Treatment/Prognosis Flashcards
Broadly speaking, what OPC pts/stage groups are deemed early, intermediate, and advanced?
Based on RTOG 0129 and AJCC 8th edition staging:
Early: stages I–II (cT1–2N0) and select III (T2N1)
Intermediate/favorable: HPV(+) stages III–IV (without T2N1) in nonsmokers/drinkers, T3N0 (exophytic) regardless of HPV/smoking status
Advanced/unfavorable: HPV(–) smokers with stages III–IV Dz, T4 Dz regardless of HPV/smoking status
What are the Tx paradigms for early oropharyngeal tumors?
Early oropharyngeal tumor Tx paradigm: surgical resection with selective neck dissection +/- PORT or definitive RT alone
What are the Tx paradigms for intermediate oropharyngeal tumors?
Intermediate-group oropharyngeal tumor Tx paradigms: Sg +/- postop CRT, altered fractionation RT, and CRT (conventional fractionation)
What are the Tx paradigms for advanced/unfavorable oropharyngeal tumors?
Advanced/unfavorable oropharyngeal tumor Tx paradigm: CRT (conventional)
When is WLE alone appropriate for OPC?
Rarely. WLE may suffice in the rare instance of a small (<1 cm), ant tonsillar pillar lesion.
Is tonsillectomy ever adequate as a definitive Tx for tonsillar cancers?
Generally, no. Simple tonsillectomy is considered an excisional Bx and thus needs further definitive Tx. Radical tonsillectomy may be adequate in select cases but results in worse functional outcomes than RT.
What type of Sg is required for the surgical management of OPC?
Historically, labiotomy and mandibulotomy were required to gain access to the OPX, but there is growing experience with transoral approaches with transoral laser microsurgery (TLM) and transoral robotic surgery (TORS).
When is PORT indicated for OPC? When is postop CRT indicated for OPC?
Similar to other H&N sites, PORT is generally for intermediate-risk factors such as T3–T4, LN+, LVSI, and PNI, while postop CRT is indicated for +margin or +ENE.
When can unilat neck Tx be considered for OPC pts?
Unilat neck Tx can be considered if the lesion is well lateralized (T1–T2, <1 cm soft palate extension, no BOT involvement) and 1 or few regional ipsi nodes <6 cm based on multiple retrospective reviews showing a very low contralat failure rate (<3%).
Which LN regions/levels should be irradiated in pts with an early T stage but N+ OPC?
Levels II–IV should always be included/irradiated; however, some data (Sanguineti G et al., IJROBP 2009) suggest that levels I and V may be omitted d/t a significantly lower incidence of nodal spread.
What is the main indication for a neck dissection after definitive CRT for OPC?
The main indication for a neck dissection after CRT is persistent nodal Dz that can be documented by fine-needle sampling, CT (at 4–6 wks), or PET/CT (at 10–12 wks).
What is the recommended timing for a neck dissection after CRT?
Neck dissection should typically occur at 6–8 wks (12–15 wks if evaluated by PET/CT).
How should OPC pts be set up for simulation?
OPC pts should be simulated supine, with arms pulled inferiorly and the head extended with a bite block or stent. Contrast is recommended with CT.
What type of custom stent can be used?
Mouth opening, tongue depressing stent
What should the pre-RT evaluation/preparation include?
Dental evaluation/fluoride prophylaxis, speech and swallow evaluation/exercises, and nutrition evaluation with a PEG tube if the pre-Tx weight loss is >10% over 3 mos
What are the typical CTVs for IMRT planning?
CTV high dose (CTVHD): primary tumor and nodal GTV with 0.5–1-cm margin
CTV intermediate dose (CTVID): soft palate, adjacent parapharyngeal space, sup tonsillar pillars for lat tumors, and nodal levels adjoining involved nodes
CTV elective dose (CTVED): levels II–IV, RP nodes. If node+, most include ipsi IB and V.
What are the typical RT doses and volumes used for OPC?
T1 and superficial T2N0: 66–70 Gy to CTVHD, 60 Gy to CTVID, and 54 Gy to CTVED, given in 30–35 fx over 6–7 wks
> T2+ without chemo: (1) 70 Gy to CTVHD, 63 Gy to CTVID, and 56 Gy to CTVED given in 35 fx over 6 wks (per Danish Head and Neck Cancer Group [DAHANCA]); (2) 70 Gy to CTVHD, 60 Gy to CTVID, and 57 Gy to CTVED given in 33 fx
> T3 or >N2 with chemo: 70 Gy to CTVHD, 63 Gy to CTVID, and 59.5 Gy to CTVED in 35 fx
What is the 2-yr LF rate after IMRT alone for early (T1–2N0–1) OPC?
RTOG 00–22 (Eisbruch A et al., IJROBP 2010) demonstrated excellent results with accelerated hypofractionated IMRT for early OPC: 2-yr LF rate was 9% (if major deviations, 50%; otherwise, 6%, SS).
What were the RT techniques and doses employed in RTOG 00–22? How was the N stage established?
In RTOG 00–22 (Eisbruch A et al., IJROBP 2010), RT was delivered with accelerated hypofractionated IMRT as follows: 66 Gy in 30 fx (2.2 Gy/fx) to the primary PTV and 54–60 Gy in 30 fx (1.8–2 Gy/fx) to the secondary PTV. Neck staging was clinical (not from CT); however, pts “upstaged” by CT (e.g., cN1 but N2 after CT) were also eligible.
What did the RTOG 90–03 study demonstrate about the use of altered fractionation in H&N cancers?
RTOG 90–03 (Fu KK et al., IJROBP 2000): 1,073 pts with H&N cancers (10% OC, 60% OPX, 13% HPX) with stage III (28%) or stage IV (68%) Dz randomized to (a) conventional 70 Gy qd, (b) 81.6 Gy in 1.2 Gy/fx bid, (c) accelerated with split, and (d) concomitant boost (1.8 Gy/fx qd × 17, with last 12 fx bid with 1.8 Gy AM, 1.5 Gy PM to 72 Gy). There was better LC with altered fx (54% vs. 46%) but no OS/DFS benefit. There was worse acute toxicity but no difference in late toxicity.
What randomized studies demonstrated better outcomes with hyperfractionated RT over conventional RT for OPC?
RTOG 90–03 (Fu KK et al., IJROBP 2000): see above.
EORTC 22791 (Horiot JC et al., Radiother Oncol 1992): 325 pts (all OPX, but no BOT): 70 Gy vs. 80.5 Gy at 1.15 Gy bid. There was better LC (60% vs. 40%) but no OS benefit. LC was best for T3 Dz.
What data showed good LC rates with RT alone for select advanced (stages III–IV) OPCs?
MDACC data (Garden AS et al., Cancer 2004): pts with small primaries but stages III–IV Dz by virtue of +LNs; treated with RT alone. There were acceptable 5-yr LF (15%), DM (19%), and OS (64%) rates.
What are 2 important randomized trials that demonstrated the importance of adding chemo to conventionally fractionated RT in OPC?
GORTEC 94–01 (Calais G et al., JNCI 1999): 222 pts with stages III–IV OPC randomized to conventional RT alone vs. conventional RT + carboplatin/5-FU, no planned neck dissection for N2–3 Dz. The CRT arm had better 3-yr OS (51% vs. 31%), DFS (30% vs. 15%), and LC (66% vs. 42%); however, there was significantly worse grades 3–4 mucositis and weight loss/feeding tube use in the CRT arm.
Head and Neck Intergroup Study (Adelstein DJ et al., JCO 2003): 295 pts with unresectable stages III–IV H&N cancers (15% OC, 55% OPX, 20% HPX), RT alone vs. CRT with cisplatin 100 mg q3 wks × 3. 3-yr OS was better in the CRT arm (37% vs. 23%). There also was improved DFS (51% vs. 33%) in the CRT arm.
Pooled analysis from which 2 important RCTs support adding chemo to PORT in H&N cancers for +margin and ECE?
EORTC 22931 (Bernier J et al., NEJM 2004): 334 pts randomized to PORT 66 Gy vs. PORT + cisplatin 100 mg/m2 on days 1, 22, and 43. Eligibility: ECE, +margin, PNI, LVI, and levels 4–5 +N from OCC/OPC. There was better OS, DFS, and 5-yr LC with CRT but ↑ grades 3–4 toxicity.
RTOG 95–01 (Cooper JS et al., NEJM 2004): 459 pts randomized to 60–66 Gy PORT vs. PORT + cisplatin 100 mg/m2 on days 1, 22, and 43. Eligibility: >2 LN, ECE, +margin. There was better DFS (43% vs. 54%) and 2-yr LRC (72% vs. 82%) but only a trend to improvement in OS (57% vs. 63%).
