Clinical calculator summary
Peritoneal Carcinomatosis Index (PCI)
Clinical calculator summary
Peritoneal Carcinomatosis Index (PCI)
A 0-39 regional score that sums lesion-size scores across 13 abdominopelvic and small-bowel regions.
Evidence-based context for fast calculator use
- Purpose:
- Documents peritoneal disease burden for CRS-HIPEC referral, operative planning, and multidisciplinary review.
- Population:
- Patients with peritoneal metastases or peritoneal surface malignancy being evaluated for staging, referral, cytoreduction, or HIPEC.
- Factors:
- 13-region disease distribution, Largest lesion size per region, Small-bowel involvement, Primary tumor biology, Feasibility of complete cytoreduction
- Reference:
- Jacquet and Sugarbaker, Cancer Treat Res. 1996.
Peritoneal Carcinomatosis Index (PCI)
PCI region map
Score 13 regions before CRS-HIPEC discussion
Right upper
Epigastrium
Left upper
Right flank
Central
Left flank
Right lower
Pelvis
Left lower
Regions 0-8 cover the abdominopelvic grid. Regions 9-12 capture small-bowel involvement, which can strongly affect complete cytoreduction feasibility.
Small bowel regions
Lesion-size score
Use before referral
Summarize tumor distribution for a peritoneal surface malignancy or tumor board review.
Flag small bowel
A modest total PCI can still be challenging when bowel or mesentery disease is extensive.
Pair with CC score
PCI describes burden before cytoreduction; CC score documents residual disease after surgery.
Clinical Context & Background
Sum LS-0 to LS-3 scores across 13 PCI regions. Max Score = 39. Small-bowel regions 9-12 are flagged when burden is high.Reference Data
| Workflow Signal | Interpretation |
|---|---|
| PCI 0 | No macroscopic peritoneal disease recorded. |
| PCI 1-9 | Low tumor burden; complete cytoreduction is generally more feasible, depending on disease biology and distribution. |
| PCI 10-19 | Moderate tumor burden; CRS-HIPEC candidacy is disease-specific and depends on distribution, performance status, and resectability. |
| PCI >=20 | High tumor burden; CRS-HIPEC feasibility may be limited, especially when colorectal peritoneal metastases or critical small-bowel involvement are present. |
| Small-bowel burden | High scores in regions 9-12 should prompt careful review of cytoreduction feasibility. |
Clinical Workflow
Use, Interpret, And Continue The Patient Pathway
Expand for workflow guidance, limitations, examples, and related next steps.
Clinical Workflow
Use, Interpret, And Continue The Patient Pathway
Expand for workflow guidance, limitations, examples, and related next steps.
When To Use
- Use when documenting peritoneal disease burden before peritoneal surface malignancy referral, tumor board review, diagnostic laparoscopy, or CRS-HIPEC planning.
- Use intraoperatively or from structured imaging/laparoscopy notes to summarize distribution across all 13 PCI regions.
- Use when comparing disease burden over time, while recognizing that imaging PCI may underestimate small implants or small-bowel mesenteric disease.
How To Interpret
- The total PCI ranges from 0 to 39 and reflects both lesion size and regional distribution.
- Low, moderate, and high burden bands are general workflow prompts; clinically meaningful cutoffs differ by colorectal, appendiceal, gastric, ovarian, mesothelioma, and other disease contexts.
- Small-bowel regions 9-12 require separate attention because bowel/mesenteric involvement can limit complete cytoreduction even when the total score is not extreme.
What To Do Next
- Pair the total PCI with a written description of small-bowel/mesenteric disease, extra-peritoneal disease status, performance status, nutrition, and systemic therapy response.
- Use the PCI vs CC score guide when preparing operative documentation or explaining why PCI and completeness of cytoreduction answer different questions.
- For colorectal pathways, connect PCI with Fong CRS, mGPS/GPS, DPYD activity score, and the colorectal calculator hub.
Limitations
- Do not use one universal PCI cutoff to decide CRS-HIPEC eligibility across all primary tumors.
- Do not treat radiologic PCI and operative PCI as interchangeable; CT can miss small implants and mesenteric disease.
- PCI describes disease burden before or during exploration; it does not document residual disease after cytoreduction.
Validated Population
Originally described for peritoneal carcinomatosis staging and widely used in peritoneal metastases/peritoneal surface malignancy workflows; interpretation depends strongly on primary tumor type and treatment intent.
Clinical Example
A patient with colorectal peritoneal metastases and PCI 12 may still be a difficult CRS-HIPEC candidate if regions 9-12 show confluent small-bowel disease. Conversely, a similar total score concentrated away from critical bowel surfaces may be discussed differently by the peritoneal MDT.
Related Tools
Frequently Asked Questions
What does the PCI score measure?
PCI measures visible peritoneal disease burden by scoring lesion size in 13 regions. It records where disease is present and how large the largest implant is in each region.
Why are small-bowel regions highlighted?
Small-bowel and mesenteric involvement can limit complete cytoreduction even when the total PCI is not extremely high. The workflow flags high burden in regions 9-12 for careful resectability review.
Is there one universal PCI cutoff for CRS-HIPEC?
No. PCI thresholds vary by disease type, tumor biology, center experience, treatment intent, patient fitness, and whether disease involves critical small-bowel surfaces.
How is PCI different from the CC score?
PCI describes disease burden before or during exploration. Completeness of Cytoreduction (CC) score describes visible residual disease after cytoreductive surgery.
Evidence-based oncology decision support. Verify with clinical guidelines.