Questions and Answers
Questions were posed by attendees throughout the meeting using the interactive online question and answer platform. Some questions were addressed during the session, and some of our faculty were able to take extra time to respond in writing after their sessions had concluded. We hope that the information helps extend and enhance the learning experience for attendees. Audio for the Social Q and A during each session is available via the Virtual Meeting.
General Session II: Tonsil and Base of Tongue
Dose/Volume De-escalation Protocols
Jimmy Caudell, MD, PhD, Moffitt Cancer Center, Tampa, Florida
- Q: PET can over-stage disease; I don’t think the right node is positive. (Editor’s Note: please see the Virtual Meeting for better context if you didn’t already view this presentation.)
- A: PPV for PET ~56 percent. Must correlate with other imaging (CT/MRI) and physical exam.
- Q: Can the panel address more specifically in the current day are we to treat under principles of the staging? This was 8th Edition Stage 1. Or do we still treat under the older staging system multimodal therapy? This is an issue in our institution.
- A: Current data is all for prior staging paradigms. Should follow until better data available for new staging paradigm.
- Q: In post-tx surgically with a lateral tongue base tumor bilateral necks and pathology demonstrating only ipsilateral nodes with no ecs, can radiation dose to contralateral neck be reduced or omitted?
- A: Base of tongue would still treat contralateral N0 neck. I use a dose of ~40 Gy in 2 Gy fractions currently for elective neck.
- Q: For p16 cisplatin ineligible p16 disease: if concurrent cetuximab is used, is altered fractionation RT necessary?
- A: Altered fractionation is an option, as most patients in Bonner trial had altered fractionation.
- Q: Are there data on SBRT or SRS instead of TORS?
- A: I assume this question is in regard to salvage. If so, please see the three articles in the March 2018 issue of Red Journal.
- Q: What does a margin positive resection really accomplish?
- A: Not much.
- Q: The CTV expansion consensus is based on scant surgical data. Is there any published clinical trial data to justify it?
- A: I would refer the questioner/commenter to the guidelines paper which reviews the surgical data underlying the recommendations quite nicely (Gregoire et al, R&O, 2017).
- Q: HN002 was a randomized phase 2 trial with arguably no standard arm. Will these results be useful to alter the standard of care?
- A: I believe so.
General Session III: Nasopharynx
Biological Selection for Treatment of Nasopharyngeal Cancer
Nancy Y. Lee, MD, FASTRO, Memorial Sloan Kettering Cancer Center, New York
- Q: Wasn’t the trial using EBV at the end of concurrent chemoRT to see who should get adjuvant chemo negative presented at ASCO 2017?
- A: In the trial that was negative, EBV DNA was done at week 6-8 post-treatment.
- Q: When is the best time to detect EBV after radiotherapy to guide adjuvant chemotherapy?
- A: The best time point is within one week after chemoradiation.
Particle Beam Therapy for NPC Re-irradiation
Jiade Lu, MD, MBA, Shanghai Proton and Heavy Ion Center, Shanghai, China
- Q: How do you define local recurrence after reirradiation biopsies are difficult for rT4 tumors?
- A: We define response and progression by the RECIST criteria and usually biopsy is not used except for superficial lesions such as nasopharyngeal cancer.
- Q: It appears that protons aren’t or are rarely used for definitive NPC radiation with IMRT preferred. What is the rationale?
- A: Proton, especially IMPT, is also a preferred modality for NPC, but proton facilities are not available in the endemic regions.
- Q: Wouldn’t it make sense and be 445M less expensive to use gamma knife or cyber knife rather than carbon ions?
- A: Collateral dose is one issue but RBE is another issue for locally recurrence after definitive IMRT. Higher LET beam has improved RBE as compared to photon therapy. In addition, locally recurrent NPC can be large in volume and GammaKnife may not be suitable. Clinical evidence has demonstrated a suboptimal outcome after SRS for NPC recurrence.
- Q: With protons and heavy ions, dose delivered is very sensitive to air tissue interfaces. The nasopharynx region is full of air tissue interfaces, so how do you deal with this?
- A: Great question. We need to be very careful and we do weekly planning CT to ensure the dose distribution is not altered.
- Q: What radiobiological principles do you rely on for maintaining a good therapeutic ratio with Carbon Ion therapy where LET is high?
- A: There are currently 2 biological models to use and we use the Local Effect Model, developed at GSI in Germany.
Tumor Board: Early Stage Disease
Questions for David Adelstein, MD, Cleveland Clinic, Cleveland
- Q: Why not a PET for the possibility of understating given the hypomobile cord? What if it involves the roof of the ventricle?
- A: Yes, would recommend a PET.
- Q: RT alone for limited cord mobility…I disagree.
- A: Please see Bhateja et al. Head Neck 38:1832-1836, 2016 in support of the addition of concurrent chemotherapy for T2b disease.
- Q: Why is current therapy based on historic experience in the face of a new staging system?
- A: This was well discussed by Dr. O'Sullivan. The new staging system is not designed to be a treatment guide; and the outcome expectations are based on previous treatment paradigms.
- Q: Given the new ICONS staging is prognostic only at this point and not proven to be predictive, should we be changing treatment recommendations based on AJCC7 v 8 staging off trial?
- A: Treatment decisions should not be based on AJCC 8
- Q: For oropharynx cancers that minimally involve posterior pharyng wall, do you always cover the entire PP wall and medial RPs?
- A: Yes.
- Q: Is the hypomobile cord that triggers the addition of cisplatin in this individual.
- A: Yes—see the reference cited above.
- Q: For which nodepositive oropharyngeal cancer patients, do you feel comfortable treating with RT alone?
- A: For the AJCC 7, T1-2, N1 patients, or for the post-operative patient with no ECE, and negative margins
General Session IV: Larynx
Systemic Therapy for Larynx Cancer
Barbara Ann Burtness, MD, Yale Cancer Center, New Haven, Connecticut
- Q: Is there an age limit for chemoradiation?
- A: No, but optimal regimen is not known for very elderly. Consider enrolling to HN004 which compares RT/cetuximab with RT/IO.
- Q: Do youqaList consider neoadjuvant or concurrent chemo for T2N0 supraglottic larynx cancer?
- A: Not generally.
- Q: Can you comment on use of CDK46 inhibitors in advanced HPV negative cancers?
- A: Promising early data, awaiting results of larger trials.
- Q: Can you comment about what percent of laryngeal cancers or HPV negative patients will have disruptive vs non-disruptive P53 mutation and which ones there is evidence of benefit of cisplatin use?
- A: Approximately 70% will have a mutation and approximately 40% will have a disruptive mutation. Ongoing studies will determine if adding cisplatin benefits these patients.
- Q: Is there data about HPV positive Supra glottis cancers and glottis cancers? There are reports quoting 10 p16 positive laryngeal cancers; do we have data on outcomes of these patients?
- A: Anecdotally, they may do better than HPV-negative but not as well as HPV-driven oropharyngeal cancers.
General Session V: Salivary Glands and Thyroid
Raja Seethala, MD, University of Pittsburgh Medical Center, Pittsburgh
- Q: What is your current paradigm on intraopertive frozen section for thyroid modules
- A: Overall both in the literature and in our experience, intraoperative FS contributes very little if there is a prior FNA read by experienced cytopathologists. Some possible exceptions include - ruling out intrathyroidal parathyroid, confirming adequate material to work up anaplastic carcinoma or lymphoma, and if a nodule is very fibrous and FNAs were non-diagnostic. In some situations, it may be helpful if the diagnosis on FNA is "suspicious (category V)."
- Q: Why are PNIPNS so common in ACC caused by mutation? It is interesting that ACC always spreads along sensory nerves…why?
- A: This is not entirely clear, but it is postulated that the neurotropism is secondary to expressions of various matrix metalloproteinases and cell adhesion molecules. Some of these may be downstream effects of MYB alterations and NOTCH mutations.
- Q: Can you please comment on the controversial SCC of salivary glands Does it truly exist If so how is it different from cSCC?
- A: Primary SCC of salivary gland is essentially a metastasis or extension until proven otherwise. In the parotid gland, it is usually a metastasis from a cutaneous primary. SCC in the parotid often shows GATA3 expression in our recent experience. Since GATA3 is preferentially expressed in cutaneous SCC rather than mucosal SCC, this is indirect evidence to suggest that parotid SCC likely represent metastases from a cutaneous primary.
Radiation Treatment for Salivary Gland and Thyroid Tumors
Sue S. Yom, MD, PhD, UCSF Helen Diller Family Comprehensive Cancer Center, San Francisco
- Q: When treating gross disease, do neutrons offer an advantage over contemporary image-guided IMRT radiation? What about protons over photons given the higher associated RBE attributed to protons?
- A: Whether neutron therapy has an advantage is not known given the small size, imbalance and outdatedness of the RTOG/MRC trial. Proton therapy remains investigational although it looks promising in reducing toxicity.
- Q: When can radiation be omitted in adenoid cystic carcinoma?
- A: Almost never.
- Q: For a myoepithrlial histology with residual gross disease postoperatively in a patient who refuses reoperation, would you recommend concurrent chemo in addition to radiation? If so, which agents?
- A: This is unfortunate, as the patient should really have surgery. If forced into this, concurrent chemoradiation with cisplatin could be a last resort treatment option with known inferiority to surgery, taking into account the reasoning by analogy to mucosal SCC.
- Q: We have seen a lot of young people with salivary gland carcinomas. What type of surveillance and/or imaging both for primary and distant sites do you advise given they may face a lifetime of ongoing imaging and radiation exposure?
- A: Clinical surveillance with qualified HN examination. After five years, imaging would be justified only for symptoms.
- Q: 78-yr-old with sacral met from FTC causing neuropathy given 3750 cGy15 fractions three months ago. Still slowly getting clinically worse. He’s had two prior RAI treatments in remote past. Recommendations?
- A: This is refractory disease and more radiation is unlikely to help given the rapid progression. Would query the medical oncology team for options.
- Q: If the facial nerve is functioning but working and found to be grossly involved during surgery, would you recommend spraying the nerve or taking the nerve?
- A: If grossly involved with cancer (which either means there is tumor pathologically found in the nerve or the nerve is so surrounded by tumor that it probably needs to be sacrificed anyway), we would take the nerve out and cable-graft and reconstruct. It should be rare that this situation cannot be predicted from preoperative assessment.
- Q: What high risk features do the panelists use to decide on chemoradiation for adjuvant therapy of salivary tumors?
- A: We do not generally recommend concurrent chemotherapy based on the uncertainty of the evidence at present, although we often discuss it with the patient esp. for high grade salivary duct carcinoma or adenocarcinoma.
- Q: For unresecrable anaplastic thyroid cancer that progressed after high dose RT, is there a role for reirradiaton?
- A: I don't reirradiate centrally. We try to avoid tracheostomies in these patients since the disease often grows out of the trach site.
- Q: What dose of fractionation do you use for metastatic ATC for local disease?
- A: There is no standard for this. High BED and more conventional fractionation if the patient has excellent KPS and minimal distant burden. Surgery can be considered if the disease is completely resectable. Otherwise, we will use very short standard schedules.
- Q: What concurrent chemo is recommended for anaplastic thyroid?
- A: We used to use concurrent doxorubicin with our BID regimens, but since participating in the NRG protocol we have used carboplatin/paclitaxel with conventional fractionation and found good results with the taxane.
- Q: Which study shows improved survival with ebrt for thyroid cancer?
- A: There is no prospective study showing this. There are retrospective series that show some subsets have some advantages. Please see the table in the talk for examples.
- Q: For cN0 patients, is a neck dissection necessary for parotid adenocarcinoma or salivary duct carcinoma?
- A: Please see the list of indications in the talk. For these histologic subtypes the multivariate analysis which was presented showed benefit for ND for cN0 patients.
- Q: Margins are always close for salivary gland tumors so as to save the facial nerve. When should one add adjuvant RT based on close margins if tumors are low grade?
- A: We add RT locally to these low-grade but high recurrence risk situations.
- Q: Is there a max dose of I131 over a lifetime a patient can have?
- A: There is no formal limit to my knowledge but at over 100 mCi doses or at lifetime doses of approximately 600-800 mCi, patients begin to experience severe cytopenias/bone marrow problems as well as elevated risks of leukemia.
- Q: Do you attempt to spare the esophagus in EBRT for thyroid cancer?
- A: Yes but I try to treat the periesophageal regions to at least 60 Gy—and if there is gross disease there you have to go even higher. So make the surgeon take it out.
- Q: Why did Sue Yom say to be careful of the TE groove especially on the left?
- A: I meant the left side of the picture but it is the right TE groove. The reason this was mentioned is because this is a very common area of long term disease failure.
- Q: Do you recommend covering IB in cN0 necks after parotidectomy for high risk tumors What about pN?
- A: We cover 1B if 2A was substantially involved with N+ disease or if the primary tumor involved the submandibular area.
- Q: Do you always hyperfractionate radiation therapy for anaplastic thyroid carcinoma with chemotherapy?
- A: We used to use concurrent doxorubicin with our BID regimens but since participating in the NRG protocol we have used carboplatin/paclitaxel with conventional fractionation and found good results with the taxane.
- Q: Do you routinely irradiate the cranial nerve path for ACC and the upper border of CTV?
- A: If the ACC had very little path PNI which was all clearly resected within the surgical bed, we will radiate locally only. However, if there is extensive/multifocal or large caliber or clinical/radiographic PNI, which is almost always the case, then we radiate to the skull base.
Molecularly Targeted Therapy for Salivary Cancer
Nicole G. Chau, MD, Dana-Farber Cancer Institute, Boston
- Q: Why the lower dose of Lupron for AR SDC compared to that given for prostate cancer?
- A: There is no set dose of Lupron for ADT in salivary duct carcinoma. Different doses have been used including similar doses as used in prostate cancer.
- In Fushimi et al. A prospective phase II study of combined androgen blockade in patients with androgen receptor- positive metastatic or locally advanced unresectable salivary gland carcinoma. Ann Oncol. 2017 Dec 1. doi: 10.1093/annonc/mdx771. [Epub ahead of print] (PMID: 29211833), Leuprorelin acetate was administered subcutaneously at a dose of 3.75 mg every 4 weeks. A dose of 11.25 mg every 12 weeks was permitted if the patient desired. Bicalutamide was orally administered at a daily dose of 80 mg.
- In Jaspers et al. Androgen Receptor-Positive Salivary Duct Carcinoma: A Disease Entity with Promising New Treatment Options. J Clin Oncol 2011, Combined androgen blockade consisted of bicalutamide 50mg dialy and goserelin 3.6mg q 4 weeks or 10.8mg q 12 weeks.
- In Locati LD et al. Clinical activity of androgen deprivation therapy in patients with metastatic/relapsed androgen receptor–positive salivary gland cancers. Head and Neck 2016, Combined androgen blockade consisted of bicalutamide 50 mg daily and triptorelin 3.75 mg intramuscular injection every 28 days.
Molecular Advances in Thyroid Cancer Management
Herbert Chen, MD, University of Alabama School of Medicine, Birmingham, Alabama
- Q: Can’t most patients who have thyroid cancer be treated w lobectomy alone according to the ATA 2015 guidelines?
- A: Yes, many patients can be treated with lobectomy alone; therefore, molecular testing has virtually no role in these instances.
- Q: Are there any genetic tumor assays to predict for RAI uptake?
- A: Not that I know of.
- Q: What is your current paradigm on intraopertive frozen section for thyroid modules?
- A: Frozen section is misleading and should not be used for bestheda 4 lesions. It is occasionally helpful for patient with besthesda 5 lesions who want to have a thyroid lobectomy.
Breakout Session II: Survivorship and Acute and Late Effects
Oral Issues for the Radiotherapy Patient
Evan B. Rosen, DMD, MPH, FACP, Memorial Sloan Kettering Cancer Center, New York
- Q: What are your dental recommendations for patients during treatment (such as the timing of fluoride trays ways for comfortable oral care brushing)?
- A: Not all patients tolerate fluoride trays during treatment. As a result, fluoride supplementation can be accomplished during and after treatment with a prescription fluoride dentrifice (ie. 1.1% NaF; 5000ppm) with an ultra-soft toothbrush. The flavorings can be caustic to the patient (especially during treatment) so patients should request plain or fruit flavored (non-mint or non-cinnamon) toothpaste to minimize this outcome. The most important element is long-term compliance - if a patient is unable or unwilling to use fluoride trays indefinitely it may be worthwhile to explore this alternative approach.
- Q: Is the value of fluoride prophylaxis validated prospectively for prevention of RT caries and are there selected patients in the IMRT era of significant salivary recovery for whom fluoride may be discontinued?
- A: We currently do not have a reliable test to evaluate the quality of patient's saliva following treatment. As a result, it is advisable to continue fluoride supplementation (prescription fluoride toothpaste or gel) indefinitely to avoid rampant dental caries.
Management of Mucositis Secondary to Cancer Therapy
Nikhil G. Rao, MD, Florida Hospital, Orlando, Florida
- Q: I often struggle in managing patients who develop thick, stringy mucus during the last 12 weeks of treatment that elicits their gag reflex and causes dry heaves. Despite hydration mouth rinses, guaifenesin salivary supplements, etc., patients still really struggle with this. Do you have any suggestions?
- A: Try Hycodan.
- Q: Any strategies for dysgeusia that frequently occurs in the first week of radiotherapy?
- A: Unfortunately, nothing really works for taste.
Tumor Board: Advanced Disease
Questions for Jonathan Irish, MD, MSc, FRCSC, FACS, Princess Margaret Cancer Centre, Toronto
- Q: Would you have avoided a neck dissection impact on swallowing and neck shoulder function?
- A: No, I think that the impact of a neck dissection on swallowing and shoulder function (with accessory nerve preservation) is negligible.
- Q: Have you studied what causes poor outcomes at non-cancer low volume centers (such as surgical complications, nursing care inexperience, etc.)?
- A: There have been a significant number of studies looking at this. To boil it down: it is the experience of the multidisciplinary team including nursing, allied health, surgery, radiation/medical oncology. Rather than using the term "Centres of Excellence" I use the term "Centres of Experience."
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