Direct inguinal hernia

«A direct inguinal hernia arises from protrusion of abdominal viscera through a weakness of the posterior wall of the inguinal canal medial to the inferior epigastric vessels, specifically through the Hesselbach's triangle. This type of hernia is termed direct as the hernial sac directly protrudes through the inguinal wall in contrast to indirect ones which arise through the deep ring and enter the inguinal canal. Since direct hernias do not have a guiding path, they seldom extend into the scrotum unless very large and chronic.»

Source: Jamanetworkcom. Available at: https://jamanetwork.com/data/Journals/JAMA/936324/jpg170007fa.png. Accessed November 27, 2017.

Source: Direct Versus Indirect Inguinal Hernia. Holistic Hernia Remediation. 2016. Available at: http://herniaremediation.org/2016/06/direct-versus-indirect-inguinal-hernia/. Accessed November 27, 2017.

Source: Imagesradiopaediaorg. Available at: https://images.radiopaedia.org/images/1779273/667e66e46b7fe1c61bfa6b9b42a571_gallery.jpg. Accessed November 27, 2017.

Bibliographic reference: Wijayagoonawardana P, et al. Direct inguinal hernia | Radiology Reference Article | Radiopaedia.org. Radiopaediaorg. Available at: https://radiopaedia.org/articles/direct-inguinal-hernia. Accessed November 27, 2017.

Leptomeninges

«The inner two meninges, the arachnoid, and the pia mater, between which circulates the cerebrospinal fluid [1].» «(...). Because the arachnoid is connected to the pia by cobweb-like strands, it is structurally continuous with the pia, hence the name pia-arachnoid or leptomeninges. They are responsible for the production of beta-trace protein (prostaglandin D synthase), a major cerebrospinal fluid protein [2-4].»

Source: Powell S. Introduction to Course and Nervous System. Imagesslideplayercom. 2011. Available at: http://images.slideplayer.com/22/6333238/slides/slide_32.jpg. Accessed November 25, 2017.

Bibliographic references:

[1] leptomeninges | Definition of leptomeninges in English by Oxford Dictionaries. Oxford Dictionaries | English. Available at: https://en.oxforddictionaries.com/definition/leptomeninges. Accessed November 25, 2017.

[2] Meninges. Enwikipediaorg. Available at: https://en.wikipedia.org/wiki/Meninges. Accessed November 25, 2017.

[3] Yamashima T, Sakuda K, Tohma Y, Yamashita J, Oda H, Irikura D, et al. Prostaglandin D synthase (beta-trace) in human arachnoid and meningioma cells: roles as a cell marker or in cerebrospinal fluid absorption, tumorigenesis, and calcification process. J Neurosci. 1997 Apr 1;17(7):2376-82.

[4] Prostaglandin D2 synthase. TheFreeDictionarycom. 2014. Available at: https://encyclopedia.thefreedictionary.com/Prostaglandin+D2+synthase. Accessed November 25, 2017.

Carcinomatous meningitis

«Carcinomatous meningitis, also called meningeal carcinomatosis, neoplastic meningitis, or leptomeningeal carcinoma, is a form of metastatic cancer that has spread to the lining of the brain and spinal cord, the parts of the body that make up the central nervous system [1].» It «is a clinical syndrome caused by leptomeningeal metastases with widespread involvement of the cerebral cortex. The disease is associated with a poor prognosis [2].»

Source: Aboutcancercom. Available at: http://www.aboutcancer.com/meniingitis_1208_bmc.jpg. Accessed November 25, 2017.

Bibliographic reference:

[1] Carcinomatous Meningitis - Dictionary definition of Carcinomatous Meningitis | Encyclopedia.com: FREE online dictionary. Encyclopediacom. Available at: http://www.encyclopedia.com/medicine/encyclopedias-almanacs-transcripts-and-maps/carcinomatous-meningitis. Accessed November 25, 2017.
[2] Kehrer JD, Stall B. 87 - Brain Metastases. In: Hristov B, Lin S, Christodouleas J. Radiation Oncology. 2nd ed. Philadelphia, USA: Wolters Klumer Health; 2015:568.

Single brain metastases

It «is only one brain lesion in addition to other sites of disease.»
Bibliographic reference: Kehrer JD, Stall B. 87 - Brain Metastases. In: Hristov B, Lin S, Christodouleas J. Radiation Oncology. 2nd ed. Philadelphia, USA: Wolters Klumer Health; 2015:567.

Solitary brain metastases

It «is only one brain lesion and the only site of disease.»
Bibliographic reference: Kehrer JD, Stall B. 87 - Brain Metastases. In: Hristov B, Lin S, Christodouleas J. Radiation Oncology. 2nd ed. Philadelphia, USA: Wolters Klumer Health; 2015:567.

Mesorectal fascia (MRF)

In total mesorectal excision (TME), «the entire mesorectal compartment including the rectum, surrounding mesorectal fat, perirectal lymph nodes, and its envelope, the MRF, is completely removed by precise dissection along anatomical planes [1].»«The mesorectal fat is surrounded by the MRF, (...) [1].» It surrounds the mesorectal fat outside the rectum or the sphincters in the lowest part [2]:

IMA: inferior mesenteric artery; IMV: inferior mesenteric vein.

Source: Khatri VP, Rodrigues-Bigas MA, Flewell R, Petrelli NJ. Operative Approach to Rectal Cancer: An Anatomical and Technical Description. Surg Oncol. 2018 Jun;27(2):A5-A15. Available at: https://doi.org/10.1016/j.suronc.2018.05.033.

Source: The Radiology Assistant: Rectal Cancer - MR staging 2.0. Radiologyassistantnl. Available at: http://www.radiologyassistant.nl/en/p56195b237699d/rectal-cancer-mr-staging-20.html. Accessed November 17, 2017.

Source: The Radiology Assistant: Rectal Cancer - MR staging 2.0. Radiologyassistantnl. Available at: http://www.radiologyassistant.nl/en/p56195b237699d/rectal-cancer-mr-staging-20.html. Accessed November 17, 2017.

«The MRF is only circumferential in the low-rectum below the anterior peritoneal reflection.The MRF does not apply to the anterior peritonealized surface of the anterior mid- and high rectum [1]»:

Source: The Radiology Assistant: Rectal Cancer - MR staging 2.0. Radiologyassistantnl. Available at: http://www.radiologyassistant.nl/en/p56195b237699d/rectal-cancer-mr-staging-20.html. Accessed November 17, 2017.

«The MRF plays a crucial role in the treatment planning. In TME the mesorectal fascia is the resection plane and it has to be tumor-free. A distance of the tumor to the mesorectal fascia of ⩽1 mm is regarded as not suitable for TME and is called an involved MRF [1].»

Source: The Radiology Assistant: Rectal Cancer - MR staging 2.0. Radiologyassistantnl. Available at: http://www.radiologyassistant.nl/en/p56195b237699d/rectal-cancer-mr-staging-20.html. Accessed November 17, 2017.

T-stage and mesorectal fascia involvement in the axial plane

Source: The Radiology Assistant: Rectal Cancer - MR staging 2.0. Radiologyassistantnl. Available at: http://www.radiologyassistant.nl/en/p56195b237699d/rectal-cancer-mr-staging-20.html. Accessed November 17, 2017.

«Low rectal cancer has a higher local recurrence rate. The distal tapering of the mesorectal fat implies that low rectal cancer more easily invades the MRF, pelvic wall, and surrounding organs [1]»:

Source: The Radiology Assistant: Rectal Cancer - MR staging 2.0. Radiologyassistantnl. Available at: http://www.radiologyassistant.nl/en/p56195b237699d/rectal-cancer-mr-staging-20.html. Accessed November 17, 2017.

«The low rectum is totally covered by the mesorectal fascia. In the mid-rectum, it is covered by the mesorectal fascia on the posterior and lateral side, but on the anterior side, it is covered by the visceral peritoneum [1].»

Bibliographic references:

[1] The Radiology Assistant: Rectal Cancer - MR staging 2.0. Radiologyassistantnl. Available at: http://www.radiologyassistant.nl/en/p56195b237699d/rectal-cancer-mr-staging-20.html. Accessed November 17, 2017.
[2] Glimelius B, Beets-Tan R, Blomqvist L, et al. Mesorectal fascia instead of circumferential resection margin in preoperative staging of rectal cancer. J Clin Oncol. 2011 Jun 1;29(16):2142-3. Available at: https://doi.org/10.1200/JCO.2010.34.4473.

UICC

Union for International Cancer Control

Circumferential resection margin

«The circumferential resection margin (CRM) is a term used in rectal carcinoma excision surgery. Pathologic evaluation of the resection margin on the excised rectum has been considered important for determining the risk of local recurrence. A margin of ≤1 mm is considered by some to be a negative prognostic factor for local recurrence (Park JS, et al., 2014, apud 1). (...). The CRM is not valid for excised colon covered by a peritoneal lining [1].» It is defined as the shortest distance from an affected region to the mesorectal fascia (MRF) and should be at least 1 mm [2]. It also called the radial margin. 

Bibliographic references:

[1] Weerakkody Y, Morgan M, et al. Circumferential resection margin | Radiology Reference Article | Radiopaedia.org. Radiopaediaorg. Available at: https://radiopaedia.org/articles/circumferential-resection-margin. Accessed November 17, 2017.
[2] Bond S, Joshi N, Petroudi S, Brady M. Estimating the mesorectal fascia in MRI. Inf Process Med Imaging. 2007;20:650-61. Available at: https://doi.org/10.1007/978-3-540-73273-0_54.

Bystander effects

«Bystander effects describe the ability of an irradiated cell to send a signal capable of eliciting a response in a nonirradiated cell. This signal may be communicated via cell-to-cell gap junction communication and/or from secreted or shed factors from irradiated cells [1].»

Bibliographic references:

[1] Varnum SM, Sowa MB, and Morgan WF. (2013). B. In: L. Brady and T. Yaeger, ed., Encyclopedia of Radiation Oncology, 1st ed. Springer-Verlag Berlin Heidelberg, pp.75.

Whole pelvic radiotherapy plus androgen deprivation therapy in prostate cancer

Better outcomes in postprostatectomy salvage radiotherapy for prostate cancer: http://www.europeanurology.com/article/S0302-2838(17)30900-4/fulltext#/article/S0302-2838(17)30900-4/fulltext.

Blogs Portugal

Há pouco tempo, aderi à plataforma Blogs Portugal (https://blogsportugal.com) e fiquei surpreendida com o ranking nacional deste blog, o Radiotherapy Dictionary. Além disso, a plataforma Blogs Portugal permite classificar os blogs portugueses no geral e por categorias e aceder a muitos benefícios, por intermédio de campanhas e através da divulgação dos blogs aderentes. Blogueiros, experimentem! (Portuguese)

Not long ago, I joined the platform Blogs Portugal and I was surprised by the national ranking of this blog, the Radiotherapy Dictionary. In addition, the Blogs Portugal platform allows ranking Portuguese blogs in general and by categories and access to many benefits, through campaigns and through the dissemination of blogs. Bloggers, try!

When cells go bad

When cells go bad

CTLA-4 (CD152)

The cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), or cluster of differentiation 152 (CD152), is a receptor on activated T cells that, functioning as an immune checkpoint, downregulates immune responses. It is constitutively expressed in regulatory T cells but only upregulated in conventional T cells after activation. It acts as an off switch when bound to CD80 or CD86 on the surface of antigen-presenting cells [2]. It binds B7 molecules with a higher affinity than CD28, downregulating T-cell responses by inhibiting CD28 signaling [1].
CD80/CD86 are members of the immunoglobulin superfamily and present on mature antigen-presenting cells. They share their ligands (CD28 and CTLA-4) on T cells and play a major role as costimulatory molecules in the major histocompatibility complex class II-mediated peptide antigen presentation [1].
B7 molecules are a family of cell-surface proteins that function as costimulatory molecules transducing second signals for T cell-dependent immune responses [1].
CD28 is an activating receptor for B7 molecules present on naive T cells. The interaction of CD28 with B7 molecules provides the costimulatory or second signal for T-cell activation [1].
«(...) there is increasing interest in the possible therapeutic benefits of blocking CTLA-4 (using antagonistic antibodies against CTLA such as ipilimumab (FDA [Food and Drug Administration] approved for melanoma in 2011) as a means of inhibiting immune system tolerance to tumours and thereby providing a potentially useful immunotherapy strategy for patients with cancer» [2].

How does CTLA-4 prevent T-cell activation? Explore how tumor cells may use CTLA-4 to suppress the immune response:

Bibliographic references:

[1] Tortora, G., Bergmann, L., Lindh, M., Cervantes-Ruiperez, A., Dziadziuszko, R., Eckhardt, S., Lenz, H., Normanno, N., Perez, D., Scarpa, A., Syrigos, K., Tabernero, J. and Troiani, T. (2014). ESMO glossary in molecular biology of cancer. Viganello-Lugano, Switzerland: European Society for Medical Oncology.
[2] CTLA-4. Enwikipediaorg. 2017. Available at: https://en.wikipedia.org/wiki/CTLA-4. Accessed November 6, 2017.