TGR (tumor regression grade) in rectal cancer

Pathological features, or TGR, of rectal cancer after preoperative radiochemotherapy:

Source: Dworak O, et al, 1997, cited by Park YJ, Oh BR, Lim SW, Huh JW, Joo JK, Kim YJ, Kim HR. Clinical significance of tumor regression grade in rectal cancer with preoperative chemoradiotherapy. J Korean Soc Coloproctol. 2010 Aug;26(4):279-86. Available at: https://doi.org/10.3393/jksc.2010.26.4.279.

TRG (tumor regression grade) in esophageal carcinoma

Pathological response grading or TRG following neoadjuvant chemoradiation in oesophageal cancer:

Source: Mandard AM, et al., 1994, cited by Gillham CM, Reynolds J, Hollywood D. Predicting the response of localised oesophageal cancer to neo-adjuvant chemoradiation. World J Surg Oncol. 2007 Aug 23;5:97. Available at: https://doi.org/10.1186/1477-7819-5-97.

December 2017 issue of «highlights» from ENLIGHT

Highlights December 2017, from ENLIGHT.

ENLIGHT

The European Network for LIGht ion Hadron Therapy.

Metastasis-directed treatment improves progression-free survival in prostate cancer

Check the Tweet @AmerUrological: https://twitter.com/AmerUrological/status/943111372270964736?s=09

Integração de novas formas de radioterapia na prática clínica (Portuguese) (integration of new forms of radiotherapy in clinical practice)

Interview with the president of SPRO (Portuguese Society of Radiation Oncology), Dr. Lurdes Trigo:

The 5 C's - remember the basics (editing)

From Visually.

Non-small cell lung cancer treatment (r)evolution: ten years of advances and more to come. ecancermedicalscience - The open access journal from the European Institute of Oncology and the OCEI

Non-small cell lung cancer treatment (r)evolution: ten years of advances and more to come. ecancermedicalscience - The open access journal from the European Institute of Oncology and the OCEI

Source: Toschi L, Rossi S, Finocchiaro G, Santoro A. Non-small cell lung cancer treatment (r)evolution: ten years of advances and more to come. ecancermedicalscience. 2017;11. doi:10.3332/ecancer.2017.787.

Source: Toschi L, Rossi S, Finocchiaro G, Santoro A. Non-small cell lung cancer treatment (r)evolution: ten years of advances and more to come. ecancermedicalscience. 2017;11. doi:10.3332/ecancer.2017.787.

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.

Medical dosimetrist

http://magicvalley.com/news/local/what-s-a-certified-medical-dosimetrist/article_105b5227-04b6-5635-aeff-a33bf0a0aca0.amp.html

PSA (prostate specific antigen) density

PSA density (ng/mL² or ng/mL/cc) is calculated preoperatively during the biopsy procedure by using transrectal ultrasound by dividing the maximum preoperative PSA value and prostate volume [1]. The latter is calculated based on the ellipse dimension theory formula [2] (D1 × D2 × D3 × pi/6), where D1 is the maximum transverse diameter, D2 is the maximum anteroposterior diameter, D3 is the maximum longitudinal diameter, and pi is a mathematical constant approximately equal to 3.14.

A study of a large cohort of patients (1662 patients) found a significant trend of worsening pathological features as PSA density increases [3]. Other studies [4,5] found that PSA density (using a pathological weight of the surgical specimen) was a better predictor of extracapsular disease, positive surgical margins, seminal vesicle invasion, lymph node invasion and biochemical recurrence than PSA.
«A PSAD of >0.15 ng/mL/cm³ identifies men with a higher risk of detecting prostate cancer on a screening biopsy» [6].

«It is used because an elevated PSA might not arouse suspicion in a man with a very enlarged prostate. The use of PSA density to interpret PSA results is controversial because prostate cancer might be overlooked in a man with an enlarged prostate» [7].

Bibliographic references:

[1] Sfoungaristos S, Perimenis P. Evaluating PSA Density as a Predictor of Biochemical Failure after Radical Prostatectomy: Results of a Prospective Study after a Median Follow-Up of 36 Months. ISRN Urol. 2013 May 16;2013:984951. Available at: https://doi.org/10.1155/2013/984951.

[2] Wolff JM, Boeckmann W, Mattelaer P, et al. Determination of prostate gland volume by transrectal ultrasound: correlation with radical prostatectomy specimens. Eur Urol. 1995;28(1):10-2. Available at: https://doi.org/10.1159/000475012.

[3] Kundu SD, Roehl KA, Yu X, et al. Prostate specific antigen density correlates with features of prostate cancer aggressiveness. J Urol. 2007 Feb;177(2):505-9. Available at: https://doi.org/10.1016/j.juro.2006.09.039.

[4] Freedland SJ, Wieder JA, Jack GS, et al. Improved risk stratification for biochemical recurrence after radical prostatectomy using a novel risk group system based on prostate specific antigen density and biopsy Gleason score. J Urol. 2002 Jul;168(1):110-5. Available at: http://dx.doi.org/10.1016/S0022-5347(05)64841-0.

[5] Sfoungaristos S, Perimenis P. PSA density is superior than PSA and Gleason score for adverse pathologic features prediction in patients with clinically localized prostate cancer. Can Urol Assoc J. 2012 Feb;6(1):46-50. Available at: https://doi.org/10.5489/cuaj.11079.

[6] Shah A. 53 - Low-Risk Prostate Cancer. In: Hristov B, Lin S, Christodouleas J. Radiation Oncology. 2nd ed. Philadelphia, USA: Wolters Klumer Health; 2015:366.
[7] Definition of PSA density. Phoenix5org. 2002. Available at: http://www.phoenix5.org/glossary/PSA_density.html. Accessed October 19, 2017.

Biochemical failure in prostate cancer

«The definition of biochemical recurrence following radiation therapy is complicated by the incomplete ablation of all functioning prostatic epithelium, which creates difficulty in establishing a meaningful absolute nadir and the phenomenon of “prostate-specific antigen (PSA) bounce”» [4]. Biochemical failure after primary radiotherapy with or without hormonal therapy in men with clinically localized prostate cancer by 2005 RTOG-ASTRO Phoenix Consensus Conference is: 1) PSA rise by 2 ng/mL or more above the nadir PSA; and 2) a recurrence evaluation should be considered when PSA has been confirmed to be increasing after radiation even if the rise above nadir is not yet 2 ng/mL, especially in candidates for salvage local therapy who are young and healthy [1]. The rise has to be at least 25% over nadir [5]. «This definition accepts some limitation on sensitivity in the interest of increased specificity for detecting failures associated with clinical outcomes other than cure» [4].
Following radical prostatectomy, a cutoff of 0.2 ng/mL has been associated with a high likelihood of subsequent PSA progression [2]. More recently, 0.4 ng/mL and rising has been proposed as a definition associated more closely with the development of distant metastases [3]. However, according to the ASTRO/AUA (American Urological Association) guidelines [6], «biochemical (PSA) recurrence after surgery is defined as detection of PSA concentration at 0.2 ng/mL, with a second confirmatory level detected at 0.2 ng/mL.»
Following salvage radiotherapy, biochemical recurrence is «defined as a rise in PSA ≥ 0.2 ng/ml above the PSA nadir followed by a sequentially equal or higher value [7].»

Bibliographic references:

[1] Roach M 3rd, Hanks G, Thames H Jr, et al. Defining biochemical failure following radiotherapy with or without hormonal therapy in men with clinically localized prostate cancer: recommendations of the RTOG-ASTRO Phoenix Consensus Conference. Int J Radiat Oncol Biol Phys. 2006 Jul 15;65(4):965-74. Available at: https://doi.org/10.1016/j.ijrobp.2006.04.029.
[2] Freedland SJ, Sutter ME, Dorey F, Aronson WJ. Defining the ideal cutpoint for determining PSA recurrence after radical prostatectomy. Prostate-specific antigen. Urology. 2003 Feb;61(2):365-9. Available at: http://dx.doi.org/10.1016/S0090-4295(02)02268-9.
[3] Amling CL, Bergstralh EJ, Blute ML, et al. Defining prostate specific antigen progression after radical prostatectomy: what is the most appropriate cut point? J Urol. 2001 Apr;165(4):1146-51. Available at: http://dx.doi.org/10.1016/S0022-5347(05)66452-X.
[4] Nielsen ME, Partin AW. The Impact of Definitions of Failure on the Interpretation of Biochemical Recurrence Following Treatment of Clinically Localized Prostate Cancer. Rev Urol. 2007 Spring;9(2):57-62.
[5] Lowrance WT, Roth BJ, Kirkby E, Murad MH, Cookson MS. Castration-Resistant Prostate Cancer: AUA Guideline Amendment 2015. J Urol. 2016 May;195(5):1444-52. Available at: https://doi.org/10.1016/j.juro.2015.10.086.
[6] Valicenti RK, Thompson I Jr, Albertsen P, et al. Adjuvant and salvage radiation therapy after prostatectomy: American Society for Radiation Oncology/American Urological Association guidelines. Int J Radiat Oncol Biol Phys. 2013 Aug 1;86(5):822-8. Available at: https://doi.org/10.1016/j.ijrobp.2013.05.029.
[7] Jackson WC, Suresh K, Tumati V, et al. Impact of Biochemical Failure After Salvage Radiation Therapy on Prostate Cancer-specific Mortality: Competition Between Age and Time to Biochemical Failure. Eur Urol Oncol. 2018 Sep;1(4):276-282. Available at: https://doi.org/10.1016/j.euo.2018.04.014. 

SBRT to personalized treatment of oligometastases

https://astroblog.weebly.com/blog/using-sbrt-to-enable-personalized-treatment-of-oligometastases?platform=hootsuite

AFU

Association Française d’Urologie, the French Association of Urology.

GETUG

Groupe d'Études des Tumeurs Uro-Génitales, the French Genitourinary Study Group.

Electromagnetic tracking system (EMTS)

Image-guided therapy relies on the localization of the equipment with respect to the patient. This localization in three-dimensional space is referred to as tracking and is a key enabling technology for computer-assisted interventions. Electromagnetic (EM) tracking has emerged as the method of choice that enables localization of small EM sensors in a given EM field without the requirement for line-of-sight [3]. The introduction of continuous EM tracking has allowed the intrafraction motion to be measured and corrected in real-time during treatment [2]. When a receiving sensor moving in space, an EMTS can accurately calculate its position and orientation, it can provide dynamic, real-time measuring position and orientation angle [1].
«The term “electromagnetic” to describe the tracking phenomenon arises from the fact that electromagnets are responsible for producing changing or quasi-static magnetic fields, which induce currents in solenoids or fluxgate sensors embedded in the detectors. The phenomenon responsible for the operation of these tracking systems relies solely on magnetic induction rather than any strict electromagnetic effect. Nevertheless, while this technology is referred to by both the terms “magnetic tracking” (MT) and “electromagnetic tracking” (EMT), the latter has become the more common, having been adopted by the manufacturers of these devices, (...) [3].»

Bibliographic references:

[1] Zhang Z, Liu G. The Design and Analysis of Electromagnetic Tracking System. Journal of Electromagnetic Analysis and Applications. 2013;5:85-9. Available at: http://dx.doi.org/10.4236/jemaa.2013.52014.

[2] Litzenberg DW, Gallagher I, Masi KJ, et al. A measurement technique to determine the calibration accuracy of an electromagnetic tracking system to radiation isocenter. Med Phys. 2013 Aug;40(8):081711. Available at: https://doi.org/10.1118/1.4813910.

[3] Franz AM, Haidegger T, Birkfellner W, et al. Electromagnetic tracking in medicine - a review of technology, validation, and applications. IEEE Trans Med Imaging. 2014 Aug;33(8):1702-25. Available at: https://doi.org/10.1109/TMI.2014.2321777.

SPECT (single photon emission computed tomography)

SPECT, or less commonly, SPET [3], is a medical imaging technique that is based on conventional nuclear medicine imaging, using gamma rays, and tomographic reconstruction methods. It is «performed by using a gamma camera to acquire multiple two-dimensional (2D) images from multiple angles» [4]. «The images reflect functional information about patients similar to that obtained with positron emission tomography (PET). Both SPECT and PET (...) give information based on the spatial concentration of injected radiopharmaceuticals» [1]. It «is a type of nuclear imaging test that shows how blood flows to tissues and organs» [2]. It is very similar to conventional nuclear medicine planar imaging using a gamma camera (that is, scintigraphy), but, it is able to provide true three-dimensional (3D) information [3]. A computer is used to apply a tomographic reconstruction algorithm to the multiple 2D projections, yielding a 3D dataset. «This dataset may then be manipulated to show thin slices along any chosen axis of the body» [4]. SPECT can be used to complement any gamma imaging study, where a true 3D representation can be helpful, (e.g., tumor imaging, infection (leukocyte) imaging, thyroid imaging or bone scintigraphy). Because SPECT permits accurate localization in 3D space, it can be used to provide information about the localized function in internal organs, such as functional cardiac or brain imaging [3].

Bibliographic references:

[1] National Research Council (US) and Institute of Medicine (US) Committee on the Mathematics and Physics of Emerging Dynamic Biomedical Imaging. Mathematics and Physics of Emerging Biomedical Imaging. Washington (DC): National Academies Press (US); 1996. Chapter 5, Single Photon Emission Computed Tomography. Available at: https://www.ncbi.nlm.nih.gov/books/NBK232492/. Accessed October 15, 2017.

[2] SPECT (single photon emission computed tomography) scan. Mayfield Brain & Spine. 2016. Available at: https://www.mayfieldclinic.com/PE-SPECT.htm. Accessed October 15, 2017.

[3] Single-photon emission computed tomography. Enwikipediaorg. 2017. Available at: https://en.wikipedia.org/wiki/Single-photon_emission_computed_tomography. Accessed October 15, 2017.
[4] Hricak H, Akin O, Vargas HA. (2013). C. In: L. Brady and T. Yaeger, ed., Encyclopedia of Radiation Oncology, 1st ed. Springer-Verlag Berlin Heidelberg, pp.790.

Dia do Interno Radioncologia (Portuguese) (Radiation Oncology Resident's Day)

• Venue: October 20, 2017 - Hospital de Santa Maria, Centro Hospitalar Lisboa Norte, EPE, Lisbon, Portugal:

• Free registration, deadline: October 2, 2017 - diadointernospro@gmail.com
• Program:

New IMRT technique used for first time on head and neck cancer patient

I wanted to share this interesting News Item from ecancer: 'New IMRT technique used for first time on head and neck cancer patient' http://ecancer.org/news/12406-new-imrt-technique-used-for-first-time-on-head-and-neck-cancer-patient.php

Endorectal Brachytherapy Boost After External Beam Radiation Therapy in Elderly or Medically Inoperable Patients With Rectal Cancer: Primary Outcomes of the Phase 1 HERBERT Study

Endorectal Brachytherapy Boost After External Beam Radiation Therapy in Elderly or Medically Inoperable Patients With Rectal Cancer: Primary Outcomes of the Phase 1 HERBERT Study: To evaluate the toxicity and efficacy of the combination of external beam radiation therapy (EBRT) followed by high-dose-rate endorectal brachytherapy (HDREBT) boost in elderly and medically inoperable patients with rectal cancer.

Preoperative chemotherapy versus chemoradiotherapy in locally advanced adenocarcinomas of the oesophagogastric junction (POET): Long-term results of a controlled randomised trial

Preoperative chemotherapy versus chemoradiotherapy in locally advanced adenocarcinomas of the oesophagogastric junction (POET): Long-term results of a controlled randomised trial: Results of the PreOperative therapy in Esophagogastric adenocarcinoma Trial (POET)
showed some benefits when including radiotherapy into the preoperative treatment.
This article is reporting long-term results of this phase III study.

ITV (internal target volume)

It consists of an internal margin added to the CTV to compensate for internal physiologic movement and variations in size, shape, and position of the CTV [1]. It's an expansion of CTV for internal (e.g. breathing) movement [2].

Bibliographic references:

[1] Reiff J. E. (2013). C. In: L. Brady and T. Yaeger, ed., Encyclopedia of Radiation Oncology, 1st ed. Springer-Verlag Berlin Heidelberg, pp.343-399.

[2] Balter J. Target definition (margin selection) for radiotherapy (IMRT). aapmorg. 2017. Available at: https://www.aapm.org/meetings/03SS/Presentations/Balter.pdf. Accessed September 11, 2017.

Moulding a radiotherapy mask

Conformity index (CI)

It is defined as the ratio of the treated volume to the PTV (planning target volume) [1]. It is a tool for treatment plan analysis in conformal radiotherapy [2].

Bibliographic references:

[1] International Commission on Radiation Units and Measurements. ICRU Report 62. Prescribing, Recording and Reporting Photon Beam Therapy. Supplement to ICRU Report 50. Bethesda, MD: ICRU; 1999.

[2] Kataria T, Sharma K, Subramani V, et al. Homogeneity Index: An objective tool for assessment of conformal radiation treatments. J Med Phys. 2012 Oct;37(4):207-13. Available at https://doi.org/10.4103/0971-6203.103606.

PARP (poly-[adenosine diphosphate-ribose] polymerase)

Poly-(ADP)-ribose polymerase is «a family of proteins involved in a number of cellular processes involving mainly DNA [deoxyribonucleic acid] repair and programmed cell death. The PARP family comprises 17 members (10 putative). They have all very different structures and functions in the cell. One important function of PARP is assisting in the repair of single-strand DNA breaks [1]». It is «a SSB [single-strand break] detector protein» [2].
«Drugs which inhibit (...) PARP (...) are particularly effective in tumors with HR [homologous recombination] deficiencies, such as breast tumors with BCRA1 or BCRA2 [breast cancer 1 or 2] deficiencies. (...) probably (...) PARP inhibitors suppress SSB repair, resulting in greater numbers of unrepaired SSBs, which therefore have a greater chance of hitting a replication fork. Under normal circumstances, the resulting DSB [double-strand break] would be repaired by HR, so the absence or reduction of this backup pathway leads to a substantial increase in DSBs and thus cellular lethality [2].»

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, p.127.

[2] Joiner, M. and Kogel, A. (2009). Basic clinical radiobiology. 1st ed. Boca Raton, Florida: CRC Press, p.24.

Cytoreduction

It is the debulking, or reduction «(...) of the size of, a cancerous tumor. Surgery and radiation therapy are two common cytoreductive treatments used to debulk tumors. Debulking means to remove as much of the cancer as possible [1].» «(...) "cytoreduction" refers to reducing the number of tumor cells [2].» «Tumor debulking may increase the chance that chemotherapy or radiation therapy will kill all the tumor cells. It may also be done to relieve symptoms or help the patient live longer [3].» 

Bibliographic references:

[1] CancerCenter.com. (2017). Cytoreductive Therapy : Cancer Glossary | CTCA. [online] Available at: http://www.cancercenter.com/terms/cytoreductive-therapy/ [Accessed 15 May 2017].

[2] En.wikipedia.org. (2017). Debulking. [online] Available at: https://en.wikipedia.org/wiki/Debulking [Accessed 15 May 2017].

[3] National Cancer Institute. (n.d.). NCI Dictionary of Cancer Terms. [online] Available at: https://www.cancer.gov/publications/dictionaries/cancer-terms?cdrid=46635 [Accessed 15 May 2017].

Adjuvant therapy

It is an «additional cancer treatment given after the primary treatment to lower the risk that (...) cancer will come back. Adjuvant therapy may include chemotherapy, radiation therapy, hormone therapy, targeted therapy, or biological therapy.»

Bibliographic reference: National Cancer Institute. (n.d.). NCI Dictionary of Cancer Terms. [online] Available at: https://www.cancer.gov/publications/dictionaries/cancer-terms?CdrID=45587 [Accessed 10 May 2017].

p53

It «(...) is one of the most commonly mutated tumor suppressors whose function is to regulate genes that control both cell cycle checkpoints and (...) apoptosis. Consequently, activation of p53 after irradiation can lead either to a block in proliferation or directly to cell death. (...) in unstressed normal cells, p53 is made continuously but is degraded and thus non-functional. Following DNA [deoxyribonucleic acid] damage, ATM [ataxia telangiectasia mutated] phosphorylates both p53 and MDM2 [murine double minute 2]. These events destabilize the p53-MDM2 interaction, and (...) p53 protein is no longer degraded. In addition to this stabilization, direct phosphorylation of p53 by ATM leads to its activation as a transcription factor and thus the upregulation of its many target genes [1].»

«Cells irradiated in the G1 phase are influenced by the action of p53. ATM protein is activated by double-strand DNA breaks and phosphorylates both MDM2 and p53. This leads to stabilization and activation of p53, which induces genes that can promote apoptosis (Bax [Bcl-2-associated X], Puma [p53 upregulated modulator of apoptosis]) and induces checkpoints. (...) cells are blocked at the G1/S border [1].»

Is has «(...) a mass of 53 kDa (hence its name); p53 protein is normally induced in cells having undergone DNA damage, (...); its principal effects are to stop the cell cycle and prevent the cell from undergoing mitosis; thus, DNA mutations/damage can either be repaired or a damaged cell can be eliminated from the organism, for example via apoptosis. p53 is also known as the guardian of the genome [2].»

Bibliographic references:

[1] Joiner, M. and Kogel, A. (2009). Basic clinical radiobiology. 1st ed. Boca Raton, Florida: CRC Press, p.17.

[2] 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, p.117.

Ratio

It's the relationship between two sets with different characteristics. The numerator is not included in the denominator. It is different from proportion.

Proportion

It's the relationship between the number of individuals who have a characteristic and the total population. The numerator is included in the denominator. It is different from ratio.

Symbols with short codes

In: Awesome Daily Staff. StumbleUpon. Stumbleuponcom. 2014. Available at: http://www.stumbleupon.com/su/2XigqH. Accessed February 25, 2017.

Lower urothelium (or lower transitional cell epithelium)

It coats the interior walls of the «urinary bladder, the ureters, the superior urethra, and the prostatic and ejaculatory ducts of the prostate.»

Bibliographic reference: Transitional epithelium. Enwikipediaorg. 2017. Available at: https://en.wikipedia.org/wiki/Transitional_epithelium. Accessed February 20, 2017.

Upper urothelium (or upper transitional cell epithelium)

It coats the interior walls of the pyelocaliceal cavities and ureter.

Bibliographic references: Rouprêt M, Babjuk M, Böhle A, et al. Upper Urinary Tract Urothelial Cell Carcinoma. EAU - European Association of Urology. 2017. Available at: https://uroweb.org/guideline/upper-urinary-tract-urothelial-cell-carcinoma/#3. Accessed February 20, 2017.

Urological organs

«The organs under the domain of urology include the kidneys, adrenal glands, ureters, urinary bladder, urethra, and the male reproductive organs (testes, epididymis, vas deferens, seminal vesicles, prostate, and penis).»

Bibliographic reference: Urology. Enwikipediaorg. 2016. Available at: https://en.wikipedia.org/wiki/Urology. Accessed February 20, 2017.

Redistribution

«Reassortment. The radiosensitivities of cells vary according to phases of the cell cycle.» «The duration of the cell cycle phases are: G1 = 1.5–14 h, S = 6–9 h, G2 = 1–5 h, and M = 0.5–1 h. The most sensitive are M and G2. The most resistant is S.» «Cells in the resistant phases of the cell cycle may progress into the sensitive phases in the next fraction, when radiation is given in fractions. Therefore, the probability of tumor cells to be exposed to radiation at sensitive phases increases. This probability will continue for the whole treatment, and the benefit from radiation will increase.»

Bibliographic reference: Beyzadeoglu M, Ozyigit G, Selek U. Radiation Oncology. 1st ed. Berlin: Springer; 2012:112-114.

¿Qué es la radioterapia?

Radiodermatitis or radiation dermatitis

It «is a cutaneous inflammatory reaction to exposure to biologically effective levels of ionizing radiation» [1]. It «can range from erythema to wet desquamation of the skin (tissue sloughing) in acute form; tissue atrophy, fibrosis, and permanent scarring in chronic form. Permanent changes in skin pigmentation can also occur» [2].

Source: Aistars J, Vehlow K. Radiation Dermatitis | Cancer Network. Cancernetworkcom. 2007. Available at: http://www.cancernetwork.com/oncology-nursing/radiation-dermatitis. Accessed March 30, 2018.

Source: Madhavan R. Radiation in oral cancers. Slidesharenet. 2017. Available at: https://www.slideshare.net/ramumpanicker/radiation-in-oral-cancers. Accessed March 30, 2018.

How to care for your skin during radiation therapy:

Bibliographic references:
[1] Radiodermatitis. (n.d.) Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. (2003). Retrieved January 7 2017 from http://medical-dictionary.thefreedictionary.com/radiodermatitis.
[2] Radiation dermatitis. (n.d.) Medical Dictionary for the Health Professions and Nursing. (2012). Retrieved January 7 2017 from http://medical-dictionary.thefreedictionary.com/radiation+dermatitis.