Stereotactic body radiation therapy versus fractionated radiation therapy for early-stage bronchopulmonary carcinoid

Role of radiotherapy in the management of rare solid thoracic tumors of the adults

Thoracic tumors include more than one hundred histopathological subtypes. Rare thoracic malignancies can be defined as representing less than 1% of all thoracic tumors. The European Rare Cancer Surveillance Project (RARECARE) identified rarity as an incidence less than 6 for 100,000 people, with significant difference of prevalence between them. Modalities of treatment for these pathologies include surgery, radiotherapy, and systemic therapies. In this article, we aim to discuss role and techniques of radiotherapy in management of rare solid thoracic tumors in adults, focusing on different anatomical locations such as lung parenchyma, mediastinum, vessels, chest wall and pleural cavity.

Early-Stage Primary Lung Neuroendocrine Tumors Treated With Stereotactic Body Radiation Therapy: A Multi-Institution Experience

PURPOSE

Current guidelines recommend surgery as standard of care for primary lung neuroendocrine tumor (LNET). Given that LNET is a rare clinical entity, there is a lack of literature regarding treatment of LNET with stereotactic body radiation therapy (SBRT). We hypothesized that SBRT could lead to effective locoregional tumor control and long-term outcomes.

METHODS AND MATERIALS

We retrospectively reviewed 48 tumors in 46 patients from 11 institutions with a histologically confirmed diagnosis of LNET, treated with primary radiation therapy. Data were collected for patients treated nonoperatively with primary radiation therapy between 2006 and 2020. Patient records were reviewed for lesion characteristics and clinical risk factors. Kaplan-Meier analysis, log-rank tests, and Cox multivariate models were used to compare outcomes.

RESULTS

Median age at treatment was 71 years and mean tumor size was 2 cm. Thirty-two lesions were typical carcinoid histology, 7 were atypical, and 9 were indeterminate. The most common SBRT fractionation schedule was 50 to 60 Gy in 5 daily fractions. Overall survival at 3, 6, and 9 years was 64%, 43%, and 26%, respectively. Progression-free survival at 3, 6, and 9 years was 88%, 78%, and 78%, respectively. Local control at 3, 6, and 9 years was 97%, 91%, and 91%, respectively. There was 1 regional recurrence in a paraesophageal lymph node. No grade 3 or higher toxicity was identified.

CONCLUSIONS

This is the largest series evaluating outcomes in patients with LNET treated with SBRT. This treatment is well tolerated, provides excellent locoregional control, and should be offered as an alternative to surgical resection for patients with early-stage LNET, particularly those who may not be ideal surgical candidates.

A multidisciplinary approach to the work up and management of pulmonary carcinoid tumors and DIPNECH: a narrative review

Background and Objective

Low and intermediate grade neuroendocrine tumors of the lung are uncommon malignancies representing 2% of all lung cancers. These are termed typical and atypical pulmonary carcinoid tumors. These can arise in the setting of diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH). The presentation, workup, management and outcomes of patients with these tumors can overlap with more common lung cancers but differ in that many of these patients have a prolonged clinical course. The objective of this narrative review is to summarize the literature and provide evidence and expert-based algorithms for work up and treatment of pulmonary carcinoids and DIPNECH.

Methods

A search of PubMed and Web of Science databases ending April 15, 2022, with the following keywords "lung carcinoid", "DIPNECH", "lung neuroendocrine," and "bronchopulmonary carcinoid".

Key Content and Findings

Pulmonary carcinoid tumors benefit from a multidisciplinary approach. Pre-treatment imaging with contrast-enhanced computed tomography, and DOTATATE positron emission tomography is required. Surgical resection is the gold standard for curative intent, and possibly including sublobar resections. Patients can recur or develop new primaries thus emphasizing the importance of surveillance; national guidelines recommend at least a 10-year follow up. A growing body of literature support the use of endobronchial therapy, with long responses documented. Systemic therapy consists of everolimus, somatostatin analogs, peptide receptor radionuclide therapy, and chemotherapy. Diffuse idiopathic pulmonary neuroendocrine tumor cell hyperplasia is rare, but series suggest somatostatin analogs may confer clinical benefit.

Conclusions

Pulmonary carcinoid tumors and DIPNECH are rare. Despite lack of regulatory approvals for advanced disease, multiple options are available but should be sequenced according to the clinical status and disease biology. Each patient should be discussed in a multidisciplinary setting and clinical trials should be considered if available.

The Role of Conventionally Fractionated Radiotherapy and Stereotactic Radiotherapy in the Treatment of Carcinoid Tumors and Large-Cell Neuroendocrine Cancer of the Lung

The occurrence of neuroendocrine tumors among the diagnosed neoplasms is extremely rare and is associated with difficulties in undertaking effective therapy due to the histopathological differentiation of individual subtypes and the scarce clinical data and recommendations found in the literature. The choice of treatment largely depends not only on its type, but also on the location and production of excess hormones by the tumor itself. Common therapeutic approaches include surgical removal of the tumor, the use of chemotherapy, targeted drug therapy, peptide receptor radionuclide therapy, and the use of radiation therapy. This article reviews the current knowledge on the classification and application of radiotherapy in the treatment of lung NETs. Case reports were presented in which treatment with conventional radiotherapy, radical and palliative radiochemotherapy, as well as stereotactic fractionated radiotherapy in the treatment of typical (TC) and atypical (AT) lung carcinoids and large cell neuroendocrine carcinoma (LCNC) were used. We hope that the solutions presented in the literature will allow many radiation oncologists to make the best, often personalized decisions about the therapeutic qualifications of patients.

Effectiveness of Thermal Ablation and Stereotactic Radiotherapy Based on Stage I Lung Cancer Histology

PURPOSE

To assess whether the effectiveness of thermal ablation (TA) and stereotactic body radiotherapy (SBRT) as initial treatments for stage I lung cancer varies depending on the histological subtype.

MATERIALS AND METHODS

The 2004-2016 National Cancer Database was queried for patients with American Joint Committee on Cancer stage I lung cancer treated with TA or SBRT. Patients <18 years, those treated with surgery or chemotherapy, or those with unknown survival and follow-up were excluded. TA and SBRT patients were 1:5 propensity score matched separately for each histological subtype to adjust for confounders. Overall survival (OS) was assessed using Cox models.

RESULTS

A total of 28,425 patients were included (SBRT, n = 27,478; TA, n = 947). TA was more likely to be used in Caucasian patients, those with more comorbidities and smaller neuroendocrine tumors (NETs) of the lower lobe, and those whose treatment had taken place in the northeastern United States. After propensity score matching, a cohort with 4,085 SBRT and 817 TA patients with balanced confounders was obtained. In this cohort, OS for TA and SBRT was comparable (hazard ratio = 1.07; 95% confidence interval,0.98-1.18; P = .13), although it varied by histological subtypes: higher OS for TA was observed in patients with non-small cell NETs (vs SBRT hazard ratio = 0.48; 95% confidence interval, 0.24-0.95; P = .04). No significant OS differences between TA and SBRT were noted for adenocarcinomas, squamous cell carcinomas, small cell carcinomas, and non-neuroendocrine large cell carcinomas (each, P > .1).

CONCLUSIONS

OS following TA and SBRT for stage I lung cancer is comparable for most histological subtypes, except that OS is longer after TA in non-small cell NETs.

Radiation treatment for adult rare cancers: Oldest and newest indication

AIM

Aim of this analysis is to review the role of RT in the management of several rare tumors for adult patients.

METHODS

Collection data regarding RT and rare tumors was made by Pubmed.

RESULTS

For mucosal melanomas, RT is prescribed, being associated with lower local recurrence rate. For trachea tumors, RT was used as adjuvant or salvage treatment for unresectable disease. For pNET, RT can be a suitable option for post-surgical or unresectable/borderline. For bronchopulmonary neuroendocrine tumors the role of adjuvant treatments is uncertain. For hepatobiliary and ovarian malignancy, stereotactic body RT (SBRT) is a promising approach. For soft tissue sarcoma, perioperative treatments are indicated, and a growing role of SBRT in oligometastatic disease is recognized. For endocrine tumors, adjuvant RT has demonstrated benefits through reducing recurrence risk.

CONCLUSION

The radiotherapy is a frequent indication in adult rare cancers; thus the role of Radiation Oncologist must not be neglected.