1.1 Patient Assessment, History, and Vital Signs

1.1 Patient Assessment, History, and Vital Signs

Comprehensive patient assessment is the cornerstone of safe, effective radiation oncology care. Radiation therapists must perform continuous, systematic evaluations before, during, and after each course of radiotherapy. Because radiation therapy is delivered over multiple weeks, baseline assessments provide the benchmark against which acute toxicities, disease progression, and treatment responses are measured.

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Oncology Health History

A detailed oncology health history establishes the patient's baseline clinical status and helps identify potential risks or contraindications during radiation delivery. The health history encompasses several core components:

1. Chief Complaint (CC): The primary symptom or diagnosis bringing the patient to radiation oncology.
2. History of Present Illness (HPI): Chronological account of tumor presentation, diagnostic biopsy results, pathological staging (TNM classification), histology, molecular markers, and anatomical localization.
3. Past Medical & Surgical History (PMH/PSH): Co-morbidities such as diabetes, cardiovascular disease, collagen vascular diseases (e.g., systemic lupus erythematosus, scleroderma—which significantly increase normal tissue radiosensitivity), and previous surgical resections.
4. Prior Oncology Interventions: Details of previous chemotherapy regimens (especially radiosensitizing agents like cisplatin or cardiotoxic agents like doxorubicin), immunotherapy, and prior external beam or brachytherapy courses (including exact field boundaries and accumulated doses to avoid normal tissue overdose).
5. Allergies & Current Medications: Documentation of known drug allergies, contrast medium hypersensitivity, anticoagulants (increasing bleeding risk during invasive procedures), and systemic corticosteroids.

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Performance Status Scoring Systems

Performance status scales quantify a cancer patient's daily functional abilities and general well-being. They guide clinical decision-making regarding treatment tolerance, dose fractionation, and palliative versus curative intent.

ECOG Performance Status Scale

The Eastern Cooperative Oncology Group (ECOG) scale grades functional impairment from 0 to 5:

Karnofsky Performance Scale (KPS)

The Karnofsky Performance Scale (KPS) uses an 11-point scale from 100 to 0 in 10-unit decrements:

• 100: Normal; no complaints; no evidence of disease.
• 90: Able to carry on normal activity; minor signs or symptoms of disease.
• 80: Normal activity with effort; some signs or symptoms of disease.
• 70: Cares for self; unable to carry on normal activity or do active work.
• 60: Requires occasional assistance, but is able to care for most of personal needs.
• 50: Requires considerable assistance and frequent medical care.
• 40: Disabled; requires special care and assistance.
• 30: Severely disabled; hospital admission indicated although death not imminent.
• 20: Very sick; hospital admission necessary; active supportive treatment necessary.
• 10: Moribund; fatal processes progressing rapidly.
• 0: Dead.

+------------------------------------------------------------------+
|                  PERFORMANCE STATUS COMPARISON                    |
+------------------------------------+-----------------------------+
| ECOG Grade                         | KPS Rating                  |
+------------------------------------+-----------------------------+
| 0 (Fully Active)                   | 90 - 100%                   |
| 1 (Restricted Strenuous Work)      | 70 - 80%                    |
| 2 (Ambulatory >50% Waking)         | 50 - 60%                    |
| 3 (Bedbound >50% Waking)           | 30 - 40%                    |
| 4 (Completely Bedbound)            | 10 - 20%                    |
| 5 (Deceased)                       | 0%                          |
+------------------------------------+-----------------------------+

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Vital Signs Assessment & Monitoring Thresholds

Baseline vital signs must be recorded prior to simulation and daily treatment when clinically indicated. Deviations from normal parameters dictate immediate intervention.

Body Temperature

• Normal Range: 36.5°C to 37.5°C (97.7°F to 99.5°F).
• Febrile Threshold: Single oral measurement ≥38.3°C (101.0°F) or ≥38.0°C (100.4°F) sustained over 1 hour.
• Clinical Significance: In immunocompromised or neutropenic oncology patients, fever may be the sole presenting sign of life-threatening sepsis. Treatment must be paused and blood cultures ordered immediately.

Pulse & Heart Rate

• Normal Range: 60 to 100 beats per minute (bpm).
• Tachycardia (>100 bpm): Associated with pain, anxiety, anemia, fever, dehydration, or cardiac toxicity.
• Bradycardia (<60 bpm): May indicate vagal stimulation, intrinsic cardiac conduction defects, or medication effects (e.g., beta-blockers).

Respiration

• Normal Range: 12 to 20 breaths per minute.
• Tachypnea (>20 breaths/min): Sign of respiratory distress, acute radiation pneumonitis, pulmonary embolism, pleural effusion, or severe anxiety.

Blood Pressure (BP)

• Normal: Systolic <120 mmHg AND Diastolic <80 mmHg.
• Hypertension Stage 1: Systolic 130–139 mmHg OR Diastolic 80–89 mmHg.
• Hypertension Stage 2: Systolic ≥140 mmHg OR Diastolic ≥90 mmHg.
• Hypotension: Systolic <90 mmHg OR Diastolic <60 mmHg. Orthostatic hypotension (drop in SBP >20 mmHg upon standing) increases fall risk during transfer from the treatment couch.

Pulse Oximetry ($SpO_2$)

• Normal: 95% to 100% on room air.
• Hypoxemia ($SpO_2 <90%$): Requires emergency supplemental oxygen administration and pulmonary assessment.

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Baseline Diagnostic Laboratory Values

Radiation therapists must review complete blood count (CBC) values, particularly when large bone marrow reserves (pelvis, spine, sternum) are within the treatment field or during concurrent chemoradiotherapy.

                      [ OXYGEN ENHANCEMENT RATIO (OER) ]
                                      |
         +----------------------------+----------------------------+
         |                                                         |
  Well-Oxygenated Tissue (Hgb ≥10)                          Hypoxic Tissue (Hgb <10)
         |                                                         |
  Free radicals fixed by O2                              Free radicals repaired
         |                                                         |
  High DNA double-strand breaks                           Increased radioresistance
  (Maximum cell kill achieved)                            (Treatment failure risk)

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Physical & Pain Assessment Protocols

Systematic physical assessment includes evaluating skin integrity, mucosal breakdown, weight change, and pain. Pain must be assessed using the standardized PQRST framework:

• P (Provocation/Palliation): What aggravates or relieves the pain?
• Q (Quality): Is the pain sharp, dull, burning, throbbing, or neuropathic?
• R (Region/Radiation): Where is the pain located, and does it radiate?
• S (Severity): 0 to 10 numerical rating scale (0 = no pain, 10 = worst imaginable pain).
• T (Timing): Is the pain continuous, intermittent, or related to swallowing/movement?

Unintentional weight loss tracking is paramount. Weight loss >5% in 30 days alters body contours, rendering immobilization devices ill-fitting and causing geometric setup errors that compromise target coverage and organ-at-risk sparing.