PSA Velocity & Doubling Time
Calculate PSA velocity and PSA doubling time for prostate cancer risk stratification. Includes PSAD calculation if prostate volume is provided. Flags biopsy and imaging thresholds per AUA/EAU guidelines.
🧮 PSA Velocity & Doubling Time — Formula
🩺 Oncology protocols vary by institution. Verify all doses with the treating oncologist and pharmacist.
📌Carter HB et al. JAMA 1992 / D'Amico AV JAMA 2004 / AUA PSA Best Practice 2023 / EAU Prostate Cancer Guidelines 2023
📊 Quick Reference
| Input / Parameter | Description | Example Value |
|---|---|---|
| Height (cm) | Patient height in centimetres at treatment visit | 168 cm |
| Weight (kg) | Current actual body weight in kilograms | 72 kg |
| BSA (m²) | Mosteller: √(H×W÷3600) | 1.79 m² |
| Protocol dose (mg/m²) | Chemotherapy dose from treatment protocol | 175 mg/m² (paclitaxel) |
| Total dose (mg) | BSA × protocol dose — verify against cap | 313 mg |
| ANC | WBC × (neutrophils% + bands%) / 100 | ANC 0.8 × 10³/μL → neutropenic |
ℹ️ About This Calculator
The PSA Velocity & Doubling Time is used in oncology or haematology to calculate treatment doses, assess disease severity, classify tumour stage, or estimate prognosis. It follows validated protocols and clinical dosing standards from the American Society of Clinical Oncology (ASCO), the European Society for Medical Oncology (ESMO), the National Comprehensive Cancer Network (NCCN), and other major oncology organisations.
Cancer treatment is among the most complex and high-stakes domains in medicine. Chemotherapy agents have some of the narrowest therapeutic windows of any drug class — effective doses and toxic doses are often separated by a small margin. A BSA-based dose that is 20% too high can cause life-threatening myelosuppression; a dose that is 20% too low may be subtherapeutic for the tumour. Accurate dose calculation, supported by this tool, is one of the first steps in a multi-layered safety system that protects patients from chemotherapy dosing errors.
The exact formula used by this calculator — including the BSA equation (Mosteller, DuBois, or other), ANC calculation, TNM staging criteria, or dose parameters — is shown in full in the Formula section below. For chemotherapy BSA calculation specifically, the Mosteller formula [BSA = √(H × W / 3600)] is used by most modern oncology protocols because it is simpler, produces similar results to DuBois in most patients, and has been incorporated into widely used oncology software.
Critical safety requirements: all chemotherapy and high-alert oncology medication doses must be independently verified by the treating oncologist and by a specialist oncology pharmacist before any preparation or administration. This double-check process is a mandatory institutional safety requirement — not a suggestion — and no calculator, however sophisticated, replaces it. Re-verify doses at every treatment cycle using the patient's current weight, as doses may need adjustment for >10% weight change, toxicity-related protocol modifications, or dose-capping rules.
All calculations run in your browser only. No patient height, weight, laboratory values, or clinical data is transmitted to any server or stored. For patients receiving chemotherapy, maintaining this privacy is important — cancer diagnosis and treatment represent highly sensitive personal health information.
For complex oncology situations — including patients with significant renal or hepatic impairment requiring dose modification, patients on trials requiring per-protocol dosing verification, or cases where ANC indicates febrile neutropenia requiring emergency management — always involve the treating oncologist and clinical pharmacist. Febrile neutropenia (ANC <500 + fever) is an oncologic emergency: empiric broad-spectrum antibiotics should be started within the first hour of presentation regardless of the calculated ANC value.
📌Clinical Reference: Carter HB et al. JAMA 1992 / D'Amico AV JAMA 2004 / AUA PSA Best Practice 2023 / EAU Prostate Cancer Guidelines 2023
📋 How to Use This Calculator
- 1
Confirm height and weight
Use the patient's measured height and actual body weight from the day of treatment. BSA is highly sensitive to weight changes — always use measurements taken at the treatment visit, not values from previous cycles.
- 2
Enter the protocol dose
Input the chemotherapy dose in mg/m² as specified in the treatment protocol. If multiple agents are included, calculate BSA-based doses for each drug separately.
- 3
Calculate the total dose
The tool multiplies BSA × protocol dose to give the total dose in mg. For some protocols, doses are capped at a maximum regardless of BSA — check the protocol for any dose-capping rules.
- 4
Review haematological parameters
For ANC calculation, enter CBC differential counts. Check that ANC, platelet count, and renal/hepatic function meet the protocol's criteria for treatment administration before proceeding.
- 5
Confirm with oncologist and pharmacist
All chemotherapy doses must be verified by the treating oncologist and independently checked by an oncology pharmacist before preparation and administration. This is a mandatory safety requirement.
🎯 When to Use This Calculator
Chemotherapy dose calculation
Calculate BSA-based chemotherapy doses at the start of each treatment cycle using current weight. Re-verify if weight has changed ≥10% since the last cycle — dose modification may be required.
Febrile neutropenia risk assessment
Calculate ANC from CBC differential to diagnose neutropenia (ANC <1500) and febrile neutropenia (ANC <500 + fever). Febrile neutropenia is an oncologic emergency requiring immediate antibiotic treatment.
Staging and prognosis counselling
Use TNM staging or disease-specific scoring systems to classify tumour stage, communicate prognosis to patients, and select treatment protocols appropriate for the stage.
Anticoagulation monitoring in cancer
Convert INR/PT to confirm therapeutic range in cancer patients on vitamin K antagonists, who have higher lability due to malnutrition, drug interactions, and hepatic involvement.
Transfusion threshold decisions
Calculate blood transfusion volume (mL = target rise × weight × 3 for RBCs) to order the correct unit volume and avoid circulatory overload, particularly in elderly or cardiac patients.
💡 Clinical Pro Tips
BSA-based chemotherapy dosing is imprecise — BSA is a surrogate for drug distribution, not a perfect predictor of pharmacokinetics. Many oncologists now advocate for weight-based dosing caps (e.g., capping at BSA 2.0 m²) to prevent toxicity in patients with very high BSA, but protocols vary. Always follow the specific protocol's capping rules.
ANC nadir typically occurs 7–14 days after chemotherapy administration. Educate patients to monitor for fever in this window and report immediately — febrile neutropenia has a 5–10% mortality rate when treatment is delayed. The absolute neutrophil count (ANC) = WBC × (neutrophils% + bands%).
TNM staging is the most important predictor of prognosis for most solid tumours, but it is a snapshot at one point in time. Stage migration (upstaging due to improved imaging or surgical staging) occurs with CT, PET-CT, and sentinel node biopsy. A Stage II cancer staged by clinical examination alone may be pathological Stage III after resection.
INR/PT values in cirrhotic patients do not reflect their true coagulation status because they do not account for reduced thrombomodulin-mediated protein C activation or decreased levels of both pro- and anti-coagulant factors. Cirrhotic patients are not necessarily anti-coagulated despite elevated INR — they have a rebalanced but fragile haemostatic system.
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