Elimination of RT to pN0 neck

[evilbooyaa]

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ASTRO 2018 Plenary Oral. Thoughts on this? If somebody has a pT2N0 tongue cancer and gets bilateral neck dissections are you OK to only radiate the primary? I'm not sure that I'm allowed to post the slides, but the abstract is below. If there's a pT2N1 tongue cancer s/p B/L neck dissection, OK to radiate just the primary and involved neck?


Eliminating Post-operative Radiation to the Pathologically Node Negative Neck: Long-Term Results of a Prospective Phase II Study

Purpose/Objective(s): The volume treated with post-operative radiation therapy (PORT) is a mediator of toxicity and reduced volumes have resulted in improved in quality of life (QOL). In this prospective study we decreased treatment volumes by omitting PORT to the pathologically negative (PN0) contralateral (CL) and/or ipsilateral (IL) neck in patients with tumors of the oral cavity (OC), oropharynx (OPX), larynx (LX), hypopharynx (HPX), and unknown primary (UP). We hypothesized that elimination of PN0 neck PORT would result in > 90% control in the unirradiated neck (UN).

Materials/Methods: Patients with tumors of the OC, OPX, LX, HPX, and UP who underwent surgical resection and neck dissection (ND) with a PN0 neck and high risk features mandating PORT to the primary and/or involved neck were eligible. Our primary objective was to evaluate the rate of control in the UN. Secondary objectives included QOL, local control (LC), regional control (RC), progression free survival (PFS), and overall survival (OS). The CTV1 and CTV2 were treated to 66 Gy and 54 Gy in 33 fractions (fx) or 60 Gy and 52 Gy in 30 fx. Chemotherapy was delivered at the discretion of the treating oncologist. QOL was collected using the MD Anderson Dysphagia Inventory and the University of Michigan Patient reported Xerostomia questionnaire. The study required accrual of 69 patients to achieve 83% power with alpha = 0.10 to show equivalence of reduced volume PORT compared to bilateral neck PORT. LC, RC, PFS, and OS were analyzed via Kaplan-Meier method and mixed modeling was used with Tukey adjustment for multiple comparisons on QOL data.

Results: From 5/2007-9/2013, 73 patients enrolled and 72 were evaluable. Median age was 56 years (range 31-81), 58 (81%) were male, and 47 (65%) used tobacco. Sites included 14 (20%) OC, 37 (51%) OPX, 4 (6%) HPX, 16 (22%) LX, and 1 (1%) UP tumor, with AJCC 7th edition stage III/IV disease in 67 (93%) patients. 51% had T3/4 disease, 59% had N2/3, and 71% of tumors involved or crossed midline. We excluded T1/2 N0-2b lateralized tonsil patients because our policy was to use IL PORT without a required CL ND. 34 patients (47%) received chemotherapy and all completed PORT. Zero patients had CL neck PORT. All but 6 patients had a CL ND; 0/6 had isolated neck failure. At median follow up of 53 mo, there were 2 failures in the PN0 UN; both also had local failures. There were no isolated UN failures. UN control was 97% (95% CI 93.4-100.0%). 5 year actuarial rates of LC, RC, PFS, and OS were 84%, 93%, 60%, and 64% respectively. QOL scores for emotional (Em), physical (Ph), functional (Fxn), and xerostomia (Xe) declined from baseline to time of PORT completion (p<0.05). By 24 mo, these scores recovered with no difference from baseline (P>0.05), except Xe, for which QOL remained reduced post PORT (P<0.05). However, global QOL was improved from baseline 24 mo post PORT (P=0.04).

Conclusion: Eliminating PORT to the PN0 neck resulted in excellent rates of control in the UN without adverse effects on global QOL. This trial met the primary endpoint with 97% control in the UN.

 

[nkmiami]

Historically, I have frequently not treated the pN0 neck. In treating primary you are often treating level 1b and II bilaterally. Didnt even realize that was controversial.

BTW: Just wanted to comment on oral tongue cancers and nodes. ASTRO/RTOG rec treatment bilateral necks even for well lateralized t1/t2 lesions. At ASTRO this year I asked Brizel this question and he said he doesnt treat bilaterally in this situation and seems like UF might not as well.

Challenging the Requirement to Treat the Contralateral Neck in Cases With >4 mm Tumor Thickness in Patients Receiving Postoperative Radiation Therapy for Squamous Cell Carcinoma of the Oral Tongue or Floor of Mouth.

O'steen L, Amdur RJ, Morris CG, Hitchcock KE, Mendenhall WM.

Am J Clin Oncol. 2018 Sep 18. doi: 10.1097/COC.0000000000000480. [Epub ahead of print]
PMID:
30234502

 

[Gfunk6]

Nicely done study. Now that trans-oral robotic surgery (TORS) is becoming more widespread, especially in academic centers, I am seeing more patients with extremely comprehensive node dissections which are node negative. It never made logical sense to treat the necks in this scenario as we would simply rely on "onco lore." However, we probably need a Phase III trial to establish this as standard of care I would think.

 

[RO2019]

Study is interesting, BUT SO MUCH more is needed for this to actually change my practice.

- there weren't actually that many oral cavity patients in the study, this is where I am most interested in potentially avoiding neck RT
- no information on how many nodes needed to be taken out for them to consider for trial
- the majority were oropharynx, and probably mostly HPV+ In a study with mostly HPV+ oropharynx, of course you're going to get away with avoiding RT.

Would love to see a prospective trial (someone should do this) in just oral cavity patients.can't change practice based on 14 patients.

 

[Palex80]

When was the last time that the radiation oncology trial ran a randomized trial in H&N cancer looking at treatment volumes? Never.
We have run dozens of trials looking into chemo, but none on volumes.

We have started lowering dose to 40 Gy for the contralateral not–high–risk neck in patients based on the Durch data that came out last year in the Green Journal.

 

[nkmiami]

Study is interesting, BUT SO MUCH more is needed for this to actually change my practice.

- there weren't actually that many oral cavity patients in the study, this is where I am most interested in potentially avoiding neck RT
- no information on how many nodes needed to be taken out for them to consider for trial
- the majority were oropharynx, and probably mostly HPV+ In a study with mostly HPV+ oropharynx, of course you're going to get away with avoiding RT.

Would love to see a prospective trial (someone should do this) in just oral cavity patients.can't change practice based on 14 patients.

On what high level evidence do you base your pre existing practice of radiating contralateral pN0 necks for small lateralized lesions?
1) HPV+ cancers are more likely to go to LN/significantly higher rate of involvement.
2) presentation at ASTRO head and neck session (Howard Liu) on leaving out both radiation and surgery to clinically negative contralateral neck in large number of small tongue/ oral cavity cancers with very low failure rates 4%.

There is a definite trend to reducing volumes in head and neck cancer since failures are mostly in high dose PTV. Over past 7 years, I have dropped coverage in (clinically node negative) in many, but not all, cases xrt to contraleral retropharyngeal,retrostyloid, submandib, supraclav, level 5.

 

[medgator]

On what high level evidence do you base your pre existing practice of radiating contralateral pN0 necks for small lateralized lesions?
1) HPV+ cancers are more likely to go to LN/significantly higher rate of involvement.
2) presentation at ASTRO head and neck session (Howard Liu) on leaving out both radiation and surgery to clinically negative contralateral neck in large number of small tongue/ oral cavity cancers with very low failure rates 4%.

There is a definite trend to reducing volumes in head and neck cancer since failures are mostly in high dose PTV. Over past 7 years, I have dropped coverage in (clinically node negative) in many, but not all, cases xrt to contraleral retropharyngeal,retrostyloid, submandib, supraclav, level 5.

I've had a few nasty oral cavity scc lesions in younger, light smokers that have ended being pN2+ despite a negative pet prior to surgery. One of them metted out to the lungs after chemo rt.

I'm still get nervous with oral cavity... I'll buy the data on avoiding contralateral rt in early node negative oropharynx. Still not ready in oral cavity

 

[RO2019]

Exactly we have long standing clear data about avoiding contralateral neck in oropharynx and we understand selection criteria.

Oral cavity is the question and there were only 14 patients on this study!