NPCBench: A Clinical Apprenticeship Benchmark for Multimodal Care-Pathway Reasoning in Nasopharyngeal Carcinoma
Organizations: The Hong Kong Polytechnic University · Sun Yat-sen University · Sun Yat-sen University Cancer Center · Monash University
Abstract
Current medical benchmarks typically break down clinical competence into isolated factual questions, single-image tasks, or static case vignettes. These tests score individual answers, but reveal less about whether a model can integrate subspecialty knowledge with multimodal evidence and track a patient's condition throughout a course of care. To close this gap, we introduce NPCBench, a clinical apprenticeship benchmark for nasopharyngeal carcinoma (NPC). NPCBench mirrors specialist training, from guideline and foundational knowledge to case planning, longitudinal review, CarePath integration, and open-ended consultation. It contains 4,777 component and consultation items and a 100-patient CarePath cohort with 417 scored diagnostic and care tasks. The episode-level evaluation tests whether diagnostic and care answers are jointly correct within a care pathway. By linking stepwise tasks to patient-level care trajectories, NPCBench evaluates whether models ground decisions in visual evidence, interpret changes in patient state, and meet clinical requirements in consultation. Across 30 evaluated models, we observe a composition gap: strong performance on individual tasks does not ensure jointly correct diagnostic and care answers for the same patient. Among 21 multimodal models, strict CarePath success reaches at most 23%. Paired controls and physician calibration further examine evidence grounding, longitudinal revision, and consultation judging. Overall, NPCBench broadens the evaluation of medical artificial intelligence beyond static question-answering paradigms to an apprenticeship-oriented assessment of clinical workflows, thereby offering a testbed for evidence-based and temporally coherent reasoning in oncology care.
Figures & tables
| Targeted Audit ( ) | Expanded Audit ( ) | |||
|---|---|---|---|---|
| Judge | Agree. | Agree. | ||
| GPT-4.1 | 77.7 | 0.553 | 77.6 | 0.547 |
| GPT-OSS-120B | 81.4 | 0.610 | 70.5 | 0.387 |
| Qwen3-30B | 73.2 | 0.472 | 76.9 | 0.538 |
| Qwen3.6-27B | 79.4 | 0.578 | 77.8 | 0.544 |
Appendix figures & tables32 assets
Supplementary material from the paper’s appendix.
Appendix
| Item | Description |
|---|---|
| Measurement target | Guideline application, image interpretation, selected care decisions, and consultation quality in NPC; component scores and joint patient correctness are reported separately. |
| Intended use | Research benchmarking, model comparison, clinical error analysis, and evaluation-method development. |
| Out-of-scope use | Direct diagnosis, treatment recommendation, triage, or patient-specific clinical decision-making without physician supervision. |
| Data boundary | Guideline-derived questions, expert-authored vignettes, de-identified patient records, pathology/MRI evidence, longitudinal checkpoints, selected CarePath decisions, and consult rubrics. |
| Privacy handling | Names, contact details, addresses, and institution-specific identifiers are removed. Dates use relative clinical time where appropriate; L4 retains dates needed to determine the applicable guideline edition. Clinically relevant age, sex, and time intervals are preserved. |
| Evaluation controls | Shared prompts, adjudicated reference answers, final-answer extraction, O1 judge comparisons, and specialist review of answer clarity. |
| Subset | Evaluation unit | Scale | Source material | Reference annotation |
|---|---|---|---|---|
| L1 | Guideline-memory MCQ | 250 questions | NPC guidelines | Expert-validated guideline knowledge |
| L2 | Short-vignette MCQ | 185 questions | Clinical vignettes | Specialist-reviewed answers |
| L3 | Pathology/MRI multimodal tasks | 69 pathology overview questions; 2,700 evaluated MRI cards; 400 T-stage cases; 400 N-stage cases; 200 MRI sequence questions | Pathology and MRI images | Expert-validated pathology, imaging, and staging labels |
| L4 | Case-level MCQ | 165 questions over 84 patients | Clinical vignettes | Specialist-reviewed plans |
| L5 | Sequential patient-turn MCQ | 100 real patients; 305 questions | De-identified longitudinal records | Physician-adjudicated decision turns |
| L6 | Selected CarePath decisions | 100 patients; 417 scored tasks (100 pathology, 100 MRI T, 217 care) | Clinical episodes | Adjudicated care decisions; 75 pathology proxies |
| Episode source | Patients | Care nodes | Pathology evidence | Treatment-selection coverage |
|---|---|---|---|---|
| Matched pathology | 25 | 115 | Patient-matched specimens | Includes selected initial-treatment decisions |
| Assigned pathology | 75 | 102 | Assigned specimen proxies | No scored initial-treatment-selection question |
| CarePath cohort | 100 | 217 | 25 matched; 75 proxy | Six treatment items are excluded from scoring |
| L5 | CarePath cohort | ||||
|---|---|---|---|---|---|
| Depth | Patients | Turns | Patients | Care nodes | Node share (%) |
| 1 | 13 | 13 | 52 | 52 | 24.0 |
| 2 | 19 | 38 | 23 | 46 | 21.2 |
| 3 | 31 | 93 | 3 | 9 | 4.1 |
| 4 | 24 | 96 | 7 | 28 | 12.9 |
| 5 | 13 | 65 | 8 | 40 | 18.4 |
| Clinical group | Questions | Core | Evidence | Conditional | Major | Minor |
|---|---|---|---|---|---|---|
| Treatment | 43 | 182 | 171 | 152 | 140 | 148 |
| Adverse-event management | 35 | 127 | 105 | 69 | 104 | 92 |
| Diagnosis | 11 | 31 | 51 | 22 | 52 | 37 |
| Special populations | 12 | 53 | 49 | 36 | 36 | 34 |
| Workup | 2 | 8 | 10 | 3 | 5 | 9 |
| Total | 103 | 401 | 386 | 282 | 337 | 320 |
| Evaluation | Scored units | Evidence and history | Endpoint |
|---|---|---|---|
| L3 direct staging | 400 T-stage and 400 N-stage patients | Structure cards or same-plane sequence groups; AJCC/UICC edition 8 | T and N accuracy; anatomical diagnostics on 100 T cases |
| CarePath cohort | 100 patients; 217 care decisions | AJCC edition 9 MRI; predicted pathology and T-stage labels and supplied clinical context; no prior care answers | Decision-weighted Care; patient-level Strict |
| Image-evidence control | 25 patients; 146 care decisions | Predicted versus reference image findings; other clinical context fixed | Paired change in patient-macro care accuracy |
| Serial control | 25 patients; 146 care decisions | Reference image labels; persistent versus stateless interaction | Paired change in all-care correctness |
| L5 history control | 100 patients; 305 turns | Full history versus a snapshot with historical time markers removed and records regrouped | Turn-accuracy change and all-turn correctness |
| Model | Input interface | Inference |
|---|---|---|
| Medical-Specific LLMs | ||
| HuatuoGPT-o1-72B | Text | Local |
| HuatuoGPT-o1-7B | Text | Local |
| Baichuan-M2-32B | Text | Local |
| Fleming-R1-32B | Text | Local |
| Fleming-R1-7B | Text | Local |
| Subset | Input | Response | Scoring unit and endpoint |
|---|---|---|---|
| L1 | Guideline MCQ | Option letter | Item accuracy over 250 questions |
| L2 | Compact vignette and MCQ | Option letter(s) | Macro accuracy over four capability groups |
| L3 | Pathology overview; MRI panels or structure cards | Diagnostic labels and structured findings | Pathology: case; T/N stage: patient; sequence: item; structure: card accuracy |
| L4 | Single-case history and MCQ | Option letter(s) | Patient-macro accuracy over 84 patients |
| L5 | Longitudinal history through the current checkpoint | Option letter | Turn accuracy and all-turn patient success; 305 turns, 100 patients |
| L6 | Images, clinical context, and care questions | Diagnostic labels and option letters | Care-node accuracy and strict patient success; 217 nodes, 100 patients |
| Symbol | Meaning and domain |
|---|---|
| Scored item set and its size; indexes one question, image item, or turn. | |
| Reference label, parsed model label, and correctness . | |
| Number of evaluated patients and patient index . | |
| Scored L6 care-node set for patient , its size , and total scored nodes . | |
| Correctness of L6 care node for patient ; a binary indicator. | |
| Binary correctness indicators for pathology and MRI T stage; these symbols are not the predicted class labels. |
| Model | Turn | Patient macro | All-turn success |
|---|---|---|---|
| API models | |||
| DeepSeek-V3.1 | 74.4 | 74.2 | 42.0 |
| GPT-5.1 | 75.7 | 73.7 | 45.0 |
| GPT-4.1 | 78.7 | 77.5 | 45.0 |
| Gemini-3.1-Pro-Preview | 87.9 | 88.6 | 71.0 |
| Gemini-2.5-Pro | 82.0 | 81.6 | 56.0 |
| Metric | Scoring target | Interpretation |
|---|---|---|
| Direct T | The final t_stage field generated by the evaluated model in the patient-level MRI prompt | Measures whether the model can output the correct stage label, but does not require the supporting structure-level evidence to be correct |
| Complete Inv. | Whether all 18 base-structure invasion labels are correct for one patient | Measures whether every scored invasion finding is correct |
| EG T | Complete Inv. plus correct Direct T for the same patient | Strict evidence-grounded staging success; a model must both extract the evidence and produce the right stage |
| Oracle-slot T | Deterministic staging after placing predicted invasion labels into the gold structure slots | Isolates invasion recognition while removing structure-localization errors |
| Model-slot T | Deterministic staging after placing predicted invasion labels into the model-predicted structure slots | Measures the full structure-localization-plus-invasion evidence chain |
| LLM-slot T | Fixed GPT-OSS-120B staging from model-generated structure-card summaries | Tests whether a stronger text stager can recover T stage from the generated evidence representation |
| Model | Path. | Struct. | Inv. | Joint | Pt. Inv. | EG T | Seq. |
|---|---|---|---|---|---|---|---|
| HealthGPT-Pro-4B | 56.5 | 9.4 | 30.4 | 2.9 | 43.3 | 0.0 | 54.0 |
| HealthGPT-Pro-8B | 56.5 | 8.6 | 41.6 | 3.6 | 48.4 | 0.0 | 50.0 |
| Hulu-Med-4B | 56.5 | 5.6 | 30.9 | 1.7 | 47.7 | 0.0 | 30.0 |
| Hulu-Med-7B | 56.5 | 7.5 | 48.0 | 3.6 | 62.4 | 5.0 | 58.0 |
| Hulu-Med-32B | 60.9 | 21.8 | 46.6 | 10.1 | 59.8 | 3.0 | 75.5 |
| Lingshu-7B | 56.5 | 9.3 | 6.8 | 0.6 | 57.9 | 4.0 | 47.0 |
| Model | Complete Inv. | Direct T | EG T |
|---|---|---|---|
| HealthGPT-Pro-4B | 0.0 | 39.0 | 0.0 |
| HealthGPT-Pro-8B | 0.0 | 33.0 | 0.0 |
| Hulu-Med-4B | 0.0 | 35.0 | 0.0 |
| Hulu-Med-7B | 5.0 | 15.0 | 5.0 |
| Hulu-Med-32B | 3.0 | 16.0 | 3.0 |
| Lingshu-7B | 4.0 | 35.0 | 4.0 |
| Model | T1 | T2 | T3 | T4 | Direct T | Bal. T | T-bal60 |
|---|---|---|---|---|---|---|---|
| HealthGPT-Pro-4B | 6.7 | 6.7 | 11.4 | 94.3 | 39.0 | 29.8 | 31.7 |
| HealthGPT-Pro-8B | 0.0 | 0.0 | 5.7 | 88.6 | 33.0 | 23.6 | 25.0 |
| Hulu-Med-4B | 26.7 | 13.3 | 8.6 | 74.3 | 35.0 | 30.7 | 26.7 |
| Hulu-Med-7B | 100.0 | 0.0 | 0.0 | 0.0 | 15.0 | 25.0 | 25.0 |
| Hulu-Med-32B | 80.0 | 0.0 | 2.9 | 8.6 | 16.0 | 22.9 | 20.0 |
| Lingshu-7B | 73.3 | 0.0 | 0.0 | 68.6 | 35.0 | 35.5 | 36.7 |
| Model | Struct. | Inv. | Joint | Gold Rule | Oracle-slot | Model-slot | Direct T |
|---|---|---|---|---|---|---|---|
| HealthGPT-Pro-4B | 9.4 | 30.4 | 2.9 | 99.0 | 35.0 | 26.0 | 39.0 |
| HealthGPT-Pro-8B | 8.6 | 41.6 | 3.6 | 99.0 | 35.0 | 23.0 | 33.0 |
| Hulu-Med-4B | 5.6 | 30.9 | 1.7 | 99.0 | 35.0 | 15.0 | 35.0 |
| Hulu-Med-7B | 7.5 | 48.0 | 3.6 | 99.0 | 30.0 | 28.0 | 15.0 |
| Hulu-Med-32B | 21.8 | 46.6 | 10.1 | 99.0 | 52.0 | 35.0 | 16.0 |
| Lingshu-7B | 9.3 | 6.8 | 0.6 | 99.0 | 35.0 | 33.0 | 35.0 |
| Model | Direct T | Rule-slot T | LLM-slot T | Bal. LLM T |
|---|---|---|---|---|
| Lingshu-7B | 35.0 | 33.0 | 32.0 | 23.8 |
| Lingshu-32B | 35.0 | 35.0 | 35.0 | 25.0 |
| InternVL3.5-38B | 33.0 | 15.0 | 15.0 | 25.0 |
| Qwen3-VL-8B-Instruct | 35.0 | 35.0 | 35.0 | 25.0 |
| Qwen3-VL-30B-A3B-Instruct | 35.0 | 33.0 | 33.0 | 23.5 |
| HealthGPT-Pro-4B | 39.0 | 26.0 | 26.0 | 25.2 |
| Model | ||||||
|---|---|---|---|---|---|---|
| HealthGPT-4B | 8 | 9 | 0 | 8 | 9 | 83 |
| HealthGPT-8B † | 5 | 4 | 0 | 5 | 4 | 91 |
| Hulu-Med-4B | 15 | 8 | 0 | 15 | 8 | 77 |
| Hulu-Med-7B | 19 | 1 | 0 | 19 | 1 | 80 |
| Hulu-Med-32B | 19 | 48 | 10 | 9 | 38 | 43 |
| Lingshu-7B | 16 | 45 | 9 | 7 | 36 | 48 |
| Matched specimens ( ) | Assigned specimens ( ) | |||||||
|---|---|---|---|---|---|---|---|---|
| Model | Care | All-care | Image | Strict | Care | All-care | Image | Strict |
| Claude-4.6 | 84.3 | 52.0 | 40.0 | 12.0 | 76.5 | 68.0 | 37.3 | 26.7 |
| GPT-4.1 | 75.7 | 32.0 | 4.0 | 0.0 | 46.1 | 28.0 | 8.0 | 2.7 |
| GPT-5.1 | 77.4 | 32.0 | 16.0 | 4.0 | 63.7 | 50.7 | 6.7 | 1.3 |
| Gemini-2.5-Flash | 60.0 | 8.0 | 28.0 | 0.0 | 70.6 | 60.0 | 17.3 | 8.0 |
| Gemini-2.5-Pro | 73.9 | 28.0 | 28.0 | 8.0 | 88.2 | 85.3 | 21.3 | 17.3 |
| Control | Held fixed | Changed | Reported endpoint |
|---|---|---|---|
| L6 image evidence (25 patients) | Patients, care decisions, supplied clinical context | Pathology, MRI T stage, and invaded structures | Patient-macro care difference |
| L5 history (100 patients) | Baseline/current evidence, question, options, reference answer | Historical time markers and record ordering | Turn-accuracy difference |
| L1 options (71 pairs) | Physician-audited target knowledge | MCQ versus option-free answer | Paired item-accuracy difference |
| MRI interface (25 patients) | Model, patients, matched image frames | Static panel versus cine presentation | T and structure differences |
| O1 Expanded Audit (1,013 labels) | Responses, criteria, physician labels | Automated judge | Agreement and polarity-specific agreement |
| Row | Model | Predicted | Reference | Difference [95% CI] | B/W/S |
|---|---|---|---|---|---|
| 1 | HealthGPT-8B | 21.1 | 17.9 | -3.2 [-10.5, 3.8] | 8/10/7 |
| 2 | Lingshu-7B | 54.4 | 53.0 | -1.4 [-5.0, 1.8] | 2/3/20 |
| 3 | Hulu-Med-4B | 48.0 | 46.8 | -1.3 [-3.9, 1.3] | 1/3/21 |
| 4 | HealthGPT-4B | 23.9 | 22.9 | -1.0 [-9.2, 8.0] | 7/9/9 |
| 5 | Qwen3.6-27B | 85.5 | 84.6 | -0.9 [-4.4, 2.4] | 2/3/20 |
| 6 | Qwen3.6-35B-A3B | 84.2 | 84.5 | +0.2 [-2.5, 2.9] | 2/2/21 |
| Model | History | Snapshot | Difference [95% CI] | |
|---|---|---|---|---|
| DeepSeek-V3.1 | 71.5 | 66.6 | +4.9 [1.4, 8.5] | 22/7 |
| Fleming-R1-7B | 59.7 | 61.3 | -1.6 [-6.5, 3.2] | 21/26 |
| GPT-4.1 | 75.1 | 75.7 | -0.7 [-4.1, 2.9] | 14/16 |
| GPT-5.1 | 71.5 | 70.5 | +1.0 [-3.2, 5.2] | 22/19 |
| GPT-OSS-120B | 48.9 | 45.6 | +3.3 [-1.6, 8.1] | 29/19 |
| GPT-OSS-20B | 52.8 | 48.2 | +4.6 [-1.4, 10.7] | 46/32 |
| Condition | Cisplatin record | Docetaxel record | Timing and position |
|---|---|---|---|
| Full history | Admission 2, day 26; induction, cycle 2; cisplatin 53.0 mg | Admission 2, day 26; induction, cycle 2; docetaxel 105.0 mg | Prefixes retained; records 23 and 24 |
| Snapshot | Induction, cycle 2; cisplatin 53.0 mg | Induction, cycle 2; docetaxel 105.0 mg | Prefixes removed; records 33 and 42 |
| Shuffled order | Admission 2, day 26; induction, cycle 2; cisplatin 53.0 mg | Admission 2, day 26; induction, cycle 2; docetaxel 105.0 mg | Full lines retained; records 19 and 29 |
| Model | Score | Major | Minor | AE | Dx | Eld. | Ped. | Tx | Workup |
|---|---|---|---|---|---|---|---|---|---|
| GPT-5.1 | 58.4 | 14.6 | 40.8 | 69.2 | 42.6 | 85.4 | 57.4 | 51.2 | 60.1 |
| Gemini-3.1 | 47.8 | 12.6 | 59.2 | 58.4 | 50.1 | 60.5 | 35.5 | 39.1 | 60.1 |
| Claude-4.6 | 47.5 | 15.5 | 58.3 | 52.1 | 41.5 | 76.7 | 49.8 | 41.5 | 63.3 |
| Qwen3.6-27B | 47.2 | 24.3 | 52.4 | 61.2 | 26.5 | 67.5 | 39.9 | 39.6 | 65.1 |
| Qwen3.5-27B | 46.8 | 19.4 | 50.5 | 59.5 | 31.7 | 61.3 | 27.4 | 42.2 | 56.7 |
| GPT-OSS-120B | 44.9 | 20.4 | 49.5 | 61.8 | 29.5 | 51.7 | 29.3 | 36.6 | 59.2 |
| Response model | Sampled resp. | Excluded resp. | Flagged labels retained | Included labels |
|---|---|---|---|---|
| GPT-5.1 | 15 | 0 | 184 | 264 |
| Qwen3.6-27B-Instruct | 8 | 0 | 0 | 136 |
| GPT-OSS-120B | 7 | 0 | 102 | 132 |
| Gemini-3.1-Pro-Preview | 18 | 17 | 0 | 16 |
| Judge model | Acc. | Bal. acc. | Sens. | Spec. | True rate | ||
|---|---|---|---|---|---|---|---|
| GPT-4.1 | 262 | 0.767 | 0.772 | 0.533 | 0.802 | 0.742 | 0.489 |
| GPT-OSS-120B | 262 | 0.840 | 0.826 | 0.665 | 0.739 | 0.914 | 0.363 |
| Qwen3-30B-A3B-Instruct | 262 | 0.752 | 0.760 | 0.506 | 0.811 | 0.709 | 0.511 |
| Qwen3.6-27B | 262 | 0.782 | 0.781 | 0.558 | 0.775 | 0.788 | 0.450 |
Clinical Reasoning
Clinical reasoning studies how AI systems interpret patient evidence, form and revise diagnoses, and support safe decisions across care settings.
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