Planning target volume margin in head and neck cancer patients undergoing radiation therapy: Estimations derived from own data and literature.

Planning target volume (PTV) to deliver the desired dose to the clinical target volume (CTV) accounts for systematic (∑) and random (σ) errors during the planning and execution of intensity modulated radiation therapy (IMRT). As these errors vary at different departments, this study was conducted to determine the 3-dimensional PTV (PTV3D) margins for head and neck cancer (HNC) at our center. The same was also estimated from reported studies for a comparative assessment. A total of 77 patients with HNCs undergoing IMRT were included. Of these, 39 patients received radical RT and 38 received postoperative IMRT. An extended no action level protocol was implemented using on-board imaging. Shifts in the mediolateral (ML), anteroposterior (AP), and superoinferior (SI) directions of each patient were recorded for every fraction. PTV margins in each direction (ML, AP, SI) and PTV3D were calculated using van Herk's equation. Weighted PTV3D was also computed from the ∑ and σ errors in each direction published in the literature for HNC. Our patients were staged T2-4 (66/77) and N0 (39/77). In all, 2280 on-board images were acquired, and daily shifts in each direction were recorded. The PTV margins in the ML, AP, and SI directions were computed as 3.2 mm, 2.9 mm, and 2.6 mm, respectively. The PTV3D margin was estimated to be 6.5 mm. This compared well with the weighted median PTV3D of 7.2 mm (range: 3.2 to 9.9) computed from the 16 studies reported in the literature. To ensure ≥95% CTV dose coverage in 90% of HNC patients, PTV3D margin for our department was estimated as 6.5 mm. This agrees with the weighted median PTV3D margin of 7.2 mm computed from the 16 published studies in HNCs. Site-specific PTV3D margin estimations should be an integral component of the quality assurance protocol of each department to ensure adequate coverage of dose to CTV during IMRT.

Carcinoma of the pyriform sinus with mediastinal metastasis successfully treated with chemoradiotherapy in resource-constraint setup.

Squamous cell carcinoma (SCC) of the pyriform sinus with metastatic mediastinal mass is staged as IVC and routinely treated with palliative intent. Here, we report a case cured with radical chemoradiotherapy without CT simulator, lead cutouts, and advanced techniques such as three-dimensional conformal radiation therapy, intensity-modulated radiation therapy, image-guided radiotherapy, and volumetric modulated arc therapy or stereotactic body radiotherapy. A 67-year-old male presented with SCC of the right pyriform sinus with mediastinal metastasis (Stage IVC). He was started with palliative chemotherapy afferent, but he could not tolerate it. Further, he was treated with radical chemoradiotherapy to dose of 60/30# to primary + neck with 6 MV photons and 50 Gy/25# to the anterior mediastinal lesion using 18 Mev electrons. Complete response to the treatment was achieved. At the close follow-up of 58 months, the patient is disease-free and follow-up is still ongoing. Limited metastatic disease can be completely cured using multimodality treatment using simple traditional 2D techniques, though optimal dose escalation becomes a limitation. Some variants of SCC do respond well even at suboptimal radiotherapy doses, so personalized treatment can be considered in such patients.

Hyperthermia: A Potential Game-Changer in the Management of Cancers in Low-Middle-Income Group Countries.

Loco-regional hyperthermia at 40-44 °C is a multifaceted therapeutic modality with the distinct triple advantage of being a potent radiosensitizer, a chemosensitizer and an immunomodulator. Risk difference estimates from pairwise meta-analysis have shown that the local tumour control could be improved by 22.3% (p < 0.001), 22.1% (p < 0.001) and 25.5% (p < 0.001) in recurrent breast cancers, locally advanced cervix cancer (LACC) and locally advanced head and neck cancers, respectively by adding hyperthermia to radiotherapy over radiotherapy alone. Furthermore, thermochemoradiotherapy in LACC have shown to reduce the local failure rates by 10.1% (p = 0.03) and decrease deaths by 5.6% (95% CI: 0.6-11.8%) over chemoradiotherapy alone. As around one-third of the cancer cases in low-middle-income group countries belong to breast, cervix and head and neck regions, hyperthermia could be a potential game-changer and expected to augment the clinical outcomes of these patients in conjunction with radiotherapy and/or chemotherapy. Further, hyperthermia could also be a cost-effective therapeutic modality as the capital costs for setting up a hyperthermia facility is relatively low. Thus, the positive outcomes evident from various phase III randomized trials and meta-analysis with thermoradiotherapy or thermochemoradiotherapy justifies the integration of hyperthermia in the therapeutic armamentarium of clinical management of cancer, especially in low-middle-income group countries.