Aim: Describe the anatomical changes and tumor displacement due to a rapid response of a patient's small cell lung cancer (SCLC) during definitive chemoradiotherapy (CRT). Background: The treatment for SCLC is based on CRT. If interfractional changes during RT are incorrectly assessed they might compromise adequate coverage of the tumor or increase dose to organs at risk. Image guided RT with cone-beam computed tomography (CBCT) allows to identify daily treatment variations. Material and methods: Describe a SCLC case with rapid changes in size, shape and location of the primary tumor during RT. Case report: A 62-year-old woman was diagnosed with SCLC with complete obstruction of the anterior and lingular bronchi and incomplete left thorax expansion due to a 12 × 15 cm mass. During CRT (45 Gy in 1.5 Gy per fraction, twice daily) the patient presented rapid tumor response, leading to resolution of bronchi obstruction and hemithorax expansion. Tumor shifted up to 4 cm from its original position. The identification of variations led to two new simulations and planning in a 3-week treatment course. Conclusions: The complete radiological response was possible due to systematic monitoring of the tumor during CRT. We recommend frequent on-site image verification. Daily CBCT should be considered with pretreatment tumor obstruction, pleural effusion, atelectasis, large volumes or radiosensitive histology that might resolve early and rapidly and could lead to a miss of the tumor or increased toxicity. Further research should be made in replanning effect in coverage of microscopic disease since it increases uncertainty in this scenario.
Around 50% of cancer patients will require radiotherapy (RT) and 10–15% of these patients could be eligible for proton beam radiotherapy (PBT). Dosimetric advantages are undeniable, mainly in pediatric and reirradiation scenarios. Though, PBT facilities are scarce worldwide and the IAEA has reported 116 functional particle facilities, of which 98 are PBT, virtually absent in low- and middle-income countries (LMIC). The Latin America and Caribbean region represent a unique opportunity for a PBT center, as there are currently no functional facilities and current RT needs are significant. The challenges can be summarized as high initial investment and maintenance, geographic coverage, required baseline technology and certification, over-optimistic workload, unclear rates and reimbursement, unmet business plan and revenue expectations, and lack of trained human resources. Investment costs for a PBT facility are estimated to be at around 140 million euros; therefore, this seems unsuitable for LMIC. Mexico’s geographical advantage, GDP, baseline technologies and high demand for RT makes it an ideal candidate. Nevertheless, a PBT center would account for a third of Mexico’s annual health expenditure for 2020. Enormous efforts must be made by both the private sector and governmental authorities to provide funding.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.