The risk of cancer following high, and very high, doses of ionising radiation

Multiple primary cancers with gastrointestinal malignant tumors as the first manifestation: Three case reports and review of literature

BACKGROUND

The incidence of malignant gastrointestinal (GI) tumors is increasing, and advancements in medical care have significantly improved patient survival rates. As a result, the number of cases involving multiple primary cancers (MPC) has also increased. The rarity of MPC and the absence of sensitive and specific diagnostic markers often lead to missed or incorrect diagnoses. It is, therefore, of vital importance to improve the vigilance of clinicians and the accurate diagnosis of this disease. Patients with GI malignancies face a higher relative risk of developing additional primary malignant tumors compared to those with other systemic tumors. Vigilant monitoring and follow-up are crucial, especially for high-risk groups, which include older adults, men, those with addictions to alcohol and tobacco, those with a family history of tumors, and those who have undergone radiotherapy.

CASE SUMMARY

In this article, we report three cases of MPC, each involving malignant tumors of the GI tract as the initial primary carcinoma, offering insights that may aid in effectively managing similar cases.

CONCLUSION

Patients with GI malignancies face a higher MPC risk. Developing screening and follow-up protocols may enhance detection and treatment outcomes.

A case of metachronous triple primary carcinoma complicated with pulmonary tuberculosis: Case report and review

RATIONALE

Multiple primary malignant neoplasms with tuberculosis are rare. The interaction between tuberculosis and tumor remains unclear. Moreover, the treatment of multiple primary tumors combined with tuberculosis is relatively complicated. Herein, we report a case of metachronous triple primary carcinoma complicated with pulmonary tuberculosis.

OBJECTIVE

This report aims to analyze the clinical characteristics of 3 primary tumors combined with tuberculosis. We report the long-term survival of this patient after personalized treatment and this patient have a good quality of life.

DIAGNOSES AND INTERVENTIONS

A 55-year-old male patient was diagnosed with squamous cell carcinoma of the lower thoracic esophagus (cT4bN1M0 IVA) and received concurrent chemoradiotherapy, followed by 2 cycles consolidate chemotherapy. During the follow-up, he was diagnosed with secondary tuberculosis (TB) and accepted anti-TB treatment. During anti-TB treatment, he was diagnosed with squamous cell carcinoma of the oropharynx (cT1N0M0 I P16(-)), then he received radical radiation therapy. However, within a year, the patient was diagnosed with oral squamous cell carcinoma (cT3N0M0 IIIA). He accepted an individualized chemotherapy with paclitaxel combined with capecitabine. Moreover, immunohistochemistry of the patient's 3 biopsies indicated positive P53 expression.

OUTCOMES

Since the patient suffered from esophageal cancer, oropharyngeal cancer, and oral floor cancer, no tumor recurrence or metastasis was observed. And he has a good quality of life. Tuberculosis, TP53 mutation, radiotherapy, smoking, and drinking history may be risk factors for multiple primary tumors.

LESSONS

The treatment of multiple primary tumors combined with pulmonary tuberculosis is complicated. Individualized treatment allows patients to achieve long-term survival while also having a good quality of life. Limitations in this case: surgery may be an alternative strategy for the patient, but the patient refused surgery.

Current practices of craniospinal irradiation techniques in Turkey: a comprehensive dosimetric analysis

OBJECTIVE

This study evaluates various craniospinal irradiation (CSI) techniques used in Turkish centers to understand their advantages, disadvantages and overall effectiveness, with a focus on enhancing dose distribution.

METHODS

Anonymized CT scans of adult and pediatric patients, alongside target volumes and organ-at-risk (OAR) structures, were shared with 25 local radiotherapy centers. They were tasked to develop optimal treatment plans delivering 36 Gy in 20 fractions with 95% PTV coverage, while minimizing OAR exposure. The same CT data was sent to a US proton therapy center for comparison. Various planning systems and treatment techniques (3D conformal RT, IMRT, VMAT, tomotherapy) were utilized. Elekta Proknow software was used to analyze parameters, assess dose distributions, mean doses, conformity index (CI), and homogeneity index (HI) for both target volumes and OARs. Comparisons were made against proton therapy.

RESULTS

All techniques consistently achieved excellent PTV coverage (V95 > 98%) for both adult and pediatric patients. Tomotherapy closely approached ideal Dmean doses for all PTVs, while 3D-CRT had higher Dmean for PTV_brain. Tomotherapy excelled in CI and HI for PTVs. IMRT resulted in lower pediatric heart, kidney, parotid, and eye doses, while 3D-CRT achieved the lowest adult lung doses. Tomotherapy approached proton therapy doses for adult kidneys and thyroid, while IMRT excelled for adult heart, kidney, parotid, esophagus, and eyes.

CONCLUSION

Modern radiotherapy techniques offer improved target coverage and OAR protection. However, 3D techniques are continued to be used for CSI. Notably, proton therapy stands out as the most efficient approach, closely followed by Tomotherapy in terms of achieving superior target coverage and OAR protection.

Responding to radiation accidents: what more do we need to know?

A short review of the various types of radiation incidents and accidents that have occurred is used to provide a context for discussing the findings on medical management of the victims of such incidents and accidents reported in a recent Special Issue of the Journal of Radiological Protection. The review demonstrates that accidents and incidents giving rise to high radiation doses may involve over-exposure of a single individual, a few individuals, or very large numbers. In general, these exposures will be relatively short-term, ranging from a few seconds to a few days, but chronic situations resulting in high exposures can occur. Some of these exposures may be highly localised, whereas others may result in almost uniform whole-body irradiation. This diversity of situations means that it is not feasible to have a single protocol for the diagnosis and treatment of over-exposed individuals. If the over-exposures are limited to one or a few individuals, these can be addressed on a case-by-case basis. However, where large numbers have been exposed or may have been exposed, there is a need to implement a rapid and effective system of triage. Furthermore, this system is likely to have to be implemented by individuals who have little or no direct experience of radiation-induced injuries. For those individuals who may have been significantly exposed, the key consideration is not to determine the radiation dose that they have received, but to establish their present clinical status and how it is likely to develop with time. There is at most a very limited role for bone-marrow transplantation in the treatment of acute radiation syndrome, whereas there are good arguments for administering various treatments to boost bone marrow function together with other supportive interventions, e.g. in control of infections and handling both fluid loss and bleeding. However, there is concern that the focus to date has been only on the licencing of drugs related to the management of haematopoietic effects. Although a great deal is known about the diagnosis and treatment of injuries arising from high dose exposures, this knowledge is biased towards situations in which there is relatively uniform, external whole-body exposure. More attention needs to be given to assessing the implications of various inhomogeneous exposure regimes and to developing medical countermeasures optimised for addressing the complex, multi-organ effects likely to arise from such inhomogeneous exposures.