. The current classification of SND could be implemented by the addition of extended selective neck dissection (ESND). The standard basic procedures for SND spare the sternocleidomastoid muscle (SCM), the internal jugular vein (IJV), and the spinal accessory nerve (SAN). When an SND is associated with the resection of 1 or more nonlymphatic structures, it should be termed ESND. All additional nonlymphatic structure(s) removed should be identified in parentheses. The proposal to subclassify SND not only in accord with the resected lymph node levels but also upon the nonlymphatic structures removed may be of some help to avoid potential misinterpretation.

Outcome with neck dissection after chemoradiation for N3 head-and-neck squamous cell carcinoma

PURPOSE

To evaluate the role of neck dissection (ND) after chemoradiation therapy (CRT) for head and neck squamous cell carcinoma (HNSCC) with N3 disease.

METHODS AND MATERIALS

From March 1998 to September 2006, 70 patients with HNSCC and N3 neck disease were treated with concomitant CRT as primary therapy. Response to treatment was assessed using clinical examination and computed tomography 6 to 8 weeks posttreatment. Neck dissection was not routinely performed and considered for those with less than complete response. Of the patients, 26 (37.1%) achieved clinical complete response (cCR) after CRT. A total of 31 (44.3%) underwent ND after partial response (cPR-ND). Thirteen patients (29.5%) did not achieve cCR and did not undergo ND for the following reasons: incomplete response/progression at primary site, refusal/contraindication to surgery, metastatic progression, or death. These patients were excluded from the analysis. Outcomes were computed using Kaplan-Meier curves and were compared with log rank tests.

RESULTS

Comparing the cCR and cPR-ND groups at 2 years, the disease-free survival was respectively 62.7% and 84.9% (p = 0.048); overall survival was 63.0% and 79.4% (p = 0.26), regional relapse-free survival was 87.8% and 96.0% (p = 0.21); and distant disease-free survival was 67.1% and 92.6% (p = 0.059). In the cPR-ND group, 71.0% had no pathologic evidence of disease (PPV of 29.0%).

CONCLUSIONS

Patients with N3 disease achieving regional cPR and primary cCR who underwent ND seemed to have better outcomes than patients achieving global cCR without ND. Clinical assessment with computed tomography is not adequate for evaluating response to treatment. Because of the inherent limitations of our study, further confirmatory studies are warranted.

[Neck dissection following chemoradiation for node positive head and neck carcinomas]

The optimal timing and extent of neck dissection in the context of chemoradiation for head and neck cancer remains controversial. For some institutions, it is uncertain whether neck dissection should still be performed upfront especially for cystic nodes. For others, neck dissection can be performed after chemoradiation and can be omitted for N1 disease as long as a complete response to chemoradiation is obtained. The question is debated for N2 and N3 disease even after a complete response as the correlation between radiological and clinical assessment and pathology may not be reliable. Response rates are greater than or equal to 60% and isolated neck failures are less than or equal to 10% with current chemoradiation protocols. Some therefore consider that systematic upfront or planned neck dissection would lead to greater than or equal to 50% unnecessary neck dissections for N2-N3 disease. Positron-emission tomography (PET) scanning to assess treatment response and have shown a very high negative predictive value of greater than or equal to 95% when using a standard uptake value of 3 for patients with a negative PET at four months after the completion of therapy. These data may support the practice of observing PET-negative necks. More evidence-based data are awaited to assess the need for neck dissection on PET. Selective neck dissection based on radiological assessment and peroperative findings and not exclusively on initial nodal stage may help to limit morbidity and to improve the quality of life without increasing the risk of neck failure. Adjuvant regional radiation boosts might be discussed on an individual basis for aggressive residual nodal disease with extracapsular spread and uncertain margins but evidence is missing. Medical treatments aiming at reducing the metastatic risk especially for N3 disease are to be evaluated.

Biologically conformal treatment: biomarkers and functional imaging in radiation oncology

'Conformal radiation therapy' is the standard of care in radiation oncology, referring to the process of shaping the radiation beam to precisely match a tumor's physical dimensions. We describe 'biologically conformal radiotherapy', in which the radiation oncologist matches the prescribed treatment to a tumor's biological characteristics and the host's predicted tolerance of radiation. This paradigm emphasizes that not all tumors are equally sensitive to radiation; conversely, some patients are especially susceptible to radiation's side effects. Patients bearing radioresistant tumors or those prone to toxicity may be best treated with the incorporation of targeted radiation modulators or, in extreme cases, by a different modality. The biological characteristics of tumors can be assessed by a wide range of techniques: functional imaging (positron emission tomography and advanced magnetic resonance imaging), single gene/protein molecular techniques and 'omic' technologies. This paper reviews the latest advances in the use of biomarkers and functional imaging in guiding patients to receive the most appropriate treatment.