The calculator in question is the TNM Classification for Duodenal Neuroendocrine Tumors. TNM stands for Tumor, Node, Metastasis, a system used to classify malignant tumors. This specific TNM classification is applicable to patients diagnosed with neuroendocrine tumors in the duodenum, a part of the small intestine.

The clinical utility of this calculator is to stage the cancer, which helps in determining the severity or extent of the cancer in the body. It provides valuable information about the size of the primary tumor (T), whether the cancer has spread to the lymph nodes (N), and the presence of distant metastasis (M). This information is crucial in planning the treatment strategy and predicting the patient's prognosis.

There are no specific exclusion criteria for the use of the TNM Classification for Duodenal Neuroendocrine Tumors. However, it is not applicable to patients with neuroendocrine tumors located in other parts of the body or to those with non-neuroendocrine tumors.

TNM classification for duodenal neuroendocrine tumors

# Criteria
 ## Tumor classification
A. Tx: Primary tumor cannot be assessed
B. T0: No evidence of primary tumor
C. T1: Tumor <= 1 cm and invades mucosa or submucosa only, confined within sphincter of Oddi for ampullary tumors
D. T2: Tumor > 1 cm or invades muscularis propria for duodenal tumors and
invades through sphincter into duodenal submucosa or muscularis propria for ampullary tumors
E. T3: Tumor invades pancreas or peripancreatic adipose tissue
F. T4: Tumor invades visceral peritoneum or other organs
## Lymph node classification
G. Nx: Regional lymph nodes cannot be assessed
H. N0: No regional lymph node metastasis
I. N1: Regional lymph nodes metastases present
## Distant metastasis
J. M0: No distant metastasis
K. M1a: Metastasis confined to liver
L. M1b: Metastases in >= 1 extrahepatic site, such as lung, ovary, nonregional lymph node, peritoneum, and bone
M. M1c: Metastases in both hepatic and extrahepatic sites

# Conditions
- C and H and J
- (D or E) and H and J
- (F and H and J) or ((C or D or E or F) and I and J)
- (C or D or E or F) and (H or I) and (K or L or M)
- true